Two cases of chronic knee pain caused by unusual injuries to the popliteus tendon.

Injuries to the popliteus tendon are less frequent than injuries to the menisci or ligamentous structures of the knee. When they do occur, injuries to the popliteus tendon tend to be the result of trauma and associated with injuries to other components of the knee. The most commonly seen injuries include tears at the musculotendinous junction and avulsion tears at the lateral femoral condyle insertion site. This report presents two unusual injuries of the popliteus tendon in patients with chronic knee pain: an isolated split tear of the tendon and a subluxed tendon residing within the lateral joint space.

Gorham-Stout disease presenting with dyspnea and bone pain in a 9-year-old girl.

Gorham-Stout (GS) disease is a rare bone disorder of unknown etiology that is characterized by local proliferation of small vascular or lymphatic channels, resulting in progressive osteolysis and bone resorption. The diagnosis of GS disease is one of exclusion, with radiography and histopathology playing key roles. We describe a 9-year-old girl who presented to us with dyspnea and bone pain. She was found to have a cystic mass of the upper extremity, multiple cystic bone lesions, multiple fractures of different ages, and pleural effusions. We review the radiologic images that helped establish the diagnosis of GS disease.

Hyperparathyroidism and hungry bone syndrome revisited.

A 36-year-old woman presented with a calcium level of 15.7 mg/dL (normal, 8.5-11.0 mg/dL) and an extremely elevated parathyroid hormone level of 1549.6 pg/mL (normal, 10.0-65.0 pg/ mL). She subsequently underwent a parathyroid scan and ultrasound evaluation, which suggested parathyroid carcinoma. Biopsy of a lytic lesion in her left iliac bone was performed because of concern for metastatic disease but revealed a brown tumor. The patient then underwent parathyroidectomy. The patient's postsurgical course was complicated by protracted symptomatic hypocalcemia consistent with hungry bone syndrome.

Imaging of disorders affecting the bone and skin.

There are a variety of conditions that manifest not only in bone but also in skin. Bone and skin structures can share common embryologic origins, and genetic defects that occur early in cell differentiation may lead to disease in both organ systems. Alternatively, diseases of bone and skin may be caused by defects in genes that participate in directing or controlling both systems. Many diseases of bone and skin can manifest with atypical radiologic findings or mimic malignant bone lesions. Upon encountering such a disease process, a radiologist who is familiar with both aspects of the disorder and consequently looks for associated skin findings can greatly benefit the patient by making a definitive diagnosis. Similarly, a clinician who encounters suggestive skin lesions should be prompted to look for concomitant skeletal lesions. By synthesizing knowledge of bone and skin manifestations, radiologists and clinicians can help correctly diagnose a number of these disease processes, thereby helping patients avoid further, often nonspecific invasive workup and advancing patient care.

Radiographic findings of Proteus Syndrome.

The extremely rare Proteus Syndrome is a hamartomatous congenital syndrome with substantial variability between clinical patient presentations. The diagnostic criteria consist of a multitude of clinical findings including hemihypertrophy, macrodactyly, epidermal nevi, subcutaneous hamartomatous tumors, and bony abnormalities. These clinical findings correlate with striking radiographic findings.

Knowledge, stigma, and behavioral outcomes among antiretroviral therapy patients exposed to Nalamdana's radio and theater program in Tamil Nadu, India.

Arts-based programs have improved HIV-related knowledge, attitudes, and behavior in general and at-risk populations. With HIV transformed into a chronic condition, this study compares patients at consecutive stages of receiving antiretroviral treatment, coinciding with exposure to a radio-and-theater-based educational program (unexposed [N = 120], just exposed [N = 77], Exposed a month ago [N = 60]). Exposure was associated with significantly higher HIV-related knowledge (15-20%, all p < .01), lower levels of stigma (2-7% lower, all p < .10), and over four times the adjusted odds of asking doctors questions about HIV (p = .07). Higher dose of exposure was associated with lower felt stigma (28% reduction per message recalled), greater odds of consistent condom use (adjusted odds ratio [AOR]: 1.12, p = .01), doctor-patient communication (AOR: 1.20, p = .003), peer advice-giving (AOR: 1.18, p = .03) and HIV-related advocacy (AOR: 2.35, p = .07). Similar partnerships between arts-based nongovernmental organizations and government hospitals may improve patient outcomes in HIV treatment settings.

Selection of hyperfunctional siRNAs with improved potency and specificity.

One critical step in RNA interference (RNAi) experiments is to design small interfering RNAs (siRNAs) that can greatly reduce the expression of the target transcripts, but not of other unintended targets. Although various statistical and computational approaches have been attempted, this remains a challenge facing RNAi researchers. Here, we present a new experimentally validated method for siRNA design. By analyzing public siRNA data and focusing on hyperfunctional siRNAs, we identified a set of sequence features as potency selection criteria to build an siRNA design algorithm with support vector machines. Additional bioinformatics filters were also included in the algorithm to increase RNAi specificity by reducing potential sequence cross-hybridization or microRNA-like effects. Independent validation experiments were performed, which indicated that the newly designed siRNAs have significantly improved performance, and worked effectively even at low concentrations. Furthermore, our cell-based studies demonstrated that the siRNA off-target effects were significantly reduced when the siRNAs were delivered into cells at the 3 nM concentration compared to 30 nM. Thus, the capability of our new design program to select highly potent siRNAs also renders increased RNAi specificity because these siRNAs can be used at a much lower concentration. The siRNA design web server is available at http://www5.appliedbiosystems.com/tools/siDesign/.

Ganglion Cyst of the Anterior Cruciate Ligament.

We present the case of a 55-year-old woman with a presumed ganglion cyst associated with the anterior cruciate ligament (ACL), demonstrated by MRI. The ACL is an uncommon location for ganglion cysts to occur.

Stump Entrapment of the Torn Anterior Cruciate Ligament.

We present a case of anterior cruciate ligament stump entrapment in a 24-year-old gentleman who traumatically injured his knee. The anterior stump became entrapped in the intercondylar notch and after a process of inflammation and fibrosis, produced a mass similar to the more familiar cyclops lesion that may complicate anterior cruciate ligament reconstruction.

LNA incorporated siRNAs exhibit lower off-target effects compared to 2'-OMethoxy in cell phenotypic assays and microarray analysis.

Despite the promise of short interfering RNAs (siRNA), contending with off-target is a challenge for RNAi users. To alleviate these problems, we have developed locked nucleic acid (LNA) modified siRNAs and optimized performance using cellular phenotypic assays as well as microarray analysis. During development, we compared LNA and 2'OMethoxy (2'OMe) chemistries placed strategically throughout the siRNA molecule and found a novel pattern of LNA placement that greatly improved the specificity of the siRNA and reduced it's toxicity in culture while preserving the potency of the siRNA. The improvements in specificity made by LNA-modified siRNAs were developed and validated by measuring the phenotypic signatures in a high content cell-based screening assay as well as comparison of the level of differentially expressed genes observed in microarray analysis between modified and unmodified siRNAs. HT screening of a collection of genes demonstrated that the LNA-modified siRNAs exhibits the best overall rate to elicit the expected phenotype, reduced toxicity and achieved an improved coherence of phenotype compared to 2'OMe-modified or unmodified siRNAs.

Lipoma Arborescens of the Knee in a 17-Year-Old Man.

We present a case of lipoma arborescens of the knee in a 17-year-old man, discuss its characteristic imaging findings, and review the relevant differential diagnoses.