Brook trout exposed to one ppb Cd; added as cadmium chloride in the holding water, accumulated the metal in the gills, kidneys, and livers with time. The greatest uptake was in the gills and posterior kidneys which showed similar accumulation patterns (r=0.99 and 0.94 respectively) with an exposure time of 93 days. Cd levels in the posterior kidneys were always higher than those in the anterior (head) kidneys in both Cd-exposed and the control fish. The Cd content in the gills and posterior kidneys in both the control and Cd-exposed fish was much higher than in the other tissues, and the levels in the muscle of the exposed fish were generally about three-fold higher than those found in the controls, but they remained low (0.030±0.014 ppm). The Cd content of the whole blood and plasma, heart, spleen, testes, stomach and skin of the Cd-exposed fish after 77 and 93 days were higher than those of the control fish. Brook trout injected with 1 g Cd/g body weight, intramuscularly (i.m.), once a week for 16 weeks also accumulated the metal, primarily in the posterior kidneys and gills, but there was less accumulation in the gills than in the fish exposed to one ppb Cd in water. Unlike the Cd-water study, a significant uptake of the metal occurred in the red cells, blood plasma, and muscle. No significant uptake occurred in the gonads. The red cells and gills had about the same Cd content (0.500–0.550 ppm), suggesting that much of the Cd in the gills may have come from the blood content, an observation which was not apparent in the fish that were exposed to Cd in the water.The results suggest that the gills and posterior kidneys were sensitive organs for testing the effects of chronic sublethal exposure of brook trout to Cd. 相似文献
Background. Whether cardiac reinnervation occurs after transplantation remains controversial. If reinnervation does occur, how sympathetic and parasympathetic efferent neurons do this remains unknown.
Methods. Power spectral analysis of heart rate variability was assessed for 1 year after cardiac autotransplantation in 9 dogs. After induction of anesthesia 13 months after transplantation, cardiac and intrinsic cardiac neuronal responses elicited by both electrical stimulation of parasympathetic or sympathetic efferent neurons and systemic or local coronary artery administration of nicotine (5 μg/kg), angiotensin II (0.75 μg/kg), and tyramine (1.2 μg/kg) were studied. The transmembrane electrical properties of intrinsic cardiac neurons were studied in vitro. Ventricular tissue catecholamine content, -tubulin expression, and β-adrenergic receptor density and affinity were studied. The presence of axons crossing suture lines was sought histologically.
Results. Nerves were identified crossing suture lines. Electrical or chemical (ie, nicotine or angiotensin II) activation of sympathetic efferent neurons enhanced cardiodynamics, as did tyramine. Stimulating vagal efferent preganglionic axons induced bradycardia in half of the dogs. Functional reinnervation did not correlate with specific power spectra derived from rate variability in the conscious state. Responding to nicotine and angiotensin II in situ, transplanted intrinsic cardiac neurons generated spontaneous activity. These neurons displayed nicotine-dependent synaptic inputs in vitro. Ventricular tissue had normal β-adrenergic receptor affinity and density but reduced catecholamine and -tubulin contents.
Conclusions. The intrinsic cardiac nervous system receives reduced input from extracardiac sympathetic efferent neurons after transplantation and inconsistent input from parasympathetic efferent preganglionic neurons. These heterogeneous neuronal inputs are not reflected in heart rate variability or ventricular β-adrenergic receptor function. Transplanted angiotensin II–sensitive intrinsic cardiac neurons exert greater cardiac control than do nicotine-sensitive ones. The intrinsic cardiac nervous system remodels itself after cardiac transplantation, and this indicates that direct assessment of extracardiac and intrinsic cardiac neuronal behavior is required to fully understand cardiac control after transplantation. 相似文献
ObjectivesTo use an “evidence-mapping” approach to assess the usefulness of Cochrane reviews in identifying research gaps in the maternal health.Study Design and SettingThe article describes the general mapping, prioritizing, reconciling, and updating approach: (1) identifying gaps in the maternal health research using published systematic reviews and formulating research questions, (2) prioritizing questions using Delphi method, (3) reconciling identified research priorities with the existing literature (i.e., searching of ongoing trials in trials registries), (4) updating the process. A comprehensive search of Cochrane systematic reviews published or updated from January 2006 to March 2011 was performed. We evaluated the “Implications for Research” section to identify gaps in the research.ResultsOur search strategy identified 695 references; 178 systematic reviews identifying at least one research gap were used. We formulated 319 research questions, which were classified into 11 different categories based on the direct and indirect causes of maternal mortality: postpartum hemorrhage, abortion, hypertensive disorders, infection/sepsis, caesarean section, diabetes, pregnancy prevention, preterm labor, other direct causes, indirect causes, and health policies and systems. Most research questions concerned the effectiveness of clinical interventions, including drugs (42.6%), nonpharmacologic interventions (16.3%), and health system (14.7%).ConclusionIt is possible to identify gaps in the maternal health research by using this approach. 相似文献
Birth defect-related demise is mainly due to congenital heart defects. In the earlier stage of pregnancy, fetus problem can be identified by finding information about the fetus to avoid stillbirths. The gold standard used to monitor the health status of the fetus is by Cardiotachography(CTG), cannot be used for long durations and continuous monitoring. There is a need for continuous and long duration monitoring of fetal ECG signals to study the progressive health status of the fetus using portable devices. The non-invasive method of electrocardiogram recording is one of the best method used to diagnose fetal cardiac problem rather than the invasive methods.The monitoring of the fECG requires development of a miniaturized hardware and a efficient signal processing algorithms to extract the fECG embedded in the mother ECG. The paper discusses a prototype hardware developed to monitor and record the raw mother ECG signal containing the fECG and a signal processing algorithm to extract the fetal Electro Cardiogram signal. We have proposed two methods of signal processing, first is based on the Least Mean Square (LMS) Adaptive Noise Cancellation technique and the other method is based on the Wavelet Transformation technique. A prototype hardware was designed and developed to acquire the raw ECG signal containing the mother and fetal ECG and the signal processing techniques were used to eliminate the noises and extract the fetal ECG and the fetal Heart Rate Variability was studied. Both the methods were evaluated with the signal acquired from a fetal ECG simulator, from the Physionet database and that acquired from the subject. Both the methods are evaluated by finding heart rate and its variability, amplitude spectrum and mean value of extracted fetal ECG. Also the accuracy, sensitivity and positive predictive value are also determined for fetal QRS detection technique. In this paper adaptive filtering technique uses Sign-sign LMS algorithm and wavelet techniques with Daubechies wavelet, employed along with de noising techniques for the extraction of fetal Electrocardiogram.Both the methods are having good sensitivity and accuracy. In adaptive method the sensitivity is 96.83, accuracy 89.87, wavelet sensitivity is 95.97 and accuracy is 88.5. Additionally, time domain parameters from the plot of heart rate variability of mother and fetus are analyzed. 相似文献
A radioimmunoassay (RIA) method using antiserum to cortisol-21-succinyl-BSA was devised to determine cortisol in fish plasma using the plasma of cod Gadus morhua. Steroid extracts were purified by thin layer chromatography before RIA. Saturated ammonium sulfate was used to separate protein-bound from free [3H]cortisol. The method is precise and accurate and validated by double isotope derivative assay (DIDA). 相似文献
Forty-six patients with Plasmodium vivax malaria were evaluated for their clinical and parasitological response to the two single doses of mefloquine in comparison with the standard 3-day treatment with chloroquine. The patients were randomly distributed into 3 groups. Group 1 with 13 patients were treated with a single dose 250 mg mefloquine, Group 2 with 15 patients were treated with a single dose 500 mg mefloquine and Group 3 with 18 cases were treated with the standard 3-day treatment course of 1,500 mg chloroquine. All patients in the three treatment group showed similar parasite, clearance time, fever clearance time and clearance time of signs and symptoms. There were no statistically significant differences between any of the groups. The age and weight, as well as the initial parasite count of the three groups were comparable. This study shows that mefloquine at the dosages used were as effective as the 3-day standard treatment with 1,500 mg chloroquine. 相似文献
Acute exacerbations of asthma are very common reasons for a presentation to emergency departments. This paper focuses on defining the high‐risk group, consideration of the concept of phenotypes of acute asthma, the assessment of severe and life‐threatening exacerbations and an emphasis on the management of the more severe end of the exacerbation severity. A number of evidence‐based guidelines exist throughout the world and are all slightly different. This reflects the poor evidence base for some of those recommendations. Thus, a large variation of treatment drugs, doses and regimen are used and clearly not standardised. This paper aims to present a summary of the best evidence and discuss some of these controversies. The most important aspect of treating an exacerbation of acute asthma is to review regularly and assess response to treatment. Severe and life‐threatening episodes should be treated with early use of intravenous treatment in a stepwise manner following the local guidelines. Non‐invasive ventilation and high flow nasal cannulae delivery of oxygen in the emergency department are evolving modalities, but evidence for their use is currently limited. 相似文献
PURPOSE: To report the efficacy of primary retrobulbar chlorpromazine injections for the management of blind and seeing painful eyes. PATIENTS AND METHODS: Retrospective case series from three university hospitals was done. Twenty eyes of 20 patients with at least 3 months of follow-up are reported. Ten of these 20 eyes did not receive any other ophthalmic medications either 2 weeks before chlorpromazine injection or at any time point after injection. Treatment was considered successful if pain control lasted for at least 3 months, without the need for reinjection or enucleation. RESULTS: Sixteen of 20 (80.0%) eyes achieved successful pain control. There were no permanent complications in any patient. CONCLUSIONS: Retrobulbar chlorpromazine appears to be safe and effective for the management of pain in blind eyes. 相似文献