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PubMedDate not supplied

Electrostatic endothelial cell transplantation within small-diameter (<6 mm) vascular prostheses: a prototype apparatus and procedure.

This article presents a novel, clinically relevant electrostatic endothelial cell transplantation (seeding/sodding) device (U.S. & Foreign Patent Protections Pending) for small-diameter (<6 mm) vascular prostheses. The prototype apparatus was designed and built to tissue engineer 4.0 mm, I.D. GORE-TEX (W.L. Gore & Associates, Inc.) standard wall graft segments varying in length from 4 to 12 cm. The prototype electrostatic endothelial cell transplantation apparatus is composed of an external and internal conductor, aluminum base, end supports, pillow blocks, filling apparatus, electric motor drive system, and a voltage source. The cylindrical capacitor arrangement of the device along with an electrical potential applied across the internal and external conductors creates the unique feature of this endothelial cell transplantation technique, an electric field within the cylindrical capacitor (within the graft lumen) which in turn induces a temporary positive surface charge on the graft (dielectric material) luminal surface. Multiple studies have shown that a positively charged substrate is more conducive to endothelial cell adhesion and morphological maturation (flattening) (1,2, 7,8,10,13-15). This induced positive surface charge dissipates immediately upon removal from the electrostatic endothelial cell transplantation device. Thus, after endothelial cell adhesion the graft luminal surface reverts back to its natural (nonthrombogenic) negative surface charge.

Blood Vessel Prosthesis↗
PubMed1988

Effect of pulsatile infusion of progesterone on the in vivo activity of the luteinizing hormone-releasing hormone neural apparatus of awake unrestrained female and male rabbits.

Eight female and eight male New Zealand White rabbits were outfitted with push-pull cannulae aimed at the tuberal region of the hypothalamus and were used in 19 perfusion experiments. Animals were treated under 2 conditions: a control condition in which female (n = 4) and male (n = 4) rabbits were perfused only with artificial medium for 5-9 h, and an experimental condition in which female (n = 4) and male (n = 5) rabbits were subjected to perfusion with artificial medium, followed by 6 pulses of progesterone (P4) (10 min on, 30 min off; 10 ng/ml) during a 240-min period. Two female rabbits were also subjected to perfusion with artificial medium, followed by 6 pulses of cholesterol (10 min on, 30 min off; 10 ng/ml) during a 240-min period. The LHRH concentration in perfusates collected every 10 min was measured by RIA. In the 4 females undergoing 6- to 7-h control push-pull perfusions, spontaneous pulses were observed, with about 1 pulse every 60 min, and a variable amplitude of the LHRH signal, with a mean release of about 0.91 pg/10 min. In the 4 does treated with pulsatile P4 at 10 ng/ml, the mean LHRH release rate increased significantly from 0.91 +/- 0.13 to 1.66 +/- 0.20 pg/10 min (P less than 0.035), primarily due to an increase in the amplitude of the LHRH pulses, which were significantly greater than controls. This response occurred with an apparent mean latency of about 50 min. Cholesterol pulses did not affect the spontaneous activity of the LHRH neural apparatus. In the 4 males undergoing 5- to 9-h control push-pull perfusions, spontaneous LHRH pulses were observed with about 1 pulse every 60 min, and the mean release increased from 1.25 +/- 0.56 to 1.54 +/- 0.55 (P less than 0.035, by Wilcoxon's matched pairs signed rank test) in the late afternoon primarily due to an increase in the amplitude of the pulses. P4 pulses did not affect the spontaneous activity of the LHRH neural apparatus compared to that in the control animals. Overall, these results clearly demonstrate that although spontaneous pulsatile LHRH release from the hypothalamus of awake unrestrained female and male rabbits is similar, pulses of P4 can activate only the female LHRH neural apparatus, with an apparent latency to peak LHRH release of approximately 50 min. In addition, there appears to be an increase in LHRH mean release levels in the late afternoon to early evening in male rabbits.

Anestrus↗
PubMed2005

Calmodulin and PF6 are components of a complex that localizes to the C1 microtubule of the flagellar central apparatus.

Studies of flagellar motility in Chlamydomonas mutants lacking specific central apparatus components have supported the hypothesis that the inherent asymmetry of this structure provides important spatial cues for asymmetric regulation of dynein activity. These studies have also suggested that specific projections associated with the C1 and C2 central tubules make unique contributions to modulating motility; yet, we still do not know the identities of most polypeptides associated with the central tubules. To identify components of the C1a projection, we took an immunoprecipitation approach using antibodies generated against PF6. The pf6 mutant lacks the C1a projection and possesses flagella that only twitch; calcium-induced modulation of dynein activity on specific doublet microtubules is also defective in pf6 axonemes. Our antibodies specifically precipitated five polypeptides in addition to PF6. Using mass spectrometry, we determined the amino acid identities of these five polypeptides. Most notably, the PF6-containing complex includes calmodulin. Using antibodies generated against each precipitated polypeptide, we confirmed that these polypeptides comprise a single complex with PF6, and we identified specific binding partners for each member of the complex. The finding of a calmodulin-containing complex as an asymmetrically assembled component of the central apparatus implicates the central apparatus in calcium modulation of flagellar waveform.

Algal Proteins↗
PubMed1975

Fine structure of the haplosporidan Kernstab, a persistent, intranuclear mitotic apparatus.

The fine structure of the haplosporidan mitotic apparatus is described from observations of plasmodial nuclei of Minchinia nelsoni, M. costalis, Minchinia sp., and Urosporidium crescens. The apparatus, which is the Kernstab of light-microscope studies, consists of a bundle of microtubules terminating in a spindle pole body (SPB) at each end of the bundle. A few microtubules extend from SPB to SPB, but most either extend from an SPB and terminate in the nucleoplasm or lie in the nucleoplasm, free of either SPB. The bundle lengthens during mitosis, increasing the SPB-to-SPB distance by a factor of 2 to 3 as compared to interphase nuclei. SPBs are not in contact with the nuclear envelope, being found always in the nucleoplasm which is delimited by the nuclear envelope throughout mitosis. The mitotic apparatus is persistent through interphase, at least in a form which is not significantly different from that found in mitotic nuclei.

Animals↗
PubMed1992

[Strain differences of mice in learning of swimming behavior and effect of hemicholinium and vasopressin. Observation by a simple water maze apparatus].

In order to determine the strain differences in learning of swimming behavior and to study the influence of vasopressin or its derivatives on hemicholinium-3-induced impairment of water maze learning in mice, we designed a new apparatus using water maze which has three panels in small fish breeding water bath (L60 x W30 x H36 cm). In the first swimming, six strains of adult male mice, ICR, ddY, ddN, C3H/He, BALB/C and C57BL were subjected to learn swimming behavior twice a day for 6 d in a straight course. Only ICR, ddN, C57BL and BALB/C strain mice were chosen for the next experiment. In the second swimming, mice (ICR, ddN, C57BL, BALB/C) were swum in the water maze apparatus. Scopolamine-induced impairment of water maze learning was produced only in ICR, BALB/C mice, but not in C57BL and ddN strain, which was recovered by physostigmine. Amnesia was not obtained by intracerebroventricular injection (i.c.v.) of cycloheximide and AlCl3 in mice (ICR). Hemicholinium-induced amnesia was improved by vasopressin and desmopressin. Lysine-vasopressin and oxytocin were without affecting hemicholinium-induced amnesia. Pretreatment with a vasopressin antagonist, ([1-(beta-mercapto-beta,beta-cyclopenta-methylene propionic acid), 2-(o-methyl)tyrosine arginine]-vasopressin) resulted in a reversible effect on the improvement of hemicholinium-induced amnesia by vasopressin. Of four different strain mice, ICR mice were the most preferable to the presently used test. They were also more responsive to hemicholinium and vasopressin than the other strains. These results suggest that the simple water maze apparatus may be useful for a pre-examination of nootropics or a study of learning of swimming behavior in mice.

Animals↗
PubMed1992

[Apparatuses for obtaining continuous 24-hour records of water intake and urinary output in dogs].

Two apparatuses were constructed to obtain continuous records of water intake and urinary output in a dog. As a validation of their accuracy, daily patterns of these measurements were observed on a beagle using these two apparatuses during non-treatment and treatment of the diuretic drug, flosemide. During the non-treatment, water intakes increased after feeding, but urinary outputs did not show a regular pattern. These patterns were the same as the previously reported patterns. During the treatment, urinary output increased within one hour after treatment. These results show these apparatuses are useful in measuring water intake and urinary output continually on the experimental dog.

Animals↗
PubMed1992

[Development of posture measuring apparatus using goniometer and inclinometer. 2. Fixation, precision and calibration of goniometer].

A new posture measuring apparatus was developed for time and motion study in the field of industrial health. This apparatus records working postures by measuring angles of joints and trunk inclination. The angles of joints were measured by the newly developed goniometers which use the bending loss of rubber optical fibers. This paper presents results of studies made on the fixation, precision and calibration of goniometers which are important in the actual application of this apparatus. Six freedoms of five joints were examined, i.e. elbow (flexion/extension), shoulder (abduction/adduction and horizontal adduction/abduction), hip (flexion/extension), knee (flexion/extension), ankle (dorsi-flexion/plantar-flexion). The results obtained were as follows; 1) Goniometers should be fixed according to the characteristics of each joint. 2) The output errors were calculated from the measured data, excluding the effects of flexed angles, subjects and fixations. The mean output error of all joints was 0.189 V (14.3 degree). 3) The output errors by the three calibration methods using logistic curves were calculated. The output errors for 2-point method (calibrated by the data of minimum and maximum angles) and 3-point method (calibrated by the data of minimum, medium and maximum angles) were 1.34 and 1.22 times larger than the output errors (0.139 V) for all-point method (calibrated by all measured data), respectively.

Calibration↗
PubMed1994

A simple apparatus using inclinometer for monitoring working postures.

A new apparatus was developed for evaluating a load on the low back caused by working postures by measuring upper body inclination. This apparatus consists of an inclinometer and a portable unit. The inclinometer that uses a magnetic resistance sensor is attached to the upper body of the subject. The portable unit, controlled by a one-chip CPU, is enclosed in a cloth case and carried by the subject on his waist belt. The inclination is measured at a certain interval and recorded in the memory of the portable unit. All the recorded data are later transferred to a host computer and then analyzed. According to the theoretical analysis by using a simple mathematical model, upper body inclination changes according to the height of work places, and one cm difference in height causes more than one degree of upper body inclination. A model work of material handling was carried out to collect sample data. Two male subjects lifted ten boxes onto a platform from a stand in several heights. Both stooped and squat lifting methods were used as the lifting protocol. The mean and standard deviation (SD) of the upper body inclination during work decreased according to the lift distance only in stooped lifting. As a practical application, working postures during the task of changing diapers for handicapped people were analyzed with out apparatus. A female subject changed diapers eight times at different height of beds. The mean value of inclination decreased according to the height of the beds.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2003

An automated feeding apparatus for in vitro maintenance of the human head louse, Pediculus capitis (Anoplura: Pediculidae).

An automated feeding apparatus was developed to maintain the human head louse (Pediculus capitis DeGeer) in vitro. With the use of valves and timers, banked human blood and saline from refrigerated reservoirs were pumped into and flushed out of the system every 7 d. During this rotational interval, bloodmeals were provided to head lice continuously and ad libitum through a stretched Nescofilm-silicone sandwich membrane. Compared with our previous in vitro human head louse-rearing apparatus, greater numbers of lice could be fed simultaneously with minimal human monitoring. Development of second to third instars and third instars to adults was significantly faster when lice were reared in vivo than on either of the in vitro rearing systems; there was no significant difference in the duration of the first instar. Although fecundity and hatch rates were significantly higher for female lice reared in vivo, similar trends have been observed for other membrane-fed arthropods. Body lice (Pediculus humanus L.) and bed bugs (Cimex lectularius [L.]) also completed most of their life cycle on this apparatus. Our automated mass-rearing system has broad applications for maintaining fluid-sucking ectoparasites and will facilitate various toxicological, behavioral, and disease-transmission investigations.

Animals↗
PubMed1995

Development of an apparatus to measure plasma colloid osmotic pressure mounted on the extracorporeal hemodialysis circuit.

We newly developed an apparatus to measure colloid osmotic pressure (COP) of blood plasma continuously by hemodialysis (HD) or extracorporeal ultrafiltration method (ECUM) without any invasive procedure or blood sampling. The COP value measured by this apparatus highly correlated with the COP value calculated from the concentration of total protein of blood plasma (TP) sampled simultaneously (y = 21.182 + 0.96256x, r2 = 0.911). Measurement of the COP with this apparatus seems to be reliable.

Adult↗
PubMed1996

A computer touch-screen apparatus for training visual discriminations in rats.

We describe an operant conditioning apparatus that uses computerized touch-screen technology and is designed for the versatile and highly controlled testing of rats in a potentially wide variety of behavioral paradigms. Although computer-controlled touch-screen systems have been developed for use with pigeons, monkeys, and humans, analogous technologies and methods have not yet been developed for rats. The development of a touch-screen system for rats could enhance the efficiency of behavioral research with rats, and may offer a unique tool for studying animal learning. In the first test of the utility of the apparatus, 3 Sprague-Dawley rats learned to activate the touch screen only after the touch-screen panel was made slightly movable. These animals then learned to discriminate visual stimuli presented on the computer monitor, but only after the food magazine and pellet dispenser were moved to the rear of the chamber opposite the stimulus display and response window. In a test of the utility of the modified apparatus, 6 Long-Evans rats learned to activate the touch screen and learned one of three different simple discriminations using computer-generated, visually presented stimuli. A basic method for training rats to activate the computer touch screen and for visual discrimination training is described. Results show that rats learned to activate the touch screen and discriminate visual stimuli presented on a computer monitor. Potential applications and advantages of the touch-screen-equipped rat operant conditioning chamber are discussed.

Animals↗
PubMed1989

Histologic evaluation of new attachment apparatus formation in humans. Part II.

There is conflicting evidence regarding the value of graft materials in enhancing the formation of new bone, cementum, and periodontal ligament (new attachment apparatus). Part II of this study compared the healing of intrabony defects with and without the placement of decalcified freeze-dried bone allograft (DFDBA) in a submerged environment. The most apical level of calculus on the root served as a histologic reference point to measure regeneration on root surfaces exposed to the oral environment. Biopsies were obtained at 6-months and evaluated histometrically by two investigators unaware of the treatment performed. Data from 9 patients with 30 grafted defects and 13 nongrafted defects were submitted for statistical analysis. Results indicate that in a submerged environment significantly more new attachment apparatus (P less than .05) and new bone (P less than .05) formed in grafted than nongrafted sites. Significantly greater loss of alveolar crest height occurred in nongrafted than grafted defects (P less than .05); regeneration of new attachment apparatus, new bone, and new cementum occurred more frequently in grafted than nongrafted defects. There was a greater chance for the regeneration of a connective tissue attachment in nongrafted intrabony defects than in grafted defects; new cellular cementum formed equally well on old cementum, dentin, or both old cementum and dentin in the same defect. The periodontal ligament was oriented parallel, perpendicular, or both parallel and perpendicular in the same defect; and, no extensive root resorption, ankylosis, or pulp death was observed in grafted or nongrafted defects.

Alveolar Process↗
PubMed1996

Treatment of equinocavovarus deformity in adults with the use of a hinged distraction++ apparatus.

We evaluated the results following the use of the Volkov-Oganesyan-Povarov hinged distraction apparatus to correct equinocavovarus deformity of the foot in sixty-five adults (eighty-three feet). The deformity was secondary to ischemic and neuropathic changes after trauma to the foot and ankle, poliomyelitis, Charcot-Marie-Tooth disease, or untreated clubfoot. The deformity often was associated with severe neurotrophic changes, extensive scarring of the skin, callosities, or osteomyelitis of the foot, all of which usually preclude operative reconstruction. The average age of the patients was twenty-six years (range, sixteen to fifty-six years). The average duration of follow-up was ten years (range, three to nineteen years). The duration of distraction was three to thirteen weeks, and the apparatus usually was kept in place for an additional two months after the desired position of correction had been achieved. The patient then wore a plaster cast for an average of eight weeks and custom-molded shoe-inserts for at least one year. A plantigrade foot was obtained with this external transosseous distraction device. Eight patients had inflammation of pin tracks, which was treated with local injection of antibiotics into the soft tissues and application of bandages soaked in antibiotics to the area around the pin sites. The pins were removed from five of the eight patients, and the apparatus was removed from three additional patients because of osteomyelitis. The results were classified as good in fifty-nine feet, satisfactory in twenty, and unsatisfactory in four. In the four feet (three patients) with an unsatisfactory result, a good result was obtained after an arthrodesis was done.

Adolescent↗
PubMed1979

Long-term continuous intravenous insulin therapy with a portable insulin dosage-regulating apparatus.

A portable insulin dosage-regulating apparatus (PIDRA) was used with five volunteer diabetic subjects for periods ranging from 1 wk to more than 3 months to explore the possibilities of achieving near normoglycemic control over long time periods with such an apparatus. PIDRA consists of a matchbox size pump with insulin reservoir and a pocket size electronic control box. It can infuse a preprogrammed basal rate of insulin plus externally manipulated supplementary doses in rectangular profiles. The quality of blood glucose control was monitored with the Miles Biostator and through self-testing by the patient in the outpatient phases. Under inpatient conditions, the relatively simple PIDRA insulin administration profile was almost as effective in achieving normoglycemia as the Biostator, and good control could be maintained over long periods of time. The apparatus allows considerably greater ease in variation of insulin dosage with less risk of hypoglycemic epidoses as compared with conventional subcutaneous injections. Several technical problems remain to be solved, but it is concluded that PIDRA represents a viable alternative as a means of achieving tight control, at least as a step toward the goal of an implanted glucose-contingent insulin infusion system.

Adolescent↗
PubMed2007

Apparatus for dynamic balance training during treadmill walking.

OBJECTIVE: A presentation of a novel apparatus for dynamic balance training during treadmill walking, which was tested in a case study. SUBJECT: The subject was a man with incomplete chronic spinal cord injury (C5), graded D on the American Spinal Injury Association Impairment Scale. METHODS: Following a 6-month baseline period, 4 weeks of control treatment (treadmill walking) and a subsequent 4 weeks of experimental treatment (treadmill walking assisted by the apparatus) were compared. Outcome measures were Lower Extremities Motor Score, Berg Balance Scale, 10-metre walking test and 9-minute walking test. RESULTS: During the baseline period the changes in the outcome measures were small. After the control treatment the balance score remained unchanged, while walking speed and walking endurance increased moderately. Experimental treatment resulted in further substantial changes in balance and walking endurance scores, while further increase in walking speed was moderate. At follow-up these values were maintained. Lower Extremities Motor Scores were almost identical in all study phases. CONCLUSION: The subject's walking and balancing abilities improved moderately after the control treatment, while greater improvement occurred during experimental treatment. This indicates that the apparatus developed might be an important tool for facilitating dynamic balancing training during treadmill walking.

Adult↗
PubMed2001

Risk factors for and outcomes of noncatastrophic suspensory apparatus injury in Thoroughbred racehorses.

OBJECTIVE: To evaluate effects of toe grabs, exercise intensity, and distance traveled as risk factors for subclinical to mild suspensory apparatus injury (SMSAI) in Thoroughbred racehorses and to compare incidence of severe musculoskeletal injury (MSI) in horses with and without SMSAI. DESIGN: Nested case-control study. ANIMALS: 219 Thoroughbred racehorses racing or in race training. PROCEDURE: Racehorses were examined weekly for 90 days to determine incidence of suspensory ligament injury and monitor horseshoe characteristics. Every horse's exercise speeds and distances were recorded daily. Conditional logistic regression was used to compare exposure variables between incident case (n = 25) and selected control (125) horses. Survival analysis was used to compare time to MSI for horses with (n = 41) and without (76) SMSAI. RESULTS: The best-fitting logistic model for the data included age (< 5 vs > or = 5 years old), toe grab height the week of injury (none vs very low, low, regular, or Quarter Horse height), and weekly distance the week preceding injury (miles). Although the 95% confidence intervals for all odds ratios included 1, the odds for SMSAI appeared to increase with the presence of a toe grab, higher weekly distance, and age > or = 5 years. Horses that had SMSAI were significantly more likely to have a severe MSI or severe suspensory apparatus injury than were horses that did not. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that pre-existing SMSAI is associated with development of severe MSI and severe suspensory apparatus injury. Modifying training intensity and toe grab height for horses with SMSAI may decrease the incidence of severe MSI.

Age Factors↗
PubMed2004

Assessment of the ultrasonographic characteristics of the podotrochlear apparatus in clinically normal horses and horses with navicular syndrome.

OBJECTIVE: To characterize the normal ultrasonographic appearance of the podotrochlear apparatus in horses by use of standardized measurements and identify soft tissue changes associated with navicular syndrome. DESIGN: Prospective study. ANIMALS: 7 clinically normal horses and 28 horses with navicular syndrome. PROCEDURE: The feasibility of identifying and measuring the soft tissue structures of the podotrochlear apparatus ultrasonographically via the transcuneal approach was assessed in 2 additional horses without navicular syndrome; both horses were euthanatized, and the structures identified ultrasonographically were confirmed at necropsy. Ultrasonographs were obtained in the study horses. Objective and subjective data were obtained to characterize ultrasonographic changes associated with navicular syndrome. RESULTS: Abnormalities of the flexor surface of the distal sesamoid (navicular) bone, the impar ligament, the distal digital annular ligament, deep digital flexor tendon (DDFT), and the podotrochlear (navicular) bursa were assessed via the transcuneal ultrasonographic approach. No significant differences were found between the measurements of the podotrochlear apparatus in normal horses and those with navicular syndrome; however, important subjective differences were detected ultrasonographically in horses with navicular syndrome. In horses with navicular syndrome, ultrasonographic findings were indicative of navicular bursitis, dystrophic mineralization of the DDFT and impar ligament, tendonitis and insertional tenopathy of the DDFT, desmitis of the impar ligament, and cortical changes in the flexor surface of the navicular bone. CONCLUSIONS AND CLINICAL RELEVANCE: Findings of ultrasonographic evaluation of the hoof appear to be useful in determining the cause of caudal heel pain and characterizing the components of navicular syndrome in horses.

Animals↗
PubMed2005

A new apparatus to study behavior of triatomines under laboratory conditions.

A new apparatus is described to study a wide range of behavior in the vectors of Chagas's disease. The device is relatively inexpensive and easy to construct. A wide range of independent variables can be studied, including potential attractants, repellents, blood, and blood products under controlled conditions. Various experimental designs can be used including the investigation of learning and social behavior. The apparatus can also be used for the mass rearing of triatomines. The efficacy of the apparatus is illustrated in experiments on the attraction of odors and on fecundity.

Animals↗