The tissue distribution of Evans blue dye in a sheep model of sentinel node biopsy

BACKGROUND: Tc-Evans blue is a 'single dose' agent for lymphatic mapping combining radioactivity and blue dye for sentinel node identification. The mechanism and distribution of blue dye retention in the lymph node is not clearly understood. OBJECTIVE: To demonstrate the cellular distribution of Tc-Evans blue in sheep sentinel lymph nodes by measuring the radioactivity of different tissue components and correlating this with pathological examination. METHODS: Tc-Evans blue was used to identify sheep lymph nodes. Part of each node was sent for pathological examination including imprint cytology, and frozen and permanent section examination. Sections were examined without stains, with only red stains and conventional haematoxylin & eosin staining. The remaining nodal tissue was homogenized and components separated by enzymatic digestion and density gradient centrifugation. Fractions representing each tissue component were counted in a gamma counter and the distribution of Tc-Evans blue calculated. RESULTS: A dispersed population of blue staining cells was found. Their distribution, number and size indicated that they were histiocytes such as macrophages or antigen presenting cells. Radioactivity was distributed throughout the lymph node. Over 70% remained in the plasma, 19% in the leukocyte layer, and 10% was associated with erythrocytes and undigested tissue. CONCLUSION: The accumulation of radioactivity and blue colour in the lymph nodes indicates the mechanism of retention is a result of the binding interaction between Tc-Evans blue-protein and lymph node histiocytes including macrophages and antigen presenting cells.     

Implant site development: clinical realities of today and the prospects of tissue engineering

The success of dental implants depends on their placement in bone of adequate density and volume in order to achieve primary stability. Optimal esthetics of implants requires their placement in a position approximating that of the natural teeth they replace. However, there is generally at least some degree of atrophy in the sites where implants are to be placed. This atrophy may occur either before or after tooth extraction. Following extraction of teeth, there is commonly alveolar ridge resorption in horizontal and vertical dimensions. Alternatively, some of the oral hard and soft tissues may be destroyed by pathologic conditions such as periodontitis, endodontic infections, or trauma. All of these conditions may potentially compromise the final esthetics and function of implant-supported restorations. During the initial years of the development of the osseointegration protocol, implants were placed with little or no modification of implant sites. Though osseointegration was successfully achieved, esthetic outcome was not a primary objective of therapy at that time. A gradual paradigm shift has occurred in implant dentistry from merely achieving successful osseointegration to achieving final restorative outcomes that mimic natural dentition and their surrounding oral tissues. These objectives have been materialized by advancements in surgical techniques, as well as availability of biomaterials to enable predictable regeneration of oral hard and soft tissues. The objective of the present review is to briefly discuss some of the techniques that are currently available for implant site development.     

Postoperative CT scans after resection of brain metastases: neurosurgical routine or added value?

Journal of Neuro-Oncology - Metastasis is the most common brain tumor in adults. It is the standard of care at most North American centers to obtain an early postoperative imaging after their...     

Cataract secondary to electrical shock from a Taser gun

A 35-year-old man presented with traumatic iritis, angle-recession glaucoma, and a retinal dialysis secondary to blunt trauma from a Taser gun in the right eye and a unique electrical cataract in the left eye. Taser guns, which can also function as stun guns, can lead to electrical cataract formation. Given the increasing use of Taser guns by law enforcement and citizens, blunt mechanical and electrical sequelae of Taser gun injuries should be recognized.     

A molecularly integrated grade for meningioma

BackgroundMeningiomas are the most common primary intracranial tumor in adults. Clinical care is currently guided by the World Health Organization (WHO) grade assigned to meningiomas, a 3-tiered grading system based on histopathology features, as well as extent of surgical resection. Clinical behavior, however, often fails to conform to the WHO grade. Additional prognostic information is needed to optimize patient management.MethodsWe evaluated whether chromosomal copy-number data improved prediction of time-to-recurrence for patients with meningioma who were treated with surgery, relative to the WHO schema. The models were developed using Cox proportional hazards, random survival forest, and gradient boosting in a discovery cohort of 527 meningioma patients and validated in 2 independent cohorts of 172 meningioma patients characterized by orthogonal genomic platforms.ResultsWe developed a 3-tiered grading scheme (Integrated Grades 1-3), which incorporated mitotic count and loss of chromosome 1p, 3p, 4, 6, 10, 14q, 18, 19, or CDKN2A. 32% of meningiomas reclassified to either a lower-risk or higher-risk Integrated Grade compared to their assigned WHO grade. The Integrated Grade more accurately identified meningioma patients at risk for recurrence, relative to the WHO grade, as determined by time-dependent area under the curve, average precision, and the Brier score.ConclusionWe propose a molecularly integrated grading scheme for meningiomas that significantly improves upon the current WHO grading system in prediction of progression-free survival. This framework can be broadly adopted by clinicians with relative ease using widely available genomic technologies and presents an advance in the care of meningioma patients.     

Pseudoangiomatous stromal hyperplasia of the breast: A case report

Pseudoangiomatous stromal hyperplasia (PASH) is a rare benign breast entity scarcely reported in the medical literature. Its pathogenesis, etiology, and optimal treatment are still unknown. PASH tumors have a broad spectrum of clinical presentations and might be mistaken for malignancies. The authors present six patients diagnosed with PASH.