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PubMed1990

[Personal laboratory data management system using optical card].

This paper describes the development and state of the medical optical card system. Recently, computerized medical information systems have been developed in many hospitals and they allow quick access and automatic processing of the patient's data in medical practice and research. However, the use of the information stored by such a system has been limited to each hospital while it is not rare for a patient to change hospitals. It is desirable to develop a personal medical data management system which allows the patient to carry his own medical records for a long period of time, and hospitals to share the information about the patient. The optical card is a transportable information medium with a large capacity. Since data are recorded optically with a laser beam, the card is tolerant to environmental factors such as static electricity, magnetism and impact which injure other transportable media such as IC card, magnetic stripe card and floppy disk. Therefore, the optical card suits our purpose. We developed a prototype of the medical optical card system. In our system, the card can contain character data, numerical data, two-valued image data and electrocardiographical data. In order to share laboratory data among different database systems, we defined a data descriptive language which enables complete and compact data description without any external code tables. The recorded patient data are presented in the original multi-window system, which allows the doctor to see any combination of any part of the patient's information simultaneously.

Clinical Laboratory Information Systems↗
PubMed2000

Genetic variability and molecular responses of root penetration in cotton.

Compacted soils restrict root penetration hindering productivity. In this paper, genetic variability of cotton (Gossipium spp.) root capacity to penetrate hard soil layers and the patterns of gene expression during penetration event were investigated. To mimic hard soil layers, wax-petrolatum mixtures were used. Genetic variability among 27 cotton genotypes for the root capacity to penetrate wax-petrolatum disks of 500-700 g wax/kg of mixture was high indicating that breeding efforts targeted to improve this trait can be successful. In the root tips of a cotton strain with high root penetrating ability (G. hirsutum HS 200) which penetrated through wax-petrolatum disks (P), quantity of four polypeptides with molecular weights 35-66 kDa increased compared to those root tips which grew in the absence of mechanical impedance (NP). Differential display showed significant differences in the sets of mRNA expressed in P and NP roots. Out of a total of 917 cDNAs scored in the differential display experiment, 118 cDNAs, or 13%, were specific to P roots and hence could be associated with the root penetration event. Further detailed study of gene expression in penetrated roots will pinpoint molecular factors involved in root penetration ability in cotton.

Journal Article↗
PubMed1992

Microstrip-antenna design for hyperthermia treatment of superficial tumors.

Microstrip antennas have many different advantages over other RF/MW radiative applicators employed for superficial hyperthermia treatment. This is mainly due to their compact and body-conformable structure as well as to printed circuit board techniques, both of which allow a wide design flexibility for superficial tumor heating. Among the wide variety of radiator configurations, three microstrip antennas of increasing complexity with electromagnetic and heating characteristics potentially suitable as applicators for superficial hyperthermia have been designed, developed, and tested in different radiative conditions: a microstrip disk, a microstrip annular-slot, and a microstrip spiral. Electromagnetic design criteria are presented together with the determinations of the applicator return loss versus frequency and thermograms of the near-field heating pattern in muscle-like phantom. The results are in good agreement with theory and indicate that: i) the operating frequency is either single or multiple according to the applicator-mode, "resonant" or "traveling-wave," and can be chosen in the useful frequency range for hyperthermia (200-1000 MHz) according to the tumor cross-section and depth; ii) the heating pattern flexibility increases going from the simple geometry disk to the annular-slot and spiral applicators; iii) a distilled-water bolus is required; iv) the annular-slot applicator exhibits the highest efficiency, while the spiral applicator provides the best performance.

Electromagnetic Phenomena↗
PubMed1993

Preparation, characterization, and dissolution kinetics of two novel albuterol salts.

The possibility of producing slowly dissolving albuterol salts was investigated as a potential means of extending the duration of action of the drug following aerosol delivery to the lung. Albuterol adipate and stearate were precipitated from alcoholic solutions of albuterol and adipic or stearic acids, respectively. Differential scanning calorimetry and hot stage microscopy showed that albuterol adipate and stearate produced single melting endotherms at 182 and 116 degrees C, respectively, which were distinct from those of albuterol (158 degrees C), adipic acid (152 degrees C), and stearic acid (70 degrees C). The aqueous solubilities of albuterol free base, sulfate, adipate, and stearate were 15.7, 250, 353, and 0.6 mg . mL-1, respectively, at room temperature. Only the solubilities of the adipate and the stearate increased significantly when the temperature was elevated to 37 degrees C (452.5 and 1.4 mg . mL-1, respectively). With a rotating disk dissolution method, albuterol free base, sulfate, and adipate were found to have intrinsic dissolution rates of 1.1, 20.4, and 24.0 mg . min-1 . cm-2, respectively, in pH 7.4 phosphate buffer at 37 degrees C. Albuterol stearate dissolved much more slowly and in a nonlinear fashion; this was explained by the deposition of a stearate-rich layer on the dissolving surface of the compacted salt.

Adipates↗
PubMed2004

Effects of potassium bromide disk formation on the infrared spectra of dried model proteins.

The most common method of sample preparation for Fourier transform infrared spectroscopic analysis of proteins in the solid state is compression after mixing with potassium bromide (KBr). Recently, questions have arisen as to whether proteins are conformationally altered by this process. In this study, the amide I Fourier transform infrared spectra of two model proteins, lysozyme and alpha-chymotrypsinogen, were measured before and after compression in KBr, and the effects of moisture exposure and the ratio of KBr to protein were examined. Contrary to earlier reports, compaction of the KBr/protein mixtures did not foster aggregation, and only minor apparent structural alterations were observed.

Bromides↗
PubMed2004

[A gearing mechanism with 4 degrees of freedom for robotic applications in medicine].

Applications in robot-aided surgery are currently based on modifications of manipulators used in industrial manufacturing processes. In this paper we describe novel rotatory kinematics for a manipulator, specially developed for deployment in robot-aided surgery. The construction of the gearing mechanism used for the positioning and orientation of a linkage point is described. Forward and inverse kinematics were calculated, and a constructive solution proposed. The gearing mechanism is based on two disk systems, each of which consists of two opposing rotatable discs. The construction was designed in such a way that the linkage point can be positioned freely anywhere within the mechanism's range of motion. The kinematics thus permits an x-y-positioning via rotating movements only. The spatial arrangement of two of such disc systems permits movements in four degrees of freedom (DOF). The construction is compact, but can be further miniaturized, is flexible and manufacturing costs are low. On the basis of this mechanical concept a new, small automated manipulator for surgical application will be developed.

Computer-Aided Design↗
PubMedDate not supplied

Microcarrier culture of lepidopteran cell lines: implications for growth and recombinant protein production.

Several microcarrier systems were screened with Sf-9 and High-Five cell lines as to their ability to support cell growth and recombinant (beta-galactosidase) protein production. Growth of both cell lines on compact microcarriers, such as Cytodex-1 and glass beads, was minimal, as cells detached easily from the microcarrier surface and grew as single cells in the medium. Cell growth was also problematic on Cytopore-1 and -2 porous microcarriers. Cells remained attached for several days inside the microcarrier pores, but no cell division and proliferation were observed. On the contrary, insect cells grew well in the interior of Fibra-Cel disks mainly as aggregates at points of fiber intersection, reaching final (plateau) densities of about 4 x 10(6) (Sf-9) and 2.7 x 10(6) (High-Five) cells mL(-1) (8 x 10(6) and 5.5 x 10(6) cells per cm(2) of projected disk area, respectively). Their growth was described well by the logistic equation, which takes into account possible inhibition effects. Beta-Galactosidase (beta-gal) production of Sf-9 cells on Fibra-Cel disks (infected at 3.3 x 10(6) cells mL(-1)) was prolonged (192 h), and specific protein production was similar to that of high-density free cell infection. Cultispher-S microcarriers were found to be a very efficient system for the growth of High-Five cells, whereas no growth of Sf-9 cells took place for the same system. Concentrations of about 9 x 10(6) cells mL(-1) were reached within 120 h, with cell growth in both microcarriers and aggregates, appearance of cellular bridges between microcarriers and aggregates, and eventual formation of macroaggregates incorporating several microcarriers. Specific protein productions after beta-gal baculovirus infection at increasing cell concentrations were almost constant, thus leading to elevated volumetric protein production: final beta-gal titers of 946, 1728, and 1484 U mL(-1) were obtained for infection densities of 3.4, 7.2, and 8.9 x 10(6) cells mL(-1), respectively.

Animals↗
PubMed2001

Preformulation studies on the S-isomer of oxybutynin hydrochloride, an Improved Chemical Entity (ICE).

(S)-Oxybutynin HCl (S-OXY) is a white crystalline solid powder with an acicular particle morphology. Differential scanning calorimetry (DSC) thermograms revealed one characteristic endotherm at 116.2 degrees C. On rescanning a sample heated to 120 degrees C, no thermal events were distinguished in the temperature range 25 degrees C to 150 degrees C. Weight loss curves determined by thermogravimetric analysis showed a continuous, gradual weight loss of about 0.15% over the temperature range 30 degrees C to 110 degrees C, followed by a change in slope and more rapid weight loss beginning at 150 degrees C. Observation by hot-stage microscopy confirmed the melting endotherm observed by DSC. Equilibrium moisture uptake studies indicated low water vapor uptake at low relative humidities (<52.8%). At relative humidities of 75.3% and 84.3%, S-OXY first deliquesced and then converted to a lower melting point crystal form. X-ray powder diffraction (XRPD) data supported the DSC findings. S-OXY underwent degradation by ester hydrolysis at alkaline pHs. The kinetics of this reaction were studied at 25 degrees C in carbonate-bicarbonate buffers. Observed rate constants of 0.008 h(-1) and 0.0552 h(-1) were determined at pH 9.69 and 10.25, respectively. The pKa of S-OXY was 7.75. The aqueous solubility of S-OXY was described as a function of pH and the free-base solubility. The mean partition coefficient log P was 3.33 using 1-octanol. The surface tensions of aqueous solutions of S-OXY decreased with increasing concentration, but no concentration-independent region was observed, indicating that S-OXY does notform micelles in aqueous solution. The dissolution rate of S-OXY from a compressed disk in 0.1 N HCl was rapid, whereas it was considerably slower at pH 7.4. Addition of 1% hexadecyltrimethylammonium bromide (CTAB) at pH 7.4 significantly improved the dissolution rate. S-OXY displayed very poor flow properties when compared to standard pharmaceutical excipients. XRPD results indicated that S-OXY exhibited a loss in crystallinity following ball milling. Hiestand tableting indices indicated that S-OXY has good bonding properties andforms strong compacts, but is likely to be susceptible to capping on ejection from the die. This indicated the needfor a plastically deformable excipient such as Avicel PH-101 in tablet formulations.

Calorimetry, Differential Scanning↗
PubMed2000

Comparison of different techniques for obturating experimental internal resorptive cavities.

Forty extracted maxillary central incisors were instrumented at the working length to a #50 file. The roots were sectioned transversely with a diamond disk at 7 mm from the anatomical apex. At the opening of the root canal of each section, hemicircular cavities were drilled with a specially designed bur. The corresponding root sections were cemented with glue, thus obtaining root canals with similar cavities that simulated internal resorptions. Teeth were embedded in plaster casts to facilitate their handling. The specimens were randomly separated into four groups of 10. The following obturation techniques were evaluated: lateral compaction (group A), hybrid technique (group B), Obtura II (group C), and Thermafil (group D). AH26 was used as the sealer. After obturation, the plaster was removed and the teeth were radiographed in buccolingual and mesiodistal directions to evaluate the quality of the obturation at the IRC. The incisors were then cut with a scalpel at the same level as the previous section, to examine, under a stereomicroscope, the type of material that filled the IRC. Obtura II gave the best results and in most of the specimens obturated with this technique, the IRC were filled mainly with gutta-percha. Statistical analysis of the data indicated that the differences between group C and the other groups were significant (P < 0.05).

Bismuth↗
PubMed2000

Proximal atrioventricular bundle, atrioventricular node, and distal atrioventricular bundle are distinct anatomic structures with unique histological characteristics and innervation.

BACKGROUND: Direct 3D analysis (ie, stereotaxic analysis of 3 planes) has shown that the atrioventricular (AV) node (AVN) is continuous with only specialized myocardium of the proximal AV bundle (PAVB) and distal AV bundle (DAVB) or His bundle. The purpose of the present study was to determine whether the PAVB, AVN, and DAVB possess histological features distinct from each other and from the ordinary myocardium. METHODS AND RESULTS: A protocol that preserves the cytoplasmic and interstitial integrity of the tissue and permits serial sections of the AV junction region to be made in 3 orthogonal planes showed that the PAVB, AVN, and DAVB are characterized by myocardium aggregated into fascicles containing approximately 8 myofibers. Myofibers within the fascicles are coiled or spiraled about each other; and spiraling is most compact in the PAVB. Collagen encases individual fascicles and segregates primary fascicles into secondary fascicles. Fascicles, and not myofibers, are in parallel array in the PAVB, interwoven in the AVN, and parallel in the DAVB. Narrow junctions of parallel fascicles separate the AVN from the PAVB and DAVB. Myocytes, which are largest in DAVB, possess clear perinuclear regions; thin finger-like end processes, which are most numerous in the AVN; uniform, delicate cross-striations; and intercalated disks, which are broader in the PAVB and form short stacks in the AVN. Sheaves of nerve terminals are found, including boutons as in skeletal muscle [corrected]. CONCLUSIONS: The PAVB, AVN, and DAVB have distinct histological features. Collagen septation of primary and secondary fascicles presents natural barriers within the tissues and to surrounding myocardium and structures. These findings confirm that the AV junction region contains a specialized conduction system that is anatomically isolated from ordinary myocardium.

Animals↗
PubMed2002

Determining the role of patterned cell proliferation in the shape and size of the Drosophila wing.

The present work is a detailed analysis of the numerical and positional parameters of cell proliferation in all of the derivatives of the wing disk. We have made use of twin clones resulting from mitotic recombination events at three different ages of development. The interfaces between twin clones indicate the relative position in the anlage of the mother cells. Interface types vary with age of clone initiation and with wing regions. They are indicative of the main allocation of postmitotic cells of the growing clones. Growth is exponential and intercalar, i.e., the progeny of ancestor cells becomes more and more separated. Clones are compact, indicating that daughter cells tend to remain side by side. The shape of the clones is wing region characteristic. Subpopulations of cells grow preferentially along veins and wing margins and show characteristic shapes in different pleural regions. The shape and size of the adult wing regions largely depend on the shape of clones and hence of the allocation of successive rounds of daughter cells. The role of mitogenic morphogens in wing size and shape is discussed.

Animals↗
PubMed1987

A computer method for the acquisition and analysis of patch-clamp single-channel currents.

The method we present instructs the computer to deliver sets of programmed membrane voltages and allows the acquisition of large amounts of digitized data, compact storage, ready identification of records and rapid, interactive analysis of channel current data. A typical cycle of analysis including amplitude determination and kinetic measurements for 10 s of continuous data digitized at 5 kHz requires 5-20 min depending on the complexity of the observed channel activity. This procedure is compatible with such storage protocols as that described by Bezanilla [Biophys. J., 47 (1985) 437-441], although there are obvious benefits to using standard computer storage devices such as hard disks, floppy disks, and Bernoulli Boxes. The programs described in this report are available from the authors.

Animals↗
PubMed1976

Postnatal development of the human temporomandibular joint. II. A microradiographic study.

Temporomandibular joint specimens from 22 subjects aged 1 month to 23 years were examined microradiographically. There occurred considerable interindividual variations in mineralization of the joints but nevertheless, systematic changes in mineralization were demonstrated during the periods of development and growth. A continuous compact bony layer formed early in the fossa and tubercle while the outer mineralized layer of the condyle consisted of calcified cartilage. A continuous bony layer around the periphery of the condyle was not fully developed before about 20 years of age. Growth of the articular tubercle was characterized by a spongy appearance of the bony layer over the tuberculum up to the end of puberty. No corresponding growth changes could be seen in the fossa. No mineralized parts could be seen in the disk or the fibrous layers of the articular surfaces.

Adolescent↗
PubMed2003

Characteristics of optic disc changes in Taiwanese patients with primary angle-closure glaucoma.

BACKGROUND AND PURPOSE: Primary angle-closure glaucoma (PACG) is the predominant form of glaucoma among Asians. Although numerous studies have been done to describe the characteristic optic disc changes in patients with primary open angle glaucoma (POAG) which is the predominant form of glaucoma among Western populations, few studies have evaluated the optic disc changes in patients with PACG. The aim of this study was to elucidate the characteristic intrapapillary and parapapillary disc changes in PACG in a cross-sectional study and to develop a practical approach to the detection of glaucomatous optic disc changes in PACG by ophthalmoscopic examination. METHODS: A total of 103 eyes in 103 PACG patients were studied. Forty one eyes of 41 age- and sex-matched healthy subjects served as controls. Three glaucoma-trained subspecialists examined stereophotographs of optic discs to evaluate the intrapapillary and parapapillary changes. The differences in PACG and control group eyes were compared. RESULTS: Concentric steep enlargement of the optic disc was found in 99 PACG eyes (96%). Local notching was noted in only 3 eyes, and vertically oval-shaped cupping of the optic disc in only 1 eye. Disc hemorrhage was not detected in any eye. Parapapillary atrophy of the alpha zone involving both temporal and nasal side of the optic disc and parapapillary atrophy of beta zone were significantly more frequent in the PACG group. The presence of an alpha zone or a beta zone simultaneously involving both the temporal and nasal side of the optic disc was associated with more severe optic nerve head damage. CONCLUSIONS: The intrapapillary change in the PACG group eyes reflected the development of cupping in PACG patients with small and compact optic discs. The parapapillary atrophy paralleled the intrapapillary optic disc cupping in eyes of the PACG group.

Case-Control Studies↗
PubMed1999

Completion of myelin compaction, but not the attachment of oligodendroglial processes triggers K(+) channel clustering.

The characteristic localization of ion channels is crucial for the propagation of saltatory conduction in myelinated nerves. Voltage-gated Na(+) channels are located at nodes of Ranvier while voltage-gated K(+) channels are mainly found at juxtaparanodal regions. Recently, a humoral factor secreted by oligodendrocytes has been reported to induce clustering of Na(+) channels in CNS axons. However, the molecular mechanisms for K(+) channel clustering as well as the role of oligodendrocytes are still uncertain. To clarify whether myelin sheath itself can induce the distinct distribution of K(+) channels, we have investigated the localization of K(+) channels in adult and developing mouse optic nerves. The CNS axons from chronic demyelinating and hypomyelinating mice were also examined to determine if myelin sheaths were required for the maintenance of clusters. In all cases, the K(+) channel clustering correlated well with compact myelin, but not with the presence of oligodendrocytes, suggesting that, in contrast to Na(+) channel clustering, the formation of compact myelin is required for initiation as well as maintenance of K(+) channel clustering. In addition, postsynaptic density protein-95 (PSD-95) or its highly related protein was found colocalized with K(+) channels, suggesting that it may interact with K(+) channels to form clusters at juxtaparanodal regions.

Animals↗
PubMedDate not supplied

Electrocardiomultigraphimeter using a home computer.

The drop in hardware costs has fostered the widespread use of home-computer systems. Because of this situation, the home computer can be profitably employed in some highly specialized fields. We believe electrocardiographic instrumentation to be one such field. We have built an electrocardiomultigraphimeter (ECXGM), which can be considered as a development of the traditional electrocardiograph that performs some additional functions. Our prototype features vectorcardiography, polar coordinate tracing, automatic measurements between fiducial points selected by the user with a joystick and screen cursor and trace filing by patient on labelled floppy disks. The standard hardware consists of a Commodore 64 console, a monitor, two floppy disk drives and an Epson HI-80 plotter, all of which are readily available. The special hardware consists of an A/D converter, which receives the electrocardiographic signal downstream of the amplifying stage, which is a standard feature of any electrocardiograph. Prototype development mostly involved the software. Difficulties were posed by the limited resources available on home computers, an important point in view of the problem to be tackled. The solutions adopted are based on the use of assembler language and overloading techniques and minimizing the interconnections among the software modules defined in a compactly built program. The result is an instrument with significantly advanced clinico-scientific capabilities as compared to current electrocardiographic instruments. This fact, and the class of the hardware used and special software built, confer originality to this work. The new instrument ought to be especially suitable for the offices of cardiologists who have an interest in such capabilities, and for schools of electrocardiography.

Computer Graphics↗
PubMed1987

[The electrocardiomultigraphimeter and the Commodore-64. How to use the home computer with great skill].

The drop in hardware costs has fostered the widespread use of home-computing systems. Because of this situation, the home-computer can be profitably employed in some highly specialized fields. We believe electrocardiographic instrumentation to be one of such fields. We have built an electrocardiomultigraphimeter (ECXGM), which can be considered as a development of the traditional electrocardiograph that fulfills some additional functions. Our prototype features vectorcardiography, polar coordinate tracing, automatic measurements between fiducial points selected by the user with a joystick and cursor on the screen and trace filing by patient, on labelled floppy disks. The conventional hardware consists of a Commodore 64 console, a monitor, two floppy disk drives and an Epson HI-80 plotter, all of them readily available. The special hardware consists of an A/D converter, which receives the electrocardiographic signal downstream of the amplifying stage which is a standard feature of any electrocardiograph. Prototype development mostly involved the software. Difficulties were posed by the limited resources available on home-computers, an important point in view of the problem to be tackled. The solutions adopted are based on the use of the ASSEMBLER language, overloading techniques and on minimizing the interconnections among the software modules defined in a compactly built program. The result is an instrument having significantly advanced clinico-scientific capabilities as compared to current electrocardiographic instruments. This factor, and the class of the hardware used and special software built confer originality to this work.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer Graphics↗
PubMed2001

An unusually massive stellar black hole in the Galaxy.

The X-ray source known as GRS1915+105 belongs to a group dubbed 'microquasars'. These objects are binary systems which sporadically eject matter at speeds that appear superluminal, as is the case for some quasars. GRS1915+105 is also one of only two known binary sources thought to contain a maximally spinning black hole. Determining the basic parameters of GRS195+105, such as the masses of the components, will help us to understand jet formation in this system, as well as providing links to other objects which exhibit jets. Using X-ray data, indirect methods have previously been used to infer a variety of masses for the accreting compact object in the range 10-30 solar masses (M middle dot in circle). Here we report a direct measurement of the orbital period and mass function of GRS1915+105, which allow us to deduce a mass of 14 +/- 4 M middle dot in circle for the black hole. Black holes with masses >5-7 M middle dot in circle challenge the conventional picture of black-hole formation in binary systems. Based on the mass estimate, we interpret the distinct X-ray variability of GRS1915+105 as arising from instabilities in an accretion disk that is dominated by radiation pressure, and radiating near the Eddington limit (the point where radiation pressure supports matter against gravity). Also, the mass estimate constrains most models which relate observable X-ray properties to the spin of black holes in microquasars.

Journal Article↗