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Biomedical subjects

S Kaihara

Publications and source records attributed to S Kaihara.

At least 19 recordsLinked to original sources
PubMed1999

Regenerative signals for intestinal epithelial organoid units transplanted on biodegradable polymer scaffolds for tissue engineering of small intestine.

BACKGROUND: Our laboratory is investigating the tissue engineering of small intestine using intestinal epithelial organoid units seeded onto highly porous biodegradable polymer tubes. This study investigated methods of stimulation for optimizing neointestinal regeneration. METHODS: Intestinal epithelial organoid units harvested from neonatal Lewis rats were seeded onto porous biodegradable polymer tubes and implanted into the omentum of adult Lewis rats in the following groups: (1) the control group (group C), implantation alone (n=9); (2) the small bowel resection (SBr) group, after 75% SBr (n=9); (3) the portacaval shunt (PCS) group, after PCS (n=8); and (4) the partial hepatectomy (PH) group, after 75% PH (n=8). Neointestinal cyst size was recorded using ultrasonography. Constructs were harvested at 10 weeks and were examined using histology. Morphometric analysis of the neomucosa was obtained using a computer image analysis program (NIH Image, version 1.59). RESULTS: Cyst development was noted in all animals. Cyst lengths and diameters were significantly larger in the SBr group at 7 and 10 weeks compared with the other three groups (P<0.05; analysis of variance [ANOVA], Fisher's protected least significant difference). Histology revealed a well-vascularized tissue with a neomucosa lining the lumen with invaginations resembling crypt-villus structures. Morphometric analysis demonstrated a significantly greater villus number, height, area, and mucosal surface in the SBr group compared with the other three groups and a significantly greater crypt number and area in the PCS group compared with group C (P<0.05; ANOVA, Fisher's protected least significant difference). CONCLUSIONS: Intestinal epithelial organoid units transplanted on porous biodegradable polymer tubes can successfully vascularize, survive, and regenerate into complex tissue resembling small intestine. SBr and, to a lesser extent, PCS provide significant regenerative stimuli for the morphogenesis and differentiation of tissue-engineered small intestine.

Animals↗
PubMed1999

Successful anastomosis between tissue-engineered intestine and native small bowel.

BACKGROUND: Previous work from this laboratory has shown that isolated intestinal epithelial organoid units on porous biodegradable polymer scaffolds formed vascularized cysts lined by a neomucosa. The purpose of this study was to demonstrate anastomosis between tissue-engineered intestine and the native small bowel and to observe the effect of this anastomosis on cyst growth. METHODS: Intestinal epithelial organoid units from neonatal Lewis rats were seeded onto porous biodegradable polymer tubes made of polyglycolic acid, and they were implanted into the omentum of adult male Lewis rats. Three weeks after implantation, the unit-polymer constructs were anastomosed in a side-to-side fashion to the native jejunum in 20 rats (group 1). The other 18 rats were closed without anastomosis (group 2). All 38 tissue-engineered constructs were harvested 10 weeks after implantation. Four rats underwent upper gastrointestinal (GI) study before they were killed. RESULTS: The rats in group 1 increased their body weights equal to those in group 2, and there was no statistically significant difference between the two groups. Upper GI examinations revealed no evidence of either bowel stenosis or obstruction at the anastomotic site. Grossly, the patency of the anastomosis was 90% and the lumen of the cyst was visualized by the upper GI study. At the second operation, there was no significant difference in the size of the cysts in either group: however, at the time the rats were killed, the length of the cysts in group 1 was significantly longer than that in group 2 (P<0.05 using Mann-Whitney U test). Histological examination showed that cysts after anastomosis were lined by a neomucosa in continuity to native small bowel across the anastomotic site and also demonstrated crypt-villus structures. Morphometric study demonstrated that cysts in group 1 had significantly greater villus number, height, and surface length than did those in group 2. CONCLUSIONS: Anastomosis between tissue-engineered intestine and native small bowel resulted in no complications after the operation, kept a high patency rate, and maintained mucosal continuity between the tissue-engineered intestine and native small bowel. Furthermore, anastomosis had a positive effect on cyst size and development of the mucosa in the tissue-engineered intestine.

Anastomosis, Surgical↗
PubMed1999

Small intestinal submucosa as a small-caliber venous graft: a novel model for hepatocyte transplantation on synthetic biodegradable polymer scaffolds with direct access to the portal venous system.

BACKGROUND/PURPOSE: Hepatotrophic factors in the portal blood are critically important for the survival of heterotopically transplanted hepatocytes. Currently, no model exists for the implantation of hepatocytes on biodegradable polymer scaffolds with direct access to the portal blood. This study investigates the use of small intestinal submucosa (SIS) as a small-caliber venous conduit that may be used for the implantation of tissue-engineered liver. METHODS: SIS was prepared from segments of rat jejunum and implanted as a venous conduit between the portal vein and inferior vena cava in 26 heparinized Lewis rats. Venograms were performed periodically, and the grafts were harvested at various time-points and examined by scanning electron microscopy (SEM) and histology. Von Willebrand Factor (vWF) staining was performed to assess endothelialization. RESULTS: Five rats died of technical complications. Seventeen of 21 rats (81%) maintained patent grafts at the time of death up to 8 weeks. Venograms demonstrated patent grafts at 3 and 8 weeks. SEM results showed a smooth luminal surface with endothelial-like cells by 3 weeks. Histology demonstrated a confluent luminal endothelial monolayer, absence of thrombus, and neovascularization in the SIS graft. VWF staining results were positive, confirming the growth of endothelial cells on the luminal surface. In preliminary studies, implantation of hepatocytes seeded on biodegradable polymer tubes into the SIS graft demonstrated clusters of viable cells after 2 days. CONCLUSIONS: Rat SIS can be prepared readily, maintains high patency as a small-caliber venous graft, and may be a useful model for the transplantation of tissue-engineered liver with access to the portal circulation.

Animals↗
PubMed1998

Formal representation of summary tables for health care statistical database management.

There is an ever-increasing demand for statistical information in health-care societies, and voluminous statistics are collected every year. When one needs information on survey results, it is generally not allowed to access the original data, and the summary tables are the most important source of information which can be shared. In order to store summary tables as a well-organized database and to perform flexible retrieval, a formal study has been made on the structure of summary tables. We introduce the notion of summary table scheme and define the operations called table transformation. A statistical database management system has been implemented based on the study. In our study, a statistical database is a collection of summary tables obtained from a survey. If a survey is conducted periodically, a database consists of all the tables obtained in the past. System utilities have been implemented for handling time-oriented information.

Algorithms↗
PubMed1998

Using a WWW-based mail user agent for secure electronic mail service for health care users.

WWW-based user interface is presented for secure electronic mail service for healthcare users. Using this method, communications between an electronic mail (WWW) server and users (WWW browsers) can be performed securely using Secure Socket Layer protocol-based Hypertext Transfer Protocol (SSL-HTTP). The mail can be encrypted, signed, and sent to the recipients and vice versa on the remote WWW server. The merit of this method is that many healthcare users can use a secure electronic mail system easily and immediately, because SSL-compatible WWW browsers are widely used and this system can be made available simply by installing a WWW-based mail user agent on a mail server. We implemented a WWW-based mail user agent which is compatible with PEM-based secure mail and made it available to about 16,000 healthcare users. We believe this approach is effective in facilitating secure network-based information exchange among medical professionals.

Computer Communication Networks↗
PubMed1997

Serotonin as a useful parameter for cold and warm ischemic injury in small bowel transplantation.

We investigated serotonin as a parameter of cold and warm ischemic injury prior to transplantation. Lewis rats were used as both donors and recipients, and the proximal 20 cm of jejunum served as the graft. The grafts were preserved in 4 degrees C lactated Ringer's solution for 0, 6, 12, 18, and 24 hr after harvest for cold ischemia (n=7/group). The superior mesenteric artery was clamped for 0, 15, 30, 60, and 120 min before harvest for warm ischemia (n=7/group). The serotonin concentration was measured in the luminal effluent and the preservation solution before transplantation, and total serotonin was calculated as the sum of these amounts. Finally, transplantation was performed heterotopically. Total serotonin increased significantly with both cold and warm ischemic time (P<0.01 by analysis of variance, Fisher's PLSD); however, between 18 hr and 24 hr of cold ischemic time only, there were no significant changes. Total serotonin levels correlated well with cold and warm ischemic time, as shown by linear regression analysis (cold ischemia: R2=80.2%, P<0.01; warm ischemia: R2=92.8%, P<0.01). We established the cutoff level of total serotonin to predict the graft survival at 2200 ng, and using this critical level, graft survival was predicted by total serotonin with a sensitivity of 71.4% and a specificity of 89.8%. Immunohistochemical staining with the serotonin antibody revealed that the number of serotonin-positive cells decreased with both cold and warm ischemic time. In conclusion, serotonin is a useful parameter of cold and warm ischemic injury before transplantation and can assist in predicting graft survival.

Animals↗
PubMed1997

Automated generation of a World Wide Web-based data entry and check program for medical applications.

The World Wide Web-based form is a promising method for the construction of an on-line data collection system for clinical and epidemiological research. It is, however, laborious to prepare a common gateway interface (CGI) program for each project, which the World Wide Web server needs to handle the submitted data. In medicine, it is even more laborious because the CGI program must check deficits, type, ranges, and logical errors (bad combination of data) of entered data for quality assurance as well as data length and meta-characters of the entered data to enhance the security of the server. We have extended the specification of the hypertext markup language (HTML) form to accommodate information necessary for such data checking and we have developed software named AUTOFORM for this purpose. The software automatically analyzes the extended HTML form and generates the corresponding ordinary HTML form, 'Makefile', and C source of CGI programs. The resultant CGI program checks the entered data through the HTML form, records them in a computer, and returns them to the end-user. AUTOFORM drastically reduces the burden of development of the World Wide Web-based data entry system and allows the CGI programs to be more securely and reliably prepared than had they been written from scratch.

Computer Communication Networks↗
PubMed1997

Dynamic link between ECG and clinical data by a CORBA-based query engine and temporal mapping.

It is important to create a dynamic link method to link distributed patient data across multiple hospitals on an "as needed" basis because the pre-defined links (an item of data has a character or group of characters that indicates the storage of another item of data) are difficult to be managed, or can only be established in part, or are not necessary to be pre-defined in many cases, especially in linking the descriptive data such as history data with the corresponding examination data across multiple hospitals. A method of linking electrocardiogram (ECG) with clinical data dynamically in a Common Object Request Broker Architecture (CORBA) environment has been achieved and verified in a real computing environment to approach to this goal. By this method, distributed patient data can be linked dynamically by a CORBA-based query engine and temporal mapping no matter where they are located on the Internet. The necessary temporal information is provided by either computing or human being. Since multiple time-axes for different databases are involved in, some temporal reasoning methods (such as mapping occurrences across temporal contexts and determining bounds for absolute occurrences, etc.) are applied to this study, and a series of temporal mappings including the first mapping, the secondary mapping, the contextual mapping, the extended mapping, the previous mapping and the next mapping are created. In comparison with the pre-defined link, the major strengths of this method are the dynamic link on an "as needed" basis, no limitation of institutional boundaries, easy creation, simplifying the data storage, and the high flexibility, etc.

Computer Communication Networks↗
PubMed1996

An ECG storage and retrieval system embedded in client server HIS utilizing object-oriented DB.

In the University of Tokyo Hospital, the improved client server HIS has been applied to clinical practice and physicians can order prescription, laboratory examination, ECG examination and radiographic examination, etc. directly by themselves and read results of these examinations, except medical signal waves, schema and image, on UNIX workstations. Recently, we designed and developed an ECG storage and retrieval system embedded in the client server HIS utilizing object-oriented database to take the first step in dealing with digitized signal, schema and image data and show waves, graphics, and images directly to physicians by the client server HIS. The system was developed based on object-oriented analysis and design, and implemented with object-oriented database management system (OODMS) and C++ programming language. In this paper, we describe the ECG data model, functions of the storage and retrieval system, features of user interface and the result of its implementation in the HIS.

Database Management Systems↗
PubMed1996

Implementation of HL7 to client-server hospital information system (HIS) in the University of Tokyo Hospital.

In developing a large-scale Hospital Information System (HIS), a client-server architecture has been gaining in popularity. It is important to introduce a standard message protocol that is independent both on the database structure and on the vender's proprietary platform. We introduced Health Level Seven (HL7) to our hospital information system. From our experiences, although we had to modify the original HL7 specifications in order to introduce the protocol to a client-server HIS especially in the area of order entry and record-oriented query, it was found that HL7 can be adopted in a client-server HIS.

Computer Communication Networks↗
PubMed1996

[Longevity science research retrieval system using the thesaurus specifically developed for the science].

Gerontology is a new field including various disciplines such as medicine, engineering science, social science etc, and is sometimes called as "longevity science". Because of the wide area of the field, it is important to show the scope of the science and the development of its thesaurus contributes to this end. We developed a relevant thesaurus based on the research funded by Longevity Science Promotion Organization, and using the thesaurus, we also developed a database and retrieval system of the gerontology research. This system can be accessed on the Internet.

Aged↗
PubMed1996

Object-oriented analysis and design of an ECG storage and retrieval system integrated with an HIS.

For a hospital information system, object-oriented methodology plays an increasingly important role, especially for the management of digitized data, e.g., the electrocardiogram, electroencephalogram, electromyogram, spirogram, X-ray, CT and histopathological images, which are not yet computerized in most hospitals. As a first step in an object-oriented approach to hospital information management and storing medical data in an object-oriented database, we connected electrocardiographs to a hospital network and established the integration of ECG storage and retrieval systems with a hospital information system. In this paper, the object-oriented analysis and design of the ECG storage and retrieval systems is reported.

Computers↗
PubMed1995

[Statistical analysis of anesthesiologists' thinking patterns concerning regulation of the blood pressure and the concentration of inhaled anesthetics].

During surgery, the anesthesiologists adjust the concentration of inhaled anesthetics according to the change in blood pressure in order to achieve good control of anesthesia. Usually the thinking patterns of individual anesthesiologists differ from one to another. We obtained data from each anesthesiologist's thinking pattern concerning the regulation of blood pressure and the concentration of inhalational anesthesia. These patterns were analyzed statistically and compared for individual anesthesiologist. The results showed that anesthesiologists' regulation rules were formed independently of the 3 drugs and were specific to individuals. Some trends depending on institution were observed, but no statistically significant difference was found.

Anesthesia, General↗
PubMed1995

[Analysis of the anesthesiologists' action patterns concerning regulation of the blood pressure and the concentration of inhalational anesthesia].

The action pattern of each anesthesiologist is different. We have developed a computer program simulating anesthesiologists' action patterns during operation and have extracted the action patterns of anesthesiologists using a computer program. The simulation program was designed to gather data on anesthesiologists' response to the change in blood pressure. The results indicate that the action pattern differs significantly from one anesthesiologist to another in responding to the change in blood pressure. That of one particular anesthesiologist remained the same, regardless of the agent used. His action pattern is directed only by the value of MAC and according to his own personal principle.

Anesthesia, Inhalation↗
PubMed1995

On the linguistic representation of medical information: natural language, controlled language, and formal language.

Language is indispensable for the representation of medical information. We classified the methods of linguistic representation into three items: natural language, controlled language, and formal language. The characteristics of these are discussed; we focus especially on the preparation of data and data quality. We present the perspective that linguistic research in medical informatics can be considered as an effort to convert natural language into formal language and vice versa. The problems related to the conversion and the role of controlled language in medical linguistics are discussed in detail.

Language↗