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111.
In natural ecosystems it is not unusual for an organism to be exposed both to chemical and physical stressful factors at the same time. Herein we present results of the study on nickel toxicity to the carabid beetle, Pterostichus oblongopunctatus, and effect of Ni and temperature on the beetles respiration rates. In the first part of the study (Experiment I) we measured the survival, respiration rates and internal Ni concentrations in animals exposed for 245 d at constant temperature (20 °C) to food contaminated with Ni at nominal concentrations 0; 600; 1,200; 2,400; 4,800; and 9,600 mg kg−1 dry weigh (dw). The LC50 was estimated at 8,351 mg Ni kg−1, with no effect on fertility. We found a significant positive correlation between Ni concentration in food and internal body concentration of Ni, and a negative correlation between Ni exposure and the respiration rate. Based on these results, the concentration of 2,400 mg kg−1 (LOEC for the respiration rate) was selected for the second part of the study (Experiment II) in which field-collected males of P. oblongopunctatus were exposed to Ni-contaminated food for 64 d and then to uncontaminated food for the next 64 d at three temperatures: 10, 15 and 20°C. In this part of the study we found that the temperature under which the beetles were kept affected their respiration rates, and that effect of Ni on the respiration was significant only in animals originating from 20°C. The results from both experiments indicate that negative effects of nickel appear only after relatively long exposure.  相似文献   
112.
Prostacyclin among prostanoids   总被引:2,自引:0,他引:2  
Prostanoids are cyclic lipid mediators which arise from enzymic cyclooxygenation of linear polyunsaturated fatty acids, e.g. arachidonic acid (20:4 n 6, AA). Biologically active prostanoids deriving from AA include stable prostaglandins (PGs), e.g. PGE(2), PGF(2alpha), PGD(2), PGJ(2) as well as labile prostanoids, i.e. PG endoperoxides (PGG(2), PGH(2)), thromboxane A(2) (TXA(2)) and prostacyclin (PGI(2)). A "Rabbit aorta Contracting Substance" (RCS) played important role in discovering of labile PGs. RCS was discovered in the Vane's Cascade as a labile product released along with PGs from the activated lung or spleen. RCS was identified as a mixture of PG endoperoxides and thromboxane A(2). Stable PGs regulate the cell cycle, smooth muscle tone and various secretory functions; they also modulate inflammatory and immune reactions. PG endoperoxides are intermediates in biosynthesis of all prostanoids. Thromboxane A(2) (TXA(2)) is the most labile prostanoid (with a half life of 30 s at 37 degrees C). It is generated mainly by blood platelets. TXA(2) is endowed with powerful vasoconstrictor, cytotoxic and thrombogenic properties. Again the Vane's Cascade was behind the discovery of prostacyclin (PGI(2)) with a half life of 4 min at 37 degrees C. It is produced by the vascular wall (predominantly by the endothelium) and it acts as a physiological antagonist of TXA(2). Moreover, prostacyclin per se is a powerful cytoprotective agent that exerts its action through activation of adenylate cyclase, followed by an intracellular accumulation of cyclic-AMP in various types of cells. In that respect PGI(2) collaborates with the system consisting of NO synthase (eNOS)/nitric oxide free radical (NO)/guanylate cyclase/cyclic-GMP. Both cyclic nucleotides (c-AMP and c-GMP) act in synergy as two energetic fists which defend the cellular machinery from being destroyed by endogenous or exogenous aggressors. Recently, a new partner has been recognized in this endogenous defensive squadron, i.e. a system consisting of heme oxygenase (HO-1)/carbon monoxide (CO)/biliverdin/biliverdin reductase/bilirubin. The expanding knowledge on the pharmacological steering of this enzymic triad (PGI(2)-S/eNOS/HO-1) is likely to contribute to the rational therapy of many systemic diseases such as atherosclerosis, diabetes mellitus, arterial hypertension or Alzheimer diseases. The discovery of prostacyclin broadened our pathophysiological horizon, and by itself opened new therapeutic possibilities. Prostacyclin sodium salt and its synthetic stable analogues (iloprost, beraprost, treprostinil, epoprostenol, cicaprost) are useful drugs for the treatment of the advanced critical limb ischemia, e.g. in the course of Buerger's disease, and also for the treatment of pulmonary artery hypertension (PAH). In this last case a synergism between prostacyclin analogues and sildenafil (a selective phosphodiesterase 5 inhibitor) or bosentan (an endothelin ET-1 receptor antagonist) points our to complex mechanisms controlling pulmonary circulation. At the Jagiellonian University we have demonstrated that several well recognised cardiovascular drugs, e.g. ACE inhibitors (ACE-I), statins, some of beta-adrenergic receptor antagonists, e.g. carvedilol or nebivolol, anti-platelet thienopyridines (ticlopidine, clopidogrel) and a metabolite of vitamin PP--N(1)-methyl-nicotinamide--all of them are endowed with the in vivo PGI(2)-releasing properties. In this way, the foundations for the Endothelial Pharmacology were laid.  相似文献   
113.
The purpose of this study was to estimate exposure of pregnant women in Poland to fine particulate matter [less than or equal to 2.5 microm in diameter (PM 2.5)] and to assess its effect on the birth outcomes. The cohort consisted of 362 pregnant women who gave birth between 34 and 43 weeks of gestation. The enrollment included only nonsmoking women with singleton pregnancies, 18-35 years of age, who were free from chronic diseases such as diabetes and hypertension. PM 2.5 was measured by personal air monitoring over 48 hr during the second trimester of pregnancy. All assessed birth effects were adjusted in multiple linear regression models for potential confounding factors such as the size of mother (maternal height, prepregnancy weight), parity, sex of child, gestational age, season of birth, and self-reported environmental tobacco smoke (ETS). The regression model explained 35% of the variability in birth weight (beta = -200.8, p = 0.03), and both regression coefficients for PM 2.5 and birth length (beta = -1.44, p = 0.01) and head circumference (HC; beta = -0.73, p = 0.02) were significant as well. In all regression models, the effect of ETS was insignificant. Predicted reduction in birth weight at an increase of exposure from 10 to 50 microg/m3 was 140.3 g. The corresponding predicted reduction of birth length would be 1.0 cm, and of HC, 0.5 cm. The study provides new and convincing epidemiologic evidence that high personal exposure to fine particles is associated with adverse effects on the developing fetus. These results indicate the need to reduce ambient fine particulate concentrations. However, further research should establish possible biologic mechanisms explaining the observed relationship.  相似文献   
114.
This paper presents the possibility of applying bacterial strains from the Bacillus group in the microbial solubilization of phosphorus-bearing waste materials. Fishbones, bones and ash from sewage sludge incineration were used as renewable phosphorus sources. Bacterial consortia in combinations of 1–4 strains were used for phosphate solubilization, including B. thuringiensis, B. megaterium, B. subtilis and B. cereus. Fishbones showed the highest degree of bioavailable phosphorus (20.5% of total content, of which 99.1% was bioavailable). The combination of two raw materials fishbone and sewage sludge ash (1:1) gave the best results of solubilization efficiency (over 70%) using a consortium containing 3 bacterial strains. A consortium consisting of B. cereus and B. thuringiensis, the activity of which resulted in the highest phosphorus concentration in the culture medium, was selected for larger scale tests. The produced application batch of liquid biofertilizer contained 0.54% P2O5 and high levels of micronutrients including iron (0.16%). The biological effectiveness of biofertilizer was confirmed in plant studies, where strong root stimulation (up to 33%) and an increase in chlorophyll content (over 20%) were observed for seeds soaked in biofertilizer. This form of application is being recommended over plant nutrition with granular phosphorus fertilizers. Through the use of waste materials, the research conducted in this paper fits into the topic of sustainability.  相似文献   
115.
ObjectiveWe previously reported an association between prenatal exposure to airborne polycyclic aromatic hydrocarbons (PAH) and lower birth weight, birth length, and head circumference. The main goal of the present analysis was to assess the possible impact of coexposure to PAH-containing barbecued meat consumed during pregnancy on birth outcomes.Materials and methodsThe birth cohort consisted of 432 pregnant women who gave birth at term (>36 wk of gestation). Only non-smoking women with singleton pregnancies, 18–35 y of age, and who were free from chronic diseases such as diabetes and hypertension, were included in the study. Detailed information on diet over pregnancy was collected through interviews and the measurement of exposure to airborne PAHs was carried out by personal air monitoring during the second trimester of pregnancy. The effect of barbecued meat consumption on birth outcomes (birth weight, length, and head circumference at birth) was adjusted in multiple linear regression models for potential confounding factors such as prenatal exposure to airborne PAHs, child's sex, gestational age, parity, size of mother (maternal prepregnancy weight, weight gain in pregnancy), and prenatal environmental tobacco smoke.ResultsThe multivariable regression model showed a significant deficit in birth weight associated with barbecued meat consumption in pregnancy (coeff = ?106.0 g; 95%CI: ?293.3, ?35.8). The effect of exposure to airborne PAHs was about the same magnitude order (coeff. = ?164.6 g; 95%CI: ?172.3, ?34.7). Combined effect of both sources of exposure amounted to birth weight deficit of 214.3 g (95%CI: ?419.0, ?9.6). Regression models performed for birth length and head circumference showed similar trends but the estimated effects were of borderline significance level. As the intake of barbecued meat did not affect the duration of pregnancy, the reduced birth weight could not have been mediated by a shortened gestation period.ConclusionIn conclusion, the study results provided epidemiologic evidence that prenatal PAH exposure from diet including grilled meat might be hazardous for fetal development.  相似文献   
116.
Osteolytic bone destruction, caused by the aberrant production and activation of osteoclasts, results in significant morbidity for patients with multiple myeloma (MM). Pamidronate [(3-amino-1-hydroxypropylidene)-1,1-bis-phosphonate] inhibits osteoclastic activity and reduces bone resorption. A potency of zoledronic acid (2-[imidazol-1-yl]-1-hydroxyethylidene-1,1-bisphosphonic acid, a new third generation bisphosphonate, as inhibitor of resorption was 850-fold greater than pamidronate, as was shown in preclinical models of bone resorption. Randomized, double-blind study was conducted to compare the efficacy and safety of zoledronic acid and pamidronate for treating myeloma bone disease. Since March 1999 the efficacy and safety of pamidronate and zoledronic acid is evaluated in MM patients all receiving anti-myeloma chemotherapy acc. to VMCP/VBAP alternating regimen. Nine patients with stage III myeloma and osteolytic lesions (3 female, 6 male, median age 57 years, range 52-67, with monoclonal protein: IgG-7, IgA-2) were randomly assigned (1:1:1 ratio) to treatment with either 4 or 8 mg of zoledronic acid via 15-minute intravenous infusion or 90 mg of pamidronate via 2-hour intravenous infusion every 3 to 4 weeks for 12 months. All patients have received 500 mg of calcium supplements and 500 IU of vit.D, orally, once daily, for the duration of administration of study medication. In extension phase of the study (June 2000-April 2002) patients did not received bisphosphonates. In 7 patients 18 cycles of assessed treatment was administered to each of them and one patient received 16 cycles. One patient died after receiving of 12 pamidronate therapy cycles at 11 month of the trial duration (and at 49 month since MM diagnosis and anti-tumour treatment). The patient's death occurred during the progression of plasma cell proliferation due to acute left ventricle cardiac failure. During the 12-month-period of bisphosphonate treatment skeletal related events (SRE) and progression of osteolysis occurred with the same frequency in 3 treatment groups. One patient experienced spinal cord compression and received radiation to bone and 2 patients experienced vertebral fracture. Time from study entry to the first SRE was 304 days in pamidronate and 366 and 392 days in 4 and 8 mg zoledronic acid group, respectively. The skeletal morbidity rate was identical in all treatment groups. Single hypocalcemic events occurred in 2 patients, mild hypertransaminasemia was observed in 3, worsening of renal function parameters in 2 patients (transient in one of them). Muscular pain and fever up to 39 degrees C (transient and self-limiting "flu-like" symptoms) occurred in 6 patients after several or some dozens of hours from study drug administration. Adverse events were similar in nature and frequency with zoledronic acid and pamidronate and were experienced by a similar proportion of patients in each treatment group. Median time of patient's observation duration after completing of administered treatment with zoledronic acid and pamidronate amounts to 20 months. At present actual median survival time of analysed patients since MM diagnosis is 42 months, since the beginning of treatment with pamidronate and zoledronic acid--33 months, and since completing treatment--20 months and is similar in 3 treatment groups. As was shown in our single center study in MM patients the safety and efficacy of pamidronate 90 mg and zoledronic acid 4 mg and 8 mg in monthly i.v. infusion are comparable. Thus the recommended dosage of zoledronic acid is 4 mg administered as a 15 minute i.v. infusion at intervals of 3 to 4 weeks.  相似文献   
117.
Background and Aims: An enterocutaneous fistula (ECF) poses a major surgical problem. The definitive surgical repair of persistent fistulas remains a surgical challenge with a high rate of re-fistulation and mortality, and the reasons for that is not the surgical technique alone. Enhanced Recovery after Surgery (ERAS®) is an evidence-based multimodal perioperative protocol proven to reduce postoperative complications. The aim of the study was to assess the clinical value of the ERAS protocol in surgical patients with ECF. Methods: ERAS protocol was used in all patients scheduled for surgery for ECF at the Stanley Dudrick’s Memorial Hospital in Skawina between 2011 and 2020. A multidisciplinary team (MDT) was in charge of the program and performed annual audits. A consecutive series of 100 ECF patients (44 females, 56 males, mean age 54.1 years) were evaluated. Postoperative complications rate, readmission rate, length of hospital stay, prevalence of postoperative nausea and vomiting were assessed. Registered under ClinicalTrials.gov Identifier no. NCT04771832. Results: ERAS protocol was successfully introduced for ECF surgeries; however, eight modifications to the ERAS program was performed in 2015. They led to improvement of surgical outcomes: reduction of postoperative nausea and vomiting (15 vs. 17% patients, p = 0.025), overall complication rate (11 vs. 10, p = 0.021), median length of hospital stay (overall and after surgery, p = 0.022 and 0.002, respectively). Conclusions: ERAS protocol can be successfully used for ECF patients. Prescheduled audits can contribute to the improvement of care.  相似文献   
118.
119.
Lipid peroxidation products measured as a malondialdehyde and activities of superoxide dism utase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-R), and concentrations of ascorbic acid,-tocopherol, and glutathione (GSH) were measured in the liver, erythrocytes, and serum of rats 6, 14, and 24 h and 2, 5, and 7 d after treatment with 3 g methanol/ kg. GSH-Px and GSSG-R activities, GSH level, and ascorbate concentration in the liver, erythrocytes, and blood serum were significantly decreased. In addition, SOD and-tocopherol in erythrocytes were diminished, while malondialdehyde (MDA) in liver, erythrocytes, and serum were elevated. Further, erythrocyte counts, hemoglobin levels, hematocrit, and mean corpuscular volume (MCV) were reduced. These results indicate that methanol intoxication in rats leads to an increase in the lipid peroxidation and impairment in the antioxidant mechanisms in liver, erythrocytes, and blood serum.  相似文献   
120.
The brain's noradrenergic system is involved in the development of behaviours induced by drugs of abuse, e.g. dependence and withdrawal, and also reward or psychomotor effects. To investigate how noradrenergic system activity is controlled in the context associated with drug-induced behaviours, we generated a Cre/loxP mouse model in which the essential glutamate NMDA receptor subunit NR1 is ablated in cells expressing dopamine β-hydroxylase (Dbh). As a result, the noradrenergic cells in NR1DbhCre mice lack the NMDA receptor-dependent component of excitatory post-synaptic currents. The mutant mice displayed no obvious behavioural alterations, had unchanged noradrenaline content and mild increase in dopamine levels in the nucleus accumbens. Interestingly, NR1DbhCre animals did not develop morphine-induced psychomotor sensitization. However, when the morphine injections were preceded by treatment with RX821002, an antagonist of α2-adrenergic receptors, the development of sensitization was restored. Conversely, pretreatment with clonidine, an agonist of α2-adrenergic receptors, blocked development of sensitization in wild-type mice. We also found that while the development of tolerance to morphine was normal in mutant mice, withdrawal symptoms were attenuated. These data reveal that NMDA receptors on noradrenergic neurons regulate development of opiate dependence and psychomotor sensitization, by controlling drug-induced noradrenaline signalling.  相似文献   
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