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At least 487 records · Page 27Linked to original sources
PubMed2001

Vardenafil increases penile rigidity and tumescence in men with erectile dysfunction after a single oral dose.

OBJECTIVES: To evaluate the effect of two doses of vardenafil hydrochloride on penile rigidity and tumescence while determining the pharmacokinetics. METHODS: Twenty-one patients with erectile dysfunction completed three oral single-dose regimens (placebo, 20 and 40 mg vardenafil) in a randomized, placebo-controlled, 3-way cross-over study. Penile rigidity and tumescence were measured at the base and tip with a Rigiscan for up to 2 h after dosing. The period included three 20-min repeated episodes of visual sexual stimulation. Blood samples were taken periodically up to 24 h after dosing. RESULTS: After 20 and 40 mg vardenafil, the mean duration of >60% rigidity of the base of the penis was greater than after placebo by 42.9 min (95% Cl 29.3-56.4) and by 49.3 min (95% Cl 35.7-62.9), respectively (p<0.001), and greater than after placebo by 34.6 min (95% Cl 22.1-47.1) for both doses at the tip. Additionally, significantly greater rigidity activity units and tumescence activity units were found for both doses compared with placebo (p<0.001). The plasma concentrations of vardenafil increased rapidly, with a median t(max) of about 40 min and a mean t1/2 of 4.4-4.8 h. Relative bioavailability was slightly higher for the 40-mg dose than for the 20-mg dose. The treatments were well tolerated, although slightly more adverse events, primarily headache, flushing and nasal congestion, were seen with the 40-mg dose compared with placebo. CONCLUSION: The findings confirm that vardenafil was able to generate stronger erections of longer duration than placebo under conditions of visual sexual stimulation in patients with erectile dysfunction. The pharmacokinetic, pharmacodynamic and tolerability profiles support vardenafil hydrochloride as a strong candidate for further testing as a treatment for erectile dysfunction.

Adolescent↗
PubMed1992

Effects of topical laryngeal lidocaine on sympathetic response to rigid panendoscopy under general anesthesia.

The sympathetic response to rigid bronchoscopy, laryngoscopy and esophagoscopy, performed under general anesthesia with isoflurane, was examined in patients who either received 5 ml of 2% lidocaine (n = 7) or 5 ml of saline (n = 7), sprayed on larynx and upper trachea under direct laryngoscopy, 2 min before the introduction of the rigid bronchoscope. Blood pressure, heart rate and plasma catecholamine and lidocaine levels were measured at specific time points of the study. Topical lidocaine led to a rapid and prolonged increase in plasma lidocaine levels. Patients treated with lidocaine showed a small but significant decrease in plasma epinephrine levels from baseline following endotracheal intubation and extubation, as compared to the saline control group. Blood pressure and heart rate response during rigid panendoscopy, isoflurane requirements and time interval from termination of panendoscopy to extubation were not different between the two groups. However, in contrast to the control group, patients who had received lidocaine had no significant rise in blood pressure and heart rate from baseline following the introduction of the rigid bronchoscope. The benefit of this moderate hemodynamic stabilizing effect of lidocaine has to be weighted against the risk of decreased protective airway reflexes due to topical laryngeal lidocaine during recovery from anesthesia.

Administration, Topical↗
PubMed1992

Molecular basis for membrane rigidity of hereditary ovalocytosis. A novel mechanism involving the cytoplasmic domain of band 3.

Hereditary ovalocytic red cells are characterized by a marked increase in membrane rigidity and resistance to invasion by malarial parasites. The underlying molecular defect in ovalocytes remained a mystery until Liu and colleagues (N. Engl. J. Med. 1990. 323:1530-38) made the surprising observation that the ovalocytic phenotype was linked to a structural polymorphism in band 3, the anion transporter. We have now defined the mutation in band 3 gene and established the biophysical sequelae of this mutation. This mutation involves the deletion of amino-acids 400-408 in the boundary between the cytoplasmic and the first transmembrane domains of band 3. The biophysical consequences of this mutation are a marked decrease in lateral mobility of band 3 and an increase in membrane rigidity. Based on these findings, we propose the following model for increased membrane rigidity. The mutation induces a conformational change in the cytoplasmic domain of band 3, leading to its entanglement in the skeletal protein network. This entanglement inhibits the normal unwinding and stretching of the spectrin tetramers necessary for membrane extension, leading to increased rigidity. These findings imply that the cytoplasmic domain of an integral membrane protein can have profound effects on membrane material behavior.

Amino Acid Sequence↗
PubMed1991

Alterations in erythrocyte rheology in patients with severe peripheral vascular disease: 1. Cell volume dependence of erythrocyte rigidity.

The erythrocyte rigidity of patients suffering from severe peripheral vascular disease (PVD) was measured by a filtration method using 3 microns pore size filters. Filtration pressures for both PVD patients and normal subjects showed a cell volume dependency, and patient filtration pressures were normalized to cell volume to evaluate intrinsic, ie, nonvolume dependent, abnormalities in erythrocyte deformability. A significant (p less than 0.001) increase in cell rigidity was found in 44 of 54 PVD patients in comparison with volume-matched normal controls. No significant difference was found between patient mean corpusculer hemoglobin (MCH) and normal MCH at any given mean corpuscular volume (MCV), indicating that observed increases in erythrocyte rigidity are not attributable to changes in patient MCH. Therefore, the mechanism of increase in erythrocyte rigidity for PVD patients still needs further investigation into such parameters as levels of adenosine triphosphate,2,3-DPG, and membrane fluidity (calcium- and/or protein-binding membrane, cholesterol and phospholipid content of membrane, etc), as well as other aspects of erythrocyte physiology.

Adult↗
PubMed2004

Rigid bronchoscope-assisted endotracheal intubation: yet another use of the gum elastic bougie.

UNLABELLED: We describe a technique by which a gum elastic bougie (GEB) is used to facilitate an anticipated difficult endotracheal intubation in a patient undergoing rigid bronchoscopy. After placing the GEB through the lumen of the rigid bronchoscope, the GEB-suction catheter assembly was used to safely withdraw the bronchoscope in a manner mimicking the withdrawal of an intubating laryngeal mask airway (LMA) over the endotracheal tube using a stabilizer rod. The rationale for management and potential advantages of this approach versus use of an airway exchange catheter (including increased stability of an intubation guide) are discussed. IMPLICATIONS: We describe a technique of using a gum elastic bougie to facilitate an endotracheal intubation in a patient undergoing rigid bronchoscopy, which can be useful in a variety of clinical situations when the rigid bronchoscope is used in patients with abnormal airway.

Adult↗
PubMed2007

The use of rigid internal fixation in the surgical management of cervical spondylosis.

In the surgical management of cervical spondylosis, the application of rigid internal fixation can enhance the immediate stability of the cervical spine. The sophistication of such internal fixation systems and the indications for their use are continuously evolving. A sound understanding of regional anatomy, biomechanics, and kinematics within the cervical spine is essential for the safe and effective application of internal fixation. Numerous options currently exist for anterior cervical plating systems; some lock the screws to the plate rigidly (constrained), whereas others allow for some rotational or translational motion between the screw and plate (semiconstrained). The role of anterior fixation in single and multilevel fusions is still the subject of some controversy. Long anterior cervical reconstructions may require additional posterior fixation to reliably promote fusion. Rigid fixation in the posterior cervical spine can be achieved with lateral mass screws or pedicle screws. Although lateral mass screws provide excellent fixation within the subaxial cervical spine, the regional anatomy of C2 and C7 often make it difficult to place such screws, and pedicle screws at these levels are advocated. Pedicle screws achieve fixation into both the anterior and posterior column and are arguably the most stable form of rigid internal fixation within the cervical spine. Familiarity with these internal fixation techniques can be an extremely valuable tool for the spine surgeon managing these degenerative disorders of the cervical spine.

Cervical Vertebrae↗
PubMed2000

Atomic force microscopic evidence for Z-band as a rigid disc fixing the sarcomere structure of skeletal muscle.

Atomic force microscopic images of single skeletal myofibrils showed periodical broad filamentous bands interspaced with narrow rigid bands corresponding to the sarcomere structures of skeletal muscle (Yoshikawa, Y., Yasuike, T., Yagi, A., and Yamada, T. 1999. Biochem. Biophys. Res. Comm., 256: 13-19). In order to identify the narrow rigid bands, comparative studies were made for intact single myofibrils and those treated with calcium-activated neutral protease by use of atomic force microscopy. It was found that (a) the periodical narrow rigid bands present in intact myofibrils were completely absent in myofibrils treated with calcium-activated neutral protease, and that (b) myofibrils treated with calcium-activated neutral protease were very fragile compared with intact myofibrils. As calcium-activated neutral protease selectively removes Z-bands of myofibrils (Reddy, M. K., Etlinger, J. D., Rabinowitz, M., Fischman, D. A., and Zak, R. 1975. J. Biol. Chem., 250: 4278-4284), these results clearly indicate that (a) the narrow rigid bands are the Z-bands, and that (b) the Z-bands are the essential disc supporting the sarcomere structure of skeletal muscle.

Animals↗
PubMed1993

Local cerebral glucose utilization in rats with decerebrate rigidity and effects of centrally acting muscle relaxants, diazepam and tizanidine.

Local cerebral glucose utilization (LCGU) was investigated in rats with decerebrate rigidity using the [14C]2-deoxyglucose (2DG) method in order to identify the site responsible for the rigidity. LCGU was increased in the medial vestibular nucleus, the fastigial nucleus, the interpositus nucleus and the dentate nucleus during decerebrate rigidity. Diazepam and tizanidine, centrally acting muscle relaxants, reduced the increase of LCGU in the vestibular and cerebellar nuclei. These results suggest that the vestibular and cerebellar nuclei are the possible sites responsible for the development of decerebrate rigidity and the action of some centrally acting muscle relaxants.

Animals↗
PubMed2001

Is reflux noted at diagnostic rigid oesophagoscopy clinically significant?

This study assessed the ability of otolaryngologists to diagnose and grade reflux disease at rigid endoscopy. Twenty-one out of 25 senior otolaryngologists who were questioned by means of a telephone survey said that if they find evidence of reflux disease at rigid endoscopy of the oesophagus and larynx, their practice is to place the patient on a proton pump inhibitor for six weeks without requesting pH and manometry studies, and without referral to a gastroenterologist. Over a two year period, 21 patients were diagnosed as having reflux disease at rigid endoscopy. This was based on the finding of fluid and erythema in the aerodigestive tract and upper oesophagus. Subsequent oesophageal pH and manometry was performed. Nine out of 21 patients were confirmed as refluxers. This demonstrated an accuracy of less than 50 per cent when using these findings to diagnose gastro-oesophageal reflux at rigid endoscopy.

Clinical Protocols↗
PubMed1997

Therapeutic rigid bronchoscopy allows level of care changes in patients with acute respiratory failure from central airways obstruction.

OBJECTIVE: To determine whether emergency rigid bronchoscopic intervention, including Nd-YAG laser resection or stenting, immediately affected the need for continued mechanical ventilation or intensive care level of support in critically ill patients with acute respiratory failure from malignant or benign central airways obstruction. DESIGN: Retrospective review of medical records of all patients with acute respiratory failure and malignant or benign tracheobronchial obstruction necessitating intubation, mechanical ventilation, or hospitalization in the ICU prior to referral for therapeutic bronchoscopy. SETTING: University of California San Diego, a tertiary care institution specialized in airway management. PATIENTS: Medical records of 32 patients with malignant or benign central airways obstruction requiring admission to the ICU prior to rigid bronchoscopic intervention between January 1994 and April 1996. INTERVENTIONS: Emergent rigid bronchoscopy with dilatation, Nd-YAG laser resection, or silicone stent insertion performed in the operating room under general anesthesia. RESULTS: Thirty-two patients with central airways obstruction requiring emergent hospitalization in the ICU were referred for therapeutic rigid bronchoscopy. Airway strictures were caused by benign disease in 18 patients, and by primary bronchogenic lung cancer in 14. Of the 19 patients who were mechanically ventilated, bronchoscopic intervention allowed immediate discontinuation of mechanical ventilation in 10 (52.6%). Twenty-five patients had indwelling artificial airways (12 endotracheal tubes, 13 tracheotomy tubes). Two, however, were considered tracheotomy-dependent because of neuromuscular disease. Of the remaining 23 patients, immediate extubation or decannulation was possible in seven (30.4%). Of seven patients with no indwelling airway, five (71.4%) were immediately transferred to a lower level of care after intervention. Of the 32 total patients, 20 (62.5%) were immediately transferred to a lower level of care immediately after intervention. CONCLUSIONS: Emergency laser resection or stent insertion can favorably affect health-care utilization in patients with acute respiratory distress from central airways obstruction. Treatment may be lifesaving and allows successful withdrawal from mechanical ventilation, hospitalization in a lower level of care environment, relief of symptoms, and extended survival in critically ill patients. In patients with regionally advanced cancer, the palliative nature of this procedure postpones death by respiratory distress and may prompt consideration for institution of conservative comfort measures to reduce patient suffering.

Bronchial Diseases↗
PubMed1981

Complications of bronchoscopy: comparison of rigid bronchoscopy under general anesthesia and flexible fiberoptic bronchoscopy under topical anesthesia.

A prospective study of 4,595 bronchoscopic procedures performed over four years (1975 to 1978) on 2,143 patients with various bronchopulmonary diseases is described. Of the 4,595 procedures, 1,146 were performed with a flexible fiberoptic bronchoscope (Olympus BF-5B2 or BF-B2) under topical anesthesia with tetracaine and procaine, and 3,449 procedures were performed with a rigid bronchoscope under general intravenous anesthesia with hexobarbital (Evipan) using a modified Sanders' technique to ventilate the patients. Complications occurred in 235 procedures (5.1 percent). Major complications that threatened the patient's life and required intensive medical treatment, surgical intervention, or resuscitative measures occurred in 51 procedures (1.1 percent); deaths occurred after 6 procedures (0.1 percent). A comparison of the complications of rigid bronchoscopy and flexible fiberoptic bronchoscopy revealed significantly higher rates of complications of fiberoptic bronchoscopy attributable to toxic effects of tetracaine and of complications of rigid bronchoscopy associated with insufficient general anesthesia. With rigid bronchoscopy, the number of major complications induced by diagnostic manipulations through the bronchoscope and the total number of major complications were significantly higher than with flexible fiberoptic bronchoscopy.

Anesthesia, General↗
PubMed2000

High tibial osteotomy with a calibrated osteotomy guide, rigid internal fixation, and early motion. Long-term follow-up.

BACKGROUND: We studied the results of sixty-four valgus-producing high tibial osteotomies performed with the use of a calibrated osteotomy cutting guide and rigid internal fixation, and followed by early motion, in fifty-six patients who had medial unicompartmental osteoarthritis and varus malalignment. Long-term studies have demonstrated that a high tibial osteotomy performed with staple fixation and followed by immobilization in a cast has an expected survival rate of approximately 85 percent at five years and 60 percent at ten years (in studies of ninety-five knees and 213 knees, respectively). To the best of our knowledge, there are no long-term reports on high tibial osteotomies performed with a calibrated osteotomy cutting guide and rigid internal fixation and followed by early motion. METHODS: The indications for high tibial osteotomy were medial unicompartmental osteoarthritis and varus malalignment. A lateral closing-wedge osteotomy was performed. The patients were reexamined to obtain a knee score, to make lateral radiographs of both knees, and to make a full-length anteroposterior radiograph (showing the entire lower extremity, including the hip and ankle) of the involved knee with the patient standing. RESULTS: Twenty-one knees were treated with a subsequent total knee arthroplasty at an average of sixty-five months after the high tibial osteotomy. The remaining forty-three knees had a good or excellent clinical result, with an average knee score of 94 points at an average of 8.5 years after the osteotomy. Survivorship analysis showed an expected rate of survival, with conversion to a total knee arthroplasty as the end point, of 85 percent at five years and 53 percent at ten years. No patient had patella baja postoperatively. There were six complications: four superficial wound infections, one superficial-vein thrombosis, and one delayed union (union occurred at five months). CONCLUSIONS: High tibial osteotomy has been criticized because of a high rate of complications, a loss of effectiveness with time, and the difficulty of conversion to a total knee arthroplasty secondary to patella baja. In our series, in which an osteotomy was performed with a calibrated osteotomy cutting guide and rigid internal fixation and was followed by early motion, the rate of complications was low and approximately two-thirds of the knees had a good or excellent clinical result at an average of 8.5 years. Conversion to a total knee arthroplasty was accomplished without difficulty in the patients who had this procedure. We highly recommend high tibial osteotomy with a calibrated osteotomy cutting guide, rigid internal fixation, and early motion for patients who wish to continue an active lifestyle.

Adult↗
PubMed1999

Rigid occipitocervical fusion.

OBJECT: Despite 50 years of neurosurgical experience, occipitocervical fusion continues to present a technical challenge to the surgeon. Traditional nonrigid techniques applied in the occiput and cervical spine often fail secondary to postsurgical cranial settling or rotational deformity. Unlike widely used nonrigid and semirigid techniques, rigid fixation of the craniocervical junction should allow correction of deformity in any plane, provide immediate stability without need for external orthosis, and prevent cranial settling. METHOD: Since 1992, the senior author (D.W.C.) has used a rigid plate and screw fixation system for occipitocervical fusions. The technique proved to be more difficult than expected, and the procedure has evolved as experience was gained. The authors present a series of 24 patients and a technique that now involves the use of a custom-designed T-plate that is attached to the midline occipital "keel" at one end and to the spine at the other end by means of screw-fixed plates. CONCLUSIONS: Although it is still evolving, the current technique for obtaining rigid occipitocervical fixation allows for immediate rigidity and stability of the spine without the use of an external orthosis (that is, in the absence of osteoporosis), may be extended to any level of the spine, may be used in the absence of posterior elements, prevents postsurgical cranial settling and restenosis, facilitates reduction of the spinal deformity in any plane, and sometimes eliminates the need for an anterior (transoral) decompressive procedure.

Adult↗
PubMed1977

Decerebrate rigidity in acute head injury.

A comprehensive study of the motor patterns, usually grouped under the heading "decerebrate rigidity," was carried out in a series of 800 patients with severe head injuries. The incidence of these manifestations was 39.6%, and when they were present chances of survival were reduced from 79.4% to 28.1%. Clinical and electromyographic investigations revealed heterogeneous and unstable motor manifestations that did not fit into the classical groups of experimental models of decerebrate rigidity. Combinations of extensor and flexor attitudes and/or responses were frequently found in same patient, but could be separated into homogeneous groups. Each recognized postural pattern had its own distinct neurological signs and prognosis. Age did not significantly affect the outcome, however, intracranial exapnding lesions (73.5%), impairment of the brain-stem oculomotor system (49.8%), and deep coma (88.9%) all contributed to an unfavorable course. Surgical treatment was effective when performed for intracranial hematomas and in patients with incomplete extensor rigidity. Good recovery was achieved in 16% of decerebrate patients, while 12.1% survived in prolonged coma or with severe disabilities. All clinical and neuropathological data suggest that extensor motor abnormalities in the acute phase of cerebral traumatic disease do not always conclusively indicate structural brain-stem damage. A critical analysis of so-called "decerebrate rigidity" (rejecting in some instances its Sherringtonian implications) may allow for a more accurate clinical assessment of the severity of head injury.

Adolescent↗
PubMed1999

Tactile roughness perception with a rigid link interposed between skin and surface.

Subjects made roughness judgments of textured surfaces made of raised elements, while holding stick-like probes or through a rigid sheath mounted on the fingertip. These rigid links, which impose vibratory coding of roughness, were compared with the finger (bare or covered with a compliant glove), using magnitude-estimation and roughness differentiation tasks. All end effectors led to an increasing function relating subjective roughness magnitude to surface interelement spacing, and all produced above-chance roughness discrimination. Although discrimination was best with the finger, rigid links produced greater perceived roughness for the smoothest stimuli. A peak in the magnitude-estimation functions for the small probe and a transition from calling more sparsely spaced surfaces rougher to calling them smoother were predictable from the size of the contact area. The results indicate the potential viability of vibratory coding of roughness through a rigid link and have implications for teleoperation and virtual-reality systems.

Adult↗
PubMed1991

[Continuous monitoring of penile rigidity and tumescence in Japanese without erectile dysfunction].

Continuous monitoring of penile rigidity and tumescence has been proved to be of use for accurate diagnosis of erectile impotence, since it provides objective recording of penile rigidity as well as circumferential expansion. Prior to clinical use of this procedure in Japan, a study was performed to clarify normal features of nocturnal penile tumescence of Japanese and to ensure safety of this procedure. The subjects consisted of 16 normal volunteers, aged from 24 to 44 years. With fully informed consent of the volunteers, nocturnal penile rigidity and circumferential expansion were simultaneously measured for three consecutive nights by means of RigiScan at the base of the penis (base) and at about five millimeters proximal to the coronary sulcus (tip). The minimum circumference of the penis was 62.7 +/- 4.6 mm (mean +/- SD) at the tip and 65.4 +/- 9.3 mm at the base. The maximum circumference, which meant full erection in the normal volunteers, was 102.5 +/- 14.2 mm at the tip and 108.6 +/- 14.7 mm at the base. The mean duration of tumescence, i.e. circumference expansion more than 10 mm, was 23.0 +/- 6.9 minutes at the tip and 38.3 +/- 12.0 minutes at the base. The mean rate of episodes of circumference expansion more than 10 mm was 0.75 +/- 0.27 per hour at the tip and 0.70 +/- 0.26 per hour at the base. The maximum rigidity lasting more than 10 minutes was 82.9 +/- 10.1% at the tip and 85.4 +/- 8.4% at the base.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Aeration time following ethylene oxide sterilization for reusable rigid sterilization containers: concentration of gaseous ethylene oxide in containers.

Because ethylene oxide (EO) gas is toxic to humans, restrictions have been imposed on its use for sterilization, specifying allowable levels of residual EO remaining in sterilized apparatus and materials. However, the aeration time that optimizes the removal of the remaining EO when a rigid sterilizing container is used for a vessel had not been identified. Therefore, polyvinyl chloride, which easily adsorbs EO, was placed in rigid sterilizing containers, and aeration was carried out after 1, 8, 12, 17, and 24 hours. After standard EO sterilization, the EO concentrations remaining in the air in the rigid containers were measured. The results indicate that a period of 17 hours of aeration is appropriate when a rigid sterilizing container is used.

Air↗
PubMed2001

Open reduction and temporary rigid internal fixation of Lisfranc fracture-dislocations.

AIM: To review the results of open reduction and temporary rigid screw fixation of Lisfranc fracture-dislocations performed in Singapore General Hospital (SGH) from 1996 to 1998. METHODS: A retrospective review of II cases of Lisfranc injuries treated with temporary rigid internal screw fixation with a minimum follow up of six months was carried out. Radiological assessment was made at follow up to ascertain the anatomical reduction achieved and complications such as post-traumatic arthritis. In addition, the patients were evaluated with a functional assessment with relation to pain, interference to usual activities and the time to resumption of work. RESULTS: Anatomical reduction was achieved in all cases. None of the cases showed loss of reduction at follow up after the temporary implants were removed. No longitudinal arch collapse or other deformities were seen. All the patients had good or excellent functional outcomes. CONCLUSIONS: Results of treatment of Lisfranc injuries are related to anatomical correction. Temporary screw fixation allows rigid internal fixation with stability to allow anatomical correction. Screws also maintain their stability longer, allowing ligamentous injuries the longer period necessary for healing. In conclusion, temporary rigid screw fixation of Lisfranc fracture maintains anatomical reduction and gives excellent functional outcomes for the patients.

Adolescent↗