Composite polysaccharide fibers prepared by electrospinning and coating

Composite polysaccharide fibers composed two oppositely charged natural polysaccharides, chitosan and hyaluronic acid, were prepared by electrospinning and subsequent coating. The fiber size distribution was characterized by scanning electron microscopy. Chitosan/hyaluronic acid composite fibers were stable in water but showed controlled release of hyaluronic acid into phosphate buffered saline, and the presence of 3-wt% hyaluronic acid coating improved the swelling ratio to 30%. The resulting composite polysaccharide fibers have a number of potential biomedical applications in wound healing applications and in drug delivery systems.

Quantification of lumbar nerve root decompression using somatosensory-evoked potentials

Intraoperative somatosensory-evoked potential (SSEP) data were collected prospectively in a consecutive series of patients with an acute lumbar herniated nucleus pulposus (HNP). Each patient underwent an open limited diskectomy, hemilaminotomy, and partial foraminotomy. The sequence of diskectomy and bony decompression was randomized, and the extent of foraminotomy was standardized. SSEP data were recorded after each operative procedure and were coded for blind interpretation. SSEP tracings were compared with each patient's baseline for changes in latency and amplitude. In the overall study, changes in amplitude and latency produced by diskectomy versus bony decompression were not statistically significant. In the six patients with lateral recess stenosis (LRS), a statistically significant reduction in latency was observed after bony decompression (averaging -2.05 ms) compared with diskectomy (-0.62 ms). In patients with underlying LRS and a HNP, minimally invasive techniques addressing the disc only may be inadequate to decompress a lumbar nerve root.

Case report 749: Primary glomus tumor of bone

We report a case of primary intraosseous glomus tumor in a 30-year-old man who was found to have an expanding, lytic lesion in the distal phalanx of his left thumb. The histological appearance was atypical in that areas of myxoid stroma resembled chondroid material. The unusual location and microscopic appearance caused diagnostic problems. Immunohistochemical studies, including strong positive staining for MSA and negative staining for keratin and S-100 protein, were helpful in establishing the correct diagnosis.

Fine-needle aspiration biopsy of malignant melanoma: a cytologic and immunocytochemical analysis

The immunoreactivity of alcohol-fixed cell blocks from 15 fine-needle aspiration (FNA) specimens of malignant melanoma was investigated using monoclonal antibodies to keratin and vimentin intermediate filaments, melanoma cytoplasmic antigen (HMB-45), and S-100, as well as polyclonal antibodies to S-100. The results were compared with the immunoprofiles obtained using formalin-fixed surgical specimens from 10 of the same patients. In all cases, immunostaining for keratin was negative and immunostaining for vimentin was positive. Immunostaining for HMB-45 was positive in 13/15 aspirates and in 9/10 surgical specimens. Immunostaining for S-100 protein showed the greatest variability in staining, with 5/15 fine needle aspiration biopsies and 9/10 surgical specimens being positive using the polyclonal antibody and only 1/15 FNA specimens and 7/10 surgical specimens being positive using the monoclonal S-100 reagent. Our findings indicate that immunocytochemical studies can be very useful as an adjunct in the FNA diagnosis of melanoma. Also included in our series is an unusual variant of malignant melanoma, the so-called signet ring melanoma. Given the location of the anal verge, the use of immunocytochemical markers was essential in establishing the correct diagnosis in this case. While S-100 protein is of limited value as a marker of melanoma in alcohol-fixed FNA specimens, a definitive diagnosis of malignant melanoma can be made using a panel of antibodies including keratin, vimentin, and HMB-45.

Malignant melanoma metastatic to the ovary

The clinical and pathologic features of 10 patients with malignant melanoma metastatic to the ovary were studied. Seven were from surgical patients who presented with possible primary ovarian neoplasms and three were autopsy cases. Six had unilateral involvement, and all but one of the metastases were grossly cystic. Two predominant histologic patterns were identified: the more common (six cases) consisted of small oval to spindle-shaped cells with inconspicuous or absent melanin pigment and a focal storiform architecture. Three of these six were initially misinterpreted as ovarian stromal neoplasms. The other four tumors had large epithelioid cells with abundant cytoplasm and melanin pigment, and were readily classified as metastatic melanoma. Six of the seven surgical cases were reactive with antibodies to S-100 protein and vimentin but nonreactive with antibodies to keratin.