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Biomedical subjects

J E Bridges

Publications and source records attributed to J E Bridges.

5 recordsLinked to original sources

Two-dimensional FDTD analysis of a pulsed microwave confocal system for breast cancer detection: fixed-focus and antenna-array sensors.

A novel focused active microwave system is investigated for detecting tumors in the breast. In contrast to X-ray and ultrasound modalities, the method reviewed here exploits the breast-tissue physical properties unique to the microwave spectrum, namely, the translucent nature of normal breast tissues and the high dielectric contrast between malignant tumors and surrounding lesion-free normal breast tissues. The system uses a pulsed confocal technique and time-gating to enhance the detection of tumors while suppressing the effects of tissue heterogeneity and absorption. Using published data for the dielectric properties of normal breast tissues and malignant tumors, we have conducted a two-dimensional (2-D) finite-difference time-domain (FDTD) computational electromagnetics analysis of the system. The FDTD simulations showed that tumors as small as 2 mm in diameter could be robustly detected in the presence of the background clutter generated by the heterogeneity of the surrounding normal tissue. Lateral spatial resolution of the tumor location was found to be about 0.5 cm.

Breast

Abdominal radical trachelectomy: a new surgical technique for the conservative management of cervical carcinoma.

Traditionally radical hysterectomy has formed the mainstay of treatment for early stage cervical carcinoma. More recently radical trachelectomy and laparoscopic lymphadenectomy have been introduced to allow preservation of fertility. We present a new approach to fertility-sparing surgery, namely abdominal radical trachelectomy. The technique is similar to a standard radical hysterectomy and lymphadenectomy. In our technique the ovarian vessels are not ligated and, following lymphadenectomy and skeletonisation of the uterine arteries, the cervix, parametrium and vaginal cuff are excised. The residuum of the cervix is then sutured to the vagina and the uterine ateries re-anastomosed.

Anastomosis, Surgical

Expression of integrin adhesion molecules in endometrium and endometriosis.

OBJECTIVE: To compare the expression of cell adhesion molecules by endometrium and endometriosis. DESIGN: A comparative study of integrin expression, determined immunohistochemically, in eutopic and ectopic endometrium biopsied synchronously from patients with endometriosis diagnosed at laparoscopy or laparotomy. SETTING: University Departments of Obstetrics and Gynaecology, and Pathology, Southampton; Department of Obstetrics and Gynaecology, Newcastle upon Tyne. SAMPLES: Eighteen paired samples of endometria and endometriosis. RESULTS: A wide distribution of collagen-laminin receptor proteins was demonstrated. alpha 1 integrin expression was limited to secretory endometrium. beta 3 expression was only demonstrated on proliferative endometrium. CONCLUSIONS: Expressions of the integrin proteins differed between the various elements of the endometrium. Cyclical changes in integrin expression also were demonstrated. No difference in cell adhesion molecule expression was seen when comparing endometrial and endometriosis samples.

Cell Adhesion Molecules

The distribution of CA 125 in the reproductive tract of pregnant and non-pregnant women.

Investigation of serum and tissue homogenates obtained from first, second and third trimester pregnancies, and from non-pregnant women, has provided further insight into the possible origin of the CA 125 antigen. Serum CA 125 levels were higher in the first trimester (median 53.6 U/ml, range 15.6-268.3 U/ml) than in non-pregnant women (median 19.3 U/ml, range 7.2-27.0 U/ml) and later in pregnancy (second trimester: median 18.5 U/ml, range 12.0-25.1 U/ml, third trimester: median 19.2 U/ml, range 16.8-43.8 U/ml) (P less than 0.05) but were two orders of magnitude less than in second trimester amniotic fluid (median 4825 U/ml, range 3200-9300 U/ml). Fetal serum CA 125 activity was consistently less than 20 U/ml. The highest tissue levels of CA 125 were detected in first trimester decidual homogenate (median 4547 U/100 mg, range 340.4-20 851 U/100 mg) and were greater than in non-pregnant endometrium (median 388 U/100 mg, range 100.9-3341 U/100 mg) (P less than 0.01) and term decidua (median 116 U/100 mg, range 32.7-449.9 U/100 mg) (P less than 0.01). These observations suggest that CA 125 is synthesized by normal endometrium and decidua and that increased CA 125 activity during pregnancy is of decidual origin.

Antigens, Tumor-Associated, Carbohydrate