226 research outputs found
Native gold of the porphyry copper mineralization in the Borov Dol deposit (Republic of Macedonia)
Dwarf Copper-Gold Porphyry Deposits of the Buchim-Damjan-Borov Dol Ore District, Republic of Macedonia (FYROM)
The metallogenic aspects, tectonic setting, magmatism, structure, and composition of Au-and Ag-bearing porphyry copper deposits in the Buchim-Damjan-Borov Dol ore district and their genetic features are considered and compared with earlier published data. Special attention is paid to supergene gold in heavy concentrate halos of the Borov Dol deposit. The total Cu reserves of the deposits discussed in this paper do not exceed 150 kt. The Buchim deposit likely is the world's smallest deposit of this type currently involved in mining. A comprehensive study of these dwarf porphyry copper deposits is undertaken to answer questions on the conditions of their formation. How do they differ from formation conditions of giant deposits
Understanding caretakers' dilemma in deciding whether or not to adhere with referral advice after pre-referral treatment with rectal artesunate
BACKGROUND: Malaria kills. A single rectal dose of artesunate before referral can
reduce mortality and prevent permanent disability. However, the success of this
intervention depends on caretakers' adherence to referral advice for follow-up
care. This paper explores the dilemma facing caretakers when they are in the
process of deciding whether or not to transit their child to a health facility
after pre-referral treatment with rectal artesunate.
METHODS: Four focus group discussions were held in each of three purposively
selected villages in Mtwara rural district of Tanzania. Data were analysed
manually using latent qualitative content analysis.
RESULTS: The theme "Caretakers dilemma in deciding whether or not to adhere with
referral advice after pre-referral treatment with rectal artesunate" depicts the
challenge they face. Caretakers' understanding of the rationale for going to
hospital after treatment--when and why they should adhere--influenced adherence.
Caretakers, whose children did not improve, usually adhered to referral advice.
If a child had noticeably improved with pre-referral treatment however,
caretakers weighed whether they should proceed to the facility, balancing the
child's improved condition against other competing priorities, difficulties in
reaching the health facilities, and the perceived quality of care at the health
facility. Some misinterpretation were found regarding the urgency and rationale
for adherence among some caretakers of children who improved which were
attributed to be possibly due to their prior understanding.
CONCLUSION: Some caretakers did not adhere when their children improved and some
who adhered did so without understanding why they should proceed to the facility.
Successful implementation of the rectal artesunate strategy depends upon
effective communication regarding referral to clinic
Self-aggression in macaques: Five case studies
Spontaneous self-aggressive behaviors were observed in five adult male rhesus monkeys ( Macaca mulatta ) housed at a university facility. All were individually caged, were free of intercurrent disease, and were being utilized in ongoing research studies. The self-aggressive behaviors observed included self-biting, self-clasping, self-slapping, self-rubbing and threatening of body parts. In several cases, wounds were inflicted and medical treatment was required due to the severity of the lesions. A review of the animals' clinical histories revealed an increased level of self-aggressive behavior in four of five monkeys during such stressful or stimulating conditions as movement of the animal to a new cage, movement of animals out of the room or escape of other monkeys from their cages. The frequency with which these behaviors occurred was quantitated experimentally. The results revealed an increased level of self-aggressive behavior in two of these animals during the videotaped sessions in response to aggressive contacts with the investigator. In contrast, one monkey exhibited self-aggressive behavior both clinically and experimentally in the absence of environmental stimuli or human contact. Clinical management of self-aggressive monkeys included housing monkeys only with physically smaller primates, decreasing the level of environmental stimuli, and drug therapy. Haloperidol was used with success in one animal that exhibited severe self-aggressive behavior.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41601/1/10329_2006_Article_BF02381460.pd
Sensitivity of the UK clinical practice research datalink to detect neurodevelopmental effects of medicine exposure in utero:comparative analysis of an antiepileptic drug-exposed cohort
Introduction: Electronic healthcare data have several advantages over prospective observational studies, but the sensitivity of data on neurodevelopmental outcomes and its comparability with data generated through other methodologies is unknown. Objectives: The objectives of this study were to determine whether data from the UK Clinical Practice Research Datalink (CPRD) produces similar risk estimates to a prospective cohort study in relation to the risk of neurodevelopmental disorders (NDDs) following prenatal antiepileptic drug (AED) exposure. Methods: A cohort of mother–child pairs of women with epilepsy (WWE) was identified in the CPRD and matched to a cohort without epilepsy. The study period ran from 1 January 2000 to 31 March 2007 and children were required to be in the CPRD at age 6 years. AED exposure during pregnancy was determined from prescription data and children with an NDD diagnosis by 6 years were identified from Read clinical codes. The prevalence and risk of NDDs was calculated for mother–child pairs in WWE stratified by AED regimen and for those without epilepsy. Comparisons were made with the results of the prospective Liverpool and Manchester Neurodevelopment Group study which completed assessment on 201 WWE and 214 without epilepsy at age 6 years. Results: In the CPRD, 1018 mother–child pairs to WWE and 6048 to women without epilepsy were identified. The CPRD identified a lower prevalence of NDDs than the prospective study. In both studies, NDDs were more frequently reported in children of WWE than women without epilepsy, although the CPRD risk estimate was lower (2.16 vs. 0.96%, p < 0.001 and 7.46 vs. 1.87%, p = 0.0128). NDD prevalence differed across AED regimens but the CPRD data did not replicate the significantly higher risk of NDDs following in utero monotherapy valproate exposure (adjusted odds ratio [ORadj] 2.02, 95% confidence interval [CI] 0.52–7.86) observed in the prospective study (ORadj 6.05, 95% CI 1.65–24.53). Conclusion: It was possible to identify NDDs in the CPRD; however, the CPRD appears to under-record these outcomes. Larger studies are required to investigate further
СТРУКТУРНО-ФУНКЦИОНАЛЬНАЯ ПЕРЕСТРОЙКА НЕЙРОНОВ ГИППОКАМПА ПОСЛЕ ОПЕРАЦИИ ПОД АНЕСТЕЗИЕЙ СЕВОФЛУРАНОМ (экспериментальное исследование)
Hippocampus plays an important role in the cognitive mnestic functions. It coordinates emotional process, defines the intensity and specificity of behavioral, neuron and hormone reactions. Structural changes in hippocampus neurons can result in learning and memory disorders. The objective: to investigate morphometric parameters of hippocampus fields in rats after abdomen surgery with exposure to sevoflurane. Subjects and methods. The experimental research was performed using Wistar rats (n = 15). Rats from the experimental group (n = 7) had abdomen surgery with anesthesia with sevoflurane with the consequent continuous exposure to it (6 hours, 2 vol. % of sevoflurane, air flow – 1 l/min.). During 21 days rats from both groups had a number of behavioral tests. In 12 hours after the last behavioral test (on the 22-th day after the start of the experiment) the rats were decapitated with consequent brain extraction. The obtained materials were fixed in 10% neutral formalin on phosphate buffer (pH 7.4) for 24 hours minimum. Preparations of CA1, Ca2, Ca3, and Ca4 fields were studied under light microscope DM-750 (Leica, Germany) using the computer image analysis software of ImageScope M with 400-fold magnification. Results. The tests showed that cytoarchitectonics of hippocampus field was intact, pyramidal neurons had a large rounded nucleus with one, two or more distinct nucleoli. No pericellular and perivascular edema was detected. In the experimental group, all fields of the hippocampus had structural and functional changes. It manifested through both quantitative and qualitative signs of neuronal damage, especially in the Ca1 field. Segments of pyramidal neurons were disorganized, morphologically modified neurons were found: hyperchromatic shriveled neurons with no nucleus or poorly visible nucleus of the irregular shape. The appearance of morphologically changed neurons and disorganization of hippocampal layers led to changes in the width of pyramidal neurons segments. Conclusion. Morphological changes of hippocampal structures of rats after surgery and anesthesia may be the cause of cognitive functions decline during the postoperative period. Гиппокамп играет важную роль в реализации когнитивно-мнестических функций. Он координирует эмоциональные процессы, определяет величину и специфику поведенческих, нейрональных и гормональных реакций. Структурные изменения нейронов гиппокампа могут приводить к нарушениям процессов обучения и памяти. Цель: изучение морфометрических показателей полей гиппокампа крыс после операции на органах брюшной полости на фоне экспозиции севофлурана. Материал и методы. Проведено экспериментальное исследование на крысах стока Вистар (n = 15). Крысы экспериментальной группы (n = 7) подвергались операции на органах брюшной полости на фоне анестезии севофлураном с последующей его длительной экспозицией (6 ч, 2 об. % севофлурана, поток воздуха 1 л/мин). В течение 21 сут у крыс обеих групп выполняли ряд поведенческих тестов. Через 12 ч после проведения последнего поведенческого теста (22-е сут после начала эксперимента) крыс декапитировали и извлекали головной мозг. Материал фиксировали в 10%-ном нейтральном формалине на фосфатном буфере (рН 7,4) не менее 24 ч. Препараты полей СА1, СА2, СА3 и СА4 изучали под световым микроскопом ДМ-750 (Leica, Германия) с помощью компьютерной программы анализа изображений ImageScope M при увеличении в 400 раз. Результаты. В контроле цитоархитектоника полей гиппокампа не нарушена, пирамидные нейроны имели крупное округлое ядро с одним, двумя и более четкими ядрышками. Перицеллюлярного и периваскулярного отека не выявлено. В экспериментальной группе структурно-функциональная перестройка затронула все поля гиппокампа. Это проявилось появлением как количественных, так и качественных признаков повреждения нейронов, в особенности в поле СА1. Отмечена дезорганизация слоев пирамидных нейронов, определены морфологически измененные нейроны: гиперхромные сморщенные без ядер или с плохо различимым ядром неправильной формы. Появление морфологически измененных нейронов и дезорганизация слоев гиппокампа приводили к изменению ширины слоя пирамидных нейронов. Вывод. Морфологическая перестройка гиппокампальных структур крыс после операции и анестезии может лежать в основе ухудшения когнитивных функций в послеоперационном периоде.
Assessment of changes in nicotine dependence, motivation, and symptoms of anxiety and depression among smokers in the initial process of smoking reduction or cessation: a short-term follow-up study
Translating research into policy: lessons learned from eclampsia treatment and malaria control in three southern African countries
<p>Abstract</p> <p>Background</p> <p>Little is known about the process of knowledge translation in low- and middle-income countries. We studied policymaking processes in Mozambique, South Africa and Zimbabwe to understand the factors affecting the use of research evidence in national policy development, with a particular focus on the findings from randomized control trials (RCTs). We examined two cases: the use of magnesium sulphate (MgSO<sub>4</sub>) in the treatment of eclampsia in pregnancy (a clinical case); and the use of insecticide treated bed nets and indoor residual household spraying for malaria vector control (a public health case).</p> <p>Methods</p> <p>We used a qualitative case-study methodology to explore the policy making process. We carried out key informants interviews with a range of research and policy stakeholders in each country, reviewed documents and developed timelines of key events. Using an iterative approach, we undertook a thematic analysis of the data.</p> <p>Findings</p> <p>Prior experience of particular interventions, local champions, stakeholders and international networks, and the involvement of researchers in policy development were important in knowledge translation for both case studies. Key differences across the two case studies included the nature of the evidence, with clear evidence of efficacy for MgSO<sub>4 </sub>and ongoing debate regarding the efficacy of bed nets compared with spraying; local researcher involvement in international evidence production, which was stronger for MgSO<sub>4 </sub>than for malaria vector control; and a long-standing culture of evidence-based health care within obstetrics. Other differences were the importance of bureaucratic processes for clinical regulatory approval of MgSO<sub>4</sub>, and regional networks and political interests for malaria control. In contrast to treatment policies for eclampsia, a diverse group of stakeholders with varied interests, differing in their use and interpretation of evidence, was involved in malaria policy decisions in the three countries.</p> <p>Conclusion</p> <p>Translating research knowledge into policy is a complex and context sensitive process. Researchers aiming to enhance knowledge translation need to be aware of factors influencing the demand for different types of research; interact and work closely with key policy stakeholders, networks and local champions; and acknowledge the roles of important interest groups.</p
An Analysis of Vascular Access Thrombosis Events From the Proactive IV irOn Therapy in hemodiALysis Patients Trial
INTRODUCTION:
Treatment of anemia in dialysis patients has been associated with increased risk of vascular access thrombosis (VAT). Proactive IV irOn Therapy in hemodiALysis Patients (PIVOTAL) was a clinical trial of proactive compared with reactive i.v. iron therapy in patients requiring hemodialysis. We analyzed the trial data to determine whether randomized treatment arm, alongside other clinical and laboratory variables, independently associated with VAT.
METHODS:
In PIVOTAL, 2141 adult patients were randomized. The type of vascular access (arteriovenous fistula [AVF], arteriovenous graft [AVG], or central venous catheter [CVC]) was recorded at baseline and every month after randomization. The associations between clinical and laboratory data and first VAT were evaluated in a multivariate analysis.
RESULTS:
A total of 480 (22.4%) participants experienced VAT in a median of 2.1 years of follow-up. In multivariable analyses, treatment arm (proactive vs. reactive) was not an independent predictor of VAT (hazard ratio [HR] 1.13, P = 0.18). Diabetic kidney disease (HR 1.45, P < 0.001), AVG use (HR 2.29, P < 0.001), digoxin use (HR 2.48, P < 0.001), diuretic use (HR 1.25, P = 0.02), female sex (HR 1.33, P = 0.002), and previous/current smoker (HR 1.47, P = 0.004) were independently associated with a higher risk of VAT. Angiotensin receptor blocker (ARB) use (HR 0.66, P = 0.01) was independently associated with a lower risk of VAT.
CONCLUSION:
In PIVOTAL, VAT occurred in nearly 1 quarter of participants in a median of just >2 years. In this post hoc analysis, randomization to proactive i.v. iron treatment arms did not increase the risk of VAT
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