Cancer risk after evaluation for infertility

To evaluate cancer risk by various causes of infertility, the authors conducted a retrospective cohort study among 2,335 women evaluated for infertility at the Mayo Clinic between 1935 and 1964. Most cancers occurred at expected frequencies, with the exception of cancers of the thyroid (standardized incidence ratio (SIR) = 2.6) and other endocrine glands (SIR = 6.7), although analyses were based on small numbers. Patients with progesterone deficiencies (31 per cent of the study subjects) had a 20 per cent higher cancer risk than did those with other causes of infertility, with excesses deriving primarily from cancers of the lung, cervix, ovary, and thyroid and from melanoma. Breast cancer risk, however, was not elevated in either patients with progesterone deficiencies (SIR = 0.9) or patients with other causes of infertility (SIR = 1.0). Examination of other parameters of infertility, including age at evaluation, type of infertility (primary vs. secondary), and years of attempted conception, showed no elevated risks of breast cancer in any subgroup. These results fail to support previous studies that have linked progesterone deficiencies among infertile women to elevated breast cancer risk. However, the data suggest a possible involvement of a progesterone deficiency in the etiology of other cancers, particularly thyroid cancer and melanoma.     

Three-dimensional quantitative structure-activity relationship analysis of human CYP51 inhibitors.

CYP51 fulfills an essential requirement for all cells, by catalyzing three sequential mono-oxidations within the cholesterol biosynthesis cascade. Inhibition of fungal CYP51 is used as a therapy for treating fungal infections, whereas inhibition of human CYP51 has been considered as a pharmacological approach to treat dyslipidemia and some forms of cancer. To predict the interaction of inhibitors with the active site of human CYP51, a three-dimensional quantitative structure-activity relationship model was constructed. This pharmacophore model of the common structural features of CYP51 inhibitors was built using the program Catalyst from multiple inhibitors (n = 26) of recombinant human CYP51-mediated lanosterol 14alpha-demethylation. The pharmacophore, which consisted of one hydrophobe, one hydrogen bond acceptor, and two ring aromatic features, demonstrated a high correlation between observed and predicted IC(50) values (r = 0.92). Validation of this pharmacophore was performed by predicting the IC(50) of a test set of commercially available (n = 19) and CP-320626-related (n = 48) CYP51 inhibitors. Using predictions below 10 microM as a cutoff indicative of active inhibitors, 16 of 19 commercially available inhibitors (84%) and 38 of 48 CP-320626-related inhibitors (79.2%) were predicted correctly. To better understand how inhibitors fit into the enzyme, potent CYP51 inhibitors were used to build a Cerius(2) receptor surface model representing the volume of the active site. This study has demonstrated the potential for ligand-based computational pharmacophore modeling of human CYP51 and enables a high-throughput screening system for drug discovery and data base mining.     

Multicentric fibromatosis of familial inheritance

This is an unusual case presentation of a young woman with a clinical history and course simulating juvenile hyaline fibromatosis, but without hyalinization in the stroma. Because of the age of onset, the apparent familial inheritance, the nonaggressive and nonregressive tumor traits, the disease cannot be classified as multicentric fibromatosis. Therefore, we are referring to this case as multicentric fibromatosis with familial inheritance, a previously unreported entity to our knowledge.     

Effect of ciprofibrate, bezafibrate, and LY171883 on peroxisomal beta-oxidation in cultured rat, dog, and rhesus monkey hepatocytes

Cultured rat hepatocytes have been used extensively to study the mechanisms of chemically induced peroxisome proliferation. Hepatocytes from nonrodent species have been used on a limited scale to study interspecies differences in the response. Because of their importance in pharmaceutical safety assessment, we have developed a model to study the response of beagle dog and rhesus monkey hepatocytes to peroxisome proliferators. Treatment of the hepatocytes with peroxisome proliferators was begun after 20 hr in culture and continued for 72 hr. Untreated rat, dog, and monkey hepatocytes retained 62, 42, and 43% of their initial (20 hr) peroxisomal beta-oxidation activity throughout 92 hr of culture. Ciprofibrate, bezafibrate, and LY171883 caused a dose-related increase in beta-oxidation in rat hepatocytes to a maximum of 10-, 8-, and 5-fold, respectively. In dog and monkey hepatocytes the increases in beta-oxidation were less than 2-fold. Peroxisome morphology in dog and monkey hepatocytes appeared to be unchanged by the drugs. Morphometric analysis in monkey hepatocytes showed no increase in peroxisome volume fraction in response to the chemicals. Treatment of dog and monkey hepatocytes with dexamethasone and glucagon during the final 24 hr in culture caused a 4- to 6-fold increase in tyrosine aminotransferase activity. This induction is characteristic of the in vivo response. The small increase in beta-oxidation reflects the relative insensitivity of the dog and monkey liver to peroxisome proliferators in vivo rather than a loss of sensitivity during culture. Cultured hepatocytes from beagle dog and rhesus monkey may provide a model for studying the mechanisms underlying the interspecies differences. Such information would help clarify the relevance of rodent data in human risk assessment.     

Preliminary evidence for a role of apolipoprotein E alleles in identifying haemodialysis patients at high vascular risk

Conventional risk factors have very low predictive power in identifying haemodialysis patients at high risk of vascular accidents. A role for apolipoprotein E isotypes was looked for in a small, but rigorously defined, cohort of longterm haemodialysis patients. In individuals with high vascular risk, as identified by higher common carotid intima/media thickness, we found an excess of apolipoprotein E4 alleles. This preliminary result requires confirmation in large patient cohorts.      

The Manner Born: Birth Rites in Cross‐Cultural Perspective

Edited by Lauren Dundes. Walnut Creek (CA): Altamira Press, 2003. 239 pages. $27.95, paperback, $75.00, hardback.