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PubMed2006

An apparatus for diagnosis of ossicular chain mobility in humans.

Confirmation of the conditions of the ossicles is essential for tympanoplasty. However, at present, ossicular mobility is experimentally estimated with palpation by a surgeon, and the results depend on the surgeon's skill. In this study, a new apparatus for quantitatively measuring ossicular mobility was developed. With this apparatus, the ossicles were displaced and the reaction force from the ossicles, (i.e. the load applied to the ossicles) was simultaneously detected. Ossicular mobility of three patients with otosclerosis or chronic otitis media was measured to evaluate the usability of the apparatus. The apparatus can distinguish the differences in ossicular mobility between normal and fixed ossicles, and it makes estimating the change of mobility between pre- and posttreatments for ossicular fixation possible. Positive correlation was seen between ossicular mobility and hearing level.

Acoustic Impedance Tests↗

PubMed1969

Immunochemical studies of 22S protein from isolated mitotic apparatus.

Evidence is presented that the "22S protein" of mitotic apparatus isolated from sea urchin eggs is not microtubule protein. An antibody preparation active against 22S protein is described, and immunochemical studies of the distribution of 22S protein in various cellular fractions and among morphological features of mitotic apparatus are reported. The protein is ubiquitous in the metaphase egg fractions that were tested but is not found in sperm flagella. It is immunologically distinct from proposed microtubule protein isolated from mitotic apparatus by the method of Sakai, and from proposed microtubule protein obtained after extraction with mild acid. It exists in nontubule material of isolated mitotic apparatus but is not detectable in microtubules.

Animals↗

PubMed1971

Selective extraction of isolated mitotic apparatus. Evidence that typical microtubule protein is extracted by organic mercurial.

Mitotic apparatus isolated from sea urchin eggs has been treated with meralluride sodium under conditions otherwise resembling those of its isolation. The treatment causes a selective morphological disappearance of microtubules while extracting a major protein fraction, probably consisting of two closely related proteins, which constitutes about 10% of mitotic apparatus protein. Extraction of other cell particulates under similar conditions yields much less of this protein. The extracted protein closely resembles outer doublet microtubule protein from sea urchin sperm tail in properties considered typical of microtubule proteins: precipitation by calcium ion and vinblastine, electrophoretic mobility in both acid and basic polyacrylamide gels, sedimentation coefficient, molecular weight, and, according to a preliminary determination, amino acid composition. An antiserum against a preparation of sperm tail outer doublet microtubules cross-reacts with the extract from mitotic apparatus. On the basis of these findings it appears that microtubule protein is selectively extracted from isolated mitotic apparatus by treatment with meralluride, and is a typical microtubule protein.

Amino Acids↗

PubMed2001

Bacteriological validation of a new apparatus for disinfection of hospital waste at the point of disposal.

OBJECTIVES: To evaluate the ability of a new apparatus (Dipsys 25, Société SGN, Bagnols sur Cèze, France) to disinfect biomedical waste, including both potentially infectious agents and the normal saprophytic flora of the waste. METHODS: Disinfection was assessed using standard methods (reference strains were fixed on reference carriers according to the French AFNOR methods) and nonstandard assays. Assays in conditions of hospital use, evaluations of bacterial survival during storage, sporicidal effect, and spore survival during storage were performed in parallel. Finally, bactericidal effect in extreme conditions (association of high contamination and high bacterial protection conditions) was tested with normal fecal flora. Bacterial counts were performed after treatment by the apparatus and without treatment (controls). All tests were carried out in triplicate. RESULTS: In all treated carriers, a bacterial population decrease of at least 5 log10 was obtained. Assays performed in hospital-use conditions did not show any bacterial growth. Concerning the evaluation of sporicidal effect and spore revival during conservation, a minimum reduction of 5 log10 was observed in all assays performed, without survival. Finally, concerning assays in extreme conditions, the decrease of bacterial population was between 5 log10 and 10 log10 for vegetative anaerobes of normal fecal flora. CONCLUSION: Under our study conditions, the study apparatus reduced the tested microbial populations by a minimal factor of 5 log10. The main advantage of the apparatus is the opportunity to treat contaminated waste inside hospital wards, at the point of initial collection, without pulverization, by nonspecialized staff.

Bacteria, Aerobic↗

PubMedDate not supplied

A new apparatus for chronic observation of the microcirculation in situ to evaluate artificial organ performance.

Chronic study of the peripheral circulation and metabolism is very important in evaluation of artificial organ performance. However, there has been no way to observe the microcirculation in situ, chronically and continuously, without restriction. In this study, the authors developed a new apparatus that could be implanted and connected to an artificial organ that would allow continuous observation of the microcirculation while the subject is awake. The apparatus uses a charge coupled device (CCD) under a new principle: thin living tissue, such as mesentery, is put directly on a highly integrated CCD and transilluminated with a light emitting diode (LED). The vascular nets in the tissue are projected onto the CCD like a contact photograph, which is sent to a television screen and can be analyzed for motion and function. A 0.5 inch CCD with 25K pixels was used in this study. The cover glass of the CCD was removed so the tissue would be able to directly contact the CCD surface. The CCD, as well as LED, were molded with hard polyurethane as electrical insulation. The apparatus is 35 mm in diameter and 10 mm high with a micro stand for lighting with the LED, which is easy to implant in a goat or calf. The resolution of this apparatus was tested by putting a micro scale on the CCD surface. Several tenths of micrometers could be seen. In an animal experiment with a rabbit, configurations of arterioles and venules and their motions could be observed continuously for a night until the electrical insulation was broken. This method might be a strong weapon in artificial organs research.

Animals↗

PubMed1993

Decreasing imposed work of the breathing apparatus to zero using pressure-support ventilation.

OBJECTIVES: To apply pressure-support ventilation with the goal of decreasing the imposed work of the breathing apparatus (endotracheal tube, breathing circuit tubing, and the ventilator's demand-flow system) to zero and to evaluate a clinical method of measuring the imposed work of breathing. DESIGN: A prospective evaluation of adult and pediatric patients receiving mechanical ventilatory support. SETTING: A surgical and a pediatric intensive care unit in a university hospital. PATIENTS: Fifteen patients (11 adult and four pediatric), who were diagnosed with acute respiratory failure from various etiologies, and who were intubated and spontaneously breathing, received continuous positive airway pressure and pressure-support ventilation. MEASUREMENTS AND MAIN RESULTS: Imposed work of the breathing apparatus was calculated by integrating pressure measured at the tracheal end of the endotracheal tube from a narrow air-filled catheter and the change in volume from a miniature pneumotachograph (flow sensor) positioned between the "Y" piece of the breathing circuit and the endotracheal tube. Pressure and volume signals were directed to a computerized, portable respiratory monitor (Bicore Monitoring Systems) that provides real-time display of the pressure-volume (work) loops and calculation of the imposed work. Imposed work was measured at 0 cm H2O pressure-support ventilation, and then incremental levels of pressure-support ventilation were applied until the imposed work decreased to zero. Imposed work decreased in a quadratic fashion after incremental levels of pressure-support ventilation (r = -.83 [r2 = .69]; p < .001). At pressure-support ventilation level of 0 cm H2O, the imposed work was 0.60 +/- 0.17 joule/L. At mean pressure-support ventilation levels of 13.5 +/- 4.8 cm H2O, imposed work decreased to 0 joule/L. CONCLUSIONS: Ideally, the imposed work of the breathing apparatus should be zero to decrease the afterload on the ventilatory muscles and, thus, the patient's work of breathing. Eliminating the imposed work is achieved using appropriate levels of pressure-support ventilation. We describe an easily applied, practical method of measuring imposed work using a commercially available, portable, bedside respiratory monitor. We recommend that all patients diagnosed with respiratory failure and compromised pulmonary mechanics and who are intubated and breathing spontaneously, receive at least a minimal level of pressure-support ventilation that results in zero breathing apparatus-imposed work of breathing.

Acute Disease↗

PubMed1987

Nonius alignment apparatus for measuring vergence.

The present paper describes an apparatus designed for the assessment of vergence. Based on the Nonius alignment system of viewing dichoptic stimuli, this apparatus provides a compact, portable, easily constructed, and easily maintained piece of equipment. It can be used for the assessment of vergence under a wide variety of viewing conditions and laboratory demands. Also included are an example of one way in which the apparatus may be set up, the equations for finding vergence angle using that set-up, and data concerning the validity and reliability of measurements made with the apparatus.

Convergence, Ocular↗

PubMed1996

An apparatus for ultraviolet B irradiation of small volumes of biological fluid under controlled oxygen tension.

BACKGROUND: The design, construction, and calibration of a unique apparatus for ultraviolet (UV) B irradiation of small volumes of biological fluid under temperature-controlled open atmospheric or closed cell conditions of defined Po2 is described. METHODS: The apparatus consists of a custom designed UV transmissible quartz silica 3 port spectrophotometric cuvette coupled to a deuterium UV B source by UV transmissible fiber optics. Fluid movement, temperature regulation, dosimetry, and miniaturized biosensors for oxygen, pH, and temperature are described along with a preliminary experiment. RESULTS: The apparatus produces a known photochemical effect using an endogenous aqueous humor UV B photosensitizer-L tryptophan. UV B radiation is contained, thus protecting laboratory personnel. The system provides a continuous spectral UV B dose of 30 mJ/cm2/hr, which is equivalent to approximately 5.5 UV sunlight hours reaching an aliquot of mammalian aqueous humor. CONCLUSIONS: This biophysical apparatus can be used to investigate antioxidant protective systems in ocular fluid (aqueous/vitreous humors and tears), and is also applicable to evaluating the interaction of radiation with ocular and nonocular tissue cell homogenate.

Animals↗

PubMed1995

An apparatus for applying pure nonconstraining moments to spine segments in vitro.

STUDY DESIGN: This article reports on the design and use of a new apparatus for creating and monitoring pure, relatively nonconstraining moments to induce flexion/extension, lateral bending, and axial rotation in cadaveric spine segments of two or more vertebrae. OBJECTIVE: The apparatus was designed to take advantage of the precision and control available in a servo-hydraulic testing frame to efficiently create and monitor testing moments. SUMMARY OF BACKGROUND DATA: Other laboratories have reported methods of flexibility testing that also use cables and pulleys. However, instead of loading the cables and pulleys using a mechanical testing frame, previous systems have used pneumatic actuators or dead weights. METHODS: Force from a uniaxial mechanical testing frame is converted to torque applied to the specimen through a system of cables and pulleys. The cable orientation is monitored to ensure that pure moments are created. Applied moments are recorded using one or two load cells. RESULTS: Sketches of the apparatus are presented and its operation is described. CONCLUSION: Because the materials required to build this apparatus are inexpensive and the equipment needed for its operation is common in mechanical testing labs, this design may be useful for researchers interested in beginning in vitro spine flexibility testing with minimal expenditure.

Biomechanical Phenomena↗

PubMed1997

Stabilizing properties of the halo apparatus.

STUDY DESIGN: A cadaveric cervical spine specimen fixed between a fiberglass torso and a plastic skull was used as a model to determine the effect of halo structural parameters on motion at a lesion simulated at C5-C6. In a second part, nine commercially available halo devices were compared. OBJECTIVES: To define the contributions of the various components of the halo apparatus to reducing motion in an injured cervical spine and to compare the stability offered by a sample of commercially available halo devices. Controversy exists concerning the ability of the halo apparatus to stabilize the injured cervical spine. SUMMARY OF BACKGROUND DATA: The halo apparatus has been shown to be the most effective nonsurgical method for stabilizing the fractured spine. Nonetheless, several clinical studies have demonstrated that unacceptably large motions can occur at the injured spinal segment stabilized with a halo apparatus. METHODS: Each cadaveric cervical spine was mounted onto a fiberglass torso and a rigid plastic skull was attached to the base of the occiput. A posterior ligamentous lesion was created between C5 and C6. The halo ring was fitted to the skull and a vest to the torso. Loads were applied to the skull in flexion, extension, and lateral bending, and relative angulation between C5 and C6 was measured with electroinclinometers. In the first part, the effect of parameters such as vest tightness, vest-thorax friction, vest deformation, and connecting bar rigidity on spinal angulation were measured using one vest. In the second part, the stability offered by each of nine commercially available halo devices was compared. RESULTS: Increasing chest strap tightness and decreasing vest deformation reduced angulation at the spinal lesion. Once connecting bar joints were tightened to 25% of their recommended torque, increased tightening or adding additional bars had no effect on rigidity. Although specific vests permitted significantly greater motion in specific directions, no vest allowed greater angulation consistently in all loading planes. CONCLUSIONS: Increasing vest tightness, decreasing the deformability of the vest, and ensuring a good fit can reduce motion in the fractured spine. Most commercially available halo vests provide similar mechanical stability to the injured cervical spine.

Biomechanical Phenomena↗

PubMed2006

Arterial blood supply of the extensor apparatus of the long fingers.

BACKGROUND: The extensor apparatus vascularization is less studied compared with flexor tendons. The aim of the present anatomical work was to study it in a more systematic way and find clinical applications. METHODS: The study was carried on 40 fingers from 10 fresh cadaver hands. Two catheters (16 gauge) were introduced into the radial and ulnar arteries on the volar side of the wrist. Acetone was used for arterial cleaning and color latex for the arterial system coloration. The authors proceeded with the dissections, always in the same manner: they first made the longitudinal dorsal incisions from the metacarpophalangeal to distal interphalangeal joints. Raising the skin, they identified the thin subcutaneous branches into the hypodermal plane; they followed their course until their origin, which allowed identification of the arterial branches of the extensor apparatus. For measurements, they used as a point of reference the emergence distance of those dorsal branches from the metacarpophalangeal and proximal and distal interphalangeal joints. RESULTS: The extensor apparatus vascularization was segmental, realized through the paratenon from the branches of a vascular cutano-tendino-osseous complex through a common trunk, issued from the propria digital artery. This complex nourished not only the extensor apparatus but also the dorsal digital skin and periosteum. Its location was consistent at the level of both proximal and middle phalanges. CONCLUSIONS: This consistency explains the anatomical basis for the realization of composite-free tissue transfer in cases of banked fingers. The osteotomies could be performed at well-defined distances from the joints.

Aged↗

PubMed1998

A novel experimental apparatus to study the impact of white noise and 1/f noise on animal populations.

This paper reports on the design and construction of a novel apparatus that allows a set of aquatic microcosms to experience complex temporal environmental fluctuations. Replicate microcosms were maintained in 18 water baths with independent environmental controls. We give results from a preliminary experiment designed to look at the effects of varying temperatures with different variance spectra (i.e. white noise or 1/f noise) on single species population dynamics. Matching time series (with identical elements, differently ordered) of environmental temperatures with different Fourier spectra were created for use as input to the apparatus using a novel spectral mimicry method. The apparatus functioned well during the course of the experiment making this an extremely useful research tool. This apparatus now provides ecologists with a means of studying how environmental variability and directional trends in this variability, are filtered and translated by real populations and micro-ecosystems.

Animals↗

PubMed1990

A new apparatus for hair regrowth in male-pattern baldness.

A newly devised apparatus (Scalp-Tension-Relaxer, STR) can efficiently promote hair regrowth in patients with male-pattern baldness. When this apparatus is applied, the scalp is pushed up to relieve tension on the vertex. The efficacy rate of hair regrowth in alopecia patients was 40%. An investigation into the basis for the hair regrowth caused by this apparatus was directed toward the changes in hemodynamics and skin temperature of the scalp. During and after use of this apparatus, subjects exhibited an increase both in the cutaneous blood flow rate (as determined by laser Doppler flowmetry) and in the cutaneous temperature (as determined by thermography).

Adult↗

PubMed1994

Magnetic resonance imaging: a new tool in the diagnosis of tumours of the nail apparatus.

Tumours of the nail apparatus are often the subject of diagnostic dilemma. Until now, no reliable imaging methods have been available to assess these lesions correctly. We report the results of high and very high-resolution magnetic resonance imaging (MRI), which have been correlated with the anatomical findings in 14 cases of nail apparatus pathology, and discuss the possible contribution of MRI to diagnosis. With very high-resolution MRI, accurate analysis of the anatomy of the nail apparatus is possible, and lesions as small as 1 mm can be detected. An expansive process can be excluded when results are negative. Glomus tumour, mucoid pseudocyst, fibrokeratoma, and exostosis can be differentiated because of their different MRI characteristics. This is of importance when the exact nature of a subungual tumour cannot be determined by clinical findings alone. Measurement, determination of the exact localization of the tumour, and the study of its relationship to the other structures, can provide guidance for subsequent surgical procedures. MRI is reliable and accurate in the delineation of lesions, and provides a new tool for the investigation of pathology of the nail apparatus.

Adolescent↗

PubMed2005

Frameshifting by transcriptional slippage is involved in production of MxiE, the transcription activator regulated by the activity of the type III secretion apparatus in Shigella flexneri.

Bacteria of Shigella spp. are responsible for shigellosis in humans. They use a type III secretion (TTS) system encoded by a 200 kb virulence plasmid to enter epithelial cells and trigger apoptosis in macrophages. This TTS system comprises a secretion apparatus, translocators and effectors that transit through this apparatus, cytoplasmic chaperones and specific transcription regulators. The TTS apparatus assembled during growth of Shigella flexneri in broth is activated upon contact with epithelial cells. Transcription of approximately 15 genes encoding effectors, including IpaH proteins, is regulated by the TTS apparatus activity and controlled by MxiE, a transcription activator of the AraC family, and IpgC, the chaperone of the translocators IpaB and IpaC. We present evidence that MxiE is produced by a frameshift between a 59-codon open reading frame (ORF) (mxiEa) containing the translation start site and a 214-codon ORF (mxiEb) encoding the DNA binding domain of the protein. The mxiEa encoded N-terminal part of MxiE is required for MxiE function. Frameshifting efficiency was approximately 30% during growth in broth and was not modulated by the activity of secretion or the coactivator IpgC. Frameshifting involves slippage of RNA polymerase during transcription of mxiE, which results in the incorporation of one additional nucleotide in the mRNA and places mxiEa and mxiEb in the same reading frame. Frameshifting might represent an additional means of controlling gene expression under specific environmental conditions.

Amino Acid Sequence↗

PubMedDate not supplied

Suspensory apparatus prosthesis in the horse. Part 1: In vitro mechanical properties.

Mechanical properties of equine suspensory apparatus preparations and three braided synthetic prostheses were evaluated in vitro. Force versus displacement plots and failure modes were recorded from single load-to-failure testing in 18 cadaver limbs before and after replacement of each suspensory apparatus with a prosthesis. Mean load at failure, energy to failure, and stiffness values of polytetrafluoroethylene (PTFE) prostheses were lower than those of the suspensory apparatus and aramid prosthesis. The PTFE prosthesis failed by elongation or rupture of the prosthesis. Mechanical properties of the aramid prosthesis with collar augmentation were not significantly different from the suspensory apparatus. The main site of failure in both aramid prostheses was at the screw fixation to bone.

Animals↗

PubMed1988

The lost neuromotor apparatus of Chlamydomonas: rediscovered.

Early light microscopic studies of the biflagellate green alga Chlamydomonas revealed a fibrous system, the neuromotor apparatus, which appeared to link physically the flagellar apparatus to the cell nucleus. Following the development of the electron microscope, the existence of a neuromotor apparatus in Chlamydomonas was cast into doubt since it was not observed in studies carried out at ultrastructural resolution. Here we show, by indirect immunofluorescence, using monoclonal antibodies and electron microscopy employing refined specimen preparation and staining techniques, that the neuromotor apparatus of Chlamydomonas does indeed exist. The functional significance of this system is discussed in light of both historic proposals and recent experimental findings.

Antibodies, Monoclonal↗

PubMed1975

The evaluation of a column-type dissolution apparatus.

An improved column-type dissolution apparatus is described. The column of the apparatus is built from standard screw-cap connected "Sovirel" glass tubes which should enable inter-apparatus variability to be reduced. The main problem with this type of device is the build up to back pressure as fragments from the disintegrating solid dosage form progressively block the filtration system, itself necessary to stop the solution process and present the solution for analysis. A simple type of light-activated switch is therefore used which works across the indicator float of a flow meter to drive a motor connected to a needle valve. As the float falls the motor is switched on to open the valve and increase the flow rate until the float rises again and causes the motor to switch off. Observation on the dissolution characteristic of dyed lactose tablets and the injection of dye solutions into the flowing stream of liquid around tablets showed that there was back-flow of solution at Reynolds Numbers below 10 but visible instability to flow at Re greater than 100. Over a range of flow rates between Re 10-70 the mass of drug released at a given time was a direct function of flow rate for a film coated product but an inverse function for a sugar coated tablet. The results are discussed in relation to the main problems which can be experienced with a column-type dissolution apparatus.

Evaluation Studies as Topic↗