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At least 883 records · Page 49Linked to original sources
PubMed1999

Importance of the mitral subvalvular apparatus for left ventricular functional anatomy.

The mitral subvalvular apparatus is so important to attain the integrity of the left ventricular geometric model and systolic pump function of the heart. We conducted a detailed dissection of the anatomic structure of mitral valve complex and left ventricle of 10 adult hearts from fixed human cadavers (eight male and two female) at Department of Anatomy. Faculty of Medicine of Istanbul University and Department of Cardiovascular Surgery, Koşuyolu Heart and Research Hospital. The distribution of chordae tendinea and classification of musculus papillaris were recorded. The distribution of chordae tendinea varied slightly both anterior and posterior groups. Musculus papillaris was not simetrical in all subjects. Four type of musculus papillaris were distinguished. The insertio angulus of musculus papillaris varied between 20 degrees and 55 degrees. The left ventricular distances (inflow-outflow) and axes (short-long) were determined as the criteria, together with the mitral subvalvular apparatus, to gain the architecture of the left ventricle. We believe that the goal a more precise data collection and developed model will influence our understanding of functional anatomy of left ventricular subvalvular apparatus, and concept of changes in left ventricular configuration after mitral valve surgery.

Adult↗
PubMed1991

Blood flow in the cochlea, vestibular apparatus and facial nerve.

Blood flow in the cochlea, vestibular apparatus and facial nerve was investigated in the 12 temporal bones of 6 guinea pigs using non-radioactive microspheres. The cochlear blood flow volume was 1.80 +/- 0.82 microliters/min and the blood flow volume of the vestibular apparatus was 0.43 +/- 0.16 microliters/min. The blood flow volume of the facial nerve in the temporal bone was 0.29 +/- 0.17 microliter/min. Regarding these blood flow volumes, the difference between the right and left was not significant, although there were large interanimal differences. The distribution of the blood flow in the cochlea, vestibular apparatus and facial nerve is also described.

Animals↗
PubMed1992

Diagnosis of middle ear disease with eardrum perforation by a newly developed sweep frequency measuring apparatus.

Dynamic characteristics of an artificial middle ear model with and without eardrum perforations were measured with our newly developed sweep frequency measuring apparatus. Then, the dynamic characteristics of patients with chronic otitis media having eardrum perforations and with traumatic perforations were measured with this apparatus, and the results were compared with those of the artificial middle ear model with an eardrum perforation. The comparison leads to the conclusion that the middle ear condition of patients with eardrum perforations can be distinguished on the basis of their measurement results. Furthermore, the ossicular chain conditions of patients with eardrum perforations can be diagnosed after putting a paper patch on the eardrum perforation. Therefore, this apparatus seems to be highly useful in the diagnosis of both ossicular chain disorders and eardrum perforations.

Acoustic Impedance Tests↗
PubMed1981

An apparatus for measuring volumes of small objects.

An apparatus for measuring volumes of small objects such as tissue blocks is described. The apparatus measures volumes by fluid displacement and consists of a micropipette adapted to fit the month of an Erlenmeyer flask, a Luer adaptor fused to the side of the flask, and a glass syringe. When assembled with fluid enclosed, the fluid rises to a low level in the micropipette. Withdrawal of fluid into the syringe lowers the fluid level below the mouth of the flask. The micropipette is raised, the object to be measured is placed in the flask, and the micropipette is joined to the flask again. Fluid returned to the flask from the syringe rises to a higher level in the micropipette. The difference between the two fluid levels equals the volume of the object measured. This apparatus gives reproducible measurements and can be calibrated for absolute volume determination. It is inexpensive to construct and easy to use.

Histological Techniques↗
PubMed1996

An apparatus (Georgiou-Petri dish) for growing fungi and other microorganisms on liquid media in a Petri dish.

This work describes a new apparatus for growing fungi and other microorganisms on liquid nutrient media in a Petri dish. The apparatus is composed of a net supporting a cellophane membrane stretched between an outer and an inner ring that is placed inside a Petri dish. This modification of the standard Petri dish offers many advantages for studying growth, metabolism, differentiation, and other aspects of fungi in liquid cultures with minimal waste of expensive chemicals. Monitoring of excreted or absorbed substances by the fungi, the aseptic transfer of undisturbed fungal colonies from dish to dish, and harvesting are made easier, using this apparatus.

Ascomycota↗
PubMed1986

Ultrasound-guided stereotaxic biopsy using a new apparatus.

A skull-mounted apparatus is described for use with ultrasound probes 16 mm in diameter (5.0-MHz probes for near-field and 7.5-MHz probes for far-field lesions). The system permits ultrasound-guided stereotaxic biopsy of intracranial lesions through a burr hole in awake or anesthetized patients. This apparatus has been used in 19 patients for biopsy of central nervous system lesions 1.5 to cm in diameter and for drainage of abscess cavities and cysts. The time required to obtain a tissue sample after incision of the skin ranged from 25 to 40 minutes. The only complication was a delayed hemorrhage in a patient with acquired immunodeficiency syndrome. The advantages of this method over those guided by computerized tomography (CT) include less time required for the entire procedure, immediate confirmation of the biopsied target by imaging the echogenic needle track, assessment of cyst or abscess drainage, and detection of hemorrhage within minutes after biopsy. The apparatus may be especially useful in pediatric patients because it obviates the need for general anesthesia during transport to and from the CT scanner. This ultrasound-guided system does not require a craniotomy, craniectomy, or two separate burr holes.

Biopsy, Needle↗
PubMed2004

A vision research apparatus for broad luminance range displays.

Lightness, the perceived gray shade of a surface, and the perception of self-luminous surfaces--that is, surfaces that appear to glow--have most often been studied with paper displays and computer-generated stimuli presented on CRT monitors. Although both methods are often effective, experiments that require a wide range of luminance values in the same display are often difficult to conduct with paper and computer displays alone. Also, color mode appearance is often an issue when surface color perception is the topic of research; CRT monitors are essentially light sources themselves and often appear in the luminous mode of color appearance. Here, we describe an apparatus in which the target is an undetected aperture whose luminance is adjustable. Whereas a typical CRT monitor offers a luminance range of about 100:1, much broader luminance ranges are possible with the described apparatus. Unlike a CRT monitor, the stimulus background will always appear in the surface mode of color perception, and the target(s) can appear as either surface colors or luminous colors. Apparatus modifications are possible, including the addition of a stereoscope or an embedded CRT for creating an adjustable region that is computer controlled.

Color Perception↗
PubMed2003

An automated apparatus for presenting depth-rotated three-dimensional objects in human and animal object recognition research.

For practical reasons, research on the recognition of objects from different viewpoints has relied almost exclusively on the use of two-dimensional representations of three-dimensional objects. We describe an apparatus that enables the presentation of three-dimensional objects in a discrimination learning paradigm. Three chambers positioned on a movable table allow each of two objects to be presented on either the left or the right side; a viewing window exposes only two of the objects at a time. The objects can be arbitrarily designated as either an S+ or an S-. In addition, they can be placed precisely in any arbitrary start position and rotated in depth in 100 steps of 3.6 degrees each. We have successfully used this apparatus to investigate recognition of depth-rotated objects by both pigeons and humans. By varying the stimuli, number of stimulus chambers, and software programs, the apparatus can be used for other types of tasks and to investigate other types of processes.

Animals↗
PubMed1981

Tuberculin skin test conversion from exposure to contaminated pulmonary function testing apparatus.

Tuberculosis is a prevalent infectious disease that is transmitted primarily from man to man by droplet nuclei. This report describes an outbreak of tuberculosis infection in a hospital in which 8 persons--7 hospital employees and 1 patient--had documented conversion of intermediate strength tuberculin tests from negative to positive in a period of about 10 weeks. The 7 employees constituted 18% of those selected for skin testing because of close contact with a patient who had newly discovered smear-positive pulmonary tuberculosis. The one patient converter had been tested on pulmonary function testing apparatus previously used by the person with active disease; 21 other patients who had also used the contaminated apparatus in the same time period did not convert. Infection of the patient who did convert is attributed to the pulmonary function testing apparatus. Epidemiological investigation revealed the importance of considering factors of inoculum, reservoir, and host in the transmission of infection.

California↗
PubMedDate not supplied

[Development of a "vortex bed" drying apparatus].

Fundamental parameters in dimensioning a "vortex bed" drying apparatus are the pressure drop across the bed and the higher and lower limit of fluidization velocity. The analysis of the Navier-Stokes equations brings to the following functional relations between dimensionless groups: (see journal). These relations define the fluidization conditions in a "vortex bed" apparatus. Experimental tests carried out on a laboratory scale apparatus will provide us with the unknown constants for industrial scale extrapolation.

Desiccation↗
PubMed1978

[Electron microscopical and ultrahistochemical investigations of erythrocytes from eel (Anguilla angiulla) and rainbow-trout (Salmo giardneri) under the specific consideration of the segregation apparatus and the marginal band (author's transl)].

Comparative studies were carried out on the fine structure of the erythrocytes of the European eel (Anguilla anguilla) and the rainbow trout (Salmo gairdneri) using electron microscopy and ultrahistochemistry. The cell organelles, the marginal band and the segregation apparatus were investigated. The 2 organelles revealed specific differences. An alkaline phosphatase activity was revealed by ultrahistochemistry at the cell surface only, while alternating activities between the nuclear membranes, in the Golgi complex and in the segregation apparatus were observed in the acid phosphatase depending on the differentiation stage of the erythrocytes. The results are being discussed relating to a function of the segregation apparatus and the marginal band.

Acid Phosphatase↗
PubMed2000

[A simple stereotaxic surgical apparatus].

A simple apparatus based on the classical stereotactic method of surgery offers the opportunity to master miniinvasive procedures in neurosurgery and neurotraumatology. This device is particularly helpful in evacuation of intracerebral spontaneous and traumatic haematomas and in stereobiopsies, i.e. the most frequent operations in clinical practice, without the need of general anaesthesia, craniotomy and interference with cerebral tissue. The reliability of the stereotactic apparatus was positively evaluated by three independent surgeons. The apparatus was registered for use in the health services.

Humans↗
PubMed2000

Patterns of systolic stress distribution on mitral valve anterior leaflet chordal apparatus. A structural mechanical theoretical analysis.

Increasing diffusion and complexity of mitral valve repair procedures may prompt an interest in the evaluation of the patterns of stress distribution on the chords, which are, from the structural mechanical point of view, the weakest element of valve apparatus. This theoretical analysis concentrates in particular on the mitral valve anterior leaflet. As is known, the vast majority of the chordae are attached to the anterior leaflet within the coaptation area; during systole they are then necessarily parallel, aligned along the same plane as that of the leaflets' coaptation surface, to which they are attached; moreover the thickness of the chordae increases significantly from the marginal chordae to the more central ones. In normal conditions during systole the progressively wider coaptation surface causes the increasing stress to be supported by an increasing number of progressively thicker chords, which are substantially parallel and aligned on the coaptation surface plane in such a way that they can share the stress between them, according to their thickness; in other words chords form a multifilament functional unit which enrolls elements of increasing thickness in response to the mounting stress. The geometrical modifications of the valve apparatus architecture (annulus dilatation, leaflet retraction, chordal elongation or retraction) often associated with valve insufficiency due to chordal rupture, have the common result of causing, during systole, a radial disarrangement of the direction of most of the secondary chordae which are no longer parallel, aligned on the coaptation surface plane. Due to the negligible elastic module of the valve leaflet, in this new arrangement the various chordae cannot share the stress between themselves as they do in a normal physiological situation; on the contrary the thinner chordae nearer to the free margin are also loaded with the peak systolic stress, thus generating conditions favoring their rupture. It can, therefore, be hypothesized that the anatomopathological picture of valve insufficiency due to chordal rupture may be the final event of a series of geometrical modifications of valve apparatus architecture, the common consequence of which is to load thinner marginal chords with peak systolic stress from which they are normally spared, thus favoring their rupture.

Animals↗
PubMed2001

Behaviour of pathogenic E. coli and Salmonella enteritidis in small domestic sewage treatment apparatus ("Johkasou").

"Johkasou" is a small sewage treatment apparatus commonly used in Japan which can effectively treat domestic wastewater in places where a public sewage system is difficult to supply. The behaviour of enterohaemorrhagic E. coli O157 and Salmonella enteritidis in a "Johkasou" was studied. Their reduction rates depended significantly on the water temperature in the "Johkasou" with minimal decrease in numbers at 10 degrees C within 48 h. The reduction rates increased at 20 degrees C and 30 degrees C where 4 log reduction could be expected. The reduction rates were influenced by the BOD of the solutions that contained the pathogens with the lower the BOD the higher the reduction rate. The reduction rates were about the same between both pathogens. The result showed that it was necessary to disinfect the effluent as some pathogens can pass through the apparatus when some users of the apparatus excrete pathogens.

Escherichia coli↗
PubMedDate not supplied

[Modeling of the structure of hemodialysis apparatuses].

By taking into account the general principles in the design of extrarenal blood clearance apparatuses, all existing hemodialysis apparatuses (HDAs) are classified by the transportation of the controlling medium, by the degree of automation, by the control of amounts of the liquid removed from the patient, and by their connection to the latter. The proposed classification of HDAs and a model of the structure of dialysate units showed the unity of principles in designing HDAs irrespective of the specific features of their design, which may be used to ensure the versatility, reproducibility, technological effectiveness, convenience in application, and efficiency of the apparatuses designed.

Equipment Design↗
PubMedDate not supplied

[Use of an apparatus for automatic lung straightening in the management of the pleural cavity in the postoperative period].

An apparatus for automatic lung straightening may be used in medical technologies employed in thoracic (lung) surgery in the postoperative rehabilitation of a patient. This apparatus may automatically (without a physician's or a nurse observance) maintain tension relief in the pleural cavity in the patient on an individual basis, which is required for complete lung strengthening. Its use greatly reduces the number of postoperative complications in the lung, such as residual cavities, edema, and empyema of the pleura. This apparatus is to go into quantity production as a cheap, expendable device to prevent AIDS and hepatitis.

Empyema, Pleural↗
PubMed2002

[Research progress [correction of progresses] of cell culture apparatus].

Cell culture apparatus (CCA) is necessary to space medicine research and space life-science research. With development of technology, CCA has been fully developed. Nowadays, CCA has been used in scientific research and production widely. In addition, space cell culture apparatus has become an indispensable tool in correlative space research. In this paper, a variety of apparatus used on ground and in space are summarized.

Aerospace Medicine↗
PubMed2002

The structure and function of the larval siphon and spiracular apparatus of Coquillettidia perturbans.

The structure of the larval siphon and spiracular apparatus of Coquillettidia perturbans and the mechanism of attachment to roots of emergent aquatic macrophytes were examined by utilizing dissection and scanning electron microscopy. The roots of these plants contain large air-filled aerenchyma channels that larvae of Cq. perturbans pierce with their specialized siphon and spiracular apparatus to breathe. The siphon contains the spiracular apparatus, comprising the saw, postabdominal spiracles, inner spiracular teeth, and the spiracular apodeme. These are the primary structures that are utilized by larvae to pierce root tissue. Once entry is made into a root, the outer spiracular teeth open fully, anchoring the larva in place.

Animals↗