Complex population history of two Anopheles dirus mosquito species in Southeast Asia suggests the influence of Pleistocene climate change rather than human-mediated effects.

Anopheles dirus and Anopheles baimaii are closely related species which feed on primates, particularly humans, and transmit malaria in the tropical forests of mainland Southeast Asia. Here, we report an in-depth phylogeographic picture based on 269 individuals from 21 populations from mainland Southeast Asia. Analysis of 1537 bp of mtDNA sequence revealed that the population history of A. baimaii is far more complex than previously thought. An old expansion (pre-300 kyr BP) was inferred in northern India/Bangladesh with a wave of south-eastwards expansion arriving at the Thai border (ca 135-173 kyr BP) followed by leptokurtic dispersal very recently (ca 16 kyr BP) into peninsular Thailand. The long and complex population history of these anthropophilic species suggests their expansions are not in response to the relatively recent (ca 40 kyr BP) human expansions in mainland Southeast Asia but, rather, fit well with our understanding of Pleistocene climatic change there.

Economic analysis of a filmless system based on the hospital information system.

A filmless system (FLS) based on a picture archiving and communication system (PACS) equipped with UNIX work- stations and a local area network (LAN) specialized for viewing radiographs has not been deemed acceptable, for reasons of economics. However, personal computers (PCs) have recently become more powerful, to the point where PCs approach UNIX workstations in terms of capabilities. As a result, a PC-based image viewing workstation (IVW) has sufficient functions for practical use. Diagnostic resolution is not equal to that of film, but is comparable. Since the hospital information system (HIS) includes many PC terminals connected by a LAN, the cost problem can be resolved by using these PC terminals as the IVWs. In order to investigate the practicability of this idea, two types of FLSs using HIS facilities were designed: one is a system based on the use of high-resolution cathode ray tubes (H-CRTs), and the other is based on the use of conventional CRTs and radiologist reports, minimizing the number of H-CRTs. The total costs of the two systems were analyzed. As a result, the former FLS was found to be about 15% more expensive than the latter, which was less expensive than a film-based system (FBS). However, whether the FLS is more profitable than the FBS from the viewpoint of hospital management strongly depends on the medical insurance system.

A new theory of phylogeny inference through construction of multidimensional vector space.

Here, a new theory of molecular phylogeny is developed in a multidimensional vector space (MVS). The molecular evolution is represented as a successive splitting of branch vectors in the MVS. The end points of these vectors are the extant species and indicate the specific directions reflected by their individual histories of evolution in the past. This representation makes it possible to infer the phylogeny (evolutionary histories) from the spatial positions of the end points. Search vectors are introduced to draw out the groups of species distributed around them. These groups are classified according to the nearby order of branches with them. A law of physics is applied to determine the species positions in the MVS. The species are regarded as the particles moving in time according to the equation of motion, finally falling into the lowest-energy state in spite of their randomly distributed initial condition. This falling into the ground state results in the construction of an MVS in which the relative distances between two particles are equal to the substitution distances. The species positions are obtained prior to the phylogeny inference. Therefore, as the number of species increases, the species vectors can be more specific in an MVS of a larger size, such that the vector analysis gives a more stable and reliable topology. The efficacy of the present method was examined by using computer simulations of molecular evolution in which all the branch- and end-point sequences of the trees are known in advance. In the phylogeny inference from the end points with 100 multiple data sets, the present method consistently reconstructed the correct topologies, in contrast to standard methods. In applications to 185 vertebrates in the alpha-hemoglobin, the vector analysis drew out the two lineage groups of birds and mammals. A core member of the mammalian radiation appeared at the base of the mammalian lineage. Squamates were isolated from the bird lineage to compose the outgroup, while the other living reptilians were directly coupled with birds without forming any sister groups. This result is in contrast to the morphological phylogeny and is also different from those of recent molecular analyses.

New approach to the medical information system for quality management in patient care: development of Problem Mapping System.

A new type of medical information system named Problem Mapping System (P-Map) has been developed, which aids physicians with solving patients' problems. With this system, physicians can define the problems of in-patients, monitor their progress clearly, and share information efficiently. In P-map, a list of problems, such as disease names, can be set for each inpatient easily. The progress of each problem is clearly shown using progress lines on a time axis. Physicians can save the Subjective Objective Assessment Plan (SOAP) notes which are linked to each problem. At the final stage of patient care, a discharge summary can be made easily. With the aid of this system, the quality of patient care is improved due to the following: (1) physicians can make the best decision; (2) medical staff in the same team can provide the best medical treatment; (3) evaluation of each medical treatment is easy; (4) saved data can be used effectively for education and research; (5) the system can improve cooperation with other medical institutes by providing discharge summary information which can be distributed using e-mail; and (6) the system can improve patients' understanding for the purpose of informed consent by providing clear and well organized information to patients.

Problems regarding the integration of medical images into the total hospital information system.

Since 1989, the integration of medical images into the total hospital information system (HIS) has been investigated and developed at Kochi Medical School. The basic concept of the integration is that, in the same way they can view text based data, doctors can retrieve and view images using the PC terminals of the total HIS. The possibility of utilizing the PC terminals of the total HIS as image viewing stations was investigated. A test run was performed in the period from October 1995 to July 1997. The test run revealed that fast image access is crucial in order for the system to be useful for doctors. After making various improvements, the final system became well used in the clinical practice. However, in order to progress to the film-less stage, the final system still has three problems that must be solved: quality of the image display, operation of multi-exams, and quality assurance of the digital image.

Fast image accessing based on an analysis of the picture archiving and communications system in Kochi Medical School.

A large-scale picture archiving and communication system was developed by Kochi Medical School. Using JPEG to achieve 90% compression, this system was capable of storing several years worth of CT and MR examination records and eliminated the bottleneck in conventional systems caused by slow data access in the filing system. Under the new system, access of image files from client PCs was checked for bottlenecks. The image file retrieval from the image database on the server was found to require the longest time. Two methods were considered to eliminate this bottleneck. One was a multiimages filing into a file. Another was an image transmission with multiparallel transmission sessions, which is proposed in this article. By adopting the latter method, the system can transmit 50 CT images from the image database server to a client PC in about 10 s.

Increase or decrease of HDL-cholesterol concentrations during pravastatin treatment depending on the pre-treatment HDL cholesterol levels.

OBJECTIVE: The effect of pravastatin was evaluated using patient data accumulated in the data base of a hospital information system (HIS). METHODS: We selected 130 patients treated with pravastatin 10 mg per day, for a minimum period of 4 weeks. RESULTS: In the t test analysis, the reduction rates of total cholesterol (TC) and low-density lipoprotein (LDL) levels for pravastatin administration were 18%, and 27%, respectively. These values were similar to previous reports. The high-density lipoprotein (HDL) level, however, did not change significantly, although previous reports have shown an elevation of HDL levels. In an attempt to explain the origin of this difference, we studied the pretreatment value dependence of the cholesterol change using regression analysis. We found that pravastatin raised the HDL level in those cases where pretreatment values were lower than 58 mg.dl-1 and reduced it for higher values. We also showed that the reductions of TC, LDL and triglyceride (TG) levels correlated positively with their pretreatment values.

Longitudinal characteristic curve of liver disease.

A longitudinal characteristic curve of chronic liver disease (LCC-LD) is derived for the first time by a new method of time series data analysis, where a hospital information system is utilized as a clinical research application of the database. It describes a typical pattern of development of disease from the beginning of chronic hepatitis to the final stage of cirrhosis. The LCC-LD is obtained by effectively using patient data with various stages of developments of liver disease and the present method is applicable to derive the LCC of other diseases. The obtained LCC-LD may be useful for a clinical decision making support such as the prospective assessment (for example, the onset time of cirrhosis) of liver disease in individual patients, an evaluation of drug effect, etc.

Dynamical monitoring network system for perinatal care.

A new type of monitoring network system for perinatal care is proposed and has been developed. The patient monitoring system and data analyzing system are connected by a local area network (LAN). The doctor can retrieve past sampled data and results of data analysis, and make a detailed analysis at the same time that the patient is being monitored. The mainframe of the hospital information system (HIS) is connected with a data server in the perinatal care area via LAN. The database in perinatal care is supplied to the HIS and the doctor through this monitoring network system. If data sampled at maternity clinics or hospitals are once transmitted to the data server on LAN via the public telephone circuit, these data are available for the specialists on LAN. This function is utilized for supporting the obstetricians.

Development of a diagnostic and therapeutic simulation system based on patient data and specialist's knowledge. I. Simulation of diagnostic process.

A new simulation system of diagnostic and therapeutic processes is developed. The aim is to train medical students for the practical use of their knowledge, utilizing patient data in a total hospital information system. The knowledge in the system is presented by the specialists for every case. In medical school there are many specialists in various fields. With their cooperation the system can grow up to a comprehensive CAI system for clinical education. The system is designed to work on the mainframe for easiness of development, maintenance and extensions of the system. The present framework has been applied to the simulation of diagnostic process. The usefulness of the present system has been confirmed by specialists and students.

Online support functions of prescription order system and prescription audit in an integrated hospital information system.

The role of the online prescription support functions of a prescription order entry system was analysed and the results of the prescription audit by pharmacists were examined. In the Kochi Medical School Hospital, an online prescription order system has been developed as part of an integrated hospital information system named IMIS (the Integrated Medical Information System), in which all the physicians enter their prescription orders into online display terminals. The prescription order entry system is provided with prescription support functions, which check the entered prescription data, issue warnings, and offer information about drugs or patients. The prescription order system reduces the incidence of simple prescription mistakes and greatly decreases the cases of inquiries by pharmacists. However, results of the analysis show that such functions as warnings of double order and repeated prescription of a drug do not work as well as expected. The system would thus require some kind of intelligence like that of the auditing pharmacists or that of the physicians with accurate knowledge of clinical pharmacology.

New control chart for multivariate data with missing values.

A new multivariate statistical quality control method has been developed. It is an extension of the method developed by Kume, which is able to find abnormal values in multivariate biochemical data of a clinical laboratory. The present method makes use of the difference between two sets of data measured from the samples of the same patient obtained on different days. The Mahalanobis' distance between two samples can be calculated from the difference of their observations. If the Mahalanobis' distance of the two data is larger than the critical value decided in advance, the reliability of the measurement is doubtful. The characteristic of the present method is that it can apply to data with missing values by estimating them from measured data. Some numerical examples are shown to demonstrate the availability of the method.

Efficacy of a computerized system applied to central operating theatre for medical records collection.

A computer system operation is introduced, which has been in use since October 1981 at Kochi medical school as one of the integral sub-systems of the total hospital information system called IMIS. The system was designed from the beginning with the main purposes of obtaining better management of operations, and detailed medical records are included for before, during and after operations. It is shown that almost all operations except emergencies were managed using the computer system rather than the paper system. After presenting some of the results of the accumulated records we will discuss the reason for this high frequency of use of the computer system.

Use of a computer in analysis of heart rate and blood pressure response to the Valsalva maneuver.

The relationship between systolic blood pressure (SBP) and R-R interval (RR) in phase II of the Valsalva maneuver was analyzed with the use of a nonlinear relation. The nonlinear relation introduced here includes time derivatives of SBP and RR, and is a natural extension from the linear one which defines the linear baroreflex sensitivity index (BRSI). The model equations of SBP and RR derived from the nonlinear relation predicted well the observed changes of SBP and RR in 11 normotensive subjects and 16 hypertensive patients. Two of the parameters of the relation were related to the activity of the compensatory mechanism, and discriminated well the hypertensives from the normotensives. For this analysis an interactive system of regression analysis has been developed to reduce the difficulties in the case of nonlinear regression curve fitting. The regression curves can be monitored on a graphic terminal during every regression step. The values of nonlinear parameters can be obtained easily and systematically with use of the system.

Analysis of the online order entry process in an integrated hospital information system.

In Kochi Medical School Hospital, many online order systems have been developed as a part of the integrated hospital information system named IMIS KOCHI. The prescription, laboratory and radiology orders are used frequently and entered into the system by physicians. The distribution of entry duration of these orders by physicians was analyzed and it was found that the order entry is a completely random event and the entry process consists of the two Poisson processes; the quick process and the slow process. The two Poisson processes were observed even in the do-prescription order without correction by trained physicians. It is speculated that the quick process depends on availability in the order entry system and the slow process depends on peculiarities in clinics, and the mental condition of physicians.

Harmonic-intensity analysis of normal and hoarse voices.

Objective evaluation of normal and hoarse voices is performed considering the characteristic that hoarse voices show a prominent fundamental frequency intensity compared with harmonics in the voice spectrum. The relative harmonic intensity Hr, obtained from a stable portion of the sustained vowel/a/, is defined as the intensity of the second and higher harmonics expressed as a percentage of the total voice intensity. Ninety-five percent of the normal voices examined have Hr larger than the critical value of 67.2%, whereas 90% of the hoarse voices have Hr smaller than the critical value. The harmonic-intensity analysis thus provides good discrimination between normal and hoarse voices.