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PubMedDate not supplied

The nuclear dry weight of liver cells from patients with virus hepatitis and from controls.

Interferometric investigations were performed at liver cell nuclei isolated in 70 per cent glycerol. In 11 patients with virus hepatitis and seven patients without liver disease the nuclear dry weight of liver cells obtained by liver biopsy was determined by interferometry. The average nuclear dry weight of diploid liver cells from controls was 39.9 pg while an average value of 45.4 pg was found for patients with hepatitis. The corresponding nuclear volumes were 241 and 274mu3 respectively. The dry mass and volume of tetraploid nuclei was twice as big as that of diploid nuclei in both materials. The nuclear water content was neither significantly different between diploid and tetraploid nuclei nor significantly different between nuclei from controls and patients with hepatitis.

Cell Nucleus↗
PubMed2000

Effects of magnetic fields on mosquitoes.

Phylogenetically diverse organisms, including some insects, are able to detect and respond to magnetic fields comparable to the Earth's magnetic field. Because of their tremendous importance to public health, mosquitoes were tested for the presence of remanent ferromagnetic material indicative of a biological compass and also tested for behavioral responses to magnetic fields. Using a superconducting quantum interferometry device, we found that significant remnant was probably due to attraction of ferromagnetic dust onto the surface of live or dead mosquitoes. Most mosquitoes placed in a 1.0-gauss, uniform magnetic field moved until they were oriented parallel to the field. Two of 3 species of mosquitoes tested took fewer blood meals in a rotating magnetic field than in the Earth's normal magnetic field.

Animals↗
PubMedDate not supplied

[Immunosensors: sources of origin, achievements and perspectives].

The analysis of the recent data in the literature and results of investigations in the field of the development and study of function efficiency of different types of immune sensors, that are performed at the Department of Biochemistry Sensory and Regulatory Systems of the A. V. Palladin Institute of Biochemistry of Ukrainian National Academy of Sciences are presented. Sources of origination and perspectives of the devlopment of biosensors are discussed as well. The paper also gives an overview of main research projects at the Department, mainly in the filed of biosensors. They include development of the scientific bases for the creation of a new generation of chemo- and biosensors for their application in medicine and ecology. Multi-immune, multi-enzyme and combined multi-parametrical sensors can provide express analyses in laboratory and field conditions with the purpose to perform immune chemical diagnostics of diabet, kidney diseases, immune defficiencies, autoimmune, allergic, pre-infarction and pre-tumor states as well as to control total toxicity of the environment and identification of main types of toxic elements in it. The investigations are based on the latest achivements in the field of physics, chemistry, information technology and electronics with the use of different types of planar electrodes, ion sensitive field effect transistors (ISFETs), semiconductor capacitive structures, termistors, optrodes, piezocrystalls and application of such methods and effects as laser correlation spectroscopy, chemiluminescence, fluorescence, surface plasmon resonance, photoluminescence of porous silicon, interferometry, evanescent wave technique, nonemmiting energy transfer and holography.

Allergy and Immunology↗
PubMedDate not supplied

[Two-dimensional reconstruction of birefringence map of the skeletal muscle sarcomere in relaxed and rigor states studied by interference microscopy].

A new method of automatized quantitative interferometry of skeletal muscle fibers was developed for the investigation of birefringence. A device based on the Linnic microscope was constructed to obtain phase images, which are two-dimensional pictures of birefringence. For the first time, two-and-three-dimensional maps of both total birefringence and birefringence for individual sarcomeres in the central part of muscle fiber were visualized using large databases. It was shown that total birefringence of fibers at rest length in the rigor state was lower as compared with the relaxed. Birefringence values from individual sarcomere interferograms revealed also that normalized A-disk birefringence was lower in the rigor state. The results obtained could be explained by a decrease of thick filaments anisotropy, due to the moving away of myosin heads from the rod during transition into the rigor state.

Animals↗
PubMed1975

Content of DNA and dry weight of the nuclei of neurons of the external geniculate body and retina of the eye in guinea pigs.

The amount of DNA and the dry weight of the nuclei of cells of the external geniculate body, as well as the photoreceptor, bipolar, and ganglionic cells of the retina of the eye, were studied at the early stages of postnatal development of guinea pigs by the methods of cytospectrophotometry and interferometry on prints of the tissue. In the photoreceptor and bipolar cells of the retina, a stable, diploid amount of DNA is detected. In the ganglionic cells and nerve cells of the external geniculate body, in addition to the diploid cells a small group of tetraploid cells was detected. The dry weight of the nuclei of the external geniculate body and retina increased appreciably on the third day of postnatal development.

Animals↗
PubMed2001

Accuracy of intraocular lens power calculations using the Zeiss IOL master. A prospective study.

PURPOSE: Partial Coherence Interferometry (PCI) is a fast, noncontact method to calculate lens implant power for cataract surgery. It has been reported as a potentially more accurate method than ultrasound biometry. Prospective study of the refractive outcomes of a consecutive series of patients undergoing phacoemulsification surgery with preoperative biometry by both ultrasound A-scan and PCI. METHODS: A series of 50 eyes of 35 patients underwent small-incision phacoemulsification cataract surgery and lens implantation by one single surgeon. All patients had preoperative biometry performed by both ultrasound using the Sonomed and IOL Master optical biometry. The IOL Master results were included in the SRK II formula to calculate the lens implant power. Postoperative refractive assessment was performed 4 weeks after surgery. RESULTS: The mean difference in axial length between ultrasound and optical biometry was 0.2 mm. The IOL Master measures a longer axial length. The mean keratometric power using the Javal instrument was 43.4 D and for the Zeiss IOL Master it was 42.9 D. At the week 4 postsurgery assessment, the overall refractive outcome was in the range of +/- 1D. Five patients were unable to undergo PCI biometry due to the density of cataract. CONCLUSIONS: Intraocular lens power calculations using the Zeiss IOL Master are easy to perform and result in excellent refractive outcomes. A-scan biometry is still needed in case of mature cataract.

Biometry↗
PubMed2001

Features of age-related macular degeneration on optical coherence tomography.

PURPOSE: To describe Optical Coherence Tomographic (OCT) findings in age-related macular lesions. PATIENTS AND METHODS: We selected 6 patients with characteristic features of age-related macular disease on OCT, 4 of whom presented with Choroidal New Vessels (CNV). OCT is analogous to ultrasound, except that light is used instead of sound. The reflected light is analysed with the technique of low-coherence interferometry. RESULTS: Classic CNV present with well-defined boundaries on OCT, whereas occult CNV can present with well- or poorly defined boundaries. Findings in Chronic Central Serous Chorioretinopathy (CSCR) and Adult Onset Vitelliform Dystrophy (AOVD) need angiographic correlation when compared to findings in CNV. CONCLUSION: OCT cannot replace conventional diagnostic techniques in exsudative Age-related Macular Degeneration. Although it accurately depicts associated changes and especially the associated serous detachment in macular disease, the imaging of neovascular membranes faces limited penetration and resolution. The interpretation of the tomograms requires further clinico-histological correlation.

Aged↗
PubMed1998

[Electronic speckle pattern interferometric analysis on force distribution of different mandibular unilateral free-end dentures].

OBJECTIVE: To study the force distribution of three kinds of mandibular unilateral free-end partial denture under vertical loading on the artificial tooth. METHODS: A fresh mandible with right 2nd and 3rd molars missing was restored with cantilever fixed partial denture (CFD), casting three arm clasp removable partial denture (CCD) and RPI removable partial denture (RPID) respectively. The force distribution on the surface of supporting bone was studied by using electronic speckle pattern interferometry (ESPI). The ESIP was displayed real-time and recorded. The fringes determining was prossed by microcomputer image processing. The corresponding out of plane displacement of the supporting bone was measured and analyzed. RESULTS: Showed all of the three kinds of dentures contribute to transmit stress to supporting bone. The corresponding out of plane displacement of supporting bone decreased, the degree of decrease was CFD < CCD < RPID in order. CONCLUSION: This finding provides a useful reference for design of denture construction.

Adult↗
PubMed2002

[The dry skull model in orthodontics].

Orthodontic therapy aims to displace teeth by means of orthodontic appliances. Forces, applied on the teeth, induce remodeling of the alveolar process in upper and lower jaw resulting in a new position of the teeth into both jaws. In this publication an attempt has been made to test a model (dry skull model) which could provide a better understanding of the effect of force application on tooth and bone displacement. Initial tooth displacement (microscopical), right after force application, could give an indication for the longitudinal tooth displacement to be expected. Variables as the point of force application, the amount and direction of the force and the localisation of the centre of resistance are determining factors for the final tooth displacement. This study attempts to forecast the longitudinal tooth displacement by evaluating the initial displacement on the dry skull. Initial tooth displacement has been measured by means of laser measuring techniques (holography, speckle interferometry and laser reflection technique). These techniques are non-invasive (non-destructive testing) and permit the measurement of small tooth and bone displacements varying between 0.5 and 15 microns. According to the results of the animal studies, it became obvious that initial tooth and bone displacements are indicative for the longitudinal effect of the same sort of force application on a short time basis (5 to 8 weeks). The final conclusion is that initial tooth displacement measured on a dry skull has a predictive value for the longitudinal effect of orthodontic force application. Moreover, the creation of a finite element model looks very promising in this respect. More research is needed to test the finite element model further and to make it useful for testing the effect of force application on skull and tooth structures of a patient.

Animals↗
PubMedDate not supplied

Immobilization of biocomponents for immune optical sensors.

Immobilisation of both human immunoglobulin(IgG) and antiimmunoglobulin (anti-IgG) was performed by means of polyelectrolyte self-assembly. This technique was compared with direct immobilisation of the immune components on bare gold and their covalent binding via glutaraldehyde as a bifunctional reagent. Additionally, the immune components were properly oriented during their immobilisation by using a predeposited layer of the protein A. Methods of the surface plasmon resonance (SPR) and planar interferometry were employed for monitoring the immobilisation as well as specific immune reaction. It was shown that in case of the use of polyelectrolyte self-assembly it is possible to achieve the sensitivity of the analysis up to 30 ng/ml for SPR and up to 1 ng/ml for planar interferometer based immune sensors.

Autoantibodies↗
PubMedDate not supplied

[Some problems in the use of holography in medical-biological studies].

Various fields of the holographic methods application in medico-biological investigations are discussed. Special consideration is given to the methods of holographic interferometry, holographic microscopy, ultrasonic holography and to the technique of optic filtration of images. The paper sets forth brief characteristics of diverse holographic methods, technical possibilities of each one of them and a review of some practical work done in this field.

Holography↗
PubMedDate not supplied

Laser medical instrumentation.

In spite of inadequate budgets, significant research and development studies have been made on laser medical instrumentation applications for both diagnosis and treatment. Diagnostic instrumentation includes the laser microprobe for cation microanalyses, cytofluorometry, interferometry, transillumination, holography and acoustical holography, and communications and information handling. Laser investigative surgical instrumentation includes lasers of argon, carbon dioxide, neodymium-YAG, and ruby, which are used as optical scalpels. Advantages of laser surgical instrumentation include precision, color absorption for lasers in the visible light range, and hemostasis.

Communication↗
PubMed1992

[Calculation of optimized and individualized hip prosthesis. A study of feasibility].

As logical consequence of a series of basic research studies on human femoral bones with unipodal support and under static stress, performed with physicomathematic modelling methods (finite-elements method) then confirmed by direct visualization of deformations resulting from such stress using holographic interferometry, the authors have worked on the definition of an optimized and individualized hip prosthesis. Thick CT sections digitized with a table and entered into a specially programmed computer allowed three-dimensional modelling of the femur as a volume, i.e. with its external contour and its medullary canal, and therefore of the implantable space. The prosthesis was then defined taking a number of hypotheses into account: necessity to regularize cortical bone spicules inside spongious bone, which are so often present opposite the rough line, partial machining at the level of the calcar, reduced tail length, presence or absence of collar. Thus an optimized and individualized prosthesis was defined. A prototype corresponding to a given femoral bone could then have been produced. However, the authors found it preferable to use simulation with computer synthetic images to check easy insertion and removal.

Acetabulum↗
PubMed1976

[Methods for oscillography on the temporal bone preparation (author's transl)].

Oscillography of the middle ear structure on the temporal bone preparation are of essential importance for the expansion of our knowledge concerning physiological process and thus also for the further development of operation techniques that improve hearing. With the increased technical possibilities we are now able to make processes in the range of only few A measurable and visible. Accordingly, the methods employed for this purpose are complicated and manifold. The goal of this paper is to summarize these techniques as far as possible, to describe them in an understandable way, and to briefly point out their pros and cons. Optical methods, nearly all of which are in use today, as well as new methods such as laser interferometry and the Moessbauer technique, which can be performed only in few laboratories, are discussed.

Bone Conduction↗
PubMed1997

The monitoring of gaseous contaminants in spacecraft cabin atmospheres.

The accumulation of toxic or otherwise harmful trace gases in a spacecraft cabin is a very serious concern in terms of the health and safety of the crew. Although methods exist for controlling the evolution of such contaminants, techniques for monitoring the success of these methods, on board and in near- real-time, are still under development. One such technique, based on the use of FTIR interferometry, is being developed in Europe. A prototype instrument has been assembled, making extensive use of 'off-the-shelf' hardware and software, and tested for its ability to detect and quantify--within a maximum period of 1 minute and in the presence of water vapour and carbon dioxide 21 of the most frequently detected contaminants on past Shuttle and Spacelab flights. Results have confirmed that such contaminants can be detected and measured with an acceptable degree of precision.

Air Pollutants↗
PubMed1992

Chondrocytic monoamine oxidase activity in the development of natural murine osteoarthritis.

Most of the male STR/ORT mice develop osteoarthritis (OA) involving the medial tibial plateau. A peculiarity of two chondroprotective drugs is the presence of a nitrogen atom so that cleavage of the molecule could generate a molecule that might act as an inhibitor of monoamine oxidase (MAO). Direct examination showed abnormal localization of MAO in the potentially osteoarthritic cartilage indicating possible abnormal response to catecholamines. In normal cartilage, the direct effect of excessive concentration of adrenaline caused considerable oedema, as measured by microscopic interferometry. It is therefore suggested that the excess of water found in the matrix of osteoarthritic cartilage may be related to disturbance of the MAO activity.

Animals↗
PubMed2005

[Sound transmission loss within the middle ear].

OBJECTIVE: To assess the amount of sound transmission loss in order to deeply understand the mechanism of middle ear sound transmission for ossicular reconstruction and for guidance of crimping between prosthesis and stapes on sound transmission in stapes surgery. METHODS: In order to get a correcting magnetic field 2 temporal bone models was used first. Temporal bone models was developed using 17 human temporal bones from fresh cadavers. To measure the sound transmission properties in the middle ear, 15 temporal bone models were detected by scanning laser Doppler interferometry with acoustical stimulation and electromechanical stimulation. An algorithm was developed to simulate acoustical stimulation with electromechanical stimulation. A sound transmission loss within the incudostapedial joint was detected by electromechanical stimulation in 10 temporal bone models. RESULTS: The average transmission loss within the incudostapedial joint remained 3 dB over the frequencies detected. CONCLUSIONS: There was a sound transmission loss within the incudostapedial joint, which was a physiological and protection way.

Acoustic Stimulation↗
PubMed1991

[Functional activity of cell membranes in multiple sclerosis].

A study was made of the activity of the marker enzymes of plasma membranes Na+,K(+)-ATPase and AChE comparatively to the changes in red blood cell suspension viscosity. Interferometry and capillary viscosimetry were employed to examine red cell membranes of 100 patients suffering from multiple sclerosis. In the interval of physiological temperatures, the two temperatures areas -35 degrees and 40 degrees C characterized by specific behavior of the enzymes and viscosity changes were discovered. These temperature areas are viewed from the standpoints of temperature-induced structural transformations. Each of them has a definite clinical importance for the estimation of the activity of the underlying process. The fact of the existence of the complexly organized system of abnormal structural transformations attests to gross imbalance of red cell membranes. This phenomenon may also be observed as regards other membranes including the membrane of the oligodendrocyte. In addition to the evidence for the membrano-patho-chemical component in the pathogenesis of multiple sclerosis, the temperature-induced structural transformations play the role of diagnostic criteria for multiple sclerosis.

Acetylcholinesterase↗