The Cole relaxation frequency as a parameter to identify cancer in breast tissue.

PURPOSE: To correlate the Cole relaxation frequencies obtained from measurements of the electrical properties of breast tissue to the presence or absence of cancer. METHODS: Four-lead impedance measurements were obtained on ex vivo specimens extracted during surgery from 187 volunteer patients. Data were acquired with a commercial Solartron impedance bridge employing 4-lead Ag-AgCl or blackened platinum (BPt) electrodes at frequencies logarithmically spaced from 1 Hz to 3.2 × 10(7) Hz utilizing 6-10 frequencies per decade. The Cole frequencies obtained from these measurements were correlated with the tissue health status (cancer or noncancer) obtained from histological analysis of the specimens. RESULTS: Analysis of the impedance measurements showed that the Cole relaxation frequencies correlated to the presence or absence of cancer in the examined tissue with a sensitivity up to 100% (95% CI, 99%-100%) and a specificity up to 85% (95% CI, 79%-91%) based on the ROC curve of the data with the Cole frequency as the classifier. CONCLUSIONS: The results show that the Cole frequency alone is a viable classifier for malignant breast anomalies. Results of the current work are consistent with recent bioimpedance measurements on single cell and cell suspension breast cell lines.

Correction of electrode polarization contributions to the dielectric properties of normal and cancerous breast tissues at audio/radiofrequencies.

Spurious contributions from electrode polarization (EP) are a major nuisance in dielectric measurements of biological tissues and hamper accurate determination of tissue properties in the audio/radiofrequencies. Various electrode geometries and/or treatments have been employed traditionally to reduce EP contributions, although none succeeded to completely remove EP from measurements on tissues for all practical frequency ranges. A method of correction for contributions of EP to the dielectric properties of tissues is proposed. The method is based on modeling the electrode impedance with suitable functions and on the observation that certain parameters are only dependent on electrodes properties and can thus be determined separately. The method is tested on various samples with known properties, and its usefulness is demonstrated with samples of normal and cancerous human female breast tissue. It is observed that the dielectric properties of the tissues over the frequency range 40 Hz-100 MHz are significantly different among different types of breast tissue. This observation is used further to demonstrate that, by scanning the tip of the measuring dielectric probe (with modest spatial resolution) across a sample of excised breast tissue, significant variations in the electrical properties are detected at a position where a tumor is located. This study shows that dielectric spectroscopy has the potential to offer a viable alternative to the current methods for detection of breast cancer in vivo.

Circumcision using bipolar diathermy scissors: a simple, safe and acceptable new technique.

BACKGROUND: Circumcision may be performed by a variety of techniques. Postoperative haemorrhage is a recognised complication of the procedure. METHOD: A method of circumcision using bipolar diathermy scissors is described. Foreskin vessels are coagulated as the foreskin is cut away. RESULTS: Thirty patients underwent this procedure without complication. CONCLUSION: Circumcision using bipolar scissors can be a safe and simple operation.

Immunohistochemical profile of monoclonal antibody O13: antibody that recognizes glycoprotein p30/32MIC2 and is useful in diagnosing Ewing's sarcoma and peripheral neuroepithelioma.

Ewing's sarcoma (ES) and peripheral neuroepithelioma (PN) are closely related tumors, and it can be difficult to distinguish them from other small-round-cell tumors (SRCTs). The glycoprotein p30/32MIC2 is highly, but not exclusively, expressed in both ES and PN. Although the monoclonal antibody (Mab) HBA71, which reacts with P30/32MIC2, has been reported to be relatively specific and highly sensitive for both neoplasms, it is not readily available. Yet, Mab O13 is commercially available, and it purportedly displays the same immunostaining characteristics as HBA71. Because O13 has not been studied extensively, we immunostained 21 ES/PNs and 147 other tumors or lesions that might show SRCT-like features with O13. The results were similar to those reported for HBA71. We found O13 to be 100% sensitive for ES/PN; and, no immunostaining was noted on the SRCTs often included in the differential diagnosis of ES/PN (i.e., conventional neuroblastoma, rhabdomyosarcoma, and non-lymphoblastic lymphomas). But, O13 immunoreacted with lymphoblastic lymphomas and some other tumors and normal tissues. Nonetheless, this nonspecific reactivity should not cause diagnostic problems, if an antibody panel containing anti-desmin and anti-leukocyte common antigen is used in conjunction with O13. We conclude that, within the proper diagnostic context, strong immunoreactivity of a SRCT tumor for O13 should be considered good evidence that the tumor is ES/PN.