Catalysis-based specific detection and inhibition of tyrosinase and their application / 药物分析学报

Tyrosinase is an important enzyme in controlling the formation of melanin in melanosome, and plays a key role in the pigmentation of hair and skin. The abnormal expression or activation of tyrosinase is associated with several diseases such as albinism, vitiligo, melanoma and Parkinson disease. Excessive deposition of melanin could cause diseases such as freckles and brown spots in the human body, and it is also closely related to browning of fruits and vegetables and insect molting. Detecting and inhibiting the activity of tyrosinase is of extraordinary value in the progress of diagnosis and treatment of these dis-eases. Therefore, many selective optical detection probes and small molecular inhibitors have been developed, and have made significant contributions to the basic and clinical research on these diseases. In this paper, the detection and inhibition of tyrosinase and their application in whitening products are reviewed, with special emphasis on development of fluorescent probes and inhibitors. Hopefully, this review will help design more efficient and sensitive tyrosinase probes and inhibitors, as well as shed light on novel treatment of diseases such as melanoma.

Sentinel Node Biopsy in Breast Cancer Using a Gamma-detection Probe

PURPOSE: Sentinel lymph node (SLN) biopsy has emerged as a substitute for a conventional axillary lymph node (ALN) dissection in early breast carcinomas. We evaluated SLN biopsy in breast carcinoma using a gamma-detection probe in order to identify its accuracy as a staging procedure for lymph node status. METHODS: Fifty-one patients with breast carcinomas who underwent a SLN biopsy followed by an ALN dissection between June 1999 and January 2001 were evaluated. Tc 99m antimony trisulfide colloid was used as a tracer and SLN biopsy using a gamma-detection probe was done following breast lymphoscintigraphy. Intraoperative imprint cytology (II C) was done for each SLN. If a SLN biopsy was free of metastasis by permanent hematoxylin and eosin (H&E) staining, immun ohistochemical (IHC) staining using pan-cytokeratin was do ne to detect micrometastasis. RESULTS: ALN metastases were identified in 21.6% of pa tients and the resection rate of SLN was 94.1%. The mean number of resected SLN was 1.8, all located at the axilla. IIC had a sensitivity of 72.7% and a spe cificity of 100%. The false-negative rate of SLN biopsy was 12.5% when SLNs were evaluated by H&E staining alone. However, the false-negative rate improved up to 0% when IHC staining was added. CONCLUSION: SLN biopsy using a gamma-detection probe proved to be a very sensitive method to detect SLN in breast carcinoma patients. Frozen biopsy should be added to im prove the outcomes of intraoperative examination of SLN. If permanent biopsy revealed that SLN was free of tumorthe by H&E staining, IHC staining should be done to improve false-negative rate of SLN biopsy.

Sentinel Node Biopsy in Breast Cancer Using a Gamma-detection Probe

PURPOSE: Sentinel lymph node (SLN) biopsy has emerged as a substitute for a conventional axillary lymph node (ALN) dissection in early breast carcinomas. We evaluated SLN biopsy in breast carcinoma using a gamma-detection probe in order to identify its accuracy as a staging procedure for lymph node status. METHODS: Fifty-one patients with breast carcinomas who underwent a SLN biopsy followed by an ALN dissection between June 1999 and January 2001 were evaluated. Tc 99m antimony trisulfide colloid was used as a tracer and SLN biopsy using a gamma-detection probe was done following breast lymphoscintigraphy. Intraoperative imprint cytology (II C) was done for each SLN. If a SLN biopsy was free of metastasis by permanent hematoxylin and eosin (H&E) staining, immun ohistochemical (IHC) staining using pan-cytokeratin was do ne to detect micrometastasis. RESULTS: ALN metastases were identified in 21.6% of pa tients and the resection rate of SLN was 94.1%. The mean number of resected SLN was 1.8, all located at the axilla. IIC had a sensitivity of 72.7% and a spe cificity of 100%. The false-negative rate of SLN biopsy was 12.5% when SLNs were evaluated by H&E staining alone. However, the false-negative rate improved up to 0% when IHC staining was added. CONCLUSION: SLN biopsy using a gamma-detection probe proved to be a very sensitive method to detect SLN in breast carcinoma patients. Frozen biopsy should be added to im prove the outcomes of intraoperative examination of SLN. If permanent biopsy revealed that SLN was free of tumorthe by H&E staining, IHC staining should be done to improve false-negative rate of SLN biopsy.