988 resultados para New occurrence


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The application of luminescence dating to young volcanic sediments has been first investigated over three decades ago, but it was only with the technical innovations of the last decade that such analyses became viable. While current analytical procedures show promise for dating late Quaternary volcanic events, most efforts have been aimed at unconsolidated volcanic tephra. Investigations into direct dating of lava flows or of non-heated volcanoclastics like phreatic explosion layers, however, remain scarce. These volcanic deposits are of common occurrence and represent important chrono- and volcanostratigraphic markers. Their age determination is therefore of great importance in volcanologic, tectonic, geomorphological and climate studies. In this article, we propose the use of phreatic explosion deposits and xenolithic inclusions in lava flows as target materials for luminescence dating applications. The main focus is on the crucial criterion whether it is probable that such materials experience complete luminescence signal resetting during the volcanic event to be dated. This is argued based on the findings from existing literature, model calculations and laboratory tests.

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Breast cancer occurring in women before the age of menopause continues to be a major medical and psychological challenge. Endocrine therapy has emerged as the mainstay of adjuvant treatment for women with estrogen receptor-positive tumours. Although the suppression of ovarian function (by oophorectomy, irradiation of the ovaries or gonadotropin releasing factor analogues) is effective as adjuvant therapy if used alone, its value has not been proven after chemotherapy. This is presumably because of the frequent occurrence of chemotherapy-induced amenorrhoea. Tamoxifen reduces the risk of recurrence by approximately 40%, irrespective of age and the ovarian production of estrogens. The worth of ovarian function suppression in combination with tamoxifen is unproven and is being investigated in an intergroup randomised clinical trial (SOFT [Suppression of Ovarian Function Trial]). Aromatase inhibitors are more effective than tamoxifen in postmenopausal women but are only being investigated in younger patients. The use of chemotherapies is identical in younger and older patients; however, at present the efficacy of chemotherapy in addition to ovarian function suppression plus tamoxifen is unknown in premenopausal patients with endocrine responsive disease. 'Targeted' therapies such as monoclonal antibodies to human epidermal growth factor receptor (HER)-2, HER1 and vascular endothelial growth factor, 'small molecule' inhibitors of tyrosine kinases and breast cancer vaccines are rapidly emerging. Their use depends on the function of the targeted pathways and is presently limited to clinical trials. Premenopausal patients are best treated in the framework of a clinical trial.

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Sampling and analyzing new families with inherited blood disorders are major steps contributing to the identification of gene(s) responsible for normal and pathologic hematopoiesis. Familial occurrences of hematological disorders alone, or as part of a syndromic disease, have been reported, and for some the underlying genetic mutation has been identified. Here we describe a new autosomal dominant inherited phenotype of thrombocytopenia and red cell macrocytosis in a four-generation pedigree. Interestingly, in the youngest generation, a 2-year-old boy presenting with these familial features has developed acute lymphoblastic leukemia characterized by a t(12;21) translocation. Tri-lineage involvement of platelets, red cells and white cells may suggest a genetic defect in an early multiliear progenitor or a stem cell. Functional assays in EBV-transformed cell lines revealed a defect in cell proliferation and tubulin dynamics. Two candidate genes, RUNX1 and FOG1, were sequenced but no pathogenic mutation was found. Identification of the underlying genetic defect(s) in this family may help in understanding the complex process of hematopoiesis.

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BACKGROUND: Though guidelines emphasize low-density lipoprotein cholesterol (LDL-C) lowering as an essential strategy for cardiovascular risk reduction, achieving target levels may be difficult. PATIENTS AND METHODS: The authors conducted a prospective, controlled, open-label trial examining the effectiveness and safety of high-dose fluvastatin or a standard dosage of simvastatin plus ezetimibe, both with an intensive guideline-oriented cardiac rehabilitation program, in achieving the new ATP III LDL-C targets in patients with proven coronary artery disease. 305 consecutive patients were enrolled in the study. Patients were divided into two groups: the simvastatin (40 mg/d) plus ezetimibe (10 mg/d) and the fluvastatin-only group (80 mg/d). Patients in both study groups received the treatment for 21 days in addition to nonpharmacological measures, including advanced physical, dietary, psychosocial, and educational activities. RESULTS: After 21 days of treatment, a significant reduction in LDL-C was found in both study groups as compared to the initial values, however, the reduction in LDL-C was significantly stronger in the simvastatin plus ezetimibe group: simvastatin plus ezetimibe treatment decreased LDL-C to a mean level of 57.7 +/- 1.7 mg/ml, while fluvastatin achieved a reduction to 84.1 +/- 2.4 mg/ml (p < 0.001). In the simvastatin plus ezetimibe group, 95% of the patients reached the target level of LDL-C < 100 mg/dl. This percentage was significantly higher than in patients treated with fluvastatin alone (75%; p < 0.001). The greater effectiveness of simvastatin plus ezetimibe was more impressive when considering the optional goal of LDL-C < 70 mg/dl (75% vs. 32%, respectively; p < 0.001). There was no difference in occurrence of adverse events between both groups. CONCLUSION: Simvastatin 40 mg/d plus ezetimibe 10 mg/d, on the background of a guideline-oriented standardized intensive cardiac rehabilitation program, can reach 95% effectiveness in achieving challenging goals (LDL < 100 mg/dl) using lipid-lowering medication in patients at high cardiovascular risk.

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Black molds or dematiaceous fungi are rare etiologic agents of intracerebral abscesses and such infections carry a high mortality of up to 70% despite combined surgical and antifungal therapy. While the growing use of immunosuppressive therapies and organ transplantation have caused an increase in the incidence of rare fungal cerebral infections, occurrence in immunocompetent hosts is also possible. We describe a 60-year-old female patient with a cerebral abscess caused by Cladophialophora bantiana. The case illustrates the clinical and radiological similarities between glioblastomas and brain abscesses and emphasizes the need to perform histological and microbiological studies prior to the initiation of any form of therapy. Long-term survival from cerebral black mold abscesses has been reported only when complete surgical resection was possible. The recommended antifungal treatment involves the use of amphotericin B combined with a triazole and, if possible, flucytosine. Highly-active new generation triazole antifungal compounds (voriconazole or posaconazole) are likely to offer improved survival rates for patients with rare mold infections. In particular, posaconazole could be a new therapeutic option given its better tolerance, lower toxicity and fewer drug-drug interactions. We discuss clinical, microbiological and practical pharmacological aspects and review current and evolving treatment options.

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Little is known about the ocular and cerebral blood flow during exposure to increasingly hypoxic conditions at high altitudes. There is evidence that an increase in cerebral blood flow resulting from altered autoregulation constitutes a risk factor for acute mountain sickness (AMS) and high-altitude cerebral edema (HACE) by leading to capillary overperfusion and vasogenic cerebral edema. The retina represents the only part of the central nervous system where capillary blood flow is visible and can be measured by noninvasive means. In this study we aimed to gain insights into retinal and choroidal autoregulatory properties during hypoxia and to correlate circulatory changes to symptoms of AMS and clinical signs of HACE. This observational study was performed within the scope of a high-altitude medical research expedition to Mount Muztagh Ata (7,546 m). Twenty seven participants underwent general and ophthalmic examinations up to a maximal height of 6,800 m. Examinations included fundus photography and measurements of retinal and choroidal blood flow, as well as measurement of arterial oxygen saturation and hematocrit. The initial increase in retinal blood velocity was followed by a decrease despite further ascent, whereas choroidal flow increase occurred later, at even higher altitudes. The sum of all adaptational mechanisms resulted in a stable oxygen delivery to the retina and the choroid. Parameters reflecting the retinal circulation and optic disc swelling correlated well with the occurrence of AMS-related symptoms. We demonstrate that sojourns at high altitudes trigger distinct behavior of retinal and choroidal blood flow. Increase in retinal but not in choroidal blood flow correlated with the occurrence of AMS-related symptoms.

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The present report describes a novel etiological agent of cutaneous leishmaniasis in horses that, at least for some cases, sporadically appeared as autochthonous infections in geographically distant regions of Germany and Switzerland. The infection was initially diagnosed upon clinical and immunohistological findings. Subsequent comparative sequence analysis of diagnostic PCR products from the internal transcribed spacer 1 (ITS1) of ssrRNA classified the respective isolates as neither Old World nor New World Leishmania species. However, four isolates subjected to molecular analyses all exhibited a close phylogenetic relationship to Leishmania sp. siamensis, an organism recently identified in a visceral leishmaniasis patient from Thailand. Future investigations will demonstrate if this form of leishmaniasis represents an emerging, and perhaps zoonotic, disease of European, or even global, importance.

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Background Working hour limitations and tight health care budgets have posed significant challenges to emergency surgical services. Since 1 January 2010, surgical interventions at Berne University Hospital between 23:00 and 08:00 h have been restricted to patients with an expected serious adverse outcome if not operated on within 6 h. This study was designed to assess the safety of this new policy that restricts nighttime appendectomies (AEs). Methods The patients that underwent AE from 1 January 2010 to 31 December 2011 (“2010-2011 group”) were compared retrospectively with patients that underwent AE before introduction of the new policy (1 January 2006–31 December 2009; “2006-2009 group”). Results Overall, 390 patients were analyzed. There were 255 patients in the 2006–2009 group and 135 patients in the 2010–2011 group. Patients’ demographics did not differ statistically between the two study groups; however, 45.9 % of the 2006–2009 group and 18.5 % of the 2010–2011 group were operated between 23:00 and 08:00 h (p < 0.001). The rates of appendiceal perforations and surgical site infections did not differ statistically between the 2006–2009 group and the 2010–2011 group (20 vs. 18.5 %, p = 0.725 and 2 vs. 0 %, p = 0.102). Additionally, no difference was found for the hospital length of stay (3.9 ± 7.4 vs. 3.4 ± 6.0 days, p = 0.586). However, the proportion of patients with an in-hospital delay of >12 h was significantly greater in the 2010–2011 group than in the 2006–2009 group [55.6 vs. 43.5 %, p = 0.024, odds ratio (95 % confidence interval 1.62 (1.1–2.47)]. Conclusions Restricting AEs from 23:00 to 08:00 h does not increase the perforation rates and occurrence of clinical outcomes. Therefore, these results suggest that appendicitis may be managed safely in a semielective manner.

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BACKGROUND Cardiac events (CEs) are among the most serious late effects following childhood cancer treatment. To establish accurate risk estimates for the occurrence of CEs it is essential that they are graded in a valid and consistent manner, especially for international studies. We therefore developed a data-extraction form and a set of flowcharts to grade CEs and tested the validity and consistency of this approach in a series of patients. METHODS The Common Terminology Criteria for Adverse Events version 3.0 and 4.0 were used to define the CEs. Forty patients were randomly selected from a cohort of 72 subjects with known CEs that had been graded by a physician for an earlier study. To establish whether the new method was valid for appropriate grading, a non-physician graded the CEs by using the new method. To evaluate consistency of the grading, the same charts were graded again by two other non-physicians, one with receiving brief introduction and one with receiving extensive training on the new method. We calculated weighted Kappa statistics to quantify inter-observer agreement. RESULTS The inter-observer agreement was 0.92 (95% CI 0.80-1.00) for validity, and 0.88 (0.79-0.98) and 0.99 (0.96-1.00) for consistency with the outcome assessors who had the brief introduction and the extensive training, respectively. CONCLUSIONS The newly developed standardized method to grade CEs using data from medical records has shown excellent validity and consistency. The study showed that the method can be correctly applied by researchers without a medical background, provided that they receive adequate training.

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The co-occurrence of warm conveyor belts (WCBs), strongly ascending moist airstreams in extratropical cyclones, and stratospheric potential vorticity (PV) streamers, indicators for breaking Rossby waves on the tropopause, is investigated for a 21-yr period in the Northern Hemisphere using Interim European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-Interim) data. WCB outflows and PV streamers are respectively identified as two- and three-dimensional objects and tracked during their life cycle. PV streamers are more frequent than WCB outflows and nearly 15% of all PV streamers co-occur with WCBs during their life cycle, whereas about 60% of all WCB outflows co-occur with PV streamers. Co-occurrences are most frequent over the North Atlantic and North Pacific in spring and winter. WCB outflows are often located upstream of the PV streamers and form earlier, indicating the importance of diabatic processes for downstream Rossby wave breaking. Less frequently, PV streamers occur first, leading to the formation of new WCBs.

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AIM Head thrusts are well documented in Joubert syndrome and ocular motor apraxia. We provide a detailed clinical characterization of head titubation in 13 young children with Joubert syndrome. METHOD Detailed characterization of head titubation was assessed by targeted clinical evaluation and/or analysis of videos. RESULTS In 12 of 13 children (eight males, five females; median age 6y, range 2mo-15y) head titubation was first recognized in the first 2 months of age and decreased in severity until spontaneous resolution. In all children, the head titubation was horizontal, high frequency (~3Hz), had small amplitude (5-10°), was never present during sleep, and did not interfere with the neurodevelopment during infancy. In the majority of children, emotion, anxiety, and tiredness were worsening factors for head titubation. INTERPRETATION Head titubation is a benign, early presentation of Joubert syndrome. Head titubation in hypotonic infants should prompt a careful search for Joubert syndrome. Awareness of its occurrence in Joubert syndrome may avoid unnecessary investigations.

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BACKGROUND AND PURPOSE To determine the frequency of new ischaemic or hemorrhagic brain lesions on early follow-up magnetic resonance imaging (MRI) in patients with cervical artery dissection (CAD) and to investigate the relationship with antithrombotic treatment. METHODS This prospective observational study included consecutive CAD patients with ischaemic or non-ischaemic symptoms within the preceding 4 weeks. All patients had baseline brain MRI scans at the time of CAD diagnosis and follow-up MRI scans within 30 days thereafter. Ischaemic lesions were detected by diffusion-weighted imaging (DWI), intracerebral bleeds (ICBs) by paramagnetic-susceptible sequences. Outcome measures were any new DWI lesions or ICBs on follow-up MRI scans. Kaplan-Meier statistics and calculated odds ratios with 95% confidence intervals were used for lesion occurrence, baseline characteristics and type of antithrombotic treatment (antiplatelet versus anticoagulant). RESULTS Sixty-eight of 74 (92%) CAD patients were eligible for analysis. Median (interquartile range) time interval between baseline and follow-up MRI scans was 5 (3-10) days. New DWI lesions occurred in 17 (25%) patients with a cumulative 30-day incidence of 41.3% (standard error 8.6%). Occurrence of new DWI lesions was associated with stroke or transient ischaemic attack at presentation [7.86 (2.01-30.93)], occlusion of the dissected vessel [4.09 (1.24-13.55)] and presence of DWI lesions on baseline MRI [6.67 (1.70-26.13)]. The type of antithrombotic treatment had no impact either on occurrence of new DWI lesions [1.00 (0.32-3.15)] or on functional 6-month outcome [1.27 (0.41-3.94)]. No new ICBs were observed. CONCLUSION New ischaemic brain lesions occurred in a quarter of CAD patients, independently of the type of antithrombotic treatment. MRI findings could potentially serve as surrogate outcomes in pilot treatment trials.

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Common endpoints can be divided into two categories. One is dichotomous endpoints which take only fixed values (most of the time two values). The other is continuous endpoints which can be any real number between two specified values. Choices of primary endpoints are critical in clinical trials. If we only use dichotomous endpoints, the power could be underestimated. If only continuous endpoints are chosen, we may not obtain expected sample size due to occurrence of some significant clinical events. Combined endpoints are used in clinical trials to give additional power. However, current combined endpoints or composite endpoints in cardiovascular disease clinical trials or most clinical trials are endpoints that combine either dichotomous endpoints (total mortality + total hospitalization), or continuous endpoints (risk score). Our present work applied U-statistic to combine one dichotomous endpoint and one continuous endpoint, which has three different assessments and to calculate the sample size and test the hypothesis to see if there is any treatment effect. It is especially useful when some patients cannot provide the most precise measurement due to medical contraindication or some personal reasons. Results show that this method has greater power then the analysis using continuous endpoints alone. ^

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Changes in Atlantic deep water circulation were reconstructed by comparing the benthic foraminiferal delta13C record at ODP Site 1090 in the South Atlantic with similar records from the North Atlantic (Sites 982, 607, 925, 929) and deep Pacific (Site 849) oceans. Important deep water circulation changes occurred in the early Pleistocene at 1.55 Myr and during the Mid-Pleistocene Transition at 0.9 Myr. At 1.55 Myr, glacial delta13C values in the Southern Ocean became significantly lower than those in the deep Pacific, establishing a pattern that persisted throughout the late Pleistocene. We propose that the lowering of delta13C values of Southern Component Water (SCW) at this time resulted from expansion of sea ice and reduced ventilation of deep water during glacial periods after marine isotope stage 52. Accompanying this change in Southern Ocean deep water circulation was enhanced interhemispheric coupling between the North and South Atlantic after 1.55 Myr. At ~0.9 Myr, the magnitude of glacial-to-interglacial variabilityin delta13C increased and shifted to a longer frequency (100 kyr) along with oceanic delta18O (ice volume). Calculation of percent Northern Component Water (NCW) using Site 1090 as the SCW end member yielded 20-30% less reduction of NCW during glacial periods of the late Pleistocene. Also, a trend toward reduced glacial suppression of NCW during the past 400 kyr is not evident. The apparent decoupling of ice volume and deep water circulation reported previously maybe an artifact of using a Pacific, rather than a Southern Ocean, carbon isotopic record to calculate past mixing ratios of NCW and SCW.

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Well-preserved Mesozoic radiolarian faunas have been recovered at four sites of Deep Sea Drilling Project Leg 62. Late Early Cretaceous assemblages, which occur always with foraminifers or calcareous nannoplankton, allow the description of 21 new species, the introduction of a new zone scheme, and calibration of the radiolarian zones with the geochronological scale.