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Notes: A new low-field resonance technique for determining the initial hard-axis permeability (μ') of materials used in thin film and magnetoresistive heads has been developed. The initial μ' is found to be less than 4πM/Hk due to the internal effective magnetostatic field caused by magnetization ripple, in agreement with the theory and transverse biased initial susceptibility measurements of Hoffmann and others.1 A proper consideration of the in-plane susceptibility for real films includes the Stoner–Wohlfarth anisotropy field (Hk)−1 dependence, modified by the factors due to ripple (B) and skew (E) as defined by Hoffmann. The latter produce internal fields that shift the Kittel resonance versus field plots (fr2 vs H) leftward from their ideal symmetric positions for angles of 0° and 90° between bias field and preferred axis. When resonance data from both orientations are computer-fit simultaneously, we determine the parameters B and E as well as Hk and Ms. The coefficients are believed to have more consistency than those obtained using Hk found from hard-axis magnetization curves. The reduction of the hard-axis μ' is by the factor (1+B+E)−1. The high frequency properties (300 kHz–3 GHz) were measured using a test jig consisting of a shorted-shield strip-line section with a one-turn inductively coupled loop containing the sample and located at the shorted end. Bias fields from zero to 100 Oe were employed. We measure fR reproducibly with an uncertainty of less than 1%. This analysis determines the parameters of interest from measurements under dynamic conditions. Results include Permalloy and amorphous TM-metalloid films. When annealed to reduce Hk, their B parameters increase in accord with theory, assuming invariant structure constants, S. Beyond head applications, the method relates to thin film microwave devices operating near fr in zero field.2

Notes: The ternary alloy system Fe-Co-Al exhibits a little-noticed anomaly in that some alloys containing Al have higher Curie points than their undiluted counterparts. New results present the evolution of Curie point and saturation magnetization as a function of Al content, especially below 7 wt % (∼13.5 at. %) in the midrange of the Fe-Co composition field. Maxima of Tc in the range of 1000–1025 °C are found for Al contents of about 2–5 wt % (4–10 at. %) for alloy series with 30- , 40- , and 50-wt % Co (∼27- , 37- , and 47-at. % Co). These values are some 25–45 °C higher than the corresponding zero-Al alloys. Correlation of low-field thermal hysteresis and saturation-field thermomagnetic curves indicate first-order Curie point behavior at low-Al content, followed by classical second-order transitions at and above the Al content corresponding to Tc maxima. The former follow the α-bcc to the γ-fcc phase transition. For the latter class the α phase has been stabilized to higher temperatures with a relatively uncommon Curie point enhancement behavior.

Notes: Disordered suspensions of conducting particles exhibit substantial permittivity enhancements beyond the predictions of the Clausius–Mossotti equation and other purely dipolar approximations. The magnitude of the enhancement depends upon the shape of the particles. A recently developed effective cluster model for spherical particles [Phys. Rev. B 42, 9319 (1990)] that treats a disordered suspension as a mixture, or mesosuspension, of isolated spheres and close-packed spherical clusters of arbitrary size is in excellent agreement with experiments on well-stirred suspensions of spheres over the entire accessible range of volume loading. In this paper, the effective cluster model is extended to be applicable to disordered suspensions of arbitrarily shaped conducting particles. Two physical parameters are used to characterize a general suspension: the angular average polarizability of an isolated particle, and the volume loading at closest packing of the suspension. Multipole interactions within the clusters are treated exactly. External particle-shape-dependent interactions between clusters and isolated particles are treated in the dipole approximation in two ways: explicitly, using the Clausius–Mossotti equation, and implicitly, using the Wiener equation. Both versions of the model are used to find the permittivity of a monodisperse suspension of conducting spheroids, for which the model parameters can be determined independently. The two versions are in good agreement when the axial ratio of the particles is not extreme.The Clausius–Mossotti version of the model yields a mesoscopic analogue of the dielectric virial expansion. It is limited to small volume loadings when the particles have an extremely nonspherical shape. The Wiener equation version of the model holds at all volume loadings for particles of arbitrary shape. Comparison of the two versions of the model leads to a simple physical interpretation of Wiener's equation. The models are compared with experiments of Kelly, Stenoien, and Isbell [J. Appl. Phys. 24, 258 (1953)] on aluminum and zinc particles in paraffin, with Nasuhoglu's experiments on iron particles in oil [Commun. Fac. Sci. Univ. Ankara 4, 108 (1952)], and with new X-band and Kα-band permittivity measurements on Ni-Cr alloy particles in a polyurethane binder.

Notes: Progress in understanding the molecular basis of carcinogenesis will undoubtedly have a major impact in gynaecologic oncology. Although the details of endometrial carcinogenesis are not as yet unravelled, important information has been accumulated in recent years. The identification of DNA repair genes responsible for the hereditary non-polyposis colorectal cancer (HNPCC) and Lynch II syndromes was an important step forward from a basic science perspective and should yield major benefits for individuals in these families. A number of steps in sporadic endometrial carcinogenesis have now been identified and it is possible to begin to construct a speculative pathway of multistep carcinogenesis. A single frequent genetic event in endometrial cancer has not yet been documented but several genetic alterations involving p53 mutation, Ki-ras mutation, loss of heterozygosity (LOH) at various chromosomal loci and amplification/overexpression of oncogenes such as c-myc and c-neu have been described. It is likely that as yet unknown and more frequent genetic alterations will eventually be identified. This information should be available during the next decade and as a result we can anticipate exciting progress in strategies for prevention, screening and therapy.

Notes: Progress in investigating the molecular basis of cancer has been rapid during recent years and has resulted in important advances in understanding ovarian carcinogenesis. These include the isolation of highly penetrant cancer susceptibility genes and the identification of alterations in other genetic elements involved in cell growth, differentiation and DNA repair. The first section of this review describes the epidemiology and genetics of familial ovarian cancer and the identification of the BRCA1 gene associated with breast/ovarian cancer and of the DNA repair genes associated with the Lynch II syndrome. The risk of cancer associated with germ line abnormalities of these genes and the management options for women with a family history of ovarian cancer are discussed. The second section describes genetic abnormalities associated with sporadic ovarian cancer. Although a detailed multistep pathway of sporadic ovarian carcinogenesis cannot yet be described a number of specific abnormalities have now been documented. These include abnormalities of growth factors (M-CSF, TGF-beta), growth factor receptors (c-fms, EGFR, Her-2/neu), genes involved in signal transduction (Ki-ras), and genes involved in transcriptional regulation (c-myc, p53) and loss of heterozygosity at various chromosomal loci. The final section of the review discusses the genetics of metastatic disease, candidate precursor lesions for ovarian cancer and the field change hypothesis of ovarian carcinogenesis.

Notes: In published trials, CA125 has been utilized to trigger ultrasound examination for the early detection of ovarian cancer. Although serum CA125 levels can be elevated prior to clinical detection of ovarian cancer, only approximately half of patients with stage I disease will have an abnormal value. A combination of CA125, macrophage colony-stimulating factor (M-CSF) and the mucin marker OVX1 will detect〉 95% of stage I patients, but it is not known whether the markers can be elevated prior to clinical detection of the disease. A postmenopausal patient was found to have small unilocular bilateral cystic adnexal lesions during an abdominal ultrasound examination. No pelvic abnormality could be palpated. Serum levels of the CA125 antigen were within the normal range. Progressive ultrasound changes prompted a laparotomy II months later, and the diagnosis of a stage IC serous cystadenocarcinoma of the ovary was established. A retrospective analysis of stored serum samples revealed that this patient had elevated serum levels of M-CSF and OVX1 at the time of the original ultrasound scan. Interpreted within the context of a potential screening strategy for ovarian cancer, these data illustrate that either or both of these tumor markers and/or ultrasound could have identified this ovarian cancer many months prior to the actual diagnosis, while the disease was at an early stage.

Notes: Fallopian tube carcinoma can be histologically indistinguishable from and has a similar clinical behavior to epithelial ovarian carcinoma. However, it is considerably less common; only approximately 1000 cases have been recorded in the literature. In the prevalence screen of 22000 women participating in The Royal London Hospital, London, UK, ovarian cancer screening project, three cases of early stage primary fallopian tube carcinoma were diagnosed following the finding of an elevated serum level of the CA 125 antigen. The ratio of epithelial ovarian : tubal cancer developing in these postmenopausal volunteers was 6:1. This is 25-fold greater than the expected ratio. It is difficult to attribute this finding to population selection bias. However, it is possible that the screening test was particularly effective in detecting tubal carcinoma or that, in clinical practice, the true primary site of origin of some tumors classified as widely disseminated ovarian cancer is in the fallopian tube.

Notes: Objective Ultrasound scanning, serum CA125 and menopausal status have previously been combined in a risk of malignancy index for the differential diagnosis of adnexal masses. Although this approach has greater accuracy than either individual tests or clinical assessment, it has a significant false positive and false negative rate. Efforts have been directed at refining differential diagnosis and this study assessed the role of radioimmunoscintigraphy using the stripped mucin 3 (SM3) antibody that has a 17-fold greater uptake in malignant than benign ovarian tumours in vitro.Design Prospective study of patients with a pelvic mass using radioimmunoscintigraphy.Setting Department of Nuclear Medicine of St Bartholomew's Hospital in collaboration with Cancer Network.Population A total of 93 patients with pelvic masses were recruited for this study of which 32 had ovarian cancer and 61 had benign lesions.Methods Radioimmunoscintigraphy was performed with Tc-99m-labelled SM3 (600 MBq), anterior and posterior pelvis imaged at 10 minutes and at 4 and 24 hours and evaluated with change detection analysis and probability mapping.Main outcome measures Sensitivity and specificity of radioimmunoscintigraphy for ovarian cancer.Results Radioimmunoscintigraphy had a sensitivity for ovarian cancer of 84% (27 true positive and 5 false negatives) and a specificity of 87% (53 true negatives and 8 false positives) giving a negative predictive value of 91%.Conclusion These results suggest that radioimmunoscintigraphy could be used to reduce the number of false positive findings in a strategy to refine differential diagnosis of the pelvic mass.

Notes: Summary. Investigation of serum and tissue homogenates obtained from first, second and third trimester pregnancies, and from nonpregnant 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 nonpregnant 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〈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 〈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 nonpregnant endometrium (median 388 U/100 mg, range 100.9–3341 U/100 mg) (P〈0.01) and term decidua (median 116 U/100 mg, range 32.7–449.9 U/100 mg) (P〈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.

Notes: Summary. Age, ultrasound score, menopausal status, a clinical impression score and serum CA 125 level were assessed to see how they could best distinguish between patients with benign (n = 101) and malignant (n – 42) pelvic masses. Each criteria used alone provided statistically significant discrimination. The most useful individual criteria were a serum CA 125 level of 30 U/ml (sensitivity 81 %, specificity 75%) and an ultrasound score of 2 (sensitivity 71%, specificity 83%). Three criteria could be combined in a risk of malignancy index (RMI) which is simply calculated using the product of the serum CA 125 level (U/ml), the ultrasound scan result (expressed as a score of 0, 1 or 3) and the menopausal status (1 if premenopausal and 3 if postmenopausal). This index was statistically virtually as effective a discriminant between cancer and benign lesions as more formal methods. Using an RMI cut-off level of 200, the sensitivity was 85% and the specificity was 97%. Patients with an RMT score of greater than 200 had, on average, 42 times the background risk of cancer and those with a lower value 0.15 times the background risk.