Comparative life cycle assessment of integrated renewable energy-based power systems.

Integrated renewable-based power cycles should be employed to produce more sustainable electricity. This is a comparative life cycle assessment (LCA) of three combined power plants, encompassing: case 1 involving combined geothermal and wind, case 2 featuring combined geothermal and solar, and case 3 integrating wind and solar systems. The base case perovskite solar cell (PSC) modelling assumes a 3-year lifespan and a power conversion efficiency of 17 %. However, diverse scenarios are evaluated through a sensitivity assessment involving enhancements in lifetime and efficiency. The base case evaluation emphasizes that the phases with the most significant negative environmental effects which includes the drilling of geothermal wells, construction of wind plants, and manufacturing and installation of PSCs. The midpoint findings indicate that boosting the power conversion efficiency of PSC from 17 % to 35 % yields a notable decrease in environmental impact. Moreover, extending the lifetime from 3 to 15 years led to reduction in CO2 emissions from 0.0373 and 0.0185 kg CO2 eq/kWh to 0.026 and 0.0079 kg CO2 eq/kWh in cases 2 and 3, respectively. Assessing worst and best-case scenarios highlights significant declines in certain impact categories. In case 3, terrestrial ecotoxicity (TE), photochemical oxidant formation (POF), human toxicity (HT), marine ecotoxicity (ME), and marine eutrophication (MU) saw reductions exceeding 88 % compared to worst-case results. The environmental effects observed in cases 2 and 3 stem from toxicity and metal depletion, mainly linked to the PSC. Endpoint results revealed that when considering a PSC lifespan of 10 years or more, the detrimental ecosystem impacts of cases 2 and 3 become less severe than those of case 1. Uncertainty assessment has been done for different cases and impact categories. The study's results are also novel in which it evaluated the innovative PSC technology when integrated with other renewable resources, contrasting it with other integrated plants.

Forecasting the ecological footprint of G20 countries in the next 30 years.

The Ecological Footprint evaluates the difference between the availability of renewable resources and the extent of human consumption of these resources. Over the past few decades, historical records have shown an accelerated decline in the availability of resources. Based on national footprint and biocapacity accounts, this analysis aims to advance the forecasting of the G20 countries' ecological footprints over a 30-year time frame. We employed a time series forecasting approach implemented in Python, which included-modular regression (Prophet) and Autoregressive Integrated Moving Average (ARIMA & Auto-ARIMA) methods. We evaluated and combined the performance of these three methods. The results indicated that among the largest economies of the G20, only four countries are projected to have a positive ecological footprint balance by 2050. These countries share the common denominator of large land areas and a moderate population growth projection. However, the overall trend of the indicator suggests that it will continue to decline.

Heat pump supply chain environmental impact reduction to improve the UK energy sustainability, resiliency and security.

Various heat pump technologies are examined from an environmental perspective using a life cycle assessment approach. The investigated heat pump systems utilize air, ground, and water as their energy sources. Additionally, an innovative heat pump powered by green hydrogen is investigated in this study, to evaluate its environmental impacts and potential to commercialise on a large scale. A range of supply chain scenarios is explored, considering the main suppliers of the UK market. The reshoring heat pump industry and supply chain are evaluated to enhance energy resilience and security within the UK. The findings indicate that the hydrogen-based heat pump presents a promising option for the UK market, offering the advantages of reducing stress on the national grid network and minimizing the environmental impacts associated with the supply chain. Furthermore, a forecasting analysis is conducted based on the UK's net-zero emission plan to provide insight into future developments.

Evaluating sustainable development practices in a zero­carbon university campus: A pre and post-COVID-19 pandemic recovery study.

This paper aims to understand the critical areas for sustainable behavioural change on a university campus in order to achieve the net zero­carbon ambition pre- and post-COVID-19 pandemic recovery. For this purpose, the current empirical study is the first attempt to statistically examine the whole campus as a system, considering staff and student views (campus users), by developing an index measuring propensity for sustainable behavioural change to achieve a net zero­carbon campus. The novelty of this study is based on the following: (i) The impact of environmental sustainability measures due to COVID-19 is examined on three themes: physical activity routines on a daily basis, research, and teaching and learning, and (ii) the index that is compatible with quantifying the behavioural change. A multi-indicator questionnaire is used to collect empirical data for each of the three themes. Based on 630 responses, descriptive statistical analysis, normality tests, significance tests, and t-tests are performed using statistical and graphical software, and conducting uncertainty and sensitivity analyses on this quantitative data. The study found that 95 % of campus users agreed to use reusable materials on campus, and 74 % were willing to pay more for sustainable products. In addition, 88 % agreed to seek alternative and sustainable transportation for short research trips, while 71 % prioritised online conferences and project meetings for sustainable hybrid working. Moreover, the COVID-19 pandemic had a negative impact on the frequency of reusable material usage among campus users, as indicated by the index analysis, which showed a significant decrease from 0.8536 to 0.3921. The statistical findings show that campus users are more likely to initiate and endorse environmental sustainability measures in research and daily life than in teaching and learning, and there is no difference in their propensity for change. This research provides net zero­carbon sustainability researchers and leaders with a crucial baseline for scientific advances in the sustainability field. It also offers practical guidelines for implementing a net zero­carbon campus, engaging users from various disciplines, which has important implications and contributions.

A critical analysis of the impacts of COVID-19 on the global economy and ecosystems and opportunities for circular economy strategies.

The World Health Organization declared COVID-19 a global pandemic on the 11th of March 2020, but the world is still reeling from its aftermath. Originating from China, cases quickly spread across the globe, prompting the implementation of stringent measures by world governments in efforts to isolate cases and limit the transmission rate of the virus. These measures have however shattered the core sustaining pillars of the modern world economies as global trade and cooperation succumbed to nationalist focus and competition for scarce supplies. Against this backdrop, this paper presents a critical review of the catalogue of negative and positive impacts of the pandemic and proffers perspectives on how it can be leveraged to steer towards a better, more resilient low-carbon economy. The paper diagnosed the danger of relying on pandemic-driven benefits to achieving sustainable development goals and emphasizes a need for a decisive, fundamental structural change to the dynamics of how we live. It argues for a rethink of the present global economic growth model, shaped by a linear economy system and sustained by profiteering and energy-gulping manufacturing processes, in favour of a more sustainable model recalibrated on circular economy (CE) framework. Building on evidence in support of CE as a vehicle for balancing the complex equation of accomplishing profit with minimal environmental harms, the paper outlines concrete sector-specific recommendations on CE-related solutions as a catalyst for the global economic growth and development in a resilient post-COVID-19 world.

Epidemiology of surgically treated patient in road traffic accident with lower extremity vascular injury from a single centre in Kelantan.

INTRODUCTION: Lower extremity vascular injury can result in either temporary or permanent disability. METHODS: This is a clinical audit involving all patients admitted to our institution from January 2008 to June 2018 of those who had undergone revascularization surgery for lower limb trauma. RESULTS: Fifty-nine patients were in this study with a mean age of 28.1 years. Most of the patients were motorcyclist involved in road traffic accidents with cars (n=30, 50.8%). The popliteal artery was most commonly seen injury (n=41, 69.5%). The mean duration of ischaemia was 14.1 hours. The limb salvage rate was 89.8%. CONCLUSION: Lower extremity vascular injury caused by RTA treated in our institution predominantly involved young patients aged between 18-30 years associated with long bone fractures causing contusion and thrombosis of the popliteal artery.

Probiotic effects of mixture of Groenewaldozyma salmanticensis and Gluconacetobacter liquefaciens on growth and immune responses in Paralichthys olivaceus.

This study was performed to evaluate the effects of dietary probiotics on growth, non-specific immune responses and disease resistance in olive flounder, Paralichthys olivaceus. During 8 weeks, the fish were fed the five experimental diets such as a basal commercial diet (CON), oxytetracycline (OTC) and three basal diets containing Bacillus subtilis (BS), a commercial microbial product (CES) and a mixture of yeast and bacterium (PI), respectively. Fish fed all the probiotics diets and OTC showed a significantly higher growth than fish-fed CON (P < 0·05). Fish-fed PI had a significantly higher nitroblue tetrazolium activity, whereas fish-fed CES showed a higher lysozyme level (P < 0·05). A 7-day challenge test also showed that fish-fed PI had a cumulative survival rate equivalent to that of fish-fed OTC (P < 0·05). Moreover, the diet (PI) appeared to increase the diversity of microbial community in the fish. All these results suggest that the probiotics diet could function as a potential antibiotic replacer in the olive flounder. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is unique in revealing that a diet mixture of yeast, Groenewaldozyma salmanticensis and bacterium Gluconacetobacter liquefaciens can enhance growth, innate immunity and diversity of microbial community including dominant species in the olive flounder. All these indicate that the diet mixture could function as a potential antibiotic replacer in one of the most commercially important fisheries in South Korea.

The environmental impact of fertilizer embodied in a wheat-to-bread supply chain.

Food production and consumption cause approximately one-third of total greenhouse gas emissions1-3, and therefore delivering food security challenges not only the capacity of our agricultural system, but also its environmental sustainability4-7. Knowing where and at what level environmental impacts occur within particular food supply chains is necessary if farmers, agri-food industries and consumers are to share responsibility to mitigate these impacts7,8. Here we present an analysis of a complete supply chain for a staple of the global diet, a loaf of bread. We obtained primary data for all the processes involved in the farming, production and transport systems that lead to the manufacture of a particular brand of 800 g loaf. The data were analysed using an advanced life cycle assessment (LCA) tool9, yielding metrics of environmental impact, including greenhouse gas emissions. We show that more than half of the environmental impact of producing the loaf of bread arises directly from wheat cultivation, with the use of ammonium nitrate fertilizer alone accounting for around 40%. These findings reveal the dependency of bread production on the unsustainable use of fertilizer and illustrate the detail needed if the actors in the supply chain are to assume shared responsibility for achieving sustainable food production.

Drivers of U.S. toxicological footprints trajectory 1998-2013.

By exploiting data from the Toxic Release Inventory of the United States, we have established that the toxicological footprint (TF) increased by 3.3% (88.4 Mt) between 1998 and 1999 and decreased by 39% (1088.5 Mt) between 1999 and 2013. From 1999 to 2006, the decreasing TF was driven by improvements in emissions intensity (i.e. gains in production efficiency) through toxic chemical management options: cleaner production; end of pipe treatment; transfer for further waste management; and production scale. In particular, the mining sector reduced its TF through outsourcing processes. Between 2006 and 2009, decreasing TF was due to decrease in consumption volume triggered by economic recession. Since 2009, the economic recovery increased TF, overwhelming the influence of improved emissions intensity through population growth, consumption and production structures. Accordingly, attaining a less-toxic economy and environment will be influenced by a combination of gains in production efficiency through improvement in emissions mitigation technologies and changes in consumption patterns. Overall, the current analysis highlights the structural dynamics of toxic chemical release and would inform future formulation of effective mitigation standards and management protocols towards the detoxification of the environment.

Identification of 'carbon hot-spots' and quantification of GHG intensities in the biodiesel supply chain using hybrid LCA and structural path analysis.

It is expected that biodiesel production in the EU will remain the dominant contributor as part of a 10% minimum binding target for biofuel in transportation fuel by 2020 within the 20% renewable energy target in the overall EU energy mix. Life cycle assessments (LCA) of biodiesel to evaluate its environmental impacts have, however, remained questionable, mainly because of the adoption of a traditional process analysis approach resulting in system boundary truncation and because of issues regarding the impacts of land use change and N(2)O emissions from fertilizer application. In this study, a hybrid LCA methodology is used to evaluate the life cycle CO(2) equivalent emissions of rape methyl ester (RME) biodiesel. The methodology uses input-output analysis to estimate upstream indirect emissions in order to complement traditional process LCA in a hybrid framework. It was estimated that traditional LCA accounted for 2.7 kg CO(2)-eq per kg of RME or 36.6% of total life cycle emissions of the RME supply chin. Further to the inclusion of upstream indirect impacts in the LCA system (which accounted for 23% of the total life cycle emissions), emissions due to direct land use change (6%) and indirect land use change (16.5%) and N(2)O emissions from fertilizer applications (17.9%) were also calculated. Structural path analysis is used to decompose upstream indirect emissions paths of the biodiesel supply chain in order to identify, quantify, and rank high carbon emissions paths or 'hot-spots' in the biodiesel supply chain. It was shown, for instance, that inputs from the 'Other Chemical Products' sector (identified as phosphoric acid, H(3)PO(4)) into the biodiesel production process represented the highest carbon emission path (or hot-spot) with 5.35% of total upstream indirect emissions of the RME biodiesel supply chain.

The effect of levonorgestrel-releasing intrauterine system use on menstrual blood loss and the hemostatic, fibrinolytic/inhibitor systems in women with menorrhagia.

BACKGROUND: Menorrhagia is known to be associated with uterine fibroids, adenomyosis, pelvic infections, endometrial polyps and clotting defects. A viable alternative therapy to hysterectomy should alleviate heavy menstrual blood flow and consequently improve the quality-of-life measures in women presenting with menorrhagia. The levonorgestrel-releasing intrauterine system (LNG-IUS) ranks higher than medical treatments in terms of efficacy, comparable improvements in quality of life and psychological well-being. OBJECTIVE: The purpose of the study was to determine the effects of 6 months of LNG-IUS use on menstrual blood loss and the hemostatic, fibrinolytic/inhibitor systems in blood and the endometrium in women with menorrhagia with known pathologic causes. PATIENTS AND METHODS: Samples from 41 women were analyzed. Hemoglobin, hematocrit, thrombelastography, tissue-type plasminogen activator (t-PA), urokinase plasminogen activator (u-PA), u-PA receptor (u-PAR), plasminogen activator inhibitor-1/2 (PAI-1/2), D-dimer and von Willebrand factor (VWF) were determined, and t-PA, u-PA and PAI-1/2 were also determined in endometrial tissue extracts. RESULTS: Menorrhagia was reduced in 89% of women by 3 months; by 6 months all women had no menorrhagia, and 39% of women had become amenorrhoeic. Hemoglobin and hematocrit levels showed improvement, and reached normal reference levels by 6 months. There were no systemic changes in the fibrinolytic/inhibitor systems and VWF, except for a decreased u-PAR level. However, in the endometrium, significant elevations in PAI-1/2 together with u-PAR levels were seen at 6 months. CONCLUSIONS: The slow levonorgestrel-release intrauterine device use results in high expression of fibrinolytic inhibitors (PAI-1/2) and upregulated u-PAR expression in the endometrium. Systemic hemostasis was not significantly altered. The study demonstrated that LNG-IUS is highly effective in the treatment of menorrhagia with known pathologic causes.

Socioeconomic and psychosocial factors influence pain or physical function in Asian patients with knee or hip osteoarthritis.

OBJECTIVE: To determine factors influencing pain or physical function in Asian patients with osteoarthritis (OA). METHODS: 126 consecutive Chinese (110), Malays (two), Indians (10), or other races (four) with knee or hip OA and a median age of 60.5 years were seen at a tertiary referral centre; 103 were women. Subjects underwent a structured assessment including the Short Form-36 (SF-36) bodily pain (BP) and physical functioning (PF) scales and assessing demographic, socioeconomic, psychosocial, and other characteristics. Factors influencing BP or PF were identified using separate multiple linear regression models. RESULTS: The index joint (that is, the most symptomatic joint) was the knee in 118 (94%) and the hip in eight (6%) patients. The median duration of pain and limitation of normal activities were three years and one year, respectively. The mean BP and PF scores of 57.7 and 56.2 points for the patients were substantially lower than the expected scores of 79.3 and 80.8 points for the general Singapore population. Multiple regression analysis showed that less pain was associated with a younger age, shorter duration of symptoms, more years of education, working, and Chinese ethnicity. Better physical function was associated with more years of education, less learned helplessness, less bodily pain, and less severe OA. CONCLUSIONS: Socioeconomic status and psychosocial factors, some of which are potentially modifiable, influence pain or physical function in Asian patients with OA in Singapore.

Hemostatic and fibrinolytic status in patients with ovarian cancer and benign ovarian cysts: could D-dimer and antithrombin III levels be included as prognostic markers for survival outcome?

We determined the hemostatic and fibrinolytic status in 60 patients with ovarian cancer and benign ovarian cysts. Hypercoagulation, increased platelets, and enhanced fibrinolysis were seen in patients with preoperative ovarian cancer compared to patients with benign ovarian cysts. Enhanced thrombin generation, evidenced by increased F1+2 and decreased antithrombin III (ATIII) levels with further enhanced fibrinolysis by elevated D-dimer, was seen in advanced cancer. Ten ovarian cancer patients died within 13 months after diagnosis and another died at 24 months, all from advanced stage of cancer, except one from stage IC cancer who died at 11 months. The survival rates from the disease at 13 months and 24 months were 66.7% and 45%, respectively. Most of the patients had gone through the complete course of chemotherapy, and those patients still alive have been disease free between 13 and 42 months. No statistical relationships for the hemostatic parameters studied in ovarian cancer patients could be found between those who died and those still living 13 and 24 months after diagnosis, except for ATIII and D-dimer levels. Elevated D-dimer levels were associated with those who died within 13 and 24 months from the disease, and the decreased ATIII levels only reached statistical significance by 24 months. It could be suggested that these two parameters might be useful as systemic prognostic markers in survival outcome from the disease for the first 24 months in advanced ovarian cancer, in addition to the known correlation with the International Federation of Gynecology and Obstetrics stage.

Effect of diazinon on behavior of Japanese medaka (Oryzias latipes) and gene expression of tyrosine hydroxylase as a biomarker.

This paper reports on the development of a biomarker used to monitor abnormal behaviors caused by diazinon in Japanese medaka (Oryzias latipes) as a model organism. Tyrosine hydroxylase (TH) activity in tissues was measured and the TH enzyme production in specific organs using a in situ cytochemical technique was monitored. These data were comparatively analyzed with those from semi-quantitative RT-PCR utilizing medaka TH gene that could be a potential biomarker for neuronal modulations and behaviors. For monitoring experiments at behavioral and molecular biological levels, the fish were treated under different sublethal conditions of diazinon (O, O-diethyl O-[6-methyl-2-(1-methylethyl)-4-pyrimidinyl] phosphorothioate) and their behavioral responses were observed. There were no significant differences in activity of TH head and body portions when the fish were exposed to lower concentrations (0.5-10 ppb) of diazinon including control treatment (0 ppb) for 24 hr. In temporal change of TH activity at 100 ppb diazinon treatment, however, the activity of body portion appeared to be inhibited during the first 30 min exposure but later seemed to recover slightly after 1 hr. TH appeared to be expressed mainly in the olfactory bulb, midbrain and brain stem regions as assessed by in situ immunohistochemistry. The treatment (1000 ppb) significantly suppressed TH protein production in the olfactory bulb, midbrain and brain stem regions. In kidney from the body portion the higher concentration treatment (1000 ppb) caused little suppression compared with the control. The RT-PCR showed that a production of TH mRNA transcript was significantly inhibited at 5 ppm diazinon treatment in the body portion. It was concluded that a suppression of TH activity would be one of the causes for the abnormal behaviors of the medaka that could be quantitatively monitored using an image processing system. This study provides molecular and neurobehavioral bases of a biomonitoring system for toxic chemicals using a model organism such as fish.

An assessment of the effects on coagulation of midtrimester and final-trimester amniotic fluid on whole blood by Thrombelastograph analysis.

UNLABELLED: The Thrombelastograph((R)) test (TEG; Haemoscope Corporation, Skokie, IL) was used to assess the effects of midtrimester and final-trimester amniotic fluid (AF) on whole blood coagulation. Different volumes of midtrimester and final-trimester AF were added to whole blood from nonpregnant volunteers in a series of TEG tests. The addition of both midtrimester and final-trimester AF resulted in significant decreases in reaction time (P < 0.001) and time from reaction to a fixed level of clot firmness (P < 0.05) and significant increases in angle (P < 0.05) and coagulation index (P < 0.05) values. This reflects accelerated clot initiation and propagation. There was no significant change in the maximal amplitude or % lysis at 30 and 60 min with the addition of either midtrimester or final-trimester AF. There was no significant difference between the effects of midtrimester and final-trimester AF on whole blood TEG. TEG may be an additional useful tool in the treatment of coagulopathy in AF embolism. IMPLICATIONS: We used the Thrombelastograph((R)) test (Haemoscope Corporation, Skokie, IL) to assess the effects of midtrimester and final-trimester amniotic fluid (AF) on whole blood coagulation. Results demonstrate that AF accelerates clot initiation and propagation. The Thrombelastograph((R)) test may be useful in assessing coagulopathy in patients with AF embolism.

A prospective study on the effects of reformulated 2-rod Norplant implant on haemostasis after five years of use.

OBJECTIVE: To evaluate the long-term effects of the new reformulated 2-rod Norplant implant on haemostasis in a prospective group of subjects who have completed 5 years of use. METHODS: Data from 11 women who have completed 5 years' use of the new reformulated 2-rod subdermal implant from the original 16 women who were recruited and randomized to receive this new improved implant in a comparative study were analysed. Clinical assessment and serial blood sampling were done prior to insertion of implant and after 1, 3, 12, 18, 24, 36, 48 and 60 months of implant use. Each subject served as its own control and Analysis of Variance with Student-Newman-Kuels test was used for statistical analysis. The following parameters were determined: plasminogen activators (t-PA, u-PA), plasminogen activator inhibitor-1 (PAI-1), D-dimer, beta-thromboglobulin (beta-TG), thrombin-antithrombin (TAT)-complex, fibrinogen, Factor VII, platelets, haematocrit and haemoglobin levels. RESULTS: No significant change was observed for t-PA levels in prolonged implant use. u-PA antigen showed a significant decrease whilst D-dimer were significantly elevated at only 24 months of implant use compared to pre-implant level. PAI-1 levels were not significantly changed but fibrinogen and FVII levels increased at 36 months and 42 months of use with enhanced platelet activation shown by beta-TG levels at 24 months. Platelet numbers were not affected by prolonged implant use. Haemoglobin concentration and haematocrit level showed significant fluctuations and then return to pre-implant level by 54 and 60 months. CONCLUSION: Enhanced fibrinolysis with platelet activation at 24 months of implant use were seen during the 60 months of 2-rod reformulated Norplant implant use. Hypercoagulable state was not observed although fibrinogen and FVII levels remain above the pre-implant levels as coagulation activation was not enhanced. The increased haemoglobin and haematocrit levels seen indicate enhanced bone marrow activity. There was no association between the use of reformulated 2-rod Norplant implant over 60 months of use and prothrombotic state.

Coagulation and fibrinolysis in viable mid-trimester pregnancies of normal, intrauterine growth retardation, chromosomal anomalies and hydrops fetalis and their eventual obstetric outcome.

A total of 71 pregnant women diagnosed by ultrasound to have viable fetus in late mid- trimester pregnancies of normal, IUGR, hydrops fetalis and chromosomal anomalies were studied for their coagulation, fibrinolytic and inhibitor levels with association on eventual obstetrics outcome. A hypercoagulable state was observed in all the pregnancies studied. However, higher hypercoagulation evidenced by significantly raised prothrombin formation and clot elasticity together with higher levels of D-dimer, uPA antigen and PAI-1 than observed in normal pregnancy suggests a hyperfibrinolytic/inhibitor state in hydrops fetalis pregnancy associated with bad obstetric outcome. In IUGR pregnancy associated with good outcome further enhanced clot elasticity was seen whilst no significant differences were observed in pregnancy with chromosomal anomalies when compared to uncomplicated normal pregnancy. Our study suggests that in hydrops fetalis pregnancy, further enhanced prothrombin formation and hyperfibrinolysis/inhibitor at late mid-trimester is associated with a poor obstetric outcome.

Effects on hemostasis after two-year use of low dose combined oral contraceptives with gestodene or levonorgestrel.

We studied 67 healthy women who were randomly allocated to receive third generation gestodene (Gynera) or second generation levonorgestrel (Microgynon 30) combination of low-dose estrogen oral contraceptives (OCs) for their hemostatic effects over 2 years. Hemostatic changes were apparent within 3 months of OC use. Hematocrit (Hct) was not affected, but hemoglobin (Hb) concentration decreased by 18 months. Shortened prothrombin time (PT) and activated plasma thromboplastin time (APTT) were associated with elevated fibrinogen within the 12-month use of both OCs. Factor VII was reduced only in Micro 30 during the 18 months of use. Enhanced thrombin-antithrombin (TAT)-complex level was seen at 18 months of Gynera use. Prothrombin fragment1+2 (F1+2) rise was seen at 3 months with Micro 30. Reduced antithrombin III (ATIII) activity was seen at 18 months with Gynera and at 24 months with Micro 30. Increased protein C activity was seen at 3 months and reduced protein S occurred at 18 months of Gynera use. Tissue plasminogen activator (t-PA) activity was enhanced for 6 months in both OCs with raised D-dimer levels for 12 months with Gynera and 6 months with Micro 30. Decreased t-PA antigen was seen at 18 months and decreased urokinaselike plasminogen activator (u-PA) antigen occurred throughout the 24 months of both OCs use. Enhanced u-PA activity was only seen in Gynera users. Elevated plasminogen levels were apparent throughout both OCs use. PAI-1 levels were significantly decreased with Micro 30. With Gynera, the decreased PAI-1 activity was seen only at 18 months and PAI-1 antigen at 12 months. No change in platelets and von Willebrand factor (vWF) were seen in long-term OC use except that beta-thromboglobulin (beta-TG) showed decreased trends reaching statistical significance by 18 and 24 months of Micro 30 use and by 24 months of Gynera use. A further significant decrease in beta-TG, u-PA antigen, ATIII, and protein S levels were seen 3 months after pill stoppage compared with pretreatment levels. Activated protein C resistance (APCR) was negative in all subjects before and during OC use. The study indicated dynamic balance between coagulation and fibrinolysis with no endothelial activation. However, because some hemostatic markers showed wide fluctuations during OC use, a longer term study is warranted to investigate any adverse hemostatic changes that might enhance the risks of venous thromboembolism in Asian subjects known to be less prone to thrombosis.

Preeclampsia: haemostatic status and the short-term effects of methyldopa and isradipine therapy.

OBJECTIVE: To determine the haemostatic status in preeclampsia and to investigate the effects of short-term use of anti-hypertensive drugs, methyldopa and isradipine. METHODS: Thirty preeclamptic (PE) women admitted to the hospital for observation and treatment were randomized to receive either methyldopa or isradipine for 2 weeks. Their blood pressure were monitored for 24 h before treatment and again at 7 days and 14 days after treatment using the programmable automated ambulatory blood pressure (ABP) monitoring system. Blood sampling was performed before commencement of anti-hypertensive treatment, 7 days and 14 days after treatment and the haemostatic parameters studied was compared before treatment with normal pregnancy and the effect of anti-hypertensive treatment. Nineteen normal pregnant subjects with a total of 30 blood sampling at various gestation and good pregnancy outcome served as controls. The following haemostatic parameters were determined; thrombelastography, fibrinogen, antithrombin III (ATIII), thrombin-antithrombin (TAT)-complex, beta-thromboglobulin (beta-TG), plasminogen activators (t-PA, u-PA), plasminogen activator inhibitors (PAI-1, PAI-2), and plasminogen. RESULTS: Significant lowering of blood pressure was evident at Days 7 and 14 of therapy with either methyldopa or isradipine. Increased mean plasma fibrinogen and decreased ATIII levels were seen in preeclampsia together with decreased u-PA and t-PA activity levels in contrast to increased t-PA antigen and beta-TG. No significant differences were seen for TAT-complex, PAI-1, plasminogen and D-dimer levels although their mean levels were higher than observed in non-pregnant subject except for PAI-2, the level was significantly reduced when compared with normal pregnancy. Two-way analysis of variance showed no significant alteration on all haemostatic parameters studied in preeclamptic women receiving either methyldopa or isradipine after 7 and 14 days of therapy. CONCLUSION: Enhance activation of coagulation was observed together with raised fibrinolysis in normal pregnancy and PE. However, in PE a further reduction in ATIII, u-PA and PAI-2 with increased fibrinogen and platelet activation could lead to an imbalance in the coagulation/fibrinolysis equilibrium which favours fibrin deposition. All these changes seen in PE including the coagulation kinetics were not altered by the short term effects of methyldopa and isradipine even though significantly lowered blood pressure were observed during therapy.