Adenoviral capsid modulates secretory compartment organization and function in acinar epithelial cells from rabbit lacrimal gland

Although adenovirus (Ad) exhibits tropism for epithelial cells, little is known about the cellular effects of adenoviral binding and internalization on epithelial functions. Here, we examine its effects on the secretory acinar epithelial cells of the lacrimal gland, responsible for stimulated release of tear proteins into ocular fluid. Exposure of reconstituted rabbit lacrimal acini to replication-defective Ad for 16-18 h under conditions that resulted in >80% transduction efficiency did not alter cytoskeletal filament or biosynthetic/endosomal membrane compartment organization. Transduction specifically altered the organization of the stimulated secretory pathway, eliciting major dispersal of rab3D immunofluorescence from apical stores normally associated with mature secretory vesicles. Biochemical studies revealed that this dispersal was not associated with altered rab3D expression nor its release from cellular membranes. Ultraviolet (UV)-inactivated Ad elicited similar dispersal of rab3D immunofluorescence. In acini exposed to replication-defective or UV-inactivated Ad, carbachol-stimulated release of bulk protein and beta-hexosaminidase were significantly (P< or =0.05) inhibited to an extent proportional to the loss of rab3D-enriched mature secretory vesicles associated with these treatments. We propose that the altered secretory compartment organization and function caused by Ad reflects changes in the normal maturation of secretory vesicles, and that these changes are caused by exposure to the Ad capsid.     

Linezolid-associated peripheral neuropathy

Linezolid is the first drug in a new class of synthetic antimicrobials, the oxazolidinones, to be approved by the Food and Drug Administration. Linezolid is active against methicillin- and vancomycin-resistant gram-positive microorganisms. We describe 2 patients who developed peripheral neuropathy after prolonged treatment with linezolid. Linezolid-associated peripheral neuropathy has not been well documented. Most reported cases of linezolid-associated peripheral neuropathy have occurred in patients who took linezolid for a period longer than the recommended 28 or fewer days. Health care providers must be alert to the potential for serious adverse effects associated with linezolid use, including peripheral neuropathy.     

Caution Required When Using an Intraoperative Knee Balancer in Total Knee Arthroplasty

Various knee balancers have been developed to assist surgeons in balancing the flexion and extension spaces during total knee arthroplasty. Devices typically are designed to measure the distance between spaces during total knee arthroplasty at a given force level. We analyzed the accuracy of one type of these devices. We found that the devices accurately measure distances, but are quite inaccurate at demonstrating reproducible forces.     

Optimal fixation for the extended trochanteric osteotomy: a pilot study comparing 3 cables vs 2 cables

The extended femoral trochanteric osteotomy allows excellent exposure of the proximal femoral canal, which facilitates resection of the canal's contents during revision total hip arthroplasty. Once the proximal femoral canal has been evacuated and a new femoral component has been placed, the osteotomy should be fixed in proper position to allow healing. The purpose of our study was to compare the fixation of an extended trochanteric osteotomy using 2 vs 3 braided cables with regard to stiffness, peak force, axial displacement, transverse displacement, and angular displacement using an in vitro biomechanical model. Nine paired cadaver femurs were loaded to failure. Movement at the osteotomy site before failure was recorded using a motion analysis system. There was no statistically significant difference between 2 vs 3 cables with regard to stiffness, peak force, or displacement in the 3 planes tested. Peak force and stiffness were both greater in the 3-cable group, whereas angular and transverse displacement were less in the 2-cable construct.     

Comparison of two methods of screw fixation in periacetabular osteotomy

The optimal method of fixation during periacetabular osteotomy is unknown. Periacetabular osteotomies were created on both sides of six whole pelves from fresh cadavers and were fixed randomly either with three long 4.5-mm cortical screws from the iliac crest to the osteotomized fragment (iliac fixation) or with two such screws supplemented by a transverse screw from the acetabular segment to the ilium (transverse fixation). Pelvis loading in simulated push-off phase of the gait cycle was accomplished using a custom-made fixture. Linear potentiometers measured displacements at the pubic and ischial osteotomies. Fracture site stiffness was calculated from actuator force and pubic osteotomy displacement data. Displacement of the pubic osteotomy averaged 12.8 mm in the iliac fixation group and average 12.45 mm in the transverse group fixation. The ultimate loads beyond which catastrophic failure occurred were measured from 531.27 N to 1103.3 N (mean, 741.5 N) and 660.9 N to 1273.9 N (mean, 930.8 N), respectively. Effective stiffness ranged from 38.9 N/mm to 117 N/mm in the iliac fixation group (mean, 77.8 N/mm), and from 99 N/mm to 315 N/mm in the transverse construct (mean, 182 N/mm). Although the transverse screw provided statistically significantly greater local stiffness to the periacetabular construct fixation, neither type of fixation provided enough stability to allow immediate weightbearing after periacetabular osteotomy.     

Popliteus Tendon Resection During Total Knee Arthroplasty: An Observational Report

Background  

The contribution provided by the popliteus tendon in patients undergoing TKA is poorly defined. Some authors believe the popliteus tendon is essential to a well-functioning arthroplasty, while others do not believe it provides a critical function.     

Radio-ulnar dissociation. A review of twenty cases.

The results of treatment were reviewed for twenty patients who had sustained concomitant injuries of the lateral compartment of the radiohumeral joint and the ipsilateral distal radio-ulnar joint. The ages of the patients ranged from eight to seventy-four years (average, thirty-five years) and the duration of follow-up ranged from four months to twenty-seven years (average, 113 months). In fifteen patients, the injury of the wrist was diagnosed after a mean delay of seven years and eleven months (range, one month to twenty-six years). In all fifteen, the radial head injury was treated by excision, either initially or after some delay. After excision of the radial head, all fifteen patients complained of severe pain at the distal radio-ulnar joint. The results, on the basis of elbow and wrist scores of fair or better without complications, were satisfactory in only three patients. In the remaining five patients, in whom the injuries of both the elbow and the wrist had been identified at the initial evaluation, the radial head was either preserved or replaced. The results, on the basis of elbow and wrist scores of fair or better, were graded as satisfactory in four of these patients. Our data show that any injury to the lateral side of the elbow should prompt a careful evaluation of the ipsilateral distal radio-ulnar joint for associated instability.     

The Decision to Accept Treatment for Osteoporosis Following Hip Fracture: Exploring the Woman’s Perspective Using a Stage-of-Change Model

Despite the availability of medications that reduce fracture risk, most women who sustain a hip fracture are not evaluated or treated for osteoporosis. While a number of studies have attributed this to a lack of physician awareness, no studies have evaluated this problem from the patient’s perspective. To explore the process a woman negotiates when deciding to accept pharmacologic treatment for osteoporosis after hip fracture, we used a stage-of-change model to characterize a consecutive series of 70 postmenopausal women (mean age 85 years) admitted to a tertiary care hospital with an acute low-impact hip fracture between May 2000 and August 2000. We measured stage-of-change using a modified form of the Weinstein Precaution Adoption Process Model (PAPM). The majority of patients (65%) were ineligible because of dementia or delirium; only 29 were eligible and 21 were enrolled. Most women (62%) were in stages 1 or 2 of the PAPM, indicating that they were unaware of osteoporosis or had never considered pharmacologic treatment for it. The only factors associated with a more advanced PAPM stage (indicating active consideration or currently taking treatment) were a previous bone mineral density (BMD) evaluation (p= 0.007) and a diagnosis of osteoporosis (p= 0.001). Although 48% of women had a previous fragility fracture and osteoporosis knowledge was poor overall (mean score 52% correct), neither was associated with a more advanced PAPM stage in this sample. In conclusion, women evaluated after hip fracture were not ready to accept pharmacologic treatment for osteoporosis; they were unaware that they had osteoporosis or had never considered treatment for it. For a woman to advance through the behavior change process, she must first be made aware of the problem that requires a change in behavior. Physicians play a crucial role in promoting awareness of the diagnosis of osteoporosis after fracture, which in turn is associated with patient advancement through the behavior change process and the decision to accept pharmacologic intervention. The large number of cognitively impaired patients in this population, however, will certainly make efforts to improve osteoporosis awareness, diagnosis and intervention more challenging. Received: 20 August 2001 / Accepted: 12 December 2001