Mitogenic Properties of Insulin-Like Growth Factors I and II, Insulin-like Growth Factor Binding Protein-3 and Epidermal Growth Factor on Human Breast Stromal Cells in Primary Culture

Insulin-like growth factors I and II (IGF-I and IGF-II) are growth factors implicated in both normal mammary gland development and breast cancer. We have previously reported on the effects of components of the IGF system on breast epithelial cells. Since data suggests that stromal-epithelial interactions play a crucial role in breast cancer, we have now investigated the mitogenic properties of IGF-I, IGF-II, insulin-like growth factor binding protein-3 (IGFBP-3) and epidermal growth factor (EGF) on human breast stromal cells in primary culture. We show that, under serum-free conditions, stromal cells are stimulated to grow in response to IGF-I and IGF-II in a dose-dependent manner. IGF-I and EGF, a potent stimulator of human breast epithelial cell growth in primary culture and also associated with breast cancer, appear to stimulate stromal cell growth in a synergistic manner. IGFBP-3 does not inhibit the stimulation of growth by IGF-I, or IGF-I plus EGF. However, IGFBP-3 does inhibit the stimulation of growth by IGF-II. In contrast to our previous results with human breast epithelial cells, IGFBP-3 does not have an IGF-independent inhibitory effect on stromal cell growth. This study is the first to address the effects of IGF-I, IGF-II and IGFBP-3 alone and in combination with EGF on human breast stromal cell growth in primary culture. Characterizing the role of the IGF system in both normal breast epithelial cells and stromal cells will aid in our understanding of the mechanisms behind the role of the IGF system in breast cancer.     

Loss of heterozygosity at chromosome 9q22-31 is a frequent and early event in ovarian tumors

Loss of heterozygosity (LOH) studies in ovarian tumors, have highlighted the chromosomal regions at 9q22-31 and 9q32-34 as being potentially important in tumor development. We have investigated LOH at 9q22-31 in 85 patients with epithelial ovarian cancer, 15 with non-epithelial tumors and 16 with benign disease. Varying patterns of LOH were observed across the markers used between different tumors, the most common (71%) being interstitial discontinuous losses. LOH was frequent, and was detected at equally high levels in malignant (71%) and benign tumors (70%). LOH occurred in epithelial invasive tumors, borderline tumors, fibromas and dermoid tumors. In malignant epithelial tumors LOH at 9q22-31 was not significantly associated with patient clinical and pathological parameters; however, survival was 29 months at the 50th centile survival, in those women whose tumors displayed LOH compared with 60 months in women whose tumors retained heterozygosity. LOH at 9q22-31 was significantly associated with LOH at the p53 locus (p=0.02) and the ovarian suppressor locus at 3p21 (p=0.05). We conclude that the chromosome region at 9q22-31, flanked by the microsatellite markers D9S1796 and D9S53, is a frequent and early event in ovarian tumorigenesis. With the of extent of discontinuous LOH, high density deletion mapping of this region using LOH as a strategy to identify candidate genes may be problematic. However with the completion of the human genome sequencing project several candidate genes are identified.     

Association of acute parvovirus B19 infection with new onset of acute lymphoblastic and myeloblastic leukaemia

AIMS: To investigate the association of acute parvovirus B19 infection with new onset of acute lymphoblastic and myeloblastic leukaemia. METHODS: Cerebrospinal fluid (CSF) samples from patients with acute myelogenous leukaemia (AML) at diagnosis (n = 2) and acute lymphoblastic leukaemia (ALL) at diagnosis (n = 14) were analysed for parvovirus B19 DNA by means of nested polymerase chain reaction. In addition, samples from patients with benign intracranial hypertension (BIH) (n = 10) and hydrocephalus (n = 13) were tested as controls. RESULTS: Four leukaemia cases were positive-common ALL (n = 2), null cell ALL (n =1), and M7 AML (n = 1)-whereas all controls were negative (Yates corrected chi(2) value, 3.97; p = 0.046; odds ratio, 16.92; confidence interval, 1.03 to 77.18). All four patients were significantly anaemic, but none was encephalitic or had evidence of central nervous system leukaemia. In three of these patients, serum tumour necrosis alpha, interferon gamma, interleukin 6, granulocyte-macrophage colony stimulating factor (range, 34.93-3800.06 pg/ml), and macrophage chemoattractant protein 1 were detectable. All of these four patients carried at least one of the HLA-DRB1 alleles, which have been associated with symptomatic parvovirus B19 infection. CONCLUSION: Erythroid suppression and immune cell proliferation are both associated with B19 infection and may also be important in the pathogenesis of acute leukaemia.     

Stability of furosemide in human albumin solution

OBJECTIVE: To determine the chemical stability of furosemide in human albumin solution over a 28-day period and to assess admixtures for microbiologic contamination. METHODS: Samples were prepared by mixing furosemide injectable solution and 25% human albumin solution in a 1:1 molar ratio. Six bulk containers were prepared and stored in the dark: 3 under refrigeration (approximately 4 degrees C) and 3 at room temperature (approximately 25 degrees C). Study samples were withdrawn from each bulk solution immediately after preparation and at predetermined intervals over the subsequent 28 days. Containers were observed for color change and precipitation against a light and dark background at each sampling interval. Total furosemide concentration was determined using HPLC. Additional vials were prepared and assessed for microbiologic growth at time points corresponding with chemical stability results. RESULTS: A mean of 94.5%+/-1.33% of the initial furosemide concentration remained after 48 hours at room temperature. Under refrigeration, 100.6%+/-1.02% of the initial concentration remained at 14 days. Beyond these respective time points, <90% of the initial furosemide concentration remained. No bacterial or fungal growth was observed. CONCLUSIONS: When combined with 25% human albumin solution and stored under darkness, furosemide is chemically stable and free of microbiologic contamination for 48 hours at room temperature and 14 days under refrigeration.     

Teaching of occupational medicine to undergraduates in UK schools of medicine

OBJECTIVES: To assess any recent change in the commitment to occupational medicine teaching in UK undergraduate medical curricula. DESIGN: A questionnaire survey of the teaching of occupational medicine to undergraduates in all medical schools listed in the UK Universities and Colleges Admissions Service prospectus for 1999-2000 (n = 24). RESULTS: Nineteen UK schools medical schools returned a completed questionnaire, giving a response rate of 79%. A comparison of results from this survey with previous surveys of teaching of occupational medicine to undergraduates in the UK shows that fewer schools now provide lectures, project work or ward-based tuition in the subject. Workplace visits were not undertaken by any institution. Only two of the schools setting an examination question also had a syllabus. CONCLUSION: Despite the prominence given to issues related to occupational health in recent UK government policy, this study suggests a declining commitment to occupational medicine on the part of UK medical schools. Urgent action needs to be taken to address the lack of training in occupational medicine in UK medical schools.