Protein phosphatase 2B (PP2B, calcineurin) in Paramecium: partial characterization reveals that two members of the unusually large catalytic subunit family have distinct roles in calcium-dependent processes.

We characterized the calcineurin (CaN) gene family, including the subunits CaNA and CaNB, based upon sequence information obtained from the Paramecium genome project. Paramecium tetraurelia has seven subfamilies of the catalytic CaNA subunit and one subfamily of the regulatory CaNB subunit, with each subfamily having two members of considerable identity on the amino acid level (>or=55% between subfamilies, >or=94% within CaNA subfamilies, and full identity in the CaNB subfamily). Within CaNA subfamily members, the catalytic domain and the CaNB binding region are highly conserved and molecular modeling revealed a three-dimensional structure almost identical to a human ortholog. At 14 members, the size of the CaNA family is unprecedented, and we hypothesized that the different CaNA subfamily members were not strictly redundant and that at least some fulfill different roles in the cell. This was tested by selecting two phylogenetically distinct members of this large family for posttranscriptional silencing by RNA interference. The two targets resulted in differing effects in exocytosis, calcium dynamics, and backward swimming behavior that supported our hypothesis that the large, highly conserved CaNA family members are not strictly redundant and that at least two members have evolved diverse but overlapping functions. In sum, the occurrence of CaN in Paramecium spp., although disputed in the past, has been established on a molecular level. Its role in exocytosis and ciliary beat regulation in a protozoan, as well as in more complex organisms, suggests that these roles for CaN were acquired early in the evolution of this protein family.

Cell electrophoresis research directed toward clinical cytodiagnosis.

The application of cell electrophoresis to cytodiagnosis requires that a scientifically established basis exists for identifying abnormal cells electrophoretically, that research to detect such differences in the cytodiagnostic setting is possible and that a rapid and simple method of cell electrophoresis is adaptable to the clinical setting. Data are presented indicating modifications of electrophoretic mobility due to herpes simplex virus type 1 infection and Rous sarcoma virus transformation of culture cells. A simple apparatus for electrophoretically separating cells on a density gradient and collecting them for subsequent analysis is described, and results of experiments with this apparatus are consistent with those obtained by microscopic electrophoresis. Laser-doppler spectroscopic electrophoresis is suggested as a rapid method adaptable to clinical application.

Cross-gender behavior and gender conflict in sexually abused girls.

OBJECTIVE: This study contrasted a group of sexually abused girls, aged 6 to 12 years, with two demographically comparable control groups, girls from a child psychiatry outpatient clinic, and girls from a general pediatric clinic, to determine whether differences in gender role behavior and identity could be demonstrated. METHOD: All girls underwent an evaluation protocol that included a semistructured interview for children, the Gender Role Assessment Schedule--Child (GRAS-C). The mothers were administered several questionnaires including two parent-report measures of gender-related behavior in their children, the Child Game Participation Questionnaire (CGPQ) and the Child Behavior and Attitude Questionnaire--Female version (CBAQ-F). RESULTS: Sexually abused girls manifested significantly more cross-gender behavior on the GRAS-C (in the areas of gender role preference and aggression) and gender identity conflict than did nonabused girls in both comparison groups. For the sexually abused and psychiatric control groups, their parents reported greater involvement in traditionally masculine games on the CGPQ, but on the CBAQ-F, no significant group differences were found. CONCLUSIONS: Findings suggest that sexual abuse in preadolescent girls is associated with cross-gender behavior and gender conflict.

Chitosan: a new hemostatic.

Chitosan is a deacetylated derivative of arthropod chitin. We found that it formed a coagulum in contact with defibrinated blood, heparinized blood, and washed red cells. When knitted DeBakey grafts were treated with chitosan, they were impermeable to blood. Examination of these grafts at 24 hours revealed no rebleeding. Examination at one, two, three, and four months showed the grafts to be encased in smooth muscle with a living endothelial lining and an abundant vasa vasorum. Control grafts showed the usual fibrous healing.

Sexual behavior problems and psychopathology symptoms in sexually abused girls.

OBJECTIVE: This study contrasted a group of sexually abused girls, aged 6 to 12 years, with two demographically comparable control groups, girls from a child psychiatry outpatient department, and girls from a general pediatric clinic to determine whether differences in sexual behavior and psychopathology symptoms could be demonstrated. METHOD: All girls and their mothers underwent an evaluation protocol composed of two parent-report inventories, the Child Behavior Checklist and the Child Sexual Behavior Inventory. RESULTS: Sexually abused girls and psychiatric controls manifested more psychopathology symptoms, including internalizing and externalizing behaviors, than the nonpsychiatric controls. Relative to both control groups, sexually abused girls manifested more sexual behavior problems: masturbating openly and excessively, exposing their genitals, indiscriminately hugging and kissing strange adults and children, and attempting to insert objects into their genitals. Abuse by fathers or stepfathers involving intercourse was associated with particularly marked sexual behavior disturbances. There was a subgroup of sexually abused girls who tended to force sexual activities on siblings and peers. All of these girls had experienced prolonged sexual abuse (more than 2 years) involving physical force which was perpetrated by a parent. CONCLUSIONS: Findings suggest that sexual abuse in preadolescent girls is associated with sexual behavior problems.

Vertebral body impactor for posterior lateral decompression of thoracic and lumbar fractures. Technical note.

A hand-held impactor is described that allows secure impaction of retropulsed vertebral body bone fragments in burst fractures of the thoracic or lumbar spine.

The use of pedicle-screw internal fixation for the operative treatment of spinal disorders.

Pedicle screws have dramatically improved the outcomes of spinal reconstruction requiring spinal fusion. Short-segment surgical treatments based on the use of pedicle screws for the treatment of neoplastic, developmental, congenital, traumatic, and degenerative conditions have been proved to be practical, safe, and effective. The Funnel Technique provides a straightforward, direct, and inexpensive way to very safely apply pedicle screws in the cervical, thoracic, or lumbar spine. Carefully applied pedicle-screw fixation does not produce severe or frequent complications. Pedicle-screw fixation can be effectively and safely used wherever a vertebral pedicle can accommodate a pedicle screw--that is, in the cervical, thoracic, or lumbar spine. Training in pedicle-screw application should be standard in orthopaedic training programs since pedicle-screw fixation represents the so-called gold standard of spinal internal fixation.

Removal of sublaminar wires after spinal fusion.

Eighteen patients who had had spinal fusion using Harrington rods with sublaminar wires underwent removal of the implants because of tenderness over the implants. There were no important complications. At final follow-up, no patient had a change in neurological function as compared with the preoperative assessment, and all reported relief of the preoperative tenderness. We concluded that the removal of rods and sublaminar wires from patients who have had a spinal fusion is clinically safe and effective.

Long-term intravenous therapy with use of peripherally inserted silicone-elastomer catheters in orthopaedic patients.

We studied the results of prolonged intravenous therapy with antibiotics through a central venous silicone-elastomer catheter that had been peripherally inserted in thirty-five orthopaedic patients. The catheters remained in place for an average of twenty-nine days (range, five to seventy-four days). The 20-gauge (one-millimeter-diameter) catheters used in our study were smaller in diameter than the triple-lumen catheters or the double-lumen Hickman catheters used in previous studies. The catheters in our study were left indwelling for as long as, or for longer than, those in other studies. Our patients had no serious complications related to the insertion or use of the catheter. However, three (8 per cent) of thirty-eight inserted catheters failed mechanically and had to be removed. Two additional catheters (5 per cent) were removed because the lumen became plugged. One catheter in each of these groups was not replaced, because a catheter was no longer necessary. We believe that the problems with the catheters were related to the small diameter of the tubing that was used in our series. Use of the small-diameter catheter reduces the risk of cardiac tamponade and other complications associated with catheters that have larger diameters, and small-diameter catheters can remain indwelling for a long time. The peripheral route of insertion eliminates the risk of pneumothorax associated with the subclavian route of placement and allows for greater ease of insertion. In addition, the use of catheters made of silicone elastomer reduces the risk of thrombosis and infection, which are associated with catheters made of polyethylene.(ABSTRACT TRUNCATED AT 250 WORDS)

Language learning and retention in young language-disordered children.

Simultaneous sign and spoken language training was conducted with young, language-disordered children under standardized training and follow-up conditions with a stringent learning criterion to determine if language learned was stable over time. Twenty-one children between 36 and 86 months with no or nonfunctional language participated in the study. Diagnoses included autism, mental retardation, combined autism and mental retardation, and developmental aphasia. Children completed a mean of 74 signed speech training sessions. Sessions were twice daily, 5 days a week. Follow-up evaluations were made approximately 6 months after training. Of the 21 children, 17 learned at least one word and 7 children learned multiple-word phrases during the training. Most language learned in training was found to be retained at follow-up approximately 6 months later. Gestural imitation, play style, language age, developmental age, and fine motor skills had strong correlations with language learning and retention.

Treatment of spondyloptosis by two stage L5 vertebrectomy and reduction of L4 onto S1.

A new method of treatment of spondyloptosis is presented utilizing a staged approach. The first stage consists of a vertebral body resection of L5 along with the L4-5 and L5-S1 discs. The second stage procedure consists of removal of the loose posterior element, the articular processes, and pedicles of L5 and reduction of L4 onto the sacrum. The technique for the procedure is reviewed along with its results in two operated patients.

Mersilene tapes as a substitute for wire in segmental spinal instrumentation for children.

Sublaminar wires for segmental fixation have been a useful adjunct to internal fixation of the spine. Concern over broken wires in the spinal canal or fear of cut-through in soft bone led to the use of Mersilene tape to supplement Harrington or Luque rod fixation in six scoliotic children. No problems of infection or hardware loosening were noted. Mersilene tapes for segmental fixation may be useful where there is concern for wires in the spinal canal or with patients with soft bone and flexible curves.

Benefits of the Harrington compression system in lumbar and thoracolumbar idiopathic scoliosis in adolescents and adults.

Adolescent and adult scoliosis exhibits deformity present in all three planes of orientation, but the principal correcting effect of the Harrington distraction system is in the frontal plan. Sagittal and horizontal deformity was addressed by adding the compression system. Twenty patients were treated with combined apparatus. The mean preoperative frontal curve was 52 degrees, and the mean postoperative curve was 16 degrees. The average preoperative tilt angel was 31 degrees, and the average postoperative angle was 8 degrees. Thoracolumbar kyphosis was reduced, and lumbar lordosis was maintained. The combined apparatus addresses the triplanar curvature more effectively than the single distraction system.

Identification of spinal cord pathways responsible for the peroneal-evoked response in the dog.

The question of whether the dorsal columns were primarily responsible for the conduction of the peroneal-evoked cortical somatosensory response was studied by making staged scalpel transections of the spinal cord at T6 in the anesthetized dog. Control evoked potentials were followed by sequential lesioning of the spinal cord, followed by 30 minutes of evaluation to determine the effect of the lesion. Although slight shifts in latency may have occurred following a particular cut, these were usually transient and recovered to control values, regardless of the order in which various quadrants were sectioned. To alter the peroneal-evoked cortical potential in the dog, at least three quadrants of the spinal cord must be damaged to cause consistent increases in latency or loss of potentials. These findings agree with other investigators' observations in the cat, monkey and human.

Accuracy of cervical pedicle screw placement using the funnel technique.

STUDY DESIGN: This was a cadaver study assessing the accuracy of cervical pedicle screw placement. OBJECTIVE: To evaluate the accuracy of the funnel technique of screw placement. SUMMARY OF BACKGROUND DATA: Although excellent results have been reported in clinical studies, with no major neurovascular injuries, several cadaveric studies have shown a high pedicle perforation rate during screw placement. METHODS: Ten fresh frozen cervical spines (C2-C7) were used (120 pedicles, 20 pedicles per level). The average specimen age was 79.6 years (range 65-97); the average height was 159 cm (range 155-175). The male-to-female ratio was 3:7. Pedicle width and angulation were measured on preoperative axial computed tomography (1-mm slices). By use of four bony landmarks and the funnel technique, screws were placed under direct vision. Critical perforations (documented contact of a screw with, or an injury to, a spinal cord, nerve root, or vertebral artery) and noncritical perforations (a perforation with no critical contact) were recorded. RESULTS: In seven pedicles (5.8%) the procedure was aborted because of a small or nonexistent pedicle medullary canal. Ninety-four pedicle screws (83.2%) were placed correctly, whereas 11 pedicles (9.7%) had noncritical perforations and 8 pedicles (7.1%) had critical perforations. The majority of the critical and noncritical perforations were at C3, C4, and C5. CONCLUSIONS: Axial computed tomography is necessary for the preoperative planning. Because of the small diameter and steep angulation of cervical pedicles, every spine surgeon who intends to use pedicle screws should first master the technique on cadavers.

The load sharing classification of spine fractures.

STUDY DESIGN: A 3 to 4 year follow-up was performed on a consecutive series of 28 patients who had three-column spinal fractures surgically stabilized by short-segment instrumentation with first generation VSP (Steffee) screws and plates and autograft fusion. The follow-up revealed 10 patients with broken screws. BACKGROUND DATA: Retrospective examination of preoperative radiographs and computed tomographic axial and sagittal reconstruction images clearly demonstrated that the screw fractures all occurred in patients with a disproportionately greater amount of injury to the vertebral body. RESULTS: A point system (the load sharing classification) was developed that grades: 1) the amount of damaged vertebral body, 2) the spread of the fragments in the fracture site, and 3) the amount of corrected traumatic kyphosis. CONCLUSIONS: This point system can be used preoperatively to: 1) predict screw breakage when short segment, posteriorly placed pedicle screw implants are being used, 2) describe any spinal injury for retrospective studies, or 3) select spinal fractures for anterior reconstruction with strut graft, short-segment-type reconstruction.

Magnetic resonance imaging evaluation of the spinal canal following arthrodesis and removal of sublaminar wires.

Seven patients who underwent posterior spinal fusion with Harrington instrumentation and sublaminar wires, and subsequently had these implants removed, were evaluated for evidence of spinal canal compromise with magnetic resonance imaging (MRI) at the sites of the sublaminar wires. All fusions were solid. The sites of 33 wires (27 levels) were evaluated with MRI. The average time the wires were in the spinal canal was 24.6 months. The average time following wire removal at the time of MRI was 61.7 months. Twenty-eight of 33 (85%) wire sites had no evidence of spinal canal compromise. Five sites had minimal (less than 15%) spinal canal compromise. The permanent structural changes in the spinal canal attributable to sublaminar wires appears to be quite modest.

Treatment of L5-S1 spondyloptosis by staged L5 resection with reduction and fusion of L4 onto S1 (Gaines procedure).

STUDY DESIGN AND OBJECTIVES: A retrospective study was performed on the two-stage Gaines procedure for the treatment of spondyloptosis, evaluating indications, techniques, results, and patient satisfaction. SUMMARY OF BACKGROUND DATA: Sixteen consecutive patients from two institutions were included. Their average age was 24 years. Average follow-up was 3.9 years, with 11 patients included in follow-up 2 or more years. Ten patients (63%) had a preoperative neurologic deficit--three with cauda equina syndrome, one with foot drop. All patients had severe back or radicular symptoms and significant disability or severe deformity. METHODS: Patient examinations, interviews, chart review, and radiographic measurements all were performed independently. A subjective questionnaire was administered to each patient comparing preoperative with postoperative changes in pain, function, and appearance, as well as their overall outcome assessment. RESULTS: Postoperatively, 12 patients (75%) had early neurologic deficits, with seven of these having had a preoperative deficit. Four of these seven had a persistent deficit at follow-up, one with a permanent foot drop and three with documented weakness that was still improving at follow-up. The patient with preoperative foot drop remained unchanged, and the remaining seven patients with early deficit all recovered within 1 year. All three patients with preoperative cauda equina syndrome recovered postoperatively. The subjective questionnaire results revealed extremely high patient satisfaction. They reported significant improvement in pain, function, and appearance. CONCLUSIONS: Despite the relatively high complication rate, with appropriate patient selection, planning, and surgical technique, this procedure appears to be a sound method for treating severe cases of spondyloptosis, yielding very high patient satisfaction.

A new orthosis for immediate postoperative bracing in idiopathic scoliosis.

The "crutch-type scoliosis brace" and the KSO are leather covered aluminum braces, which have been successfully used in treating scoliosis patients at the Kosair Spinal Deformity Center both nonoperatively and postoperatively. This report defines the measurements, materials, and construction details for effective use of these braces and reports the very encouraging results of the KSO in a group of instrumented idiopathic scoliotic patients.

Response variability of somatosensory evoked potentials during scoliosis surgery.

Somatosensory evoked potentials (SSEP) were recorded from the scalp for intraoperative monitoring of patients undergoing surgical correction of spine deformities or spine fractures. Alterations in the SSEP with distraction, spine manipulation, anesthesia, hypotension, and other intraoperative variables are described. When loss of the SSEP occurred and a waiting period was undertaken until it returned, all patients with an SSEP present upon closing, which was within +/- 2 SD of their anesthetized control values, had no neurologic complications. Alterations in SSEP consisting of increases in latency of 15% and decreases in amplitude of 50% were not associated with any postoperative neurologic deficits.