Various forms of chemically induced liver injury and their detection by diagnostic procedures.
(1/387)
A large number of chemical agents, administered for therapeutic or diagnostic purposes, can produce various types of hepatic injury by several mechanisms. Some agents are intrinsically hepatotoxic, and others produce hepatic injury only in the rare, uniquely susceptible individual. Idiosyncrasy of the host is the mechanism for most types of drug-induced hepatic injury. It may reflect allergy to the drug or a metabolic aberation of the host permitting the accumulation of hepatotoxic metabolites. The syndromes of hepatic disease produced by drugs have been classified hepatocellular, hepatocanalicular, mixed and canalicular. Measurement of serum enzyme activities has provided a powerful tool for studies of hepatotoxicity. Their measurement requires awareness of relative specificity, knowledge of the mechanisms involved, and knowledge of the relationship between known hepatotoxic states and elevated enzyme activities. (+info)
Oral contraceptive use and risk of gestational trophoblastic tumors.
(2/387)
BACKGROUND: Gestational trophoblastic disease refers to a spectrum of rare benign and malignant gynecologic disorders whose pathogenesis is not well understood. Recent studies from China and the United States have raised the hypothesis that long-term use of oral contraceptives before conception may increase the risk of gestational trophoblastic tumors. A multicenter case-control study of gestational trophoblastic tumors was undertaken to test this hypothesis. METHODS: Telephone interviews were conducted with 235 case patients, including 50 with gestational choriocarcinoma, and 413 control subjects matched on recentness of pregnancy, age at pregnancy, and area of residence. Relative risks (odds ratios) were computed by conditional logistic regression. Reported P values are two-sided. RESULTS: The relative risk estimate for ever having used oral contraceptives before the index pregnancy was 1.9 (95% confidence interval [CI] = 1.2-3.0), and the risk increased with duration of use (P for trend = .05). The estimate was highest for women who used oral contraceptives during the cycle in which they became pregnant (relative risk = 4.0; 95% CI=1.6-10), but there was no consistent pattern according to the time interval since last use. Separate analyses of choriocarcinoma and persistent mole yielded similar results, i.e., the relative risk estimates for oral contraceptive use were 2.2 (95% CI=0.8-6.4) and 1.8 (95% CI=1.0-3.0), respectively. Control for the number of sexual partners, which was independently associated with risk (P for trend = .05), did not materially change the results. CONCLUSIONS: This study, the largest to date, indicates that long duration of oral contraceptive use before conception increases the risk of gestational trophoblastic tumors. These findings may provide clues to the pathogenesis of this rare disease. Changes in use of oral contraceptives are not warranted, however, because the incidence attributable to oral contraceptive use is very low. (+info)
Reproductive factors of ovarian and endometrial cancer risk in a high fertility population in Mexico.
(3/387)
A case-control study was carried out in Mexico City during 1995-1997 among women with epithelial ovarian cancer (84 cases) and endometrial cancer (85 cases). The control group consisted of 668 healthy women, matched according to age categories. In a multivariate analysis, the reproductive risk factors for ovarian and endometrial cancer are similar. The risk of ovarian cancer was inversely related to the number of full-term pregnancies; the odds ratio (OR) was 0.17 and the 95% confidence interval (CI) was 0.05-0.54 when comparing nulliparous women versus those with more than seven pregnancies. For endometrial cancer, a similar association was observed (OR, 0.11; 95% CI, 0.04-0.34). The use of oral contraceptive hormones was inversely associated with both ovarian (OR, 0.36; 95% CI, 0.15-0.83) and endometrial cancer risk (OR, 0.36; 95% CI, 0.14-0.90). In women with a history of more than 8.7 years without ovulation, the risk of ovarian cancer decreased four times (OR, 0.23; 95% CI, 0.10-0.50), and that of endometrial cancer decreased more than five times (OR, 0.17; 95% CI, 0.08-0.35). These two neoplasms are clearly typified as hormone dependent, and it is possible to establish that "ovulation" and "exfoliative" mechanisms jointly determine the level of risk for both ovarian and endometrial cancer. (+info)
Jugular vein thrombosis: a rare presentation of atypical chronic myeloproliferative disorder in a young woman.
(4/387)
Venous thromboembolism is common in subjects with chronic myeloproliferative disorders and is a recognized presenting feature of occult myeloproliferation. We report the case of a young woman who presented with acute thrombosis in the right jugular vein and pulmonary embolism. Splenomegaly and myeloid proliferation with bone marrow fibrosis, in the absence of the criteria for typical myeloproliferative disorders, allowed a diagnosis of an atypical form of chronic myeloproliferative disorder. This form carries a high risk of thrombosis and venous thromboembolism can be the presenting feature, though the course is often indolent. Acute thrombosis in the right jugular vein has not been so far described in these subjects. The outcome of young people with myelofibrosis is unpredictable, but a normal level of hemoglobin and the absence of blast cells and constitutional symptoms at presentation identifies subjects with a low probability of rapid disease progression. (+info)
Effects of oral contraceptives on body fluid regulation.
(5/387)
To test the hypothesis that estrogen reduces the operating point for osmoregulation of arginine vasopressin (AVP), thirst, and body water balance, we studied nine women (25 +/- 1 yr) during 150 min of dehydrating exercise followed by 180 min of ad libitum rehydration. Subjects were tested six different times, during the early-follicular (twice) and midluteal (twice) menstrual phases and after 4 wk of combined [estradiol-norethindrone (progestin), OC E + P] and 4 wk of norethindrone (progestin only, OC P) oral contraceptive administration, in a randomized crossover design. Basal plasma osmolality (P(osm)) was lower in the luteal phase (281 +/- 1 mosmol/kgH(2)O, combined means, P < 0.05), OC E + P (281 +/- 1 mosmol/kgH(2)O, P < 0.05), and OC P (282 +/- 1 mosmol/kgH(2)O, P < 0. 05) than in the follicular phase (286 +/- 1 mosmol/kgH(2)O, combined means). High plasma estradiol concentration lowered the P(osm) threshold for AVP release during the luteal phase and during OC E + P [x-intercepts, 282 +/- 2, 278 +/- 2, 276 +/- 2, and 280 +/- 2 mosmol/kgH(2)O, for follicular, luteal (combined means), OC E + P, and OC P, respectively; P < 0.05, luteal phase and OC E + P vs. follicular phase] during exercise dehydration, and 17beta-estradiol administration lowered the P(osm) threshold for thirst stimulation [x-intercepts, 280 +/- 2, 279 +/- 2, 276 +/- 2, and 280 +/- 2 mosmol/kgH(2)O for follicular, luteal, OC E + P, and OC P, respectively; P < 0.05, OC E + P vs. follicular phase], without affecting body fluid balance. When plasma 17beta-estradiol concentration was high, P(osm) was low throughout rest, exercise, and rehydration, but plasma arginine vasopressin concentration, thirst, and body fluid retention were unchanged, indicating a lowering of the osmotic operating point for body fluid regulation. (+info)
Tamoxifen therapy for breast cancer and endometrial cancer risk.
(6/387)
BACKGROUND: Tamoxifen is effective in treating breast cancer, reduces breast cancer incidence among high-risk women, and is associated with increased endometrial cancer risk. This study was designed to examine the possible modifying effects of endometrial cancer risk factors on the tamoxifen-endometrial cancer association. METHODS: We conducted a case-control study of endometrial cancer (324 case patients and 671 individually matched control subjects) nested within a population-based cohort of patients with breast cancer diagnosed from 1978 through 1992 within four regions of the United States. We obtained information on breast cancer treatment and endometrial cancer risk factors through interviews and reviews of medical records. All P values reported are two-sided. RESULTS: Endometrial cancer risk was associated with tamoxifen therapy for breast cancer (odds ratio = 1.52; 95% confidence interval [CI] = 1. 07-2.17). Risk increased with duration of tamoxifen use (P for trend =.0002). Women with more than 5 years of exposure to tamoxifen had 4. 06-fold greater odds of developing endometrial cancer than nonusers (95% CI = 1.74-9.47). Prior use of estrogen replacement therapy (ERT) increased risk associated with tamoxifen use (P for homogeneity of trends <.0001). Risk associated with tamoxifen use was stronger among heavier women than among thinner women, although trends did not differ statistically (P =.10). Tamoxifen dose-response effects were more pronounced among women with both previous ERT exposure and higher body mass index than among women in other risk groups. CONCLUSIONS: ERT use and obesity, both established endometrial cancer risk factors and markers of estrogen exposure, substantially modify the association between tamoxifen use and endometrial cancer risk among patients with breast cancer. Women with positive ERT histories and those who are obese, when prescribed tamoxifen, may warrant closer surveillance for endometrial cancer than women without such histories. (+info)
Gene-gene and gene-environment interactions determine risk of thrombosis in families with inherited antithrombin deficiency.
(7/387)
To analyze inherited antithrombin deficiency as a risk factor for venous thromboembolism in various conditions with regard to the presence or absence of additional genetic or acquired risk factors, we compared 48 antithrombin-deficient individuals with 44 nondeficient individuals of 14 selected families with inherited antithrombin deficiency. The incidence of venous thromboembolism for antithrombin deficient individuals was 20 times higher than among nondeficient individuals (1.1% v 0.05% per year). At the age of 50 years, greater than 50% of antithrombin-deficient individuals had experienced thrombosis compared with 5% of nondeficient individuals. Additional genetic risk factors, Factor V Leiden and PT20210A, were found in more than half of these selected families. The effect of exposure to 2 genetic defects was a 5-fold increased incidence (4.6% per year; 95% confidence interval [CI], 1.9% to 11.1%). Acquired risk factors were often present, determining the onset of thrombosis. The incidence among those with exposure to antithrombin deficiency and an acquired risk factor was increased 20-fold (20.3% per year; 95% CI, 12.0% to 34.3%). In conclusion, in these thrombophilia families, the genetic and environmental factors interact to bring about venous thrombosis. Inherited antithrombin deficiency proves to be a prominent risk factor for venous thromboembolism. The increased risks among those with exposure to acquired risk factors should be considered and adequate prophylactic anticoagulant therapy in high-risk situations seems indicated in selected families with inherited antithrombin deficiency. (+info)
Exogenous estrogen exposures and changes in diabetic retinopathy. The Wisconsin Epidemiologic Study of Diabetic Retinopathy.
(8/387)
OBJECTIVE: To investigate whether the use of exogenous estrogen is associated with changes in the severity of diabetic retinopathy and the incidence of macular edema. RESEARCH DESIGN AND METHODS: The study design involved observation of two well-defined cohorts of women with diabetes. One group was diagnosed with diabetes at < 30 years of age and used insulin (younger-onset group), and the other group was diagnosed at > or = 30 years of age with no criteria regarding therapy (older-onset group). Subjects received standard examinations, medical interviews, and retinal photography in 1980-1982. Specific questions about exogenous hormone exposure were added to the study questionnaire at the first follow-up examination 4 years after the baseline examination. Change in the severity of retinopathy 6 and 10 years after the 4-year follow-up examination were examined regarding the use of oral contraceptives at the first follow-up examination in the younger-onset group and at 6 years after the first follow-up examination regarding hormone replacement therapy in the older-onset group. RESULTS: Changes in the severity of retinopathy and incidence of macular edema were unrelated to either type of estrogen exposure in univariable and multivariable analyses. CONCLUSIONS: These data are compatible with the hypothesis that the medications used by our population do not affect the severity of diabetic retinopathy or macular edema. (+info)