441 research outputs found
Sinnvoller Einsatz von Tumormarkern
Tumor markers refer to all detectable and measurable analytes which are able to indicate a solid tumor or contribute to its characterization or judgment concerning tumor spread and therapy efficacy. Among the markers, humoral circulating tumor substances, such as precursors of normal antigens, ectopically produced hormones or enzymes, ontogenetic old reactivated antigens, hybridoma-defined mucins and cytokeratins are of special interest. Up to now, no tumor specific biomarker has been detected, all markers known so far are physiological components of blood; thus, their diagnostic capacity is more related to quantity than to quality. The tumor marker concentration depends on the tumor blood supply and reflects tumor mass and tumor spread as a sum of marker expression, synthesis, release, the catabolism of the organism, as well as the marker excretion. Changes in biomarker levels without correlation to tumor load can be due to impairment of the liver and kidney function or due to invasive diagnostic methods (endoscopy, biopsy, ureteral catheter) or due to acute reactions on treatment (surgery, radio-chemotherapy). Due to problems with standardization between assays from different producers measuring the same antigen, interpretation of biomarkers of single measurements, such as PSA (prostate specific antigen), must be performed using assay specific reference ranges and interpretation of serial measurements must be performed using the identical assay. The test result has to be indicated together with the assay used (kit and producer). Among the potential indications for tumor marker determinations, the early detection or screening of a tumor is unrealistic - except PSA in prostate cancer detection. In rare cases, biomarkers can be helpful in tumor localization (HTG (human thyreoglobuline), PSA) and support of primary diagnosis, the knowledge about their prognostic relevance is increasing, the most widely used indication is therapy control and follow-up care in context with medical imaging. Provided that markers are critically selected following the localization of the tumor, that serial determinations are performed using the identical assay and that the clinical question is relevant, tumor markers contribute to a significant degree to diagnosis, prognosis, therapy control and early detection of metastatic or recurrent disease. Especially in the field of diagnostic oncology, the quality of the investigator is significantly linked to the quality of the test result
Murrili meteorite's fall and recovery from Kati Thanda
On the 27th of November 2015, at 10:43:45.526 UTC, a fireball was observed
across South Australia by ten Desert Fireball Network observatories lasting 6.1
s. A kg meteoroid entered the atmosphere with a speed of
13.68\pm0.09\,\mbox{km s}^{-1} and was observed ablating from a height of 85
km down to 18 km, having slowed to 3.28\pm0.21 \,\mbox{km s}^{-1}. Despite
the relatively steep 68.5 trajectory, strong atmospheric winds
significantly influenced the darkfight phase and the predicted fall line, but
the analysis put the fall site in the centre of Kati Thanda - Lake Eyre South.
Kati Thanda has metres-deep mud under its salt-encrusted surface.
Reconnaissance of the area where the meteorite landed from a low flying
aircraft revealed a 60 cm circular feature in the muddy lake, less than 50 m
from the predicted fall line. After a short search, which again employed light
aircraft, the meteorite was recovered on the 31st December 2015 from a depth of
42 cm. Murrili is the first recovered observed fall by the digital Desert
Fireball Network (DFN). In addition to its scientific value, connecting
composition to solar system context via orbital data, the recover demonstrates
and validates the capabilities of the DFN, with its next generation remote
observatories and automated data reduction pipeline
Malnutrition enteropathy in Zambian and Zimbabwean children with severe acute malnutrition: A multi-arm randomized phase II trial.
Malnutrition underlies almost half of all child deaths globally. Severe Acute Malnutrition (SAM) carries unacceptable mortality, particularly if accompanied by infection or medical complications, including enteropathy. We evaluated four interventions for malnutrition enteropathy in a multi-centre phase II multi-arm trial in Zambia and Zimbabwe and completed in 2021. The purpose of this trial was to identify therapies which could be taken forward into phase III trials. Children of either sex were eligible for inclusion if aged 6-59 months and hospitalised with SAM (using WHO definitions: WLZ <-3, and/or MUAC <11.5 cm, and/or bilateral pedal oedema), with written, informed consent from the primary caregiver. We randomised 125 children hospitalised with complicated SAM to 14 days treatment with (i) bovine colostrum (n = 25), (ii) N-acetyl glucosamine (n = 24), (iii) subcutaneous teduglutide (n = 26), (iv) budesonide (n = 25) or (v) standard care only (n = 25). The primary endpoint was a composite of faecal biomarkers (myeloperoxidase, neopterin, α1-antitrypsin). Laboratory assessments, but not treatments, were blinded. Per-protocol analysis used ANCOVA, adjusted for baseline biomarker value, sex, oedema, HIV status, diarrhoea, weight-for-length Z-score, and study site, with pre-specified significance of P < 0.10. Of 143 children screened, 125 were randomised. Teduglutide reduced the primary endpoint of biomarkers of mucosal damage (effect size -0.89 (90% CI: -1.69,-0.10) P = 0.07), while colostrum (-0.58 (-1.4, 0.23) P = 0.24), N-acetyl glucosamine (-0.20 (-1.01, 0.60) P = 0.67), and budesonide (-0.50 (-1.33, 0.33) P = 0.32) had no significant effect. All interventions proved safe. This work suggests that treatment of enteropathy may be beneficial in children with complicated malnutrition. The trial was registered at ClinicalTrials.gov with the identifier NCT03716115
Tumor markers in breast cancer - European Group on Tumor Markers recommendations
Recommendations are presented for the routine clinical use of serum and tissue-based markers in the diagnosis and management of patients with breast cancer. Their low sensitivity and specificity preclude the use of serum markers such as the MUC-1 mucin glycoproteins ( CA 15.3, BR 27.29) and carcinoembryonic antigen in the diagnosis of early breast cancer. However, serial measurement of these markers can result in the early detection of recurrent disease as well as indicate the efficacy of therapy. Of the tissue-based markers, measurement of estrogen and progesterone receptors is mandatory in the selection of patients for treatment with hormone therapy, while HER-2 is essential in selecting patients with advanced breast cancer for treatment with Herceptin ( trastuzumab). Urokinase plasminogen activator and plasminogen activator inhibitor 1 are recently validated prognostic markers for lymph node-negative breast cancer patients and thus may be of value in selecting node-negative patients that do not require adjuvant chemotherapy. Copyright (C) 2005 S. Karger AG, Basel
Mortality following development of breast cancer while using oestrogen or oestrogen plus progestin: a computer record-linkage study
The literature on the relationship between breast cancer mortality and postmenopausal oestrogen and combined oestrogen/progestin therapy is seemingly contradictory. This study explored survival after exposure to oestrogen or oestrogen plus progestin at or in the year prior to breast cancer diagnosis. Information on patients first diagnosed with invasive breast cancer between 1993 and 1998 was linked with outpatient pharmacy data from 1992 to 2000. Patients were classified according to use of oestrogen alone or oestrogen plus progestin at or in the year prior to diagnosis. Compared to nonusers, and adjusting for age at diagnosis, race/ethnicity, tumour size and grade, oestrogen receptor status, surgery status, and chemotherapy and hormone therapy for breast cancer treatment, oestrogen plus progestin users had lower all-cause mortality (stage I hazard ratio (HR)=0.69, 95% confidence interval (CI)=0.48–0.99; stage II HR=0.53, 95% CI=0.39–0.72) and breast cancer mortality (stage I HR=0.52, 95% CI=0.26–1.04; stage II HR=0.69, 95% CI=0.48–0.98). Oestrogen users experienced little or no survival benefit for all-cause mortality (stage I HR=1.04, 95% CI=0.77–1.42; stage II HR=0.86, 95% CI=0.65–1.14) or breast cancer mortality (stage I HR=1.23, 95% CI 0.72–2.10; stage II HR=1.01, 95% CI 0.72–1.41). Our findings suggest, relative to nonusers, a lower risk of death from all causes and from breast cancer in patients who were diagnosed with breast cancer while exposed to oestrogen plus progestin, but not in patients exposed to oestrogen only
Policies, Political-Economy, and Swidden in Southeast Asia
For centuries swidden was an important farming practice found across the girth of Southeast Asia. Today, however, these systems are changing and sometimes disappearing at a pace never before experienced. In order to explain the demise or transitioning of swidden we need to understand the rapid and massive changes that have and are occurring in the political and economic environment in which these farmers operate. Swidden farming has always been characterized by change, but since the onset of modern independent nation states, governments and markets in Southeast Asia have transformed the terms of swiddeners’ everyday lives to a degree that is significantly different from that ever experienced before. In this paper we identified six factors that have contributed to the demise or transformation of swidden systems, and support these arguments with examples from China (Xishuangbanna), Laos, Thailand, Malaysia, and Indonesia. These trends include classifying swiddeners as ethnic minorities within nation-states, dividing the landscape into forest and permanent agriculture, expansion of forest departments and the rise of conservation, resettlement, privatization and commoditization of land and land-based production, and expansion of market infrastructure and the promotion of industrial agriculture. In addition we note a growing trend toward a transition from rural to urban livelihoods and expanding urban-labor markets
Mechanism of Assembly of the Dimanganese-Tyrosyl Radical Cofactor of Class Ib Ribonucleotide Reductase: Enzymatic Generation of Superoxide Is Required for Tyrosine Oxidation via a Mn(III)Mn(IV) Intermediate
Ribonucleotide reductases (RNRs) utilize radical chemistry to reduce nucleotides to deoxynucleotides in all organisms. In the class Ia and Ib RNRs, this reaction requires a stable tyrosyl radical (Y•) generated by oxidation of a reduced dinuclear metal cluster. The Fe[superscript III][subscript 2]-Y• cofactor in the NrdB subunit of the class Ia RNRs can be generated by self-assembly from Fe[superscript II][subscript 2]-NrdB, O[subscript 2], and a reducing equivalent. By contrast, the structurally homologous class Ib enzymes require a Mn[superscript III][subscript 2]-Y• cofactor in their NrdF subunit. Mn[superscript II][subscript 2]-NrdF does not react with O[subscript 2], but it binds the reduced form of a conserved flavodoxin-like protein, NrdI[subscript hq], which, in the presence of O[subscript 2], reacts to form the Mn[superscript III][subscript 2]-Y• cofactor. Here we investigate the mechanism of assembly of the Mn[superscript III][subscript 2]-Y• cofactor in Bacillus subtilis NrdF. Cluster assembly from Mn[superscript II][subscript 2]-NrdF, NrdI[subscript hq], and O[subscript 2] has been studied by stopped flow absorption and rapid freeze quench EPR spectroscopies. The results support a mechanism in which NrdI[subscript hq] reduces O[subscript 2] to O[subscript 2]•– (40–48 s[superscript –1], 0.6 mM O[subscript 2]), the O[subscript 2]•– channels to and reacts with Mn[superscript II][subscript 2]-NrdF to form a Mn[superscript III]Mn[superscript IV] intermediate (2.2 ± 0.4 s[superscript –1]), and the Mn[superscript III]Mn[superscript IV] species oxidizes tyrosine to Y• (0.08–0.15 s[superscript –1]). Controlled production of O[subscript 2]•– by NrdI[subscript hq] during class Ib RNR cofactor assembly both circumvents the unreactivity of the Mn[superscript II][subscript 2] cluster with O[subscript 2] and satisfies the requirement for an “extra” reducing equivalent in Y• generation.National Institutes of Health (U.S.) (Grant GM81393)United States. Dept. of Defense (National Defense Science and Engineering Graduate (NDSEG) Fellowships
- …