Publications

Low-income women are at increased risk of developing cervical cancer compared with middle- and upper-income women. How can poor women be reached for screening and early diagnosis of cervical cancer and its precursor stages? One answer to this question is based on the observation that a high percentage of the unscreened population has received some form of medical care within the previous 5 years. Emergency centers and sexually transmitted disease (STD) clinics often provide such care to patients who lack a regular source of health care. Thus, they represent potential resources for cervical cancer screening. However, in a survey of 19 hospitals whose patient populations include a high proportion of low-income patients, only five reported a protocol for cervical cancer screening in their emergency centers. Similarly, all 11 STD clinics included in this survey reported that fewer than 5% of their female patients had a Papanicolaou smear taken even though virtually all of them received a pelvic examination. Based on these findings, it appears that health care administrators and policymakers could intensify their cancer prevention programs by mobilizing these resources for cancer control.

The past 15 years have seen major advances in the characterization of extracellular matrix proteins and structure of matrix. As a by-product of this work, investigators now have an array of molecular and immunological reagents for monitoring matrix metabolism. Progress in the isolation and culture of individual cell types from liver has made possible direct measurement of matrix protein production and also has opened the way to studies of matrix degradation. The expanding knowledge of soluble mediators of inflammation is being applied to the regulation of matrix protein synthesis and degradation. Finally, experimental models of fibrosis in vivo are available for defining the complexity of matrix metabolism in the intact tissue and for validating the findings from cell culture and in vitro systems.

The polymerase chain reaction (PCR) for human immunodeficiency virus type 1 (HIV-1) DNA was performed on specimens from 197 homosexual and bisexual men enrolled in studies of HIV-1 infection. Thirty cycles of amplification were conducted, followed by detection with probes corresponding to two gag primer pairs (SK 38/39 and SK 101/145). Of 107 men who were HIV-1 antibody-negative, 105 (98%) were PCR-negative. Two who were initially PCR-positive antibody-negative were PCR- and antibody-negative on repeat testing of both the same specimen and specimens drawn 8-10 months later; this suggests that the first PCR results were false-positive. Of 90 men who were antibody-positive, PCR was positive in 87 (97%), including all 13 with AIDS, all 22 with AIDS-related conditions, all 11 with generalized lymphadenopathy only, and 41 (93%) of 44 without signs or symptoms of HIV-1 infection. On repeat testing, all 3 PCR-negative, antibody-positive men were PCR-positive. In this population and with this technique, PCR had excellent agreement with the HIV-1 antibody test.

Lymphokine-dependent T cell proliferation is regulated in part by the cell surface expression of high affinity interleukin-2 receptors (IL-2R). The functional, high affinity form of the IL-2 receptor is comprised of two ligand binding components, IL-2R alpha (Tac, p55) and IL-2R beta (p70/75). In the absence of the other subunit, IL-2R alpha and IL-2R beta bind ligand with only low or intermediate affinity, respectively. The inducible and transient expression of IL-2R alpha regulates the display of high affinity receptors, while IL-2R beta appears to contribute importantly to growth signal transduction. Although the primary structure of both receptor chains has now been elucidated, the mechanism of growth signal transduction through the high affinity IL-2R remains undefined. Of note, IL-2R beta belongs to a novel family of cytokine receptors including the binding proteins for IL-3, IL-4, IL-6, erythropoietin, and granulocyte-macrophage colony-stimulating factor. These various receptors may well utilize a common intracellular signalling pathway.