Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Rotation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,711 records · Page 95Linked to original sources
PubMedDate not supplied

Possible patterns of nuclear rotation in binucleate hepatocytes in vivo: static examination with fluorescence and electron microscopy.

To demonstrate nuclear rotation in the intact organism, we induced the formation in vivo of internuclear chromatin bridges in binucleate hepatocytes and examined their morphological arrangement in static conditions. Fixed isolated hepatocytes were observed by fluorescence microscopy and solid liver tissue by electron microscopy. The morphological patterns provided information about different modalities of nuclear rotation, related to equatorial (stationary nuclei), peripheral (nuclei rotating in opposite direction) or oblique (nuclei rotating in the same direction) dispositions of chromatin bridges. Moreover, data indicate that the entire nucleus can rotate. The independence of the bridge arrangements from the cell cycle phases (G1, S, G2) suggests that the nuclear rotation is probably not due to exchange of substances between the active chromatin and the cytoplasm.

Animals↗
PubMed1990

Rotation of the anatomic regions used for insulin injections and day-to-day variability of plasma glucose in type I diabetic subjects.

Treatment of type I diabetes mellitus is hindered by the often large fluctuations in blood glucose concentration experienced by affected individuals. To determine to what extent day-to-day variation in blood glucose levels can be reduced if insulin is injected in the same anatomic region rather than in different regions using a rotational scheme, as is commonly recommended, 12 type I diabetic subjects were studied. Insulin injections were given in the abdomen for 3 days and rotated among arms, abdomen, and thighs for 3 days using a crossover design with random assignment of treatment order. Blood samples for measurement of plasma glucose levels were obtained at nine scheduled times on each day. Insulin dose, diet, and physical activity were held constant for each subject. During the abdominal injection period, the mean SD of plasma glucose levels and the mean variance of plasma glucose levels were both less at all nine time points than during the rotating injection period. Overall values for the SD of plasma glucose levels were 2.7 +/- 0.2 mmol/L for the abdominal injection period and 3.7 +/- 0.3 mmol/L for the rotating injection period. Overall values for the variance of plasma glucose levels were 9.2 +/- 1.4 mmol2/L2 for the abdominal injection period and 17.4 +/- 2.2 mmol2/L2 for the rotating injection period. We conclude that the common clinical practice of rotating the anatomic regions used for insulin injections increases day-to-day variation in blood glucose concentration. Use of a single anatomic region, eg, the abdomen, for all insulin injections may reduce this variation and allow greater precision in the adjustment of insulin doses.

Abdomen↗
PubMed1990

Rotational characteristics and stability of soft toric lenses.

Toric soft contact lenses of a double slab-off design were fitted to 72 patients (128 days) with varying refractive requirements. Rotational characteristics and lens stability were studied as related to sphere power, cylinder power, and axis orientation. The patients were followed over a 1-month period. Although rotation of all lenses was skewed nasally, the total number of all lenses showing no rotation or temporal was somewhat greater than those with nasal rotation. In addition lenses of oblique axis displayed the least amount of rotational instability. Finally this study suggests some differences when comparing the rotational characteristics between with-the-rule and against-the-rule astigmatism correction, low vs. high myopia, and myopia vs. hyperopia.

Adult↗
PubMed1989

[Rotational deformities following pediatric femoral shaft fracture].

At the beginning of 1983 65 children who had been treated at our hospital for fractures of the femoral shaft could be followed-up both clinically and radiologically at an average of 29 months after the injury. The radiological examination was performed with special regard to the rotational deformity; the torsion was measured using Rippstein's method. Out of 65 patients, 19 patients showed a difference between the angles of antetorsion of more than 10 degrees (29.2%) which we considered to be "rotational malpositions" (8 patients with endorotational and 11 patients with exorotational deformities). 40% of all fractures localized in the proximal third of the femur were accompanied by a rotational deformity of more than 10 degrees as compared to the other side. Exactly 4 years later a second examination of antetorsion was made using the same methodical procedure. 18 out of the 19 patients with rotational malpositions and 2 patients with a difference between the AT-angles of exactly 10 degrees could be re-examined. The average correction in the overall population was 3.4 degrees (-10 degrees to +5 degrees). In 15 cases we found a decrease in the difference between the angles of antetorsion by 5.8 degrees on an average, 1 patient showed no change in the difference, and in 4 patients the difference had increased by 3 degrees on an average. In 7 of the 20 patients (35%) the difference between the angles of antetorsion was less than 10 degrees, whereas the rotational malposition persisted in 13 cases. The extent of correction was much larger in patients with exorotational deformities than in those with endorotational deformities. A very close relation could be seen between the age of the children and the extent of correction. Furthermore, rotational deformities caused by fractures of the proximal third of the femoral shaft showed significantly less tendency towards correction than fractures with a more distal location.

Adolescent↗
PubMed1989

Reduction of redundant shadows using new rotational panoramic radiograph "PM 2002 CC".

Rotational panoramic radiography has diagnostic limitations caused by redundant shadows of the mandibular ramus or the cervical vertebrae. This study compared the appearances of redundant shadows in the PM 2002 CC, a new rotational panoramic radiograph, and the popular Orthopantomograph OP 5. Redundant shadows caused by the mandibular ramus and superimposed on the opposite molar and ramus regions, were carefully analyzed. A considerable difference was observed with respect to x-ray beam alignment. Since the rotational axis of the OP 5 was in the region medial to and behind the third molars, the mandibular ramus created a shadow between the x-ray tube and the rotational axis throughout the period of projection. On the other hand, the rotational axis of the PM 2002 CC was located outside and behind the mandibular ramus during the early stage of projection and with further shifting moved to the region medial to and in front of the mandibular ramus. Accordingly, in the PM 2002 CC, the mandibular ramus was superimposed on the opposite side as a real image and ghost image. The appearance of redundant shadows was influenced by differences in the position of the mandibular ramus in relation to the rotational axis of the x-ray beam. The PM 2002 CC reduced redundant shadows by significantly decreasing the scanning sphere through which x-ray beams from the opposite side project the mandibular ramus. Furthermore, altering the positions of the dry mandibular bone used in the experiments, such as the inclination of the occlusal plane or anterior and posterior shifts, caused greater reduction of redundant shadows in the PM 2002 CC than in the OP 5. Further appearances of redundant shadows caused by metallic wire, plates or bone screws used for the jaw reconstruction were also significantly reduced in the PM 2002 CC.

Humans↗
PubMed1989

The benefit of head rotation on pharyngoesophageal dysphagia.

This study examined the effect of head rotation on the mechanics of swallowing in healthy subjects, as well as the effects of this postural change on the oropharyngeal swallow of five patients with lateral medullary syndrome (LMS). Videofluoroscopic studies of swallowing in the normal subjects revealed that head rotation to either side increased upper esophageal sphincter (UES) opening diameter by an average of 2mm without affecting the period of UES opening or the oropharyngeal transit time. Maximal rotation of the head to the right or left caused the bolus to lateralize away from the direction of rotation, and also caused a significant (18mmHg or 35%) fall in UES pressure. In the face forward position, the LMS patients exhibited barium residue in the pharynx and pyriform sinuses, as well as diminished UES opening diameter. The fraction of the bolus swallowed and the UES opening diameter increased significantly with the head turned toward the paretic side in the LMS patients. We conclude that head rotation can improve swallowing in patients with unilateral oropharyngeal dysphagia. Two potentially beneficial effects were observed: (1) functional exclusion of the relatively flaccid, weakened pharyngeal wall, and (2) reduced UES tone. Which of these mechanisms is operative probably depends on the dominant mechanisms of dysphagia. In individuals with substantial impairment of UES opening, head turning reduces the resistance of the sphincter that must be overcome by pharyngeal contraction. In individuals with a flaccid hemipharynx, which dissipates pharyngeal pressure, head rotation excludes these structures from the bolus path and allows pharyngeal pressure to be directed at the UES.

Adult↗
PubMed1989

Rotational stability of diaphyseal fractures of the radius and ulna fixed with Rush pins and/or fracture bracing.

The rotational stability of fractures of the radius and ulna treated with Rush pins and/or fracture bracing was studied in six fresh cadaver forearms. Forearm rotation and fracture site motion (rotation) were measured as functions of applied forearm torque and rotation (pronation-supination). Values were obtained from the forearm: (1) intact and with both bones fractured; (2) without fixation; (3) with a fracture brace; (4) with Rush pins; and (5) with a combination of Rush pins and a fracture brace. A brace was ineffectual in reducing fracture site motion when the wrist was rotated to specified angles compared to fracture site motion for the forearm with no fixation treatment rotated to the same angles. When loading to specific torque levels, however, the brace reduced fracture site motion to one-half the motion with no fixation treatment. Under both loading conditions, Rush pin fixation significantly and markedly reduced the fracture site motion (to approximately one-eighth of the motion with no fixation treatment), whereas a brace in conjunction with Rush pins did not significantly further reduce the fracture site motion. The radius showed more motion at fracture site than the ulna.

Bone Nails↗
PubMedDate not supplied

Rotation-induced Taylor vortex enhances filtrate flux in plasma separation.

Techniques of plasma filtration with rotating flat membranes are capable of producing a Taylor vortex and concomitantly reducing concentration polarization by formed elements. The present study describes filtration characteristics of a small-sized rotating filter that is superior to a capillary filter in terms of filtrate flux. The rotating filter with a surface area of 60 cm2 was composed of two concentric cylinders, with the inner cylinder mobile, with a flat polycarbonate membrane (pore diameter: 0.8 micron), and the outer cylinder fixed. Filtration experiments were performed using bovine blood to determine filtrate flux at rotational speeds from 600 to 4,500 rpm. Photographic observations using aluminum powder revealed that many Taylor vortices were present in the radial gap (0.6 mm). Filtrate flux increased with transmembrane pressure until a maximum filtrate flux of 0.02 cm/min at 600 rpm, 0.42 cm/min at 1,800 rpm, 0.60 cm/min at 3,600 rpm, and 0.69 cm/min at 4,500 rpm were reached at a blood flow rate of 100 ml/min. Based on the filtration resistance model, values for fractional filtration resistance of the red blood cell polarization layer ranged from 0.25 to 0.80 at a rotational speed of 3,600 rpm, whereas those of a capillary filter range from 0.80 to 0.90. This indicates that Taylor vortices promote back diffusion of red blood cells accumulated on membrane surfaces. Thus, the filtrate flux of a rotating filter is two orders of magnitude higher than that of a capillary filter because of the back diffusion of red blood cells facilitated by Taylor vortices.

Animals↗
PubMed1986

[Surgical approach for jugular foramen neurinoma--combined suboccipital and infralabyrinthine approach using a rotatable head holder].

A 36-year-old male with jugular foramen neurinoma was operated upon using a rotatable head holder, which enables the surgeon to rotate the patient's head at any time during the procedure and to gain access in multiple directions to the tumor. The tumor was situated primarily in the jugular foramen and showed partial extension into intracranial as well as into extracranial space. The patient was placed in the lateral position with a rotatable head holder, which allows rotation of the patient's head with the range of 10 degrees face up to 80 degrees face down from the horizontal plane. A linear skin incision was made, beginning behind the auricle and extending along the anterior margin of the sternocleidomastoid muscle, and the sternocleidomastoid muscle was divided just below the tip of the mastoid process. During mastoidectomy and suboccipital craniectomy, the patient's head was rotated 15 degrees face down and sigmoid sinus was exposed toward the jugular foramen, meanwhile the posterior fossa dura mater was opened and the intracranial portion of the tumor was removed with the head positioned 45 degrees-60 degrees face down. The patient's head is then turned 30 degrees face down and the facial canal was opened to displace the facial nerve forward. This oblique posterior approach minimized facial nerve displacement and provided excellent exposure of the large tumor rest which was situated mainly in the jugular foramen and partly extended extracranially. The rotatable head holder allows excellent access in multiple directions and is very helpful in approaching to jugular foramen neurinomas which grow primarily in the jugular foramen and extend both into intra- and extracranially.

Adult↗
PubMed1983

[Drug effect on the rotation thromboelastogram in newborn infants].

The impact of the antibiotics carbenicilin and gentamycin on the aggregation and adhesiveness of thrombocytes and on the rotation thrombelastogramme is investigated in healthy newborns. Thrombocyte aggregation was markedly inhibited by carbenicilline; gentamycine had no influence. Thrombocyte adhesiveness was less influenced by both medicaments. The parameters of TEG, viz. reaction time, clotforming time, thrombus elasticity and index were compared before and after rotation and with and without medicaments. Under carbenicilline a prolongation of the clotforming time and a decrease of thrombus elasticity could be shown to exist after rotation. The impact of medicaments on the rotation thrombelastogramme can only be conceived by comparing the values before and after rotation in each case with and without medicament and not simply evaluating it, so that the rotation thrombelastogramms cannot be recommended to be used for assessing the disturbance of thrombocyte function induced by medicaments.

Azlocillin↗
PubMed1984

Rotational diffusion of the ADP/ATP translocator in the inner membrane of mitochondria and in proteoliposomes.

The ADP/ATP translocator was selectively labeled with the triplet probe eosin-5-maleimide (EMA) after pretreatment with N-ethylmaleimide in beef heart mitochondria, as reported previously for submitochondrial particles (Müller, M., Krebs, J. J. R., Cherry, R. J., and Kawato, S. (1982) J. Biol. Chem. 257, 1117-1120). The EMA binding was completely inhibited by carboxyatractylate. 0.7-1.1 molecules of EMA conjugated with 1 molecule of the dimeric translocator with Mr approximately 65,000. The EMA binding decreased [14C]ADP uptake by about approximately 25%. The EMA-labeled translocator bongkrekate complex was purified and reconstituted in liposomes by removing Triton X-100 with Amberlite XAD-2. The liposomes were composed of phosphatidylcholine/phosphatidylethanolamine/cardiolipin and the lipid to protein ratio by weight was (L/P) = 60. Rotational diffusion of the ADP/ATP translocator around the membrane normal was measured in reconstituted proteoliposomes and in the mitochondrial inner membranes by observing the flash-induced absorption anisotropy, r(t), of EMA. In proteoliposomes with L/P = 60, the translocator was rotating with an approximate average rotational relaxation time of phi congruent to 246 microseconds and a normalized time-independent anisotrophy [r3/rr(0)]min congruent to 0.55. In intact mitochondria, values of phi congruent to 405 microseconds and r3/rr(0) congruent to 0.79 were obtained. The higher value of r3/rr(0) in mitochondria compared with proteoliposomes indicates the co-existence of rotating and immobile translocator (phi greater than 20 ms) in the inner mitochondrial membrane. Based on the assumption that all the translocator is rotating in the lipid-rich proteoliposomes, the population of the mobile translocator at 20 degrees C was calculated to be approximately 47%. By removing the outer membrane, the mobile population was increased to approximately 70% in mitoplasts, while approximately 53% of the translocator was rotating in submitochondrial particles. The above results indicate a significant difference in protein-protein interactions of the ADP/ATP translocator in the different types of inner membranes of mitochondria. The immobile population of the translocator could be due to nonspecific protein aggregates caused by the very high concentration of proteins in the inner membrane of mitochondria (L/P approximately 0.4).

Adenosine Diphosphate↗
PubMed1984

Rotational humeral osteotomy for recurrent anterior dislocation of the shoulder associated with a large Hill-Sachs lesion.

Rotational subcapital osteotomy of the humerus for recurrent anterior dislocation of the shoulder associated with a large Hill-Sachs lesion was performed first by us in 1964 as a trial. From 1967 through 1981, 207 rotational humeral osteotomies were performed. Follow-up was possible on 180 of these shoulders. The over-all redislocation rate was 5.7 per cent and the rate of non-traumatic redislocation, 1.1 per cent. Limitation of motion of more than 10 degrees was present in only 3.9 per cent, the maximum limitation of external rotation being 15 degrees in one patient. The average loss of external rotation was less than 5 degrees, without noticeable diminution of power or function in most patients. The results as graded by a standard rating scale were good to excellent in 90 per cent, fair in 3 per cent, and poor in 7 per cent of the patients. The fair and poor results were due to redislocation, delayed union or non-union, post-traumatic arthritis, and over-rotation at the osteotomy site. Reoperation was necessary in two patients with a non-traumatic recurrence, in six patients with delayed union or non-union, and in one patient with excessive rotation at the osteotomy site. Plate removal was performed one to two years postoperatively in 107 of the 180 shoulders. Of the 321 recurrent dislocations seen over the fourteen-year period, 65 per cent were associated with a moderate to severe posterior-superior impression fracture of the humeral head (Hill-Sachs lesion).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

Functional brain tissue transplantation: reversal of lesion-induced rotation by intraventricular substantia nigra and adrenal medulla grafts, with a note on intracranial retinal grafts.

Using a rotational behavior animal model, it has been found that embryonic substantia nigra (SN) can be homologously transplanted to the brain lateral ventricles to reverse the effects of SN lesions. These grafts were found to decrease the lesion-induced rotational behavior that was provoked either by apomorphine or amphetamine. This effect was not duplicated by grafts of other embryonic brain regions. The SN grafts produced a dopaminergic reinnervation of the dorsomedial striatum that appeared to be responsible for the behavioral amelioration. Long-term studies demonstrated that behavioral efficacy and survival continued for at least 6 months to 1 1/2 years. The catecholaminergic "chromaffin" cells of the adrenal medulla possess a remarkable ability to change morphologically and biochemically in response to their environmental hormonal milieu. This plasticity was exploited by transplanting adrenal medulla to the rat brain to reverse the effects of SN lesions. This tissue changed biochemically by producing large amounts of dopamine, and morphologically, by extending coarse fiber processes. Although these grafts appeared to secrete catecholamines, they did not reinnervate the striatum. Rotational behavior was reduced by these grafts, apparently as a consequence of the catecholamine secretion. When adrenal chromaffin tissue was obtained from 1- or 2-year-old donors, however, lesion-induced rotational behavior was not reduced. It is suggested that adrenal chromaffin cell grafts from young donors possess a biochemical plasticity that is the basis for the behavioral effect, but that this plasticity is lost with maturity of the tissue. An important issue for future applications of these procedures is the immunological privilege of the brain lateral ventricles. We found that both embryonic brain tissue and adult adrenal medulla "allografts" from Brown Norway rat donors consistently survived for at least 6 months in the ventricles of Fisher 344-strain rat hosts. These strains differ in major histocompatibility antigens and, as expected, Fisher 344 rats rapidly rejected Brown Norway skin grafts. Skin graft survival times were not influenced by the presence of established brain grafts, nor did brain grafts elicit systemic humoral immunity. Conversely, however, independent elicitation of systemic immunity by skin grafting resulted in the rejection of long-established brain grafts concomitant with rejection of the skin grafts. Rotational behavior in Fisher 344 hosts was reduced by brain grafts from Brown Norway donors; yet, after rotation had been reduced it could be brought back to baseline levels through systemic immunization and associated brain graft rejection.(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenal Medulla↗
PubMed1980

[Studies on the performance of the dental air turbine handpieces. (Part 2) Classification and rotational performance of the dental air turbine handpieces (author's transl)].

For the purpose of the clinical and technical uses, air turbine handpieces are widely used for the high speed cutting instruments. And then, there are the many kinds of air turbine handpieces which are classified with the standard, minutia and torque types etc. So, in this paper, we examined the rotational properties of air turbine handpieces in the consideration of these classifications. And the relations between the reduction of the rotational speed and the rotational loads on the handpieces are fundamentally investigated. As the results of these investigations, it was revealed that rotational forces of the toque type air turbine are very excellent and the rotational speed of the air bearing type air turbine is higher than that of other type handpieces. And we obtained the practical properties of the rotational ability of air hand pieces.

Air↗
PubMed1981

[Studies on the performance of the dental air turbine handpieces. (Part 5) Rotational performance of various kinds of dental air turbine handpieces (N = N0--CvFv gamma) (author's transl)].

Making research on the rotational performance of the dental air turbine handpieces widely used for dental cutting instruments, we investigated with the relation between rotational speed and load on many kinds of dental handpieces used for clinical divisions and with the applications of the theoretical equations to have be shown in the previous report. And then we have the investigation on these properties. Dental handpieces to measured with these properties were classified the four types, standard types, torque type, miniature type and air bearing type. And we applied the experimental equations to these experimental values and determined the rotational coefficients, gamma and Cv. The rotational speed N and normal force Fv, which occurred the maximum work of air turbine handpieces, were calculated with our analysis and then these values of N and Fv were compared with the experimental results. These results, that is, experimental and calculated values have a good agreement and the development of the theoretical approach is useful for the estimation of the rotational performance. And we examined the possibility of rotational performance's estimation with the process of simple experiment on these air turbine handpieces.

Dental High-Speed Equipment↗
PubMed1982

Subscapular muscle transposition for repair of chronic rotator cuff tears.

Subscapularis transposition into a supraspinatus or supraspinatus and infraspinatus rotator cuff defect has been overlooked as a method of tendon repair. The surgical technique for this type of repair, with or without the concomitant use of a glenohumeral resurfacing prosthesis, is described. Postoperatively, the extremity is supported in a position that does not allow stress to be placed on a repair until healing has occurred. Generally, physical therapy is begun early and continued for many months. In the present series, satisfactory relief of pain was achieved in 22 of the 26 patients. Active abduction in the plane of the scapula averaged 120 degrees for patients with rotator cuffs repair and prosthetic replacement and 130 degrees for those with rotator cuff repair alone. Twelve patients gained more than 30 degrees active abduction, and four lost this amount of motion, or greater, as compared with preoperative capabilities. In two of the 26 patients, the rotator cuff repair was completely disrupted during the acute postoperative period. Twenty-five of the 26 patients were satisfied with the surgical procedure. This type of repair seems to be a secure repair, bring healthy tendon tissue into an area of tendon degeneration and loss of tissue substance. As such, it satisfies the basic surgical principles of achieving repair with healthy tissue that is not under tension. The results compare favorably with those reported in the literature on rotator cuff repair and further suggest that this technique is an acceptable alternative for repairing large or massive rotator cuff tears that have tendon substance loss. However, this technique should not be used for smaller tears, for which more simple techniques are more adequate, because if a retear occurs during the postoperative period, the cuff detect might be quite large, with significant pain postoperatively and functional limitations resulting.

Adult↗
PubMed1982

Developmental and differential aspects of mental rotation in early adolescence.

A chronometric mental rotation paradigm was applied to examine manipulation of visual imagery in early adolescence in relation to age, sex, mental rotation ability (measured psychometrically), and socioeconomic background. Fifth- and seventh-grade boys and girls from middle and lower socioeconomic backgrounds viewed tachistiscopically letters of the alphabet presented at 0 degrees, 60 degrees, 120 degrees, and 180 degrees of rotation and were asked to judge whether the letter was forward or backward. In one condition, children were given no information about the test letter, and in the other, advance visual information about its identity and orientation was provided. With age, children became more skillful at rotating and were more likely to show evidence of using the advance information as a visual image. There were no sex differences. Socioeconomic differences were more pronounced in the fifth than the seventh grade. Children showing high mental rotation ability were more likely than low-ability children to show evidence of rotating visual stimuli on the chronometric measure. The findings are discussed in terms of adolescent cognitive development.

Age Factors↗
PubMed1994

[Trans-trochanteric rotation osteotomy for femoral head necrosis. Long-term results].

PURPOSE OF THE STUDY: The aim of this study was to appreciate the long term result of transtrochanteric rotational osteotomy for femoral head necrosis. MATERIAL: Twenty six transtrochanteric rotational osteotomies were performed in twenty five patients for femoral head necrosis during a five year period (1983-1988). METHODS: Thirteen hips were operated on with the original Sugioka's technique and thirteen with a slightly modified technique (fixation by nail-plate) in order to obtain rotational control and to avoid a modification of the neck-shaft angle. RESULTS: Short-term (1 to 3 years of follow-up) and long term results (5 to 9 years of follow-up) are reported. Two patients were lost to follow-up. Twelve hips had been revised by hip replacement with a delay to revision between 9 months and 7 years. The twelve other hips were reviewed at a mean of seven years and the results were satisfactory in only four hips (17 per cent). Fifteen hips showed further collapse. DISCUSSION: Its seems that there is further vascular compromise when performing rotational osteotomy. Study of various parameters does not allow determining good indications for transtrochanteric rotational osteotomy. CONCLUSIONS: Long term result of rotational osteotomy are very poor and a total replacement will be necessary in almost all cases. We have abandoned this technique.

Adolescent↗