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PubMed1976

Psychophysiological reactions as a function of life stress and behavioral rigidity.

Studies have shown that vulnerability to disease is a function of psychosocial factors. This study hypothesized that disease onset is antedated by life changes and is influenced by the individual's "behavioral rigidity." The subjects were 160 female college students from three undergraduate general elective courses. An index of life change (LCI) was administered to each subject, presenting descriptions of important pressures and conflicts, with instruction that she indicate which ones she had personally experienced during the past calender year. A test of behavioral rigidity was also administered. Responses to the LCI indicated that low life change subjects reported significantly fewer illnesses than did the high life change subjects. The results supported the hypothesis that life stress plays a significant role in the development of illnesses. Responses to the behavioral rigidity measure and subsequent analysis of the interaction between this variable and life change did not prove to be statistically significant. It should be noted, however, that high flexibility subjects did report fewer illnesses than low flexibility subjects within the low and high life change groups. Additional studies must be undertaken in order to assess the trend found for interaction effects.

Adult↗
PubMedDate not supplied

The rigid lingual connector: is it a paradox?

The design of removable partial dentures has progressed both clinically and in laboratory research. Nonetheless, there still appears to be a conflict between the empirical practice and the scientific data available. On this basis, the authors question several aspects of the lingual connector. If lingual connectors are required to be rigid, how is this best achieved and can it be assured that designs impart sufficient rigidity? On the contrary, is it possible to make the connector too rigid? No conclusions are attempted in this theoretical discussion, but research to resolve the dilemma is encouraged.

Denture Design↗
PubMed1990

[Clinico-psychological correlations of mental rigidity in anorexia nervosa].

A study was made of mental rigidity in patients suffering from anorexia nervosa and their relatives using the Tomsk rigidity questionnaire. Based on examinations of 40 patients with anorexia nervosa, 22 of whom suffered from schizophrenia, 18 with borderline pathology (16 with an active method of weight losing, 24 with the bulimic variant of anorexia nervosa) and of 58 close relatives (mothers, fathers, sisters) the data were obtained on the level of mental rigidity. In the patients' group, it was found to depend to a greater measure on the stage of anorexia nervosa, whereas in the relatives, on the nosological appurtenance of the syndrome in their children.

Adolescent↗
PubMed1991

Effect of red blood cell rigidity on tumor blood flow: increase in viscous resistance during hyperglycemia.

Elevated glucose level and low pH have been shown to increase red blood cell (RBC) rigidity. This increased rigidity has been proposed as one factor which mediates the tumor blood flow (TBF) reduction during hyperglycemia by (a) causing RBC entrapment and hence increasing geometric resistance and (b) increasing viscous resistance to blood flow. However, due to the inability to measure these resistances in vivo in tumors directly, the relative contribution of RBC rigidity in TBF reduction has not been quantified. In the present study, blood flow resistance was measured in "tissue-isolated" mammary adenocarcinoma R3230AC perfused ex vivo with (a) normally deformable, (b) glutaraldehyde-hardened, and (c) glucose-incubated RBC suspensions. Flow resistance measured during tumor perfusion with Krebs-Henseleit buffer prior to and following perfusion with the glutaraldehyde-hardened RBC suspensions showed no significant change, suggesting constant geometric resistance and lack of RBC entrapment. Instead, our measurements indicated increased viscous resistance with loss of deformability due to glutaraldehyde and glucose incubation even though glucose incubation did not significantly alter the apparent blood viscosity measured in vitro. Thus, the TBF reduction during hyperglycemia may be due to subtle changes in RBC deformability. These results suggest the development of strategies to increase the delivery of drugs or oxygen must take into account any changes in intratumor viscous resistance. For example, the increase in the oxygen-carrying capacity of blood using RBC transfusion or fluorocarbon emulsions may be offset by the increase in viscous resistance and the corresponding reduction in TBF.

Adenocarcinoma↗
PubMedDate not supplied

[Bond strength and rigidity modulus of non-precious alloys].

The use of non-precious alloys in construction of metalceramic restorations has been increasing since 1979. This was the reason to study the bond strength and rigidity modulus of four selected base metal alloys developed for use with bonding porcelain. Three point loading design test was performed to evaluate the bond strength. The specimens made of Co-Cr-Mo alloys showed porcelain fracture at bond failure in a high percentage. Ni-Cr-Mo alloys showed mainly lamelar failure of the bond. The highest bond strength and rigidity modulus were found, in alloy containing titanium. It was noticed that ceramic can increase the rigidity of modulus metal by almost ten times. All studied alloys are technically very sensitive and manufacturer's instruction must be closely followed.

Adhesiveness↗
PubMed1990

Early screw removal for correction of occlusal discrepancies following rigid internal fixation in orthognathic surgery.

Occlusal discrepancies that occur after orthognathic surgery in which rigid internal fixation was used are technically difficult to correct. These discrepancies often lead to prolonged postoperative orthodontics and possibly to compromised results. The effectiveness of the removal of rigid internal fixation in correcting these changes was studied retrospectively. Of 169 patients who underwent bilateral sagittal osteotomies of the mandible, 13 developed postoperative malocclusions, and their rigid internal fixation was removed (an average of 21 days postoperatively). Occlusion was improved in 11 of the patients. In the two patients who showed no improvement in occlusion, fixation had been removed at 5 weeks in one and at 6 weeks in the other. One patient had a slight relapse 6 months postoperatively. All other patients had stable occlusions and experienced no complications. Recommendations for use of the technique and potential complications are discussed.

Bone Screws↗
PubMed1990

[A case of rigid spine syndrome with rimmed vacuole].

A case of rigid spine syndrome associated with rimmed vacuoles in muscle biopsy is reported. A 36-year-old man was admitted to our hospital because of gait disturbance and limited mortality of the spine. His family was free from any neuromuscular disorders. He was born in normal pregnancy and delivery. His physical development was normal. At age 7, he was unable to run fast. At age 36, he had right hemiparesis and dysarthria. He was diagnosed as cerebral infarction of the left basal ganglia by brain CT. Neurological examination revealed moderate proximal dominant muscular atrophy and weakness. His spine was straight, showing loss of physiological cervical and lumbar lordosis. The neck flexion was limited but the extension was full. And he had contracture of bilateral ankle joint. Laboratory findings were all normal. The electrocardiogram showed negative T wave in V4, V5 and QT interval elongation. The echocardiogram showed diffuse decrease of ventricular wall motion. Respiratory function test revealed decrease of vital capacity. Arterial blood gases on room air showed that the PaO2 and PaCO2 were 70 mmHg and 49 mmHg, respectively. The findings of electromyogram were compatible with myopathic change. Biopsy specimen of the biceps brachii muscle showed marked variation in fiber size, type 1 fiber predominancy and atrophy, and type 2B fiber deficiency. Numerous rimmed vaculoes were found in the same muscle. Four cases of the rigid spine syndrome with rimmed vacuoles have been described. Among them, three patients died in young ages and two suffered from constrictive respiratory failure. In rigid spine syndrome with rimmed vacuole formation, the cardiac and respiratory problems must be taken account intensively.

Adult↗
PubMed1990

[Removal of foreign bodies from the trachea. Indications for tracheobronchoscopy with a rigid instrument].

Intrathoracic disease is nowadays better investigated by fibreoptic endoscopy than by the use of rigid endoscopes. Nevertheless the use of rigid systems is still indicated for the removal of foreign bodies, especially in children. In this paper diagnostic procedures and techniques are reviewed. Seventy per cent of all inhaled or ingested foreign bodies present in children, 55% of them under 4 years of age. The foreign bodies should be extracted with the patient under general anaesthesia. Since many physicians now perform endoscopy, the foreign body cases should be concentrated in one institution in each region to ensure that one group has sufficient experience with rigid systems.

Adult↗
PubMed1990

Microtubule assembly inhibitor protein consists of a rigid globule essential for its activity and highly mobile coils.

The structure of microtubule assembly inhibitor protein (MIP) was studied by proton nuclear magnetic resonance (NMR) and limited proteolysis. Spin-diffusion experiments revealed that MIP has a tightly folded structure, a "rigid globule." This globule was irreversibly denatured by heat treatment at 80 degrees C, and the denatured MIP showed little ability to inhibit microtubule assembly. This indicates that the native globular structure is essential for the activity. By spin-diffusion and spin-echo experiments, the other part of the molecule was found to be highly mobile. We termed the region "highly mobile coils." Most of the acidic residues appeared to be clustered in the highly mobile coils. By limited proteolysis using subtilisin, the mobile region was digested into shorter pieces, and a single 17-kDa fragment remained. Proton NMR spectrum of this fragment was much the same as the spin-diffusion subspectra of the rigid globule in the intact MIP molecule. Furthermore, the 17-kDa fragment was found to retain the activity to inhibit the microtubule assembly. These results indicate that MIP consists of two moieties; one domain forms a rigid globule which is essential for its activity to inhibit microtubule assembly, and the other acidic one is highly mobile and tails from the globule. The tertiary structures of these two domains appear to be independent from each other. These domains may be responsible for two different functions of MIP, the interaction with the cytoskeleton and the interaction with, for example, nuclear components.

Amino Acids↗
PubMed1989

[Rigid and flexible ureteroscopy. Apropos of 200 consecutive cases].

191 patients underwent a total of 200 ureteroscopies. Indications for these were as follows: ureter stones (172 cases); ureteral anomalies undiagnosed by other methods (20 cases); therapeutic ureteroscopy (8 cases). Stones: ureteroscopy for stones was carried out using either a rigid instrument (156 cases) or a flexible ureteroscope (16 cases). The localization of the stones was pelvic (123 cases), iliac (18 cases) or lumbar (10 cases). The stones were either removed directly using the basket under visual control (74/139 cases), or removed by ultrasonic/laser fragmentation (65/139 cases). As regards the rigid ureteroscope, success rates were 89% (139/156); 15 patients required additional therapy. Repeated ureteroscopic interventions always provided positive results. As concerns flexible ureteroscopy, we only had one positive result; 15 failure cases warranted repeated additional treatments. In three instances, failure with flexible ureteroscopy was corrected by using the rigid device during the same surgical period. We observed a single case of major complication in this series, i.e., a laterovesical urinoma which necessitated surgical drainage and was linked to the lack of ureteral drainage following ureteroscopy. Diagnostic ureteroscopic examinations: in 20 instances, ureteroscopy allowed to diagnose with precision the ureteral abnormality. No complication was reported following diagnostic ureteroscopy. Therapeutic ureteroscopy: such interventions were carried out to introduce a guide into the renal cavities (3 cases); to remove a double J stent, the lower extremity of which had moved up into the ureter (3 cases); or to carry out endoscopic ureterotomy (2 cases). Ureteroscopy is a safe and reliable method for the treatment of ureteral stones, and more particularly of stones localized in the distal part of the ureter.(ABSTRACT TRUNCATED AT 250 WORDS)

Cystoscopes↗
PubMed1989

Rigid fixation: variations in osteotomy design and technique.

The application of rigid fixation devices has expanded the craniomaxillofacial surgeon's armamentarium and allows greater versatility of osteotomy design and fixation. Further studies are under investigation to determine the degree of "interference" with growth as a result of application of rigid fixation devices. Our preliminary thought is that bone is dynamic and "liquid" enough to allow the driving forces of the developing cerebral tissue to remodel and recontour the bone tissue into a normal configuration and contour. Problems with relapse and resorption appear greatly reduced for both bone grafts and bone flaps. As the biomaterials industry continues to perfect rigid fixation devices, further advances will be forthcoming.

Bone Plates↗
PubMed1989

Aspheric rigid gas permeable contact lenses: practitioner discrimination of base curve increments using fluorescein pattern evaluation.

Evaluation of the fluorescein pattern is the main clinical indicator of the fit of a rigid gas permeable (RGP) contact lens to the cornea. Traditionally, manufacturers inventory RGP lenses in 0.05-mm base curve increments. The objective of this study was to test the hypothesis that experienced practitioners are not able to discern base curve/cornea relations of aspheric design lenses correctly to within +/- 0.05 mm. Eleven clinicians with expertise in fitting rigid lenses were asked to interpret fluorescein patterns and lens fittings of the Bausch & Lomb Quantum aspheric RGP lens on five adapted rigid lens wearers. The results showed that the experienced practitioners used in this study were not able to discriminate cornea/base curve relations of Quantum aspheric lenses within +/- 0.05 mm more than 67% of the time (p less than 0.05). There were no patient-to-patient differences based on type of lens fit (interpalpebral or lid attachment) or degree of corneal toricity. Lenses fitted in 0.10-mm base curve steps were judged as being as acceptable as lenses fitted in 0.05 mm steps (p less than 0.05). It was concluded that Quantum aspheric design lenses need only be trial fitted in 0.10-mm base curve steps.

Computers↗
PubMed1989

The significance of condylar position using rigid fixation in orthognathic surgery.

Rigid fixation in orthognathic surgery has major advantages, particularly the elimination of postoperative intermaxillary fixation, which makes the procedure more comfortable for the patient. The main disadvantage of rigid fixation in these procedures is that errors in the position of bony segments and dislocations of the mandibular condyle during surgery may result in errors of the occlusion and cause adverse effects on the temporomandibular joint. When rigid fixation is used, the presurgical position of the condyles should be maintained. The principles of condylar positioning are described.

Fracture Fixation, Internal↗
PubMed1979

A prospective study of the rehabilitation of the above-knee amputee with rigid dressing. Comparison of immediate and delayed ambulation and the role of physical therapists and prosthetists.

Twenty-four above-knee amputees (AKA) treated with rigid plaster dressings were randomized to receive ambulation on pylon within 24 hours of surgery or at time of suture removal. Casts were applied by physical therapists in half of each group, and by a prosthesist in the other half. There were no statistically significant differences among the groups with respect to age, sex, stump length, gait characteristics and wound healing. Time to prescription of final prosthetis was similar in all groups. Specifically, there was no delay in the group ambulated immediately. The immediate ambulators did have significantly greater stump pain requiring more analgesia than the group ambulated after suture removal. Patients with case applied by physical therapists used their prostheses more than patients with cases applied by prosthetists. There was no detectable difference among treatment groups with regard to participation in therapy, acceptance of prosthesis, and psychological status. Recommendation for management of AKA's include: use of rigid dressing; ambulation on pylon after suture removal; utilization of physical therapist for application of rigid dressings and alignment of pylon.

Adolescent↗
PubMed1986

Rigid fixation of phalangeal and metacarpal fractures.

Rational use of rigid fixation in hand surgery requires awareness of the advantages as well as the potential pitfalls of this relatively complex method of fracture management. A rational decision also necessitates familiarity with closed techniques of internal fixation which, in most cases, provide superior alternatives for the phalanges and metacarpals. The optimal application of screws, plates, and tension-band wires to small bone fractures can be ascertained only by critical assessment of large series of cases employing these devices and comparisons with similar series using other techniques of internal fixation. Nonetheless, rigid fixation is the logical choice for treatment of unstable fractures when other methods are predictably less effective. Injuries most suitable for screw or plate fixation include displaced phalangeal condylar fractures, irreducible oblique phalangeal fractures, irreducible transverse metacarpal fractures, disabling malunions, and nonunions requiring multiple adjunctive procedures. For selective fractures, especially those with established deformity or serious joint contractures, the capacity of rigid fixation to effect immediate skeletal stability and facilitate early digital motion can considerably enhance recovery. Complications are minimized by precision--in case selection and surgical techniques.

Bone Nails↗
PubMed1986

[Dimensions, volume and rigidity of the penis. Fundamental elements in the study of the erection and its dysfunctions].

The length and the proximal and distal circumferences of the flaccid and erect penis were measured as part of the aetiological investigation of 62 impotent patients. These measurements, compared with the quantitative study of penile rigidity, demonstrate the lack of correlation between circumference changes and rigidity and constitute a simple method for the measurement of penile volume variations and, when compared with penile rigidity, provide important information concerning the physiology of erection and its dysfunction.

Erectile Dysfunction↗
PubMed1987

Porous removable rigid dressing for complicated below-knee amputation stumps.

For management of complicated below-knee amputation stumps, a porous removable rigid dressing has been fabricated that can be suspended with a supracondylar cuff or with a waist belt. In addition to permitting frequent observation, eliminating the need for elastic stump bandaging, and maintaining the advantage of the conventional rigid dressing of soft-tissue immobilization to reduce the pain and prevent trauma to the stump, the porous removable rigid dressing facilitates edema reduction and wound healing, prevents moisture building, permits frequent change of dressings and promotes fast stump shrinkage.

Amputation Stumps↗
PubMed1985

Correlation of ocular rigidity and blue sclerae in osteogenesis imperfecta.

A previous study of 16 patients and 16 controls had indicated that the mean ocular rigidity value was significantly lower in Osteogenesis Imperfecta (OI) patients than in normal controls (p = 0.001). These preliminary results have been confirmed in the present study of 46 patients and 53 controls where the difference in mean ocular rigidity between the patient and control group was statistically significant at the p less than 0.0001 level. Of particular interest was the inverse correlation between blueness of sclera and ocular rigidity in patients with OI. The establishment of such a relationship depended upon the availability of a larger sample size than had previously been examined.

Adolescent↗