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Biomedical subjects

George W Elgart

Publications and source records attributed to George W Elgart.

12 recordsLinked to original sources
PubMed2006

Molecular cloning of Chinese hamster 1q31 chromosomal fragile site DNA that is important to mdr1 gene amplification reveals a novel gene whose expression is associated with spermatocyte and adipocyte differentiation.

DNA amplification plays important roles in the development of drug resistance and tumor progression. One mechanism of DNA amplification involves the breakage-fusion-bridge (BFB) cycle. We previously reported that in Chinese hamster ovary (CHO) cell line, breakage at fragile site 1q31 was associated with mdr1 gene amplification through the BFB mechanism. To elucidate the molecular basis of BFB-mediated DNA amplification, we cloned 1q31 fragile site DNA from a Chinese hamster cell line containing an integrated neomycin-resistance marker. Sequence analyses revealed many characteristics similar to those in other common fragile sites. Moreover, this fragile site contains an evolutionarily conserved novel gene, designated fragile site-associated (FSA) gene. FSA encodes a approximately 16-kb mRNA, from which an unusually large open reading frame (orf) of 5005 amino acids can be deduced. The C-terminal portion of FSA shares a striking sequence similarity to that of Caenorhabditi elegans lipid depleted-3 (lpd-3) gene whose function has been demonstrated to involve in lipid storage. We also demonstrated that expression of FSA is associated with the developmental programs of spermatogenesis and adipogenesis. Our results suggest that the Chinese hamster 1q31 fragile site has many important functions including regulation of mdr1 amplification and differentiation of adipocytes and spermatocytes.

Adipocytes↗
PubMed2006

High proliferative activity excludes dermatofibroma: report of the utility of MIB-1 in the differential diagnosis of selected fibrohistiocytic tumors.

CONTEXT: Dermatofibroma is a benign fibrohistiocytic tumor composed of a mixture of fibroblastic and histiocytic cells. The diagnosis of this tumor is generally uncomplicated; however, rare variants may be difficult to distinguish from malignant fibrohistiocytic tumors. Deep penetrating dermatofibroma may be difficult to distinguish from dermatofibrosarcoma protuberans, and pseudosarcomatous dermatofibroma and dermatofibroma with monster giant cells share morphologic similarities with malignant fibrous histiocytoma and atypical fibroxanthoma. OBJECTIVE: To find an immunohistochemical marker or markers that differentiate between fibrohistiocytic lesions of skin. DESIGN: We evaluated the immunophenotypic characteristics of 83 fibrohistiocytic tumors (36 typical dermatofibromas, 16 cases of dermatofibrosarcoma protuberans, 16 malignant fibrous histiocytomas, and 15 atypical fibroxanthomas) using antibodies against MIB-1 (Ki-67), factor XIIIa, CD34 (HPCA-1), HHF35 (muscle-specific actin), 1A4 (smooth muscle actin), cytokeratin (AE1/AE3, CAM 5.2, and 34betaE12), S100 protein, and desmin. RESULTS: A high proliferative index detected by MIB-1 staining excluded the possibility of dermatofibroma and was diagnostically useful in separating this entity from dermatofibrosarcoma protuberans, malignant fibrous histiocytoma, and atypical fibroxanthoma. A low proliferative index, however, could not differentiate dermatofibroma from dermatofibrosarcoma protuberans. Factor XIIIa reactivity was not helpful for the diagnosis of dermatofibroma, whereas CD34 reactivity was statistically significant in the diagnosis of dermatofibrosarcoma protuberans. The sensitivity of these 2 markers is low and therefore of questionable practical diagnostic value. CONCLUSION: Evaluation of the proliferative index may further assist in distinguishing dermatofibroma from dermatofibrosarcoma protuberans, atypical fibroxanthoma, and malignant fibrous histiocytoma.

Biomarkers, Tumor↗
PubMed2005

Accuracy and predictors of basal cell carcinoma diagnosis.

BACKGROUND: Basal cell carcinoma (BCC) is the most common cancer in the United States. Therefore, prospective assessment of dermatologists' acumen in diagnosing BCC is important but, unfortunately, is lacking. OBJECTIVE. We sought to determine the positive predictive value (PPV) for clinically diagnosing BCC based on how confident the physician is of the diagnosis. We also sought to determine which clinical and historical factors most influence a dermatologist's perception that a tumor is a BCC and to determine which factors are correlated with a lesion being a BCC. METHODS: Dermatology attending faculty at the University of Miami performing biopsies on their patients in whom BCC was a consideration were asked to complete a questionnaire. They recorded how confident they were of their clinical diagnosis of BCC. They also recorded various clinical and historical factors about the patients and the lesions biopsied. RESULTS: The PPV for clinically diagnosing BCC when the clinician was most confident was 80%. Age (> 64 years) and the presence of pigmentation, telangiectasias, and a pearly border were statistically associated with a greater confidence level and a histologic diagnosis of BCC. Sunscreen use was associated with fewer diagnoses of BCCs. CONCLUSION: This is the first study to determine a relevant PPV for the clinical diagnosis of BCC because the PPV was based on clinical confidence level. These results highlight the role of diagnostic biopsies, could improve patient referral, and may help increase the PPV in the future.

Adult↗
PubMed2004

Documenting dermatology practice: ratio of cutaneous tumors biopsied that are malignant.

BACKGROUND: Skin biopsy is an important part of dermatology practice. Little is known regarding dermatologist biopsying practices. OBJECTIVE: The objective was to assess the ratio of malignant lesions biopsied in practice and factors that influence this ratio. METHODS: Using a dermatopathology database, we analyzed tumors biopsied by dermatologists to determine the ratio of malignant to all tumors (malignancy ratio). Additional analyses were performed for factors influencing this ratio. RESULTS: Over 6 months, 11,072 tumors were submitted. Overall, the malignancy ratio was 41.7%, 3.8% for pigmented lesions. Practice type, location, or use of dermatoscopy did not influence this ratio; provider age was positively correlated with a higher malignancy ratio (r=0.51; p=0.02) and was a predictor of malignancy ratio (b=0.02; p=0.04). CONCLUSION: Approximately 40% of biopsied tumors were malignant. Dermatologists exhibit a wide range in their individual practice patterns. Increasing provider age predicted higher malignancy ratios with a 2% increase for each incremental year.

Biopsy↗
PubMed2003

Axillary polymastia.

"Polymastia" is a term used to describe the presence of more than 2 breasts in human beings. It is synonymous with supernumerary or accessory breast tissue. Accessory breast tissue has the potential to undergo the same benign and malignant changes as normal pectoral breast tissue.

Adult↗
PubMed2003

Ivermectin.

Ivermectin is a potent antiparasitic drug and the first commercially available member of a new class of drugs (macrocyclic lactones) that has been approved for human use. Ivermectin has already proven to be highly effective in the elimination of river blindness as a public health burden. Side effects have been minor, and patient acceptance is good. Promising results in off-label applications for ectoparasitic infestations are increasingly important as resistance to topical therapy becomes more prevalent Ivermectin represents an advance in the therapeutic armamentarium and should be considered in appropriate cases.

Antiparasitic Agents↗
PubMed2003

585-nm pulsed dye laser in the treatment of surgical scars starting on the suture removal day.

BACKGROUND: The optimal time frame to improve the quality and cosmetic appearance of scars by laser therapy has not been clearly elucidated by prior controlled clinical trials. OBJECTIVE: To determine the efficacy of the 585-nm pulsed dye laser (PDL) in the treatment of surgical scars starting on the day of suture removal. METHODS: Eleven patients (skin types I-IV) with 12 postoperative linear scars that were greater than 2 cm were treated three times on monthly intervals with the 585-nm PDL (450 micro s, 10-mm spot size, 3.5 J/cm2 with 10% overlap) on one scar half, whereas the other half received no treatment. Scars were later evaluated by a blinded examiner using the Vancouver Scar Scale (VSS) for pigmentation, vascularity, pliability, and height. Scars were then blindly examined for cosmetic appearance using a visual analog scale. RESULTS: One month after the last treatment, final scar analysis by the blinded examiner revealed a significant difference between treated and untreated sites, with the treated halves scoring better in all scar parameters in the VSS and in cosmetic appearance. The treated halves demonstrated an overall average improvement in the VSS between the first treatment score and the final score of 54% versus 10% in the controls (P=0.0002). The cosmetic appearance score (0=worst; 10=best) at final assessment was significantly better for the treated scars, scoring 7.3 versus the averaged control score of 5.2 (P=0.016). CONCLUSION: The 585-nm PDL is effective and safe in improving the quality and cosmetic appearance of surgical scars in skin types I-IV starting on the day of suture removal.

Adult↗
PubMed2003

Blau syndrome: a new kindred.

Blau syndrome is a rare condition typically defined by granulomatous arthritis, skin eruption, and uveitis occurring in the absence of lung or other visceral involvement. Other characteristic physical findings include synovial cysts and camptodactyly. We describe a new kindred demonstrating autosomal dominant inheritance and anticipation.

Adolescent↗
PubMed2003

Dermoscopy for congenital melanocytic nevi.

Small and medium congenital melanocytic nevi are relatively common but present a small but significant risk of malignant transformation. Because prophylactic excision of all nevi is impractical, dermoscopic evaluation has a role in the clinical decision-making process. Dermoscopy of benign congenital nevi reveals a globular or homogenous pattern, black or brown dots and globules, small milia-like cysts within the globules, and terminal hairs. Dermoscopic criteria of melanoma are outlined here, with discussion of common scoring methods, the seven-point checklist, the ABCD rule, pattern analysis, and the Menzies criteria. Serial examination of congenital nevi with dermoscopy and excision of those lesions with malignant criteria are useful in the management of congenital melanocytic nevi.

Cell Transformation, Neoplastic↗
PubMed2003

Necrobiotic xanthogranuloma associated with a benign monoclonal gammopathy.

Necrobiotic xanthogranuloma (NXG) is a disorder characterized by indurated, yellow-red nodules or plaques, primarily involving the face and, less frequently, the trunk and extremities. NXG may be associated with paraproteinemia, multiple myeloma, and hypertension. Histologically, xanthogranulomatous features with hyaline necrosis or necrobiosis are present. No first-line treatment has been established. This disease is a chronic process, and a patient's prognosis depends on the degree of extracutaneous involvement and the presence of visceral malignancies. We describe a patient with typical cutaneous and histologic findings of NXG with an associated monoclonal gammopathy.

Biopsy, Needle↗