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PubMed1995

A treadmill apparatus and harness support for evaluation and rehabilitation of gait.

This report describes a treadmill apparatus for the evaluation and rehabilitation of gait in disabled persons. The apparatus incorporates a body weight support system as well as mechanisms to change certain conditions: treadmill belt speed, upward-downward and lateral slopes, and provision of obstacles. The apparatus enables elements of a treadmill walking pattern to be visible in persons for whom gait evaluation or rehabilitation may not otherwise be possible. It also allows for exploration of factors that limit the adaptability of gait in person after disease or injury by changing the mechanical demand of the locomotor task.

Adult↗

PubMed2003

Increased Ca2+-sensitivity of the contractile apparatus in end-stage human heart failure results from altered phosphorylation of contractile proteins.

OBJECTIVE: The alterations in contractile proteins underlying enhanced Ca(2+)-sensitivity of the contractile apparatus in end-stage failing human myocardium are still not resolved. In the present study an attempt was made to reveal to what extent protein alterations contribute to the increased Ca(2+)-responsiveness in human heart failure. METHODS: Isometric force and its Ca(2+)-sensitivity were studied in single left ventricular myocytes from non-failing donor (n=6) and end-stage failing (n=10) hearts. To elucidate which protein alterations contribute to the increased Ca(2+)-responsiveness isoform composition and phosphorylation status of contractile proteins were analysed by one- and two-dimensional gel electrophoresis and Western immunoblotting. RESULTS: Maximal tension did not differ between myocytes obtained from donor and failing hearts, while Ca(2+)-sensitivity of the contractile apparatus (pCa(50)) was significantly higher in failing myocardium (deltapCa(50)=0.17). Protein analysis indicated that neither re-expression of atrial light chain 1 and fetal troponin T (TnT) nor degradation of myosin light chains and troponin I (TnI) are responsible for the observed increase in Ca(2+)-responsiveness. An inverse correlation was found between pCa(50) and percentage of phosphorylated myosin light chain 2 (MLC-2), while phosphorylation of MLC-1 and TnT did not differ between donor and failing hearts. Incubation of myocytes with protein kinase A decreased Ca(2+)-sensitivity to a larger extent in failing (deltapCa(50)=0.20) than in donor (deltapCa(50)=0.03) myocytes, abolishing the difference in Ca(2+)-responsiveness. An increased percentage of dephosphorylated TnI was found in failing hearts, which significantly correlated with the enhanced Ca(2+)-responsiveness. CONCLUSIONS: The increased Ca(2+)-responsiveness of the contractile apparatus in end-stage failing human hearts cannot be explained by a shift in contractile protein isoforms, but results from the complex interplay between changes in the phosphorylation status of MLC-2 and TnI.

Adult↗

PubMed1996

Halothane counteracts acetylcholine-induced increase in Ca2+ sensitivity of the contractile apparatus in airway smooth muscle.

The direct relaxing effect of halothane on airway smooth muscle has been reported to involve the reduction of the cytosolic Ca2+ concentration ([Ca2+]i) and the [Ca2+]i-independent inhibitory mechanism. To clarify the extent of the contribution of these mechanisms, the effect of halothane on the [Ca2+]i-tension relationship in porcine tracheal smooth muscle strips was evaluated, using fura-2 fluorometry. The control [Ca2+]i-tension relationship was constructed from data of [Ca2+]i and tension during the contractions induced by the stepwise increment of extracellular Ca2+ concentrations under high K+ depolarization. In the presence of acetylcholine (1 microM), the [Ca2+]i-tension relationship shifted upward, which indicated the acetylcholine-induced increase in the Ca2+ sensitivity of the contractile apparatus. Halothane (0.034 mM), in the absence of acetylcholine, did not alter the increases in either [Ca2+]i or tension, hence no change in the [Ca2+]i-tension relationship. However, in the presence of acetylcholine, halothane did attenuate the acetylcholine-induced upward shift of the [Ca2+]i-tension relationship. Halothane proved to have a potent attenuating effect on the acetylcholine-induced increase in Ca2+ sensitivity of the contractile apparatus with little influence on [Ca2+]i. This desensitization of the contractile apparatus to [Ca2+]i may play a major role in the direct airway relaxing effect of halothane.

Acetylcholine↗

PubMed2003

Simple cervical spine traction using a halo vest apparatus: technical note.

BACKGROUND: A halo vest apparatus, commonly used for external immobilization and protection of the cervical spine, offers several advantages. We present here a simple, accurate, easy, and safe cervical traction technique using a halo vest apparatus. METHODS: The distinguishing feature of our technique is that, after application of a halo vest apparatus, the halo crown is distracted gradually and stepwise by turning the bilateral screw bolts that hold the halo crown over a period of one to several weeks. After each of these steps, care must be taken to check neurologic, radiologic, and skin conditions, as well as cranial pin tightening. CONCLUSIONS: This distance control technique can provide a strong and accurate traction force by simply turning the bolts without the risk of overdistraction or the need for bed rest, and can be used in conjunction with radiologic examination and transportation of patients, even those unable to walk. The Sugita head fixation system constitutes a safe and easy way to facilitate surgical management after correction of cervical dislocation.

Cervical Vertebrae↗

PubMed2000

NMR imaging investigations of drug delivery devices using a flow-through USP dissolution apparatus.

A system for performing NMR imaging experiments on drug delivery devices within a flow-through dissolution apparatus, USP Apparatus 4, has been developed. The system was used to image the physical changes that occur in solid dosage forms during dissolution in the flow-through apparatus. Simultaneous cumulative drug release measurements were also made. The NMR images obtained under these conditions and the drug release data provide a better understanding of the processes involved in the release of drugs from drug delivery systems based on diffusion, dissolution and osmosis mechanisms.

Drug Delivery Systems↗

PubMed2001

The initiation of elongation growth during long-term low-temperature stay of spring-type oilseed rape may trigger loss of frost resistance and changes in photosynthetic apparatus.

The aim of the present investigation was to determine if the loss of frost resistance observed in spring-type oilseed rape during winter may be the effect of the tendency to start elongation growth during the prolonged low-temperature stay. Interactions between elongation growth rate, properties of photosynthetic apparatus and frost resistance were studied under these conditions in spring and winter cultivars of oilseed rape. Both spring and winter cultivars of oilseed rape reached the maximal frost resistance after 6 weeks at +5 degrees C. Photosynthetic apparatus of both cultivars acclimated to functioning in cold. The resistance of winter type plants remained unchanged at the end of the experiment (10 weeks) whereas spring-type plants lost the maximal resistance in subsequent weeks. It was preceded in the 7th week of low-temperature stay by acceleration of elongation growth without an increase in dry matter accumulation. A gradual loss of photosynthetic activity was also observed during this period. It was manifested as a decrease in antenna trapping efficiency, photochemical and non-photochemical fluorescence quenching and actual quantum yield of PSII without affecting apparent quantum yield of PSII. At the 70th day of the experiment, a decrease in CO(2) exchange and dry matter accumulation were even observed. The possible relationships between growth rate and functioning of photosynthetic apparatus are discussed.

Journal Article↗

PubMed1996

Suction apparatus and the suctioning procedure: reducing the infection risks.

Serious infection has been related to the use of suction apparatus and to the suctioning procedure. Prevention of infection focuses on aseptic technique, handwashing, decontamination and sterilization of apparatus where appropriate. This article considers the infection risks arising from use of suction apparatus, the suctioning procedure and sets out recommendations for infection prevention.

Cross Infection↗

PubMed1998

Simple X-ray film holder for lateral view of the anterior jaws using dental X-ray apparatus.

A new X-ray apparatus, the occlusal X-ray film holder, was devised so that the lateral view of the jaw could be studied. This apparatus could easily be adjusted to a dental X-ray cone. In 21 cases of impacted teeth, cysts or foreign body in the maxilla and mandible and 6 cases that necessitated examination before or after implantation, the efficacy of this apparatus was confirmed. Its advantages are: it is applicable to dental X-ray equipment; it is cheap; there is no need for image intensifying to get a clear image; and follow-up examination is possible. We believe that this film holder would be useful for the diagnosis of lesions in the anterior maxilla and mandible as well as in the general dental clinic.

Foreign Bodies↗

PubMed2001

Testing apparatus and experimental procedure for position specific normalization of electromyographic measurements of distal upper extremity musculature.

OBJECTIVE: An apparatus and procedure are described to determine position specific normalization coefficients for surface EMG of upper extremity musculature. STUDY DESIGN: Thirty-nine subjects were tested three times. Repeatability of EMG measurements across test sessions was determined by computing intraclass correlation coefficients. Two-way analysis of variance was used to test upper extremity position dependent differences in EMG measurements. BACKGROUND: EMG measurements are susceptible to error from skin movement and muscle length changes, both of which may occur when upper extremity positions vary. Normalization of the EMG signal without consideration for such positional influences may lead to erroneous conclusions regarding muscle activation during functional tasks. METHOD: An apparatus was designed that allowed subjects to perform three repetitions of maximum elbow flexion, forearm pronation, wrist extension, and wrist flexion with the forearm in neutral and pronated positions. Surface EMG was sampled from eight muscles. Mean EMG on maximum voluntary contraction was computed, and resting EMG was subtracted to obtain EMG normalization coefficients. RESULTS: Upper extremity position affected the EMG normalization coefficient for biceps brachii, which was lower in the pronated position, and extensor carpi radialis, which was higher in the pronated position (P<0.00625). CONCLUSIONS: The apparatus accommodates various combined positions of the elbow, forearm and wrist. The normalization procedure is efficient for testing subjects who are being observed during functional tasks. Only two muscles were affected by upper extremity position, but group trends were not always consistent with individual behavior. This method would ensure the use of appropriate EMG normalization coefficients regardless of individual variation. RELEVANCE: This method is effective for normalizing EMG signals using task specific upper extremity positions. It may be used to test isometric exertions of distal upper extremity musculature for clinical and research purposes.

Adult↗

PubMed1981

An apparatus for observing behavior of pouch-young opossums.

Opossum fetuses undergo most of their neurological development within the mother's pouch. This extrauterine growth offers unique opportunities not shared by placenta mammals for early behavior studies. Described here are an apparatus and technique for observing the behavior of pouch young. The apparatus restrains the mother and retracts the pouch flaps within an environmentally controlled setting similar to that inside the mother's pouch, allowing the opossum young to be observed in an almost natural state. The investigator has ready access to the young pouch through side windows that have slotted curtains to prevent sudden changes in the chamber environment. Because this apparatus provides a simple noninvasive approach, fetal behavior can be observed long-term, encompassing the entire sequence of behavior development within a chosen time-interval.

Animals↗

PubMed2002

Performance of USP calibrator tablets in flow-through cell apparatus.

USP dissolution calibrator tablets were analysed by the flow-through cell method with the intention of examining its applicability for the flow-through cell apparatus suitability test. Test was performed with Dissotest CE-6 apparatus, (Sotax, Switzerland) in flow-through cells for tablets and capsules: smaller cells of 12 mm diameter and larger ones of 22.6 mm diameter. Analyses were performed with laminar and turbulent flow of dissolution medium. The flow rates were 16 and 8 ml/min for laminar flow and only 16 ml/min for turbulent flow. From the results it can be concluded that both salicylic acid tablets and prednisone tablets could be used for apparatus suitability test also for the flow-through cell under the conditions of laminar flows of 16 and 8 ml/min in cells phi 12 and 22.6 mm. As regards the turbulent flow of 16 ml/min, without a holder, cells phi 12 mm could be used for salicylic acid tablets and both cells (phi 12 and 22.6 mm) for prednisone tablets.

Calibration↗

PubMed1995

Type VI collagen is phagocytosed by fibroblasts and digested in the lysosomal apparatus: involvement of collagenase, serine proteinases and lysosomal enzymes.

Type VI collagen is present in most connective tissues, where it is considered to play a crucial role in the attachment of cells to the extracellular matrix and/or in the three-dimensional organization of the collagen meshwork. Although some information is available on its formation, the mechanisms involved in its degradation are not understood. Here, we present evidence for lysosomal digestion of type VI collagen by fibroblasts of periosteal explants. In the lysosomal apparatus of these cells, broad-banded filamentous aggregates characterized by 100-nm periodicity were found, which proved to consist of type VI collagen as indicated by their stainability with anti-type VI collagen antibodies. By interfering with synthesis (ascorbate or alpha, alpha-dipyridyl), intracellular translocation of collagen-containing vesicles (colchicine) as well as phagocytosis (cytochalasin B), it was shown that the intracellular broad-banded type VI collagen represented phagocytosed material. In the presence of acidotropic agents (NH4Cl and methylamine) the amount of intracellular type VI collagen increased significantly (5- to 10-fold), suggesting that a rise of pH in the endosomal/lysosomal apparatus causes inhibition of its degradation. By using a variety of proteinase inhibitors, it was found that inhibition of collagenase (when used in combination with NH4Cl), or inhibition of cysteine proteinases (both with and without NH4Cl), resulted in an increased amount of intracellular type VI collagen, whereas inhibition of serine proteinases significantly lowered the level of intracellular type VI collagen. The data presented are the first to indicate a pathway by which type VI collagen degradation may occur: fibroblasts phagocytose type VI collagen and subsequently digest this collagen in their lysosomal apparatus. Degradation depends on the activity of several enzymes, among them collagenase and serine proteinases, probably exerting their activity in the extracellular space just before the actual internalization. After uptake, digestion involves pH-sensitive lysosomal enzymes, including those belonging to the class of cysteine proteinases.

Animals↗

PubMed1999

Dry platelets with the Dideco Excel apparatus.

Dry platelets are required to prevent hemolytic and nonhemolytic febrile reactions after transfusion to ABO mismatched recipients, to reduce the risk of HLA immunization and to prevent allergic or anaphylactic reactions. Previously we have shown that the collection of single donor platelets almost free of plasma is possible with different cell separators. With the systems we described for the CS 3000+/Amicus and AS 104-204 apparatuses collection of dry platelets implies their resuspension in non plasma solutions after opening the circuit. With the new system developed by Dideco for the Excel apparatus this moreover is no longer required since the platelet bag can be connected to the resuspending medium through a dedicated line with an antibacterial filter. Platelets are collected cyclically and the resuspending solution is added when the procedure is over. In this study 53 collections were evaluated, 21 of which were erythrothrombocytapheresis. In 60-65 min 4.21 of anticoagulated blood (1/12) were processed with platelet collection automatically done after 6-700 ml cycles. The platelet yield averaged 4.67 +/- 0.7 x 10(11), with a platelet efficiency per minute of 7.18 +/- 0.9 x 10(9). The WBC contamination averaged 2.6 +/- 0.7 x 10(5) and contamination did not exceed 0.87 x 10(6). The quality of platelets was satisfactory as measured by aggregation, morphology score, and CD 62 membrane glycoprotein externalization. These results were comparable to those obtained with three other Excel apparatuses used in the conventional way to collect platelets resuspended in plasma or with the Amicus used to collect dry platelets using an open system.

Cell Separation↗

PubMed2000

A homologue of the bacterial cell division site-determining factor MinD mediates placement of the chloroplast division apparatus.

BACKGROUND: Chloroplast division in plant cells occurs by binary fission, yielding two daughter plastids of equal size. Previously, we reported that two Arabidopsis homologues of FtsZ, a bacterial protein that forms a cytokinetic ring during cell division, are essential for plastid division in plants, and may be involved in the formation of plastid-dividing rings on both the stromal and cytosolic surfaces of the chloroplast envelope membranes. In bacteria, positioning of the FtsZ ring at the center of the cell is mediated in part by the protein MinD. Here, we identified AtMinD1, an Arabidopsis homologue of MinD, and investigated whether positioning of the plastid-division apparatus at the plastid midpoint might involve a mechanism similar to that in bacteria. RESULTS: Sequence analysis and in vitro chloroplast import experiments indicated that AtMinD1 contains a transit peptide that targets it to the chloroplast. Transgenic Arabidopsis plants with reduced AtMinD1 expression exhibited variability in chloroplast size and number and asymmetrically constricted chloroplasts, strongly suggesting that the plastid-division machinery is misplaced. Overexpression of AtMinD1 inhibited chloroplast division. These phenotypes resemble those of bacterial mutants with altered minD expression. CONCLUSIONS: Placement of the plastid-division machinery at the organelle midpoint requires a plastid-targeted form of MinD. The results are consistent with a model whereby assembly of the division apparatus is initiated inside the chloroplast by the plastidic form of FtsZ, and suggest that positioning of the cytosolic components of the apparatus is specified by the position of the plastidic components.

Amino Acid Sequence↗

PubMed2003

Mixing apparatus for preparing NMR samples under pressure.

The size limit for protein NMR spectroscopy in solution arises in large part from line broadening caused by slow molecular tumbling. One way to alleviate this problem is to increase the effective tumbling rate by reducing the viscosity of the solvent. Because proteins generally require an aqueous environment to remain folded, one approach has been to encapsulate hydrated proteins in reverse micelles formed by a detergent and to dissolve the encapsulated protein in a low-viscosity fluid. The high volatility of suitable low-viscosity fluids requires that the samples be prepared and maintained under pressure. We describe a novel apparatus used for the preparation of such samples. The apparatus includes a chamber for mixing the detergent with the low-viscosity solvent, a second chamber for mixing this with hydrated protein, and a 5-mm (o.d.) zirconium oxide NMR sample tube with shut-off valves designed to contain pressures on the order of 10 bar, sufficient for liquid propane. Liquids are moved from one location to another by introducing minor pressure differentials between two pressurization vessels. We discuss the operation of this apparatus and illustrate this with data on a 30-kDa protein complex (chymotrypsin:turkey ovomucoid third domain) encapsulated in reverse micelles of the detergent, sodium bis (2-ethylhexyl) sulfosuccinate, aerosol-ot (AOT), dissolved in liquid propane.

Animals↗

PubMed2003

[Adaptations of the hoatzin (Opisthocomus hoazin) to leaf-eating. Morphological characteristics and functional features of its bill and hyoid apparatus].

The hoatzin remains one of the most enigmatic birds. A morphofunctional analysis of its bill and hyoid apparatus throws new light on its feeding adaptation as well as on its systematic relationships. Bony and muscular skull, rhamphotheca, palate, and hyoid apparatus were described in details. Though keeping into the general organisation pattern found among Neognathae (except Galliformes), bill and hyoid apparatus of the hoatzin displays a series of species-specific features, some unique among birds. This species appears particularly well adapted to tear of leaves and process them inside the bill before ingestion. Because of very important anatomical and thence functional differences in bill and hyoid structure, any close relationship between the hoatzin and Galliformes cannot be envisioned. Such a hypothesis would implicate a counter-selective evolutionary reversion.

Adaptation, Biological↗

PubMed1976

Neonatal infection due to Salmonella worthington transmitted by a delivery-room suction apparatus.

An outbreak of diarrhoea due to Salmonella worthington in five newborn babies, 5 weeks after a similar outbreak in 13 babies for which no cause had been found, occurred in the nursery of a maternity ward. The source of infection was traced to the contaminated rubber tubing of a mechanical suction apparatus. S. worthington was isolated from the rubber tubing and the Y connexion of the suction apparatus from which all the five infected babies had received suction. Reflux of contaminated amniotic fluid into the sterile catheter connected to the apparatus some time before use could have been the means of introducing the infected material to the oropharynx of the newborn babies, and amniotic fluid, acting as a good medium to support the growth of S. worthington, might be responsible for the long-lasting contamination.

Cross Infection↗

PubMed2003

Automated bead alignment apparatus using a single bead capturing technique for fabrication of a miniaturized bead-based DNA probe array.

We have developed an automated bead alignment apparatus for fabricating a bead-based DNA probe array inside a capillary. The apparatus uses 16 micro vacuum tweezers to extract single beads from among a large amount of beads in bead stock wells. It then manipulates single beads into the probe array capillaries. Single 100-microm-diameter beads were successfully extracted from the water-contained bead-stock well by the vacuum tweezers, which have inner and outer diameters of 50 and 150 microm. An interesting aspect is that unexpected extra beads adsorbed on the outer wall of the vacuum tweezers can be removed using the surface tension force between the water and the atmosphere. In testing the total performance of this apparatus, the DNA probe arrays with 10 sets of probe-conjugated beads and 2 plain beads were produced in the intended order in the capillaries. The time needed to align the 12 beads was 10 min, and the 16 bead arrays were fabricated simultaneously. After hybridization experiments using these fabricated DNA probe arrays, fluorescence from each bead was clearly observed.

Base Sequence↗