Metacarpophalangeal Joint Reconstruction of a Complex Hand Injury with a Vascularized Lateral Femoral Condyle Flap Using an Individualized 3D Printed Model-A Case Report.

This case report describes the surgical management of a patient with a complex hand trauma. This injury included tendon, vascular, and nerve injuries, a partial amputation of the index finger, fractures of the third proximal phalanx, and destruction of the metacarpophalangeal joint of the fifth finger. Firstly, the acute treatment of a complex hand injury is described. Secondly, the planning and execution of a joint reconstruction using a vascularized lateral femoral condylar flap, assisted by an individual 3D model, is illustrated. Precise reconstruction of the affected structures resulted in good revascularization as well as an anatomical bone consolidation. Intensive physical therapy, including autonomous proprioceptive range-of-motion exercises by the patient, resulted in significant functional improvement of the hand in daily life. Overall, we report on the successful reconstruction of a metacarpophalangeal joint by using a vascularized flap from the lateral femoral condyle. Furthermore, this case report highlights the efficacy of integrating individualized 3D printing technology to plan complex reconstructions, opening up promising opportunities for personalized and optimized interventions.

Simultaneous determination of electrical conductivity and thickness of nonmagnetic metallic foils using two-sided multifrequency eddy current techniques.

In this paper, we describe a simple method for performing multifrequency eddy current characterization of free-standing uniform-thickness metallic foils using a forked inductive coil arrangement. The method involves measuring the mutual inductance between two coils when a foil is present between the coils, and when it is not present; the ratio of these mutual inductances is compared with an analytical solution, and foil conductivity, thickness, and sheet resistance are simultaneously estimated using numerical inversion and least-squares fitting. This method was used to characterize 34 non-ferrous metallic samples with thicknesses between 50 and 640 µm and with conductivities between 0.8 × 107 and 5.8 × 107 S/m. The estimated thicknesses from eddy current characterization agreed well with those measured using confocal optical techniques; the two approaches agreed to within 1 µm for samples that were thinner than 200 µm, and to within 0.5% for samples that had a thickness of 200 µm or greater. The estimated conductivities from eddy current characterization were in close agreement with expected values, given knowledge of the materials used. A particular strength of this approach is that the instrumentation needed is broadly available in research and development laboratories and the associated fixturing is easy to manufacture and assemble. A calibration procedure is described that can be used to reduce errors from geometric uncertainties. This calibration requires a sample that has only a known conductivity or thickness; both do not need to be known. The method described herein is likely extensible to conductivities and thickness well outside the ranges measured as part of this work.

Vascularized osteochondral free flaps from the femoral trochlea as versatile procedure for reconstruction of osteochondral lesions of the talus.

BACKGROUND: Osteochondral lesions of the talus (OLT) are defects affecting the articular cartilage as well as the subchondral bone, on the lateral shoulder possibly associated with trauma. This study presents the results of reconstructing OLT using vascularized osteochondral flaps from the femoral trochlea. METHODS: We treated 19 patients with osteochondral talar shoulder defects, using osteochondral flaps from the medial (MFT) or lateral (LFT) femoral trochlea. Functional outcome was evaluated by clinical investigation, visual analogue scale (VAS, 0-10), American Orthopaedic Foot and Ankle Society-Ankle and Hindfoot Scale (AOFAS, 0-100) and The Foot and Ankle Disability Index (FADI, 0-104). Radiographic postoperative follow-up was done by anterior-posterior and lateral X-rays and union of the transferred osteochondral flaps was documented by CT scans. RESULTS: The osteochondral flaps fused in all of the 19 cases. After a median follow-up of 45.5 months, the patients showed an average FADI of 94.9 and AOFAS-Ankle and Hindfoot Scale of 91.2. All of them were walking free and normal. Subjective median satisfaction was 1.3 in a scale from 1 to 5. CONCLUSION: Vascularized transfer of osteochondral flaps from the femoral trochlea is a reliable treatment option for symptomatic OLT of the medial and lateral talar edge. LEVEL OF CLINICAL EVIDENCE: Therapeutic IV.

Medial Femoral Trochlea Osteochondral Flap: Applications for Scaphoid and Lunate Reconstruction.

Vascularized osteochondral flaps are a new technique described for the reconstruction of challenging articular defects of the carpus. The medial femoral trochlea osteochondral flap is supplied by the descending geniculate artery. This osteochondral flap has shown promise in the treatment of recalcitrant scaphoid proximal pole nonunions and advanced avascular necrosis of the lunate. The anatomy, surgical technique, and results are discussed, with clinical cases provided.

The fasciocutaneous iliotibial band perforator flap in soft tissue and tendon reconstruction of the foot: A case report.

In cases of large defects of the limbs, post-traumatic deformity and disability can have devastating effects on patients' quality of life. The purpose of this report is to describe the technique for raising a fasciocutaneous iliotibial perforator flap and present its application in the reconstruction of a complex soft tissue defect of the foot. The patient was a 13-year-old male who had suffered a crush injury to the foot in a motor vehicle accident 5 years earlier. Due to retraction of the skin, together with the extensor tendons of the digits, the patient could not flex the digits II, III, IV, and V. To reconstruct the defect, the authors harvested a fasciocutaneous flap based on a perforator branch of the superior lateral genicular artery and accompanying veins. The immediate postoperative course was uneventful, with progressive and complete recovery of power and range of motion in the foot and knee within 6 weeks. Despite the tendency to form hypertrophic scars again, the functionality of the operated foot was excellent 29 months after the reconstruction. According to the American Orthopedic Foot and Ankle Society scale, the patient scored 100 points on the midfoot section and 93 points on the section forefoot rays two to five. The iliotibial perforator flap could be a new tool for a state-of-the-art functional reconstruction of soft tissues defects of the limbs and head and neck.

Nonvascularized Cartilage Grafts Versus Vascularized Cartilage Flaps: Comparison of Cartilage Quality 6 Months After Transfer.

PURPOSE: Subchondral perfusion of osteochondral grafts has been shown to be important in preventing long-term cartilage degeneration. In carpal reconstruction, subchondral perfusion from the graft bed is limited. This study's purpose was to compare the histological characteristics of cartilage in osteochondral grafts supported by synovial imbibition alone to cartilage of vascularized osteochondral flaps that have both synovial and vascular pedicle perfusion. METHODS: Two adjacent osteochondral segments were harvested on the medial femoral trochlea in domestic 6- to 8-month-old pigs. Each segment measured approximately 12 mm × 15 mm × 17 mm. One segment was maintained on the descending geniculate artery vascular pedicle. The adjacent segment was separated from the pedicle to serve as a nonvascularized graft. A thin layer of methylmethacrylate cement was used to line the harvest site defect to prevent vascular ingrowth to the subsequently replaced specimens. The pigs were maintained on a high-calorie feed and returned to ambulation and full weight-bearing on the surgical legs. The animals were sacrificed after 6 months and the specimens were reharvested, sectioned, and examined. The cartilage was graded by 2 pathologists blinded to the origin of specimens as vascularized flaps or nonvascularized grafts. RESULTS: All specimens were assigned scores utilizing the International Cartilage Repair Society grading system. Scoring for chondrocyte viability, cartilage surface morphology, and cell and matrix appearance was significantly higher in the vascularized osteochondral group than in the graft group. CONCLUSIONS: When deprived of subchondral perfusion from underlying bone, osteochondral vascularized flaps in an intrasynovial environment demonstrate superior cartilage quality and survival compared with nonvascularized grafts. CLINICAL RELEVANCE: In locations in which perfusion from surrounding bone may be limited (ie, proximal scaphoid or proximal lunate reconstruction), articular reconstruction using vascularized osteochondral flaps will yield superior cartilage organization and architecture than nonvascularized osteochondral grafts. The clinical and functional relevance of this finding requires further study.

The use of osteochondral flaps in the treatment of carpal disorders.

Vascularized osteochondral flaps have been described for use in reconstruction of the wrist, providing the benefits of osteochondral grafts in addition to the benefit of osseous and subchondral perfusion via the microvascular pedicle. Various harvest sites have been described including the medial and lateral femoral trochlea and the proximal third metatarsal. The reconstructed surfaces described include the cartilage surfaces of the scaphoid, lunate, capitate and radius. The ability to transfer analogous osteochondral surfaces poses the possibility for new motion-preserving alternatives for difficult articular problems previously treated with salvage procedures. A description of the procedures and reported outcomes are provided, as well as a discussion of the role of these procedures in the future of wrist surgery.

Medial Femoral Trochlea Osteochondral Flap: Applications for Scaphoid and Lunate Reconstruction.

Vascularized osteochondral flaps are a new technique described for the reconstruction of challenging articular defects of the carpus. The medial femoral trochlea osteochondral flap is supplied by the descending geniculate artery. This osteochondral flap has shown promise in the treatment of recalcitrant scaphoid proximal pole nonunions and advanced avascular necrosis of the lunate. The anatomy, surgical technique, and results are discussed, with clinical cases provided.

Anatomy of the Vascularized Lateral Femoral Condyle Flap.

BACKGROUND: The perforators of the free lateral femoral condyle flap have yet to be adequately described in humans. Therefore, the authors investigated the perforator vessels of the lateral femoral condyle flap in an anatomical study and discussed potential clinical applications with a particular interest in its indication with vascularized bone and/or iliotibial band for tendon repair surgery. METHODS: The authors dissected thighs of 28 cadavers to evaluate the anatomical properties of perforator vessels that branch from the superior lateral genicular artery and supply bone, cartilage, subcutaneous tissue, and the iliotibial band of the lateral femoral condyle. RESULTS: In each dissected thigh, the superior lateral genicular artery was present and the average pedicle length was 38 ± 10 mm. The average diameter of the superior lateral genicular artery, proximal to its distribution into the deep articular and superficial patellar branches, was 2 ± 0.5 mm. A communication between deep articular and superficial patellar branches was seen in 96 percent of the dissected thighs. In 24 cases (86 percent), the authors were able to show the iliotibial band perforating vessel and harvest a free lateral femoral condyle flap as an osteochondral fasciocutaneous bone flap with vascularized tendon. CONCLUSIONS: Altogether, the authors' results indicate that the blood supply of the lateral femoral condyle flap is consistent and the lateral femoral condyle flap could serve as a free composite flap for complex indications in hand or limb reconstructive surgery. Clinical studies to compare the lateral femoral condyle to other well-established microsurgical free flaps are warranted.

Knee Donor Site Morbidity Following Harvest of Medial Femoral Trochlea Osteochondral Flaps for Carpal Reconstruction.

PURPOSE: This study examines donor site morbidity associated with the medial femoral trochlea (MFT) when used as a donor site for vascularized osteochondral flaps for reconstruction of challenging carpal defects such as proximal pole scaphoid nonunion and advanced Kienböck disease. METHODS: The retrospective study population included all patients who had undergone MFT flap harvest for scaphoid or lunate reconstruction. Chart review, patient questionnaires, and validated knee function assessment tools were used: International Knee Documentation Committee Subjective Knee Form scores ranged from 0 (maximal disability) to 100 (no disability). Western Ontario and McMaster Universities osteoarthritis index scores ranged from 0% (no disability) to 100% (maximal disability). Magnetic resonance imaging and radiographs were obtained on the donor knee on the majority of patients. RESULTS: Questionnaire response rate was 79% (45 of 57 patients). Average patient age was 35 ± 11 years (range, 19-70 years). Average postoperative follow-up was 27 ± 17 months (range, 9-108 months). The indication for MFT flap reconstruction was scaphoid nonunion in 30 patients and Kienböck disease in 15 patients. All 45 patients had a stable knee on examination. Magnetic resonance and radiographic imaging obtained on 35 patients exhibited no pathological changes. Average duration of postoperative pain was 56 ± 59 days (range, 0-360 days); average duration until patients reported the knee returning to normal was 90 ± 60 days (range, 14-360 days). Forty-three of 44 patients would have the same surgery again if needed; overall satisfaction with the surgery was rated as 5 ± 1 (range, 2-5) on a scale from 0 (no satisfaction) to 5 (maximal satisfaction). Average International Knee Documentation Committee score was 96 ± 9 (range, 56.3-100) and the average Western Ontario and McMaster Universities score was 6% ± 16% (range, 0%-68%). CONCLUSIONS: Medial femoral trochlea osteochondral flap harvest results in minimal donor site morbidity in the majority of patients. Symptoms are time limited. Intermediate-term follow-up demonstrates excellent results in subjective outcome measures. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Vein graft thrombi, a niche for smooth muscle cell colonization - a hypothesis to explain the asymmetry of intimal hyperplasia.

UNLABELLED: Essentials Vein graft failure is the most frequent late onset complication of coronary artery bypass grafting. Cuff technique-based interposition mouse model including new anticoagulation regime was conducted. Early vein graft thrombi may serve as a niche for smooth muscle cell colonization. The focal character of early thrombi may form the basis for the asymmetry of intimal hyperplasia. SUMMARY: Background Autologous saphenous veins are widely used in coronary artery bypass grafting; however, 10 years after surgery, 40% of grafts are completely occluded, and another 30% show reduced blood flow. Objective In the past, the central processes and signaling pathways responsible for this loss of patency have been identified. However, one central finding in the process of graft failure is so far not understood: the asymmetric character of intimal hyperplasia. It was the goal of the present study to address this aspect. Methods By the use of a cuff technique-based vein interposition mouse model with a new anticoagulation regime, alterations in vein grafts were analyzed 1 h, 1 day, 2 days, 3 days, 7 days and 21 days after reperfusion by means of immunolabeling, histochemistry, and high-resolution ultrasound. Results The novel and major finding of this study is that the vein graft thrombus may serve as a niche that is infiltrated and colonized by smooth muscle cells (SMCs). Fibroblast growth factor-1 and platelet-derived growth factor-B may be the SMC-attracting factors in the thrombus. The focal character of early thrombi may define the focal and asymmetric character of vein graft intimal hyperplasia. Conclusions Inhibiting the formation and reducing the size of early thrombi is an old concept for reducing vein graft failure. However, in light of the present new findings obtained under a clinic-like anticoagulation regime, early vein graft thrombus prevention/size reduction should be revisited in the prevention of graft failure.

Lateral Femoral Condyle Flap: An Alternative Source of Vascularized Bone From the Distal Femur.

PURPOSE: To elucidate the vascular anatomy of the superolateral geniculate artery (SLGA) and its supply to the periosteum of the lateral femoral condyle (LFC) and to provide guidelines for flap design and describe an illustrative case. METHODS: Thirty-one fresh cadaveric limbs were dissected. The vascular anatomy of the SLGA and its distal branches to skin, muscle, and periosteum were identified. Fluoroscopic images were taken during continuous perfusion of a radiopaque contrast dye into the SLGA. Intra-arterial injections of latex rubber were performed in 12 cadaver limbs. The vascular territory was traced from the SLGA to its distal branches, and surrounding soft tissues were dissected. RESULTS: The SLGA originated from the popliteal artery 4.9 ± 1.2 cm (range, 2.8-7 cm) from the knee joint and its pedicle diameter was 1.8 ± 0.5 mm (range, 1-3 mm). SGLA pedicle-specific fluoroscopic angiography demonstrated a dense filigree of vessels over the lateral distal femur. Arterial latex injections confirmed that the SLGA supplied the periosteum of the LFC and distal femur shaft. The proximal-most extent of periosteal perfusion was 11.7 ± 2.1 cm (range, 9.3-14.1 cm) from the knee joint. The average pedicle length of LFC osteoperiosteal flaps was 4.8 ± 0.9 cm (range, 3.5-6.3 cm). CONCLUSIONS: The LFC flap consistently demonstrated almost 12 cm of femur length perfusion based on the SLGA pedicle. The anatomy of this flap enables chimeric designs combining soft tissue, bone, and cartilage. CLINICAL RELEVANCE: The vascularized LFC flap is an option for reconstruction of osseous defects of the upper extremity.

A Predictive Degree Day Model for the Development of Bactericera cockerelli (Hemiptera: Triozidae) Infesting Solanum tuberosum.

Bactericera cockerelli (Sulc) (Hemiptera: Triozidae) is a pest of potato (Solanum tuberosum L.) that vectors the bacterium that putatively causes zebra chip disease in potatoes, 'Candidatus Liberibacter solanacearum.' Zebra chip disease is managed by controlling populations of B. cockerelli in commercial potato fields. Lacking an integrated pest management strategy, growers have resorted to an intensive chemical control program that may be leading to insecticide-resistant B. cockerelli populations in south Texas and Mexico. To initiate the development of an integrated approach of controlling B. cockerelli, we used constant temperature studies, nonlinear and linear modeling, and field sampling data to determine and validate the degree day parameters for development of B. cockerelli infesting potato. Degree day model predictions for three different B. cockerelli life stages were tested against data collected from pesticide-free plots. The model was most accurate at predicting egg-to-egg and nymph-to-nymph peaks, with less accuracy in predicting adult-to-adult peaks. It is impractical to predict first occurrence of B. cockerelli in potato plantings as adults are present as soon cotyledons break through the soil. Therefore, we suggest integrating the degree day model into current B. cockerelli management practices using a two-phase method. Phase 1 occurs from potato planting through to the first peak in a B. cockerelli field population, which is managed using current practices. Phase 2 begins with the first B. cockerelli population peak and the degree day model is initiated to predict the subsequent population peaks, thus providing growers a tool to proactively manage this pest.

Osteochondral flaps from the distal femur: expanding applications, harvest sites, and indications.

BACKGROUND: The medial and lateral femur provide a source of convex osteochondral vascularized bone. The medial trochlea has been demonstrated to have similar contour to the proximal scaphoid, lunate, and capitate. Other sites of osteochondral harvest such as the posteromedial femur and the lateral trochlea are similar in morphology to the humeral capitellum and medial talus, respectively. These analogous structures offer potential solutions to difficult articular problems. PATIENTS AND METHODS: Patients who underwent osteochondral reconstruction of the extremities were reviewed. These included 16 medial femoral trochlea (MFT) scaphoid nonunion reconstructions, 16 MFT Kienböck lunate reconstructions, 5 MFT capitate reconstructions, 2 lateral femoral trochlea osteochondral reconstructions of medial tarsal avascular necrosis, and 5 posteromedial femoral osteochondral reconstructions of the humeral capitellum for posttraumatic arthritis. RESULTS: Computed tomography (CT) imaging demonstrated 15 of 16 reconstructed scaphoids achieving union. Follow-up wrist motion averaged 46.0 degrees extension and 43.8 degrees flexion, similar to preoperative measurements. CT imaging confirmed healing in 15 of 16 reconstructed lunates. Lichtman staging remained unchanged in 10 patients, improved in 4 patients (3A-2), and worsened in 2 patients (3A-3B). All but one patient experienced improvement in wrist pain. Wrist range of motion at follow-up averaged 50 degrees extension and 38 degrees flexion, similar to preoperative measurements. Capitate, talar, and capitellar reconstructions all resulted in achievement of osseous healing and restoration of joint alignment. CONCLUSIONS: Vascularized osteochondral flaps provide a useful tool in the treatment of difficult articular problems in the extremities. Clinical experience thus far demonstrates a high rate of achieving union with acceptable range of motion and good pain relief.

Vascularized medial femoral trochlea osteochondral flap reconstruction of advanced Kienböck disease.

PURPOSE: To describe the operative technique and report the results of 16 consecutive cases of arthroplasty for advanced Kienböck disease using a vascularized osteochondral graft from the medial femoral trochlea (MFT) with a minimum 12-month follow-up. METHODS: Chart reviews of 16 cases of osteochondral MFT flap transfers for lunate reconstruction were performed in 2 institutions. Mean patient age was 35 years (range, 19-51 y). Preoperative Lichtman staging was 2 in 7 patients, 3a in 8 patients, and 3b in 1. Five of 16 patients had undergone a previous procedure for Kienböck disease (3 radial shortening osteotomies, 1 wrist denervation, and 1 distal radius vascularized bone grafting). Ulnar variance recorded at the time of the MFT reconstruction was negative in 8 patients, positive in 6 patients, and neutral in 2 patients. Follow-up data were recorded at a minimum of 12 months (average, 19 mo). Radiographic parameters recorded included preoperative ulnar variance, preoperative and final follow-up radioscaphoid angle, lunate height, lunate diameter, and the Stahl index and Lichtman stage. RESULTS: Healing was confirmed in 15 of 16 reconstructed lunates. Lichtman staging remained unchanged in 10 patients, improved in 4 patients from grade 3a and 3b to 2, and worsened in 2 patients from grade 3a to 3b. All but 1 patient experienced improvement in wrist pain (12/16 complete relief; 3/16 incomplete relief). Wrist motion at follow-up averaged 50° extension and 38° flexion, similar to preoperative measurements. Grip strength at follow-up was 85% of the contralateral side. CONCLUSIONS: Osteochondral vascularized MFT flaps provided a reliable means of lunate reconstruction in advanced Kienböck disease. This flap allowed resection of the proximal portion of the collapsed lunate and reconstruction with an anatomically analogous convex segment of vascularized cartilage-bearing bone. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Vascularized medial femoral trochlea osteocartilaginous flap reconstruction of proximal pole scaphoid nonunions.

PURPOSE: The descending geniculate artery's branching pattern includes periosteal vessels supplying the cartilage-bearing trochlea of the medial patellofemoral joint. Previous cadaveric studies described anatomic similarities between the greater curvature of the proximal scaphoid and the convex surface of the medial femoral trochlea (MFT). We describe the technique and report our first 16 consecutive cases of vascularized osteocartilaginous arthroplasty for chronic scaphoid proximal pole nonunions using the MFT, with a minimum of 6 months of follow-up. METHODS: Chart reviews of 16 consecutive cases of osteocartilaginous MFT flap transfers for scaphoid reconstruction were performed at 2 institutions. Follow-up data were recorded at a minimum of 6 months, with an average of 14 months (range, 6-72 mo). Patient age and sex, duration of nonunion, number of previous surgical procedures, surgical technique, achievement of osseous union, preoperative and postoperative scapholunate angles, preoperative and postoperative range of motion, and pain relief were recorded. RESULTS: Computed tomography imaging confirmed healing in 15 of 16 reconstructed scaphoids. Mean patient age was 30 years (range, 18-47 y). The average number of previous surgical procedures was 1 (range, 0-3). All patients experienced some wrist pain improvement (12/16 complete relief, 4/16 incomplete relief). Wrist range of motion at follow-up averaged 46° extension (range, 28° to 80°) and 44° flexion (range, 10° to 80°), which was similar to preoperative measurements (average 46° extension and 43° flexion). Scapholunate relationship remained unchanged with average scapholunate angles of 52° before surgery and 49° after surgery. CONCLUSIONS: Osteochondral vascularized MFT flaps provide a reliable means of achieving resolution of difficult proximal pole scaphoid nonunions. These flaps allow resection of the proximal portion of the unhealed scaphoid and reconstruction with an anatomically analogous convex segment of cartilage-bearing bone. This technique provides the advantages of vascularized bone and ease of fixation. Early follow-up demonstrates a high rate of union with acceptable motion and pain relief. CLINICAL RELEVANCE: Early follow-up suggests that the vascularized MFT osteocartilaginous flap is a valuable tool for treating challenging proximal pole scaphoid nonunions.

Epitaxial cobalt oxide films on Ir(100)-the importance of crystallographic analyses.

Epitaxial cobalt oxide films on Ir(100) exhibit a rich scenario of different structural phases which are reviewed in this paper. The great majority of phases could be, as a rare case, crystallographically described by the joint application of atomically resolved STM and quantitative LEED, whereby structural surprises were more the rule than the exception. So, the oxide grows in the polar (111) orientation for both the Co3O4 and CoO stoichiometry on the bare Ir substrate in spite of the latter's square symmetry. Moreover, the film orientation can be tuned to non-polar (100) growth when one or several pseudomorphic Co layers are introduced as an interface between oxide and Ir substrate. By using the nanostructured Ir(100)-(5 × 1)-H phase as a template a nanostructured Co film can be formed whose oxidation leads to a nanostructured oxide. The nominally polar films circumvent the polarity problem by appropriate surface terminations. That of CoO(111) is, again as a surprise, realized by a switch from rocksalt-type to wurtzite-type stacking near the surface, by which the latter becomes metallic. The stepwise oxidation of a pseudomorphic Co layer on the bare Ir substrate leads to the sequential formation of rocksalt-type tetrahedral Co-O building blocks (with intermediate BN-type blocks) whereby the Co species more and more assume positions determined by the inner-oxidic binding.

HHV8-Negative Primary Effusion Lymphoma of B-Cell Lineage: Two Cases and a Comprehensive Review of the Literature.

Primary effusion lymphoma (PEL) is a rare extranodal lymphoma that typically presents in a body cavity in the absence of a detectable tumor mass and that occurs predominantly in immunosuppressed individuals. The neoplastic lymphoid cells are frequently infected with human herpes virus 8 (HHV8), also known as Kaposi sarcoma herpes virus (KSHV). We describe two HIV-negative patients who presented with primary effusion lymphoma of B-cell lineage involving the pleural cavity, but whose tumor cells lacked infection by HHV8. We review the English language literature of HHV8-negative PEL of B-cell lineage and compare these lymphomas to HHV8-associated PEL with regard to clinical and pathological characteristics, therapy, and outcome.

Safety status of farm tractors that operate on public highways in four rural Kentucky counties.

Kentucky FFA students inspected 153 farm tractors for safety features that prevent operator injuries during tractor overturns, highway collisions, runovers, and power take-off (PTO) entanglements. Tractor mean age was 23.6 years (SD = 20.9). Rollover protective structures (ROPS) were present on 50.66% of tractors, but only 33.33% of these had functional seatbelts. Loose and damaged seats were found on 30.46% of tractors. In 38.99% of cases, tractor rear-wheel fenders exposed operators to moving tractor tires, and 48.67% of tractors had dangerously worn or damaged tires. Tractors with a narrow front-end stance comprised 16.11% of the total. Only 53.06% of the tractors had starters with secure hard cover by-pass starting shields that fully covered the starter terminals, and 37.37% had fully exposed terminals with no cover. PTO master shields with all parts present and undamaged were present on only 29.27% of the tractors, and in 39.02% of cases the entire shield was missing. Only 44.67% of the tractors had properly mounted and fully functional mounting and dismounting access steps and handholds. SMV emblems were missing on 53.64% of tractors and in the proper place and condition in only 25.83% of cases. Tractors with properly mounted and fully functional head and tail lights comprised 40.94% of the sample, and tractors with no functional lights comprised 24.16%. Properly mounted, clean, and functional rearview mirrors were present on only 19.87% of the tractors, and 69.54% had no rearview mirrors. The project increased farming and non-farming students' awareness of tractor safety issues, provided empirical data about the safety status of a sample of tractors that frequently travel public highways in four rural Kentucky farming counties, and promoted dialog about these issues with adult farmers and other community members with whom the students interacted.

Phases and phase transitions of hexagonal cobalt oxide films on Ir(100)-(1 × 1).

Cobalt oxides on the unreconstructed Ir(100) surface were prepared by reactive deposition of Co established by simultaneous oxygen flux at about 50 °C and subsequent annealing. The films were investigated by low-energy electron diffraction (LEED), scanning tunnelling microscopy (STM) and thermal desorption spectroscopy (TDS). We show that in spite of the quadratic unit mesh of the substrate, oxide films of (111) orientation develop. As long as oxygen-rich conditions are maintained they are of spinel-type Co(3)O(4)(111). They are non-pseudomorphic and transform to rocksalt-type CoO(111) when oxygen loss is induced by annealing at elevated temperatures. Thin films of CoO(111) are commensurate, and so, in order to realize that, they exhibit a slightly distorted unit cell when below a thickness equivalent to about seven cobalt monolayers. With increasing film thickness the uniaxial strain accompanied by the commensurability is gradually relieved by the insertion of dislocations so that eventually the film assumes ideal hexagonality. All CoO(111)-type surfaces are reconstructed at low sample temperatures equivalent to a [Formula: see text] superstructure. They reversibly transform into a (1 × 1) phase at about 50 °C.