Acute exposure to realistic concentrations of Bisphenol-A trigger health damage in fish: Blood parameters, gene expression, oxidative stress.

Despite much information regarding BPA toxicity in fish and other aquatic organisms, data is still misleading as most studies have utilized concentrations several orders of magnitude higher than those typically found in the environment. As an illustration, eight of the ten studies investigating the impact of BPA on the biochemical and hematological parameters of fish have employed concentrations on the order of mg/L. Therefore, the results may not accurately represent the effects observed in the natural environment. Considering the information above, our study aimed to 1) determine whether or not realistic concentrations of BPA might alter the biochemical and blood parameters of Danio rerio and trigger an inflammatory response in the fish liver, brain, gills, and gut and 2) determine which organ could be more affected after exposure to this chemical. Findings pinpoint that realistic concentrations of BPA prompted a substantial increase in antioxidant and oxidant biomarkers in fish, triggering an oxidative stress response in all organs. Likewise, the expression of different genes related to inflammation and apoptosis response was significantly augmented in all organs. Our Pearson correlation shows gene expression was closely associated with the oxidative stress response. Regarding blood parameters, acute exposure to BPA generated biochemical and hematological parameters increased concentration-dependent. Thus, it can be concluded that BPA, at environmentally relevant concentrations, threatens aquatic species, as it prompts polychromasia and liver dysfunction in fish after acute exposure.

Hematological effects of glyphosate in mice revealed by traditional toxicology and transcriptome sequencing.

The herbicide glyphosate is being used worldwide. Hematological toxicity caused by glyphosate exposure has been reported, but the underlying mechanisms remain unclear. In this study, classical toxicology methods and RNA sequencing were performed to explore the molecular mechanisms related to glyphosate hematotoxicity. We found that 500 mg/kg b.w. glyphosate-based herbicide (GBH) significantly decreased leukocyte, neutrophil, lymphocyte and monocyte counts, as well as inhibited colony-forming abilities of CFU-GM, CFU-G and CFU-GEMM. RNA sequencing identified 82 and 48 differentially expressed genes (DEGs) in BM cells after treatment with 250 mg/kg and 500 mg/kg GBH, respectively. Meanwhile, GO and KEGG analyses revealed that the MAPK signaling pathway, hematopoietic cell lineage and cytokine-cytokine receptor interactions were vital pathways involved in GBH-induced toxicity in BM cells. Notably, Nr4a, Fos, Thbs1 and tnfrsf19 contributed to the hematotoxicity of GBH by regulating hematopoietic stem cell functions. In summary, our efforts enhance the understanding of the glyphosate hematotoxic responses and facilitate future studies on its corresponding mechanisms.

A high-throughput assay for screening the abilities of per- and polyfluoroalkyl substances in inducing plasma kallikrein-like activity.

The plasma consists of multiple functional serine zymogens, such as plasma kallikrein-kinin system (KKS), which are vulnerable to exogenous chemical exposure, and may closely relate to the deleterious effects. Testing whether the anthropogenic chemicals could increase the kallikrein-like activity in plasma or not would be of great help to understand their potentials in triggering the cascade activation of the plasma zymogens and explain the corresponding hematotoxicity. In this study, a novel high-throughput ex vivo assay was established to screen the abilities of emerging chemicals like per- and polyfluoroalkyl substances (PFASs) in inducing kallikrein-like activities on basis of using rat plasma as the protease zymogen source. Upon the optimization of the conditions in the test system, the assay gave sensitive fluorescent response to the stimulation of the positive control, dextran sulfate, and the dose-response showed a typical S-shaped curve with EC50 of 0.24 mg/L. The intra-plate and inter-plate relative standard deviations (RSDs) were less than 10% in the quantitative range of dextran sulfate, indicating a good reliability and repeatability of this newly-established assay. Using this method, several alternatives or congeners of perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), including 6:2 chlorinated polyfluoroalkyl ether sulfonate (6:2 Cl-PFESA), Ag-PFOA, K-PFOA, Na-PFOA and ammonium pentadecafluorooctanoate (APFO), were further screened, and their capabilities in inducing kallikrein-like activities were identified. The ex vivo assay newly-developed in the present study would be promising in high-throughput screening of the hematological effects of emerging chemicals of concern.

Oxidative stress, metallomics and blood toxicity after subacute low-level lead exposure in Wistar rats: Benchmark dose analyses.

Exposure to lead (Pb) is still rising concern worldwide, having in mind that even low-dose exposure can induce various harmful effects. Thus, in-depth knowledge of the targets of Pb toxicity and corresponding mechanisms is essential. In the presented study, the six groups (male Wistar rats, n = 6) received 0.1; 0.5; 1; 3; 7; 15 mg Pb/kg body weight/day for 28 days, each day by oral gavage, while the control group received distilled water only. All animals were sacrificed 24 h after the treatment, and blood was collected for the analysis of hematological, biochemical, oxidative status and essential elements levels. An external and internal dose-response relationship was performed using PROASTweb 70.1 software. The results showed that low doses of Pb affect hematological parameters and lipid profile after 28 days. The possible mechanisms at examined Pb dose levels were a decrease in SOD, O2•- and Cu and an increase in Zn levels. The dose-dependent nature of changes in cholesterol, HDL cholesterol, O2.-, SOD, AOPP in serum and hemoglobin, Fe, Zn, Cu in blood were obtained in this study. The most sensitive parameters that were alerted are Cu blood levels (BMDL5: 1.4 ng/kg b.w./day) and SOD activity (BMDL5: 0.5 µg/kg b.w./day). The presented results provide information that may be useful in further assessing the health risks of low-level Pb exposure.

Evaluation of postoperative pain and toxicological aspects of the use of dipyrone and tramadol in cats.

OBJECTIVES: The aim of this study was to evaluate the effects of dipyrone and tramadol, used for 5 days, on postoperative pain, hematological and biochemical parameters, and oxidative markers on erythrocytes. METHODS: Twenty-eight healthy cats underwent ovariohysterectomy and were randomly allocated to four groups (each n = 7), according to the postoperative treatment administered intravenously: control (saline 1 ml q8h), DIP1 (dipyrone 25 mg/kg q24h), DIP2 (dipyrone 25 mg/kg q12h) and DIP3 (dipyrone 25 mg/kg q8h). All animals received tramadol (2 mg/kg q8h). Pain was assessed by visual analog (VAS), multidimensional UNESP and Glasgow pain scales for cats preoperatively and at 3, 6, 12, 24, 36 and 48 h after extubation. Venous blood was collected daily for 5 days, and on day 10, to perform a complete blood count (CBC) and determine the percentage of Heinz bodies (HBs). Serum biochemistry was evaluated preoperatively and on days 5 and 10; superoxide dismutase (SOD), catalase (CAT), myeloperoxidase (MPO) and lipoperoxidation were evaluated preoperatively and on days 3, 5 and 10. RESULTS: Control cats had higher pain scores than DIP3 cats by UNESP (P = 0.0065), and DIP2 (P = 0.0035) and DIP3 cats (P = 0.0108) by VAS 3 h postoperatively. Rescue analgesia was required by two animals in the control group and one each in the DIP1 and DIP2 groups. There was no difference in SOD or CAT among groups. On day 5, MPO was more active in DIP2 than in DIP3 cats (P = 0.0274). No difference in lipoperoxidation among treatment and control cats was found. CBC remained constant and without statistical difference among groups. Control, DIP2 and DIP3 cats presented a similar percentage of HBs on day 10. Biochemical variables were similar among groups and times. CONCLUSIONS AND RELEVANCE: The administration of dipyrone in cats, when used in combination with tramadol, did not ensure better analgesia than tramadol alone. Dipyrone did not significantly affect biochemical variables and oxidative markers, despite minimal, clinically irrelevant, hematological differences between groups.

Hematological parameters on the effect of the jellyfish venom Cassiopea andromeda in animal models.

For the first time, we previously recorded an enormous population of the Cassiopea andromeda jellyfish that had increased dramatically from Bushehr coasts of Iran. The sub-acute toxicity of the jellyfish venom in rat organs was correspondingly carried out. The data presented in this paper relate to the in vivo and in vitro hematological effects of this venomous species of jellyfish venom.

Effect of Repeated Administration of Cefquinome on Biochemical and Hematological Parameters in Buffalo Calves.

AIM: Cefquinome, a fourth generation of cephalosporins have been developed for use in animals. Similar to other species, it may also have some adverse reactions in buffalo calves at therapeutic dosage. In the present study, effect of repeated administration of cefquinome on biochemical and hematological parameters was studied in buffalo calves. MATERIALS AND METHODS: Animals were divided into two groups having three animals in each group. Group 1 was kept as control and animals of Group 2 were given cefquinome at dose rate of 2 mg.kg(-1) body weight by intramuscular route for continuously 7 days. Blood samples were collected daily and 3 days post treatment. RESULTS: The values of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGTP), and alkaline phosphatase (ALKP) in control animals were in the range of 127.7-148.3 IU/L,49.0-55.6 IU/L, 14.0-17.3 IU/L, and 111.0-134.3 IU/L, respectively. The repeated administration of cefquinome did not influence the plasma activities of AST, ALT, GGTP, and ALKP in treated animals. The level of blood urea nitrogen (BUN) and creatinine before treatment was 14.3 ± 0.88 mg/dl and1.70 ± 0.04 mg/dl, which significantly increased on 3(rd) day (21.0 ± 1.53 mg/dl) and 2(nd) day (2.33 ± 0.07 mg/dl), respectively. Among hematological parameters, there was significant variation in levels of hemoglobin (Hb), total erythrocyte count (TEC), erythrocyte sedimentation rate (ESR), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) in treated animals. No abnormal clinical symptoms were observed in any animal. CONCLUSION: The results revealed that clinically, the therapy of cefquinome may be continued up to 7 days.

A comparison of hemodynamic data derived by pulmonary artery flotation catheter and the esophageal Doppler monitor in preeclampsia.

OBJECTIVE: This study was undertaken to compare hemodynamic data derived with the esophageal Doppler monitor against those obtained with a pulmonary artery flotation catheter in women with complicated preeclampsia. STUDY DESIGN: Seventeen women with severe preeclampsia who had a pulmonary artery flotation catheter placed for clinical indications also had an esophageal Doppler monitor inserted. Hemodynamic data were recorded on 2 occasions separated by several hours with both the pulmonary artery flotation catheter and the esophageal Doppler monitor simultaneously. RESULTS: The esophageal Doppler monitor underestimated cardiac output by 36% +/- 14% (mean +/- SD). The esophageal Doppler monitor accurately estimated cardiac output in 3 women >40 years old, whereas in the remaining women (all <35 years old) the esophageal Doppler monitor underestimated cardiac output by 38% +/- 11%. The esophageal Doppler monitor accurately reflected changes in cardiac output with time when compared with the pulmonary artery flotation catheter. CONCLUSION: In women with preeclampsia the esophageal Doppler monitor consistently underestimated cardiac output by approximately 40%. It is not known whether the apparent increase in accuracy among the women >40 years old arose by chance or reflected a real improvement in performance. The esophageal Doppler monitor accurately reflected the direction and magnitude of the changes in cardiac output with time.

Changes in menstrual and haematological indices among Norplant acceptors.

A longitudinal study of women using Norplant(R) was conducted to determine the effects of levonorgestrel implants on menstrual and haematological indices among the acceptors. Packed cell volume (PCV), white blood cell (WBC) concentrations (total and differential), and platelet concentration were performed at pre-insertion and at the 12-month follow-up. Each acceptor received a menstrual calendar to chart all bleeding, and spotting events. The mean PCV was 40.5 +/- 2. 4 at insertion and had a statistically significant (p <0.01) rise to a mean value of 42.2 +/- 2.6 at 12 months. The mean WBC concentration had a significant decrease at 12 months (p <0.001) when compared with the pre-insertion value. Similarly, the neutrophil and lymphocyte concentration had a statistically significant decrease (p <0.05 and p <0.01, respectively) at 12 months of use. The reduced values in the concentrations of monocytes, eosinophils and basophils did not reach significant levels. The mean value of the platelet concentrations had a significant decline at 12 months of use (p <0.001). Reduced bleeding patterns were more commonly reported compared to increased bleeding episodes. This pattern was associated with increased PCV, a change that may prevent anaemia in developing countries. The decline in the platelet concentration at 12 months of study was, however, a source of concern that will require follow-up.

Assessment of different sources of variation in the antibody responses to specific malaria antigens in children in Papua New Guinea.

BACKGROUND: A potential problem for malaria vaccine development and testing is between-host variation in antibody responses to specific malaria antigens. Previous work in adults in an area highly endemic for Plasmodium falciparum in Papua New Guinea found that genetic regulation partly explained heterogeneity in responsiveness. We have now assessed the relative contributions of environmental and genetic factors in total IgG responses to specific malaria antigens in children, and quantified temporal variation within individuals of total IgG responses. METHODS: Total IgG responses against schizont extract, merozoite surface protein-1, merozoite surface protein-2, ring-infected erythrocyte surface antigen, and SPf66 were measured by ELISA. Variance component analysis was used to estimate the variation explained by genetic and environmental factors in these antibody responses. Intra- and inter-class correlations of antibody responses within relative pairs were estimated. We adjusted for age, P. falciparum density, sex and village differences either within or prior to the analysis. RESULTS: For all malaria antigens, temporal variation in the total IgG response was the predominant source of variation. There was substantial familial aggregation of all IgG responses, but it remained unclear how much this clustering was attributable to genetic factors and how much to a common environment in the household. The remaining variance, which could not be explained by either of the above, was very small for most of the antigens. CONCLUSIONS: Temporal variation and clustering of immune responses to specific malaria antigens need to be taken into account when planning, conducting and interpreting immuno-epidemiological and vaccine studies.

Hemostatic effects of smoking and oral contraceptive use.

This review addresses current knowledge of the effects of lower dose oral contraceptives (containing 35, 30, or 20 micrograms of ethinyl estradiol) on hemostasis in smoking and nonsmoking women. Evidence suggests that formulations containing 30 and 35 micrograms ethinyl estradiol induce a significant activation of coagulation, whereas oral contraceptive preparations with 20 micrograms ethinyl estradiol appear to have a negligible effect or no effect. In nonsmokers who take oral contraceptives any procoagulatory effects that may occur are counterbalanced by fibrinolytic effects. In smokers, however, compensatory fibrinolytic effects to offset the procoagulatory effects seen with 30-micrograms ethinyl estradiol oral contraceptive formulations are absent, shifting the hemostatic profile toward a hypercoagulable state. This suggests that a formulation with the lowest dose of ethinyl estradiol may be most suitable for smokers who wish to use this form of contraception.

PIP: This review addresses current knowledge of the effects of lower-dose oral contraceptives (OCs) (containing 35, 30, or 20 mcg of ethinyl estradiol) on hemostasis in smoking and nonsmoking women. Data showed that the OCs containing 30-35 mcg ethinyl estradiol influence a significant activation of coagulation parameters compared to the 20-mcg formulations, which appear to have little or no procoagulatory effect. However, procoagulatory effects of these OCs showed to be counterbalanced by the compensatory anticoagulation effects within the fibrinolytic system. This would indicate that most healthy women taking lower-dose OCs, particularly those containing 20 mcg ethinyl estradiol, are not at increased risk for thromboembolic disease. However, this compensatory activity of the fibrinolytic system does not occur in women who both smoke and use OCs. Studies documented that simultaneous smoking and OC use could lead to hypercoagulation. This suggests that OCs with the lowest effective dose of ethinyl estradiol are the best contraceptives for smokers.

Effects of oral contraceptives on hemostasis and thrombosis.

OBJECTIVE: The object of the study was to determine the effects of oral contraceptives on blood coagulation, in particular on the protein C pathway. STUDY DESIGN: Plasma samples from healthy men, from healthy female users and nonusers of oral contraceptives, and from heterozygous and homozygous male and female carriers of the factor V Leiden mutation (some of whom used oral contraceptives) were tested for their sensitivity to activated protein C by means of a new activated protein C resistance test developed in our laboratory. This assay is based on measurement of the effect of activated protein C on the endogenous thrombin potential, the time integral of thrombin generation initiated in plasma through the extrinsic coagulation pathway. RESULTS: The normalized activated protein C sensitivity ratio ([ETP+APC/ETP-APC]plasma/[ETP+APC/ETP-APC]normal plasma, where ETP is endogenous thrombin potential, +APC is with activated protein C, and -APC is without activated protein C) of men was lower than that of healthy female nonusers of oral contraceptives. The normalized activated protein C sensitivity ratio of the users of oral contraceptives was significantly higher than that of nonusers of oral contraceptives. The normalized activated protein C sensitivity ratio of women who were using oral contraceptives with third-generation progestogens was higher than that of users of oral contraceptives with second-generation progestogens. Furthermore, the normalized activated protein C sensitivity ratio of 80% of the users of third-generation preparations fell within the 5th to 95th percentile of the normalized activated protein C sensitivity ratio of female carriers of factor V Leiden, a mutation that is associated with hereditary resistance to activated protein C and with an increased risk of venous thromboembolism. CONCLUSION: Acquired activated protein C resistance may explain the increased risk of venous thromboembolism among users of oral contraceptives reported in epidemiologic studies and the higher risk of venous thromboembolism among users of oral contraceptives with third- versus second-generation progestogens.

PIP: The studies described in this review were designed to examine the in vitro effects of oral contraceptives (OCs) on blood coagulation, particularly their effects on the protein C pathway. The sensitivity to activated protein C was tested using a new developed activated protein C resistance. Data showed that the use of OCs is associated with acquired activated protein C resistance; also, plasma samples of women who use third-generation OCs show more resistance than those of second-generation OC users. There appears to be a remarkable correlation between the normalized activated protein C sensitivity ratio determined with the endogenous thrombin potential-based assay and the increased risks of venous thromboembolism. The normalized activated protein C sensitivity ratio of OC users was significantly higher than in non-OC users. It is shown that 80% of users of third-generation OCs had normalized activated protein C sensitivity ratios, which fell within the 5th-95th percentile for the factor V Leiden heterozygous carriers. Moreover, OC use and factor V Leiden mutation appears to intensify and affects the activity of protein C pathway. This review indicates that the acquired activated protein C resistance explains the increase in venous thromboembolism among users of OCs with third- vs. second-generation progestogens.

Decreased plasma tissue factor pathway inhibitor in women taking combined oral contraceptives.

Use of combined oral contraceptives (OC) is associated with a significant risk of thrombosis. The mechanisms of this effect are not clearly defined. Tissue factor pathway inhibitor (TFPI) is a circulating anti-coagulant that inhibits the earliest steps in activation of the extrinsic coagulation pathway. It plays a central role in control of coagulation but its contribution to the thrombotic risk associated with OC has not been assessed. Plasma TFPI antigen and activity, factor VIIa, prothrombin fragments 1&2, von Willebrand antigen, fibrinogen, and low density lipoprotein cholesterol were measured by standard assays in women taking OC (aged 16 to 45 years, n = 40) and age-matched women not taking OC (controls, n = 40). Plasma TFPI antigen did not vary significantly across the menstrual cycle in controls. Women on OC had a 25% reduction in plasma TFPI antigen (median 51.0 ng/ml; 95% confidence intervals [CI] 37.5 to 85.5; control 68.0 ng/ml, CI 61.0 to 95.0; P < 0.001) and a 29% reduction in TFPI activity (78.5 U/ml, CI 57.5 to 107.5; control 111.0 U/ml, CI 79.5 to 171.0; P < 0.001) compared to controls. Plasma factor VIIa activity and prothrombin fragments 1&2 were also significantly increased in women using OC (both P < 0.001), indicating activation of the extrinsic coagulation pathway. These results demonstrate that normal cyclic variations in estrogen and/or progesterone do not significantly alter plasma TFPI levels. However, estrogens and/or progestogens in OC result in activation of the extrinsic coagulation pathway and significantly reduce plasma TFPI, its major circulating inhibitor. Reduced plasma TFPI levels may underlie the thrombotic effects of OC.

PIP: This article reports the findings of a study that determined whether use of oral contraceptive (OC) is associated with significant changes in plasma tissue factor pathway inhibitor (TFPI), which may contribute to thrombotic risk. Plasma TFPI antigen and activity, factor VIIa, prothrombin fragments 1 and 2, von Willebrand antigen, fibrinogen, and low density lipoprotein cholesterol were measured by standard assays in 40 women aged 16-45 taking OCs and 40 age-matched women not taking OCs. Results revealed that the plasma TFPI antigen did not vary significantly across the menstrual cycle in controls. Women on OCs had a 25% reduction in plasma TFPI antigen (median, 51.0 ng/ml; 95% confidence interval (CI), 37.5-85.5; controls, 68.0 ng/ml; CI, 61.0-95.0) and a 29% reduction in TFPI activity (78.5 U/ml; CI, 57.5-107.5; controls, 111.0 U/ml; CI, 79.5-171.0) compared to controls. Plasma factor VIIa activity and prothrombin fragments 1 and 2 were also significantly increased in women using OCs, indicating activation of the extrinsic coagulation pathway. These results demonstrate that normal cyclic variations in estrogen and/or progesterone do not significantly alter plasma TFPI levels. However, estrogens and/or progesterone in OCs result in activation of the extrinsic coagulation pathway and significantly reduce plasma TFPI, its major circulation inhibitor. In conclusion, reduced plasma TFPI levels may underlie the thrombotic effects of OCs.

Metabolic and fibrinolytic response to changed insulin sensitivity in users of oral contraceptives.

The fundamental role of insulin resistance for metabolic changes linked to cardiovascular disease and type 2 diabetes is increasingly recognized. Oral contraceptives (OC) may affect insulin sensitivity, and a detailed characterization hereof, as well as the secondary effects on related metabolic systems, are relevant in the evaluation of the risk of developing vascular disorders or diabetes in OC users. We studied insulin sensitivity index (S(I)), glucose effectiveness (S(g)), and insulin response in young, healthy women by frequently sampled intravenous glucose tolerance tests before and after randomization to 6 months of treatment with ethinyl estradiol in triphasic combination with norgestimate (n = 17) or gestodene (n = 20). Measurements of fasting triglycerides and antigen concentrations of tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type 1 (PAI-1) were also included. Both compounds increased fasting plasma insulin and reduced S(i) but did not affect S(g). The relationships between S(i) and insulin response were unchanged. No consistent correlation between insulin sensitivity and triglycerides, t-PA, or PAI-1 were demonstrated before or during treatment. We conclude that the treatments were followed by a compensated decrease in insulin sensitivity that was unrelated to changes in triglycerides, t-PA, or PAI-1 antigen.

Correlation of coagulation abnormalities with clinical outcome in neonates of mothers with pregnancy induced hypertension.

Abnormalities in coagulation profile were correlated with clinical outcome in neonates (n = 30) of mothers with pregnancy induced hypertension (PIH). Same number of neonates born to normotensive mothers was taken as control. Significant correlation was observed between decreasing gestational age and alterations in all coagulation parameters. Higher incidence of prematurity, hyperbilirubinaemia and significant prolongation in partial thromboplastin time with kaolin (PTTK) and thrombin time (TT) values were observed with increasing severity of PIH. Incidence of disseminated intravascular coagulation (DIC) was higher in preterm neonates than in term neonates.

PIP: The association between coagulation abnormalities and pregnancy outcome was investigated in a case-control study conducted at Lady Hardings Medical College and Associated Hospitals in New Delhi, India, in 1991-92. Enrolled were 30 neonates born to mothers with pregnancy-induced hypertension (PIH) and 30 infants of normotensive mothers. Compared with control infants, infants of mothers with PIH had significantly elevated levels of prothrombin time (PT), partial thromboplastin time with kaolin (PTTK), thrombin time (TT), and fibrinogen and fibrinogen degradation products (FDP) and significantly reduced platelet counts and fibrinogen. PTTK and TT were significantly higher in neonates born to mothers with hypertension of more than 1 month's duration, but the difference in PT, fibrinogen, and platelet count was not significant. Also observed was a significant correlation between decreasing gestational age and derangement in all coagulation parameters and between decreasing birth weight and an increase in FDP level. The incidence of disseminated intravascular coagulation was higher in preterm than term neonates. 43.3% of neonates required admission to the neonatal intensive care unit and the perinatal mortality rate was 3.3%.

Resistance to activated protein C in women using oral contraceptives.

Resistance to activated protein C (APC resistance) is an important and common risk factor for deep vein thrombosis. The majority of patients with APC resistance carry a mutation on the factor V gene at nucleotide position 1691 (G/A), called factor V Leiden mutation. Besides the factor V Leiden mutation several acquired risk factors like lupus anticoagulant, elevated levels of acute phase proteins (increased plasma levels of factor VIII and fibrinogen), pregnancy, or the use of oral contraceptives are known to induce APC resistance in plasma. We studied the effect of oral contraceptives (OC) on hemostasis variables known to be risk factors for venous thromboembolism, especially looking for acquired APC resistance and the plasmatic factors of the protein C system. We studied 821 women, who were randomly selected and enrolled in the BATER- cohort study (Bavarian Thromboembolic Risk Study), which was carried out in Bavaria (Germany) from 1996 to 1997. Current use of any OC type compared with noncurrent use showed a significantly impaired response to APC. There was no difference in APC response among women currently using OCs of different generations. Coagulation factor VIII was the only factor of the protein C pathway that was not altered under OC use. All other plasmatic factors of the protein C system changed in the expected range as described before. On the other hand, coagulation factor VIII was the only factor of the protein C system which negatively correlated with the APC response in the assays applied. Thus, APC resistance is significantly lower in OC users than in nonusers but cannot be attributed to increased factor VIII levels. Whether a decreased response to APC in OC users is of clinical relevance has to be proven in further studies.

PIP: Activated protein C (APC) resistance has been identified in many studies as a major cause of venous thromboembolism. The most common genetic polymorphism of clinical relevance causing APC resistance is the factor V Leiden mutation (FVL). Besides the FVL mutation, several acquired risk factors like lupus anticoagulant or elevated levels of acute phase proteins are known to induce APC resistance in plasma. Oral contraceptive (OC) users are known to be at higher risk for deep vein thrombosis than nonusers. Therefore, this BATER-cohort study (Bavarian Thromboembolic Risk Study) was conducted in Bavaria, Germany, during 1996-97. A total of 821 women were randomly selected and enrolled in the study to examine the effects of OCs on hemostasis variables known to be risk factors for venous thromboembolism, especially looking for acquired APC resistance and the plasmatic factors of the protein C system. Findings revealed that APC resistance was significantly lower in OC users in comparison with nonusers and was not attributable to the increased factor VIII:C levels. APC methods applied in this study revealed no significant difference between OC users of any type. Therefore, an increase of the risk related to OC use and/or FVL mutation was statistically insignificant.

Humoral immunity status in neonates born to pre-eclamptic toxaemia mothers.

A prospective study on 90 neonates born to age matched normal mothers (set I) and mothers (set II) with pre-eclamptic toxaemia (PET) was undertaken to assess and compare the humoral immunity status of the neonates. All of them had normal vaginal delivery. IgG, IgA and IgM were estimated by radial immunodiffusion technique from cord blood of neonates. It was observed that IgA and IgM levels were insignificant in the cord blood. IgG level was low in normal birth weight (NBW) neonates born to PET mothers, when compared to that of NBW neonates born to normal mothers. Again low birth weight (LBW) babies of both the sets showed lower values of IgG than that of NBW babies. Apgar scoring showed direct relationship with IgG levels e.g., higher the Apgar score higher the level of IgG. Thus the IgG level was directly related to the birth weight of the neonates of the respective sets as well as with the Apgar scoring of the neonates.

PIP: A prospective study conducted at the Medical College in Calcutta, India, assessed the immunoglobulin G (IgG) levels of infants born to mothers with pre-eclamptic toxemia (PET). 90 low-income mothers 17-32 years of age admitted to the facility in 1992-93 were enrolled; 46 had normal pregnancies and 44 had PET. Women with PET were admitted at 28-30 weeks of gestation to ensure adequate rest and nutrition before delivery. 67.4% of infants of women with a normal pregnancy and 54.4% of those in the PET group were low birth weight. Apgar scores were good to excellent in both groups. In both study groups, IgG levels were higher in infants of normal birth weight and higher Apgar scores than in those with low birth weight and lower Apgar scores. The lower level of IgG in low-birth-weight infants is probably attributable to blockage of the IgG-specific Fc receptor site in the placenta due to acute atherosis and reduced uteroplacental perfusion.

Urbanization and childhood leukaemia in Taiwan.

BACKGROUND: In the 1980s socioeconomic development was dramatically rapid in the urbanized municipalities of Taiwan due to a prospering economy. This study addressed the question: Could differences in the incidence of childhood leukaemia (age <15) be demonstrated between urban and rural communities in Taiwan between 1981 and 1990? METHODS: The log-linear regression model was used to assess the effects of age, level of urbanization, and calendar year on the variation of childhood leukaemia incidence rates between 1981 and 1990. RESULTS: Between 1981 and 1990, the overall incidence rate of childhood leukaemia increased by 20% (rate ratio (RR) = 1.2, 95% CI: 1.0-1.5). As compared to rural areas, metropolitan regions showed a significantly higher incidence rate during the study period (RR = 1.3, 95% CI: 1.1-1.6). This urban-rural difference was particularly notable among children <5 years old (RR = 1.5, 95% CI: 1.2-1.9). Dose-response analysis further indicated that risk of childhood leukaemia was monotonically associated with levels of urbanization. The significant gradient in the risk of childhood leukaemia with urbanization was contributed solely by children in the 0-4 years age group. CONCLUSIONS: We noticed a relationship between urbanization and risk of leukaemia in children. Because of a dramatic influx of people into metropolitan areas during the 1980s, our findings may have provided support for the putative association between 'population mixing' or 'population density' and risk of childhood leukaemia. Whether such association can be attributable to virus infection or other aetiologically related leukemogens warrants further investigations.

PIP: A log-linear regression model was applied to national cancer registry data on all childhood leukemia cases diagnosed and reported in Taiwan during 1979-90 in a study to measure the effects of age, level of urbanization, and calendar year upon the variation of childhood leukemia incidence rates between 1981 and 1990. Urban Taiwan underwent a period of rapid socioeconomic development during the 1980s. 1498 cases of leukemia among people under age 15 years were diagnosed during 1981-90 and reported to the Cancer Registry Center of Taiwan. 57.6% of these cases were acute lymphoblastic leukemia, 25.6% were nonlymphoblastic leukemia, and 16.8% were chronic leukemia and those unclassified. Acute lymphoblastic leukemia was the most common subtype in all age groups, with a pronounced peak at 0-4 years. The overall incidence rate of childhood leukemia in Taiwan increased by 20%. When compared to rural areas, metropolitan regions had a significantly higher incidence rate during the study period. That urban-rural difference was especially notable among children under age 5 years. Dose-response analysis further indicated that risk of childhood leukemia was monotonically associated with levels of urbanization. The significant gradient in the risk of childhood leukemia with urbanization was contributed solely by children aged 0-4 years.

Hemostatic effects of oral contraceptives in women who developed deep-vein thrombosis while using oral contraceptives.

OBJECTIVE: Comparison of the effect of oral contraceptives on hemostatic variables in venous thrombosis patients (thrombosis while using oral contraceptives) with the effect in healthy control subjects. Our aim was to assess whether some of these effects were more pronounced in women who had suffered thrombosis, i.e., whether these were "hemostatic hyperresponders". STUDY DESIGN: A population-based case-control study, the Leiden Thrombophilia Study. MATERIALS AND METHODS: We investigated 99 pre-menopausal women, age 15-49 years, who had used oral contraceptives at the time of a first, objectively confirmed episode of deep-vein thrombosis. They were not pregnant, nor in puerperium, nor had had a recent miscarriage, and were not using injectable progestogens, nor suffering from inherited coagulation defects. The median time between occurrence of deep-vein thrombosis and venepuncture was 18 months, and 30 of the 99 women were still using oral contraceptives, while 69 had discontinued oral contraceptive use. In addition, a group of 153 control women (54 of them were oral contraceptive users and 99 were non-users) were studied. The following hemostatic variables were measured: APTT, factor VII, factor VIII, factor XII, fibrinogen, prothrombin, total antithrombin, normalised activated protein C sensitivity ratio (n-APC-sr), protein C, protein S and free protein S. RESULTS: We found marked and significant effects of oral contraceptive use on the levels of several clotting factors, with an increase in factor VII, factor XII, protein C and a decrease in antithrombin, n-APC-sr and protein S. Less marked effects that were non-significant or only significant in either patients or controls, were an increase in factor VIII, fibrinogen and prothrombin and a decrease in the APTT and free protein S. In the former thrombosis patients several of these effects of oral contraceptives were more pronounced than in healthy women: specifically on factor VII, antithrombin, n-APC-sr and protein C. CONCLUSIONS: Our results of the effects of oral contraceptives generally confirm previous reports in healthy volunteers. Our data also show that in former deep-vein thrombosis patients these effects are more pronounced. Apparently some women become "high hemostatic responders" when exposed to oral contraceptives, and they may be the women most vulnerable to its thrombogenic effects.

PIP: This population-based case-control study compared the effect of oral contraceptives (OCs) on hemostatic variables in venous thrombosis patients with the effect on healthy control subjects. A total of 99 premenopausal women aged 15-49 years, who had used OCs at the time of a first, objectively confirmed episode of deep-vein thrombosis, were studied. The median time between occurrence of deep-vein thrombosis and venepuncture was 18 months, and 30 of the 99 women were still using OCs, while 69 had discontinued OC use. In addition, a group of 153 control women (54 of them were OC users and 99 were nonusers) were also studied. The following hemostatic variables were measured: activated thromboplastin time (APTT), factor VII, factor VIII, factor XII, fibrinogen, prothrombin, total antithrombin, normalized activated protein C (n-APC-sr), protein C, protein S, and free protein S. Findings revealed significant effects of OC use on the levels of several clotting factors, with an increase in factors VII and XII and protein C and a decrease in antithrombin, n-APC-sr, and protein S. Less marked effects that were nonsignificant or only significant in either patients or controls were an increase in factor in VIII, fibrinogen, and prothrombin and a decrease in APTT and free protein S. Several of these effects of OCs were more pronounced in former thrombosis patients than in healthy women specifically on factor VII, antithrombin, n-APC-sr, and protein C. In conclusion, former deep-vein thrombosis patients are most vulnerable to the thrombogenic effects of OCs.

Effects on hemostatic variables of desogestrel- and gestodene-containing oral contraceptives in comparison with levonorgestrel-containing oral contraceptives: a review.

In some studies third-generation oral contraceptives have been reported to be associated with a higher risk of venous thromboembolism than are second-generation oral contraceptives, whereas recent, more refined studies have not confirmed this. The reasons for the alleged differences are under discussion, and differential effects on hemostasis have been proposed. Eighteen studies comparing second- and third-generation oral contraceptives with respect to their effects on hemostasis were analyzed. Significant changes from baseline were reported for many variables with both second- and third-generation oral contraceptives without significant between-group differences. Also, in a combined analysis of nonsignificant changes, no consistent pattern of change emerged for any marker, with the exception of higher factor VII levels associated with third-generation oral contraceptives. However, factor VII is not related to venous thromboembolism risk. In addition, 1 cross-sectional study with an unvalidated assay reported a higher ratio of activated protein C sensitivity with third-generation oral contraceptives. Only 2 components of the hemostatic system (factor VII and activated protein C sensitivity ratio) emerged as potentially differentially affected by second- and third-generation oral contraceptives; the association with venous thromboembolism risk is questionable in the former case and unknown in the latter.

PIP: The initial finding of an increased risk of venous thromboembolism in users of third-generation oral contraceptives (OCs) has not been confirmed in recent, more methodologically refined studies. This article reviews 17 prospective studies with healthy volunteers and one cross-sectional study that compared second- and third-generation OCs in terms of their effects on markers of hemostasis. Significant changes from baseline were reported for many variables with both second- and third-generation OCs. For example, activated partial prothrombin clotting time, protein S, and tissue plasminogen activator and its inhibitor were reduced during OC treatment. However, none of the studies reported statistically significant differences between treatment groups for any of these markers. In a combined analysis of nonsignificant changes, no consistent pattern emerged for any coagulation or fibrinolysis parameter with the exception of higher factor VII levels (not related to venous thromboembolism risk) associated with third-generation formulations. The cross-sectional study with an unvalidated assay found a higher ratio of activated C protein sensitivity with third-generation OCs. Only two components of the hemostatic system--factor VII and activated protein C sensitivity ratio--emerged as potentially differentially affected by second- and third-generation OCs. The association with venous thromboembolism risk is questionable in the former cases and unknown in the latter.