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The treatment of severe or recurrent deep venous thrombosis. Beneficial effect of the co-administration of antiplatelet agents with or without rheological effects, and anticoagulants.

Deep venous thromboses can be divided into two groups according to their pathogenesis, anatomical features and differing responses to therapy. The first and most frequent consists of so-called simple venous thrombosis while the second group, which is less common, comprises severe or recurrent venous thrombosis characterised by a multifactorial pathogenesis, a mixed thrombus rich in platelets and by an incomplete response to both prophylactic and therapeutic treatment with anticoagulants (heparin or vitamin K antagonist). In a randomized, prospective blind study in patients with severe or recurrent venous thrombosis, which included 6 groups each of 100 patients, co-administration of anticoagulants with various types of antiplatelet agent, either with rheological effects (piracetam, buflomedil, pentoxifylline) or without them (dipyridamole), has shown a beneficial potentiating antithrombotic effect with those drugs possessing rheological effects and the absence of this effect with dipyridamole.

Adult↗

Hemostasis activation in patients with liver cirrhosis.

In patients with liver cirrhosis a decrease of the coagulant potential is well-documented and has been linked to the high bleeding tendency among these patients. Whether the decrease of the coagulant potential is only due to a reduced hepatic synthesis of coagulation factors or also to its consumption by disseminated intravascular coagulation is debatable. We investigated hemostasis activation markers thrombin-antithrombin III complexes (TAT), fibrin degradation products (D-Dimer) and plasmin-alpha 2-antiplasmin complexes (PAP) in 41 outpatients with liver cirrhosis (Child-Pugh index 1 n = 18, 2 n = 15, 3 n = 8). Compared to controls similar in terms of age and sex, TAT, D-Dimer and PAP was elevated in the whole group of patients. A progressive increase of D-Dimer and PAP from Child 1 to 3 indicates a relationship between the severity of cirrhosis and the amount of hemostasis activation. Investigation of the natural anticoagulant potential showed significant decreases of antithrombin III (AT III), protein C, and protein S, most pronounced in Child 3 patients. Statistical analysis revealed significant negative correlations between levels of D-Dimer and both AT III and protein C, indicating that hemostasis activation is linked to the loss of anticoagulant potential.

Adult↗

Erythrocytes from diabetics with neuropathy have fewer sodium pumps.

Erythrocytes from diabetics with neuropathy had fewer binding sites for ouabain and, therefore, fewer sodium pumps than did erythrocytes from diabetics without neuropathy or from age-matched controls (P less than 0.001). Diabetics with neuropathy excreted in their urine significantly less C-peptide immunoreactivity (CPR) than those without neuropathy, which is a sign of lower endogenous insulin secretion levels. Significant positive correlations existed between the number of pumps and tibial motor nerve conduction velocity (MNCV) and urinary CPR in diabetics, and between urinary CPR and MNCV. This suggests that there is close correlation between the fall in the number of pumps in diabetics and diabetic neuropathy and insulin deficiency.

Biomarkers↗

Blood group antigens in the intrahepatic biliary tree. II. Type 1 chain N-acetyllactosamine-related carbohydrate antigens in the proliferated bile ductules.

The expression of the carbohydrate antigens related to type 1 chain N-acetyllactosamine (1NAcLc) in the proliferated bile ductules was immunohistochemically examined in liver tissues of 10 cases of chronic hepatitis (CH), 9 of liver cirrhosis (LC) and 8 of alcoholic hepatitis. The ductular expression of the examined blood group antigens was essentially the same among these pathological conditions. The backbone structure, i.e., 1NAcLc (Gal beta 1----3GlcNAc beta 1----3Gal beta 1----3R), was not detected in the proliferated ductules as in the normal bile ductules. Its fucosylated structures (Le(a), Le(b) and type 1 chain H) were more strongly expressed in the proliferated ductules than in the normal ductules. Sialyl-Le(a) which was not found in the normal ductules was detected weakly but definitely in the proliferated ductules. Besides proliferated ductules, single or small numbers of epithelial cells expressing the 1NAcLc-related antigens were found intralobularly. This suggests possible migration of biliary epithelial cells into the hepatic lobules. In conclusion, within the proliferated bile ductules (a) synthesis of the 1NAcLc-related antigens is increased compared to the normal ductules, (b) the backbone structure is completely sialylated or fucosylated as in the normal ductules and (c) alpha 1----4fucosylation of sialyl-1NAcLc, i.e., sialyl-Lea, formation occurs despite its absence in the normal ductules.

Adolescent↗

Accurate prediction of human drug toxicity: a major challenge in drug development.

Over the past decades, a number of drugs have been withdrawn or have required special labeling due to adverse effects observed post-marketing. Species differences in drug toxicity in preclinical safety tests and the lack of sensitive biomarkers and nonrepresentative patient population in clinical trials are probable reasons for the failures in predicting human drug toxicity. It is proposed that toxicology should evolve from an empirical practice to an investigative discipline. Accurate prediction of human drug toxicity requires resources and time to be spent in clearly defining key toxic pathways and corresponding risk factors, which hopefully, will be compensated by the benefits of a lower percentage of clinical failure due to toxicity and a decreased frequency of market withdrawal due to unacceptable adverse drug effects.

Clinical Trials as Topic↗

Effects of the insecticide permethrin on three life stages of the grass shrimp, Palaemonetes pugio.

Toxicity of the pyrethroid insecticide permethrin was assessed using three life stages of the estuarine grass shrimp, Palaemonetes pugio. Adult and larval shrimp were tested with and without sediment. An aqueous embryo test was also conducted. Cellular stress biomarkers, glutathione, and lipid peroxidation, were assessed. Larval shrimp were the most sensitive life stage with a 96-h lethal concentration (LC(50)) value of 0.05 microg/L, compared to 0.25 microg/L for adults, and 6.4 microg/L for embryos. The presence of sediment significantly decreased toxicity of permethrin to both adult and larval shrimp. Permethrin exposure increased time to hatch in embryos and decreased swimming behavior of larvae. Lipid peroxidation levels were significantly decreased in the adult shrimp, but increased in larval shrimp exposed to permethrin. Low levels of permethrin may negatively affect grass shrimp health and survival. Permethrin use in the coastal zone should be carefully managed to avoid adverse impacts on nontarget estuarine organisms.

Animals↗

Subcutaneous microchip-associated tumours in B6C3F1 mice: a retrospective study to attempt to determine their histogenesis.

Fifty-two subcutaneous tumours associated with microchip were collected from three carcinogenicity B6C3F1 mice studies. Two of these 52 tumours were adenocarcinoma of the mammary gland located on the dorsal region forming around the chip. All the other 50 were mesenchymal in origin and were difficult to classify on morphological grounds with haematoxylin-eosin. These sarcomas were investigated using a panel of immunohistochemistry and special stains consisting of desmin, smooth muscle actin (SMA), myogenin, S100, mouse macrophages, phosphotungstic acid haematoxylin (PTAH) and Masson's trichrome (MT). All the sarcomas displayed the same histochemical characteristics and a close immunophenotype, characterized by desmin +/-, SMA+, myogenin--, S100--, mouse macrophages + and PTAH-. These tumours thus appear to have similar histologic-type lineage and designation as sarcomas not otherwise specified (NOS) with a large myofibroblastic component appears today to be more appropriate and it is likely to clarify them in the future with the emergence of new markers.

Animal Identification Systems↗

Investigation of volatile biomarkers in lung cancer blood using solid-phase microextraction and capillary gas chromatography-mass spectrometry.

In the present work, solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) was developed for investigation of lung cancer volatile biomarkers. Headspace SPME conditions (fiber coating, extraction temperature and extraction time) and desorption conditions were optimized and applied to determination of volatiles in human blood. To find the biomarkers of lung cancer, investigation of volatile compounds in lung cancer blood and control was performed by using the present method. Concentrations of hexanal and heptanal in lung cancer blood were found to be much higher than those in control blood. The two molecules of hexanal and heptanal were regarded as biomarkers of lung cancer. By comparison of volatiles in breath and in blood, it is demonstrated that hexanal and heptanal in breath were originated from blood and screening of lung cancer by breath analysis be feasible. These results show that SPME/GC-MS is a simple, rapid and sensitive method very suitable for investigation of volatile disease markers in human blood.

Adult↗

Long-term trends in accumulated metals (Cd, Cu and Zn) and metallothionein in bivalves from lakes within a smelter-impacted region.

Temporal monitoring studies are needed to detect long-term trends in ecosystem health. In the present study, we tested metallothionein (MT) as a potential biomarker for long-term variations in trace metal levels in lakes subject to atmospheric metal inputs from a nearby copper smelter. Over a 13-year period, we estimated on several occasions ambient free Cd2+, Cu2+ and Zn2+ concentrations at the sediment-water interface in six lakes with contrasting metal levels, and measured metal and metallothionein concentrations in gills of bivalves (Pyganodon grandis) living in these lakes. All but one of the study lakes had comparable drainage ratios, so inter-lake differences in hydrological export of metals from contaminated watersheds to receiving waters were likely minimal. Declines in the metal emissions from the smelter (especially for Cd and Zn) during the 1980s led to appreciable decreases in both calculated free Cd2+ ion concentrations in the study lakes (-59+/-21% between 1989 and 1998) and accumulated Cd levels in their clam populations (-46+/-12% between 1989 and 2002). Taking all lakes into account, MT concentrations in bivalves have comparatively dropped by 44% (+/-10%) since 1989. In contrast to what we found for Cd, there were no significant reductions in the calculated free Cu2+ and Zn2+ concentrations in the various lakes during our study period (-2 and -10%, respectively, with 95% confidence intervals spanning zero). Overall, observed decreases in MT in bivalves over time were best correlated with similar decreases in both ambient and accumulated Cd levels (r = 0.77, P = 0.0003 and r = 0.79, P < 0.0001, respectively, both P-values corrected for temporal autocorrelation), suggesting that long-term trends in gill MT concentrations in P. grandis may be useful as predictors of temporal changes in environmental Cd contamination in lakes.

Animals↗

Multistep and multifactorial carcinogenesis: when does a contributing factor become a carcinogen?

Our greatest successes in fighting cancer derive from the identification and removal or inactivation of carcinogenic substances, and from the identification and removal of pre-malignant lesions. In comparison, our successes at treating already formed malignancies have been minimal. Therefore, emphasis should be put in identifying and removing pre-malignant lesions, and in the identification and removal of those agents that cause or contribute to cancer development. It is important to target initiators, co-carcinogens and promoters, since by removing any one of them, tumor growth may be prevented. Identification of these agents is difficult. Epidemiological studies largely study cancer after it has occurred. It would be preferable to identify potential carcinogenic substances at an earlier stage before they have caused a large number of malignancies and thus become identifiable by epidemiology. During the past three decades, we have accumulated an impressive amount of evidence concerning molecular pathways that when altered contribute to malignant growth. It is time that we start applying this knowledge to the identification of human carcinogens. Here, we review the molecular changes that are required for carcinogenesis and propose some criteria that, in the absence of epidemiological evidence, can be used to identify agents that cause or contribute to human cancer development. In the absence of epidemiological evidence, a given agent should be considered a human carcinogen when: (1) the agent causes or contributes to the development of tumors in animals that are of the same type as those tumors associated with exposure to the agent in humans; (2) the agent transforms or contributes to the transformation of human cells in culture and these cells are of the same type from which associated human malignancies arise; (3) there is molecular evidence that the agent interferes with one or more key molecular pathways in human cells which leads to the formation of human cancer.

Animals↗

The associations between leisure-time physical activity and inflammatory and coagulation markers related to cardiovascular disease: the ATTICA Study.

BACKGROUND: As coronary heart disease is increasingly seen as an inflammation process, we evaluated the hypothesis whether physical activity reduces coronary heart disease risk by modifying the levels of inflammatory and coagulation markers. METHODS: From May 2001 to December 2002, we randomly enrolled 1524 adult men and 1518 women, without any evidence of cardiovascular disease, stratified by age-gender (census 2001), from the greater area of Athens, Greece. We assessed the relationship between self-reported physical activity status and inflammation markers (high sensitivity C-reactive protein, serum amyloid-A, fibrinogen, interleukin-6, tumor necrosis factor-alpha, and white blood cell counts), after taking into account the effect of several confounders. RESULTS: Eight hundred seventy-four (57%) of men and 903 (59%) of women were classified as sedentary. Multivariate statistical analysis after adjustment for gender, age, smoking habits, body mass index, total cholesterol, blood glucose, and systolic and diastolic blood pressure levels showed that participants devoted to high physical activity (>7 kcal/min expended) had 29% lower levels of C-reactive protein, 19% of white blood cell counts, 22% lower concentrations of amyloid-A, 20% lower levels of tumor necrosis factor-alpha, 32% of interleukin-6, and 11% of fibrinogen (all P<0.05) as compared to those who were devoted to sedentary life. CONCLUSIONS: Our findings suggest that the adoption of a physically active lifestyle modifies the inflammation process in healthy individuals.

Adult↗

Embolized ischemic lesions of toes in an afibrinogenemic patient: possible relevance to in vivo circulating thrombin.

Fibrinogen plays a complex role in hemostasis, thrombosis, and vascular disease. Hyperfibrinogenemia is an independent vascular risk factor and dysfibrinogenemia can provoke thrombosis. Afibrinogenemia is usually responsible for hemorrhagic diathesis, and unexpected ischemic lesions are intriguing. We report the case of an afibrinogenemic patient, who at the age of 30 developed ischemic lesions of the feet related to severe stenosis of the iliac and hypogastric arteries. The biopsy of the iliac artery lesion showed an intense myointimal hyperplasia. We performed standard hemostatic analysis and analyzed the activation markers of platelets and coagulation factors and the kinetics of thrombin generation in the patient and in normal control plasmas treated or not with reptilase. Occlusive arterial lesions were attributed to a disruptive hematoma penetrating the vascular lumen. Thrombin concentration after calcium addition increase markedly in the afibrinogenemic patient and in defibrinated normal plasma, as compared to untreated normal plasma. Thrombin-antithrombin complexes (T-AT) were markedly enhanced while F1+2 prothrombin fragments stayed in the normal range. These results suggested activation of coagulation and in vivo circulating thrombin. Thrombin activates the platelets that secrete growth factors for smooth muscle cells and generate the intimal hyperplasia. Recurrent hemorrhage within the vessel wall might induce injury and local thrombin generation. Thrombin not trapped by the clot is available for platelet activation and smooth muscle cell migration and proliferation. The absence of a protective fibrin cap on the intima might account for intima vulnerability and embolization. Afibrinogenemia appears in this paradoxical situation as a vascular risk factor.

Adult↗

The effect of delayed analysis or freeze-thawing on the measurement of natural anticoagulants, resistance to activated protein C and markers of activation of the haemostatic system.

We provide a centralised thrombophilia screening service with sample transfer by courier or first class mail, a practice common to many centres. Sample quality is of prime importance, thus we have assessed the effect of delayed sample handling upon the haemostatic variables within our thrombophilia profile. This comprises screening for familial natural anticoagulant deficiency and APC resistance (1-4), and acquired lupus anticoagulant (5,6). The effect upon hypercoagulable markers were also assessed to facilitate evaluation of these in prospective clinical studies (7).

Anticoagulants↗