113 research outputs found
Electronic and physico-chemical properties of nanmetric boron delta-doped diamond structures
Heavily boron doped diamond epilayers with thicknesses ranging from 40 to less than 2 nm and buried between nominally undoped thicker layers have been grown in two different reactors. Two types of [100]-oriented single crystal diamond substrates were used after being characterized by X-ray white beam topography. The chemical composition and thickness of these so-called deltadoped structures have been studied by secondary ion mass spectrometry, transmission electron microscopy, and spectroscopic ellipsometry. Temperature-dependent Hall effect and four probe
resistivity measurements have been performed on mesa-patterned Hall bars. The temperature dependence of the hole sheet carrier density and mobility has been investigated over a broad temperature range (6K<T<450 K). Depending on the sample, metallic or non-metallic behavior was observed. A hopping conduction mechanism with an anomalous hopping exponent was detected in the non-metallic samples. All metallic delta-doped layers exhibited the same mobility value, around 3.660.8 cm2/Vs, independently of the layer thickness and the substrate type. Comparison with previously published data and theoretical calculations showed that scattering by ionized impurities explained only partially this low common value. None of the delta-layers showed any sign of confinement-induced mobility enhancement, even for thicknesses lower than 2 nm.14 page
Utility of recombinant human TSH stimulation test in the follow-up of patients with differentiated thyroid cancer depending on basal thyroglobulin results
Background: Thyroglobulin (Tg) is fundamental for differentiated thyroid cancer (DTC) monitoring. Tg detection can be enhanced using recombinant human thyroidstimulating hormone (TSH) (rhTSH). This study is aimed to evaluate the use of the rhTSH stimulation test when using a high-sensitivity Tg assay.
Methods: We retrospectively studied 181 rhTSH tests from 114 patients with DTC and negative for antithyroglobulin antibodies (anti-TgAb). Image studies were performed in
all cases. Serum Tg and anti-TgAb were measured using specific immunoassays.
Results: rhTSH stimulation in patients with basal serum Tg (b-Tg) concentrations lower than 0.2 ng/mL always resulted in rhTSH-stimulated serum Tg (s-Tg) concentrations lower than 1.0 ng/mL and negative structural disease. In patients with bTg concentration between 0.2 and 1.0 ng/mL, s-Tg detected one patient (1/30) who showed biochemical incomplete
response. Patients with negative images had lower s-Tg than thosewith nonspecific or abnormal findings (p<0.05).Receiver operating characteristic curve analysis of the s-Tg to detect altered images showed an area under the curve of 0.763 (p<0.05).With an s-Tg cutoff of 0.85 ng/mL, the sensitivity was 100%, decreasing to 96.15% with an s-Tg cutoff of 2 ng/mL.
Conclusions: Patients with DTC with b-Tg concentrations equal or higher than 0.2 ng/mL can benefit from the rhTSH stimulation test
Clinical implications of changing thyroglobulin and antithyroglobulin antibodies analytical methods in the follow-up of patients with differentiated thyroid carcinoma
Background and aims: Patients’ response to treatment in differentiated thyroid cancer (DTC) is classified according to serum thyroglobulin concentrations (Tg), usually using the American Thyroid Association guidelines
and considering potential interfering anti-thyroglobulin antibodies (Ab-Tg). We aim to evaluate the clinical
implications of changing Tg and Ab-Tg quantification method.
Material and methods: Tg and Ab-Tg were quantified in 82 serum samples (60 from DTC patients) by Elecsys and
Access immunoassays.
Results: Elecsys immunoassay rendered higher values of Tg than Access: mean bias 5.03 ng/mL (95%CI:-
14.14–24.21). In DTC patients, there was an almost perfect agreement for response classification (kappa index =
0.833). Discrepancies appeared in patients with undetermined response, with a more tendency to subclassification with Access. Ab-Tg showed a poor correlation (r = 0.5394). When Elecsys cut-off was reduced to 43 IU/
mL, agreement for positive/negative classification improved from a kappa index of 0.607 to 0.650. Prospective
study with personalized follow-up showed that only 6.3% of Tg results required an analytical confirmation, being
confirmed 93% of them.
Conclusions: Despite the biases observed, clinical impact of an analytical change is minimal in patients’ management. However, cautious and personalized follow-up period after the change is still mandatory, especially in
patients with Tg levels between 0.2 and 1 ng/mL
Epibenthic communities of sedimentary habitats in a NE Atlantic deep seamount (Galicia Bank)
En prens
EXPLORE: A Prospective, Multinational, Natural History Study of Patients with Acute Hepatic Porphyria with Recurrent Attacks
BACKGROUND AND AIMS: Acute hepatic porphyria
comprises a group of rare genetic diseases caused by mutations in genes involved in heme biosynthesis. Patients can
experience acute neurovisceral attacks, debilitating chronic
symptoms, and long-term complications. There is a lack of
multinational, prospective data characterizing the disease and
current treatment practices in severely affected patients.
APPROACH AND RESULTS: EXPLORE is a prospective,
multinational, natural history study characterizing disease activity and clinical management in patients with acute hepatic
porphyria who experience recurrent attacks. Eligible patients
had a confirmed acute hepatic porphyria diagnosis and had
experienced ≥3 attacks in the prior 12 months or were receiving prophylactic treatment. A total of 112 patients were enrolled and followed for at least 6 months. In the 12 months
before the study, patients reported a median (range) of 6
(0-52) acute attacks, with 52 (46%) patients receiving hemin
prophylaxis. Chronic symptoms were reported by 73 (65%)
patients, with 52 (46%) patients experiencing these daily.
During the study, 98 (88%) patients experienced a total of
483 attacks, 77% of which required treatment at a health
care facility and/or hemin administration (median [range] annualized attack rate 2.0 [0.0-37.0]). Elevated levels of hepatic
δ-aminolevulinic acid synthase 1 messenger ribonucleic acid levels, δ-aminolevulinic acid, and porphobilinogen compared with
the upper limit of normal in healthy individuals were observed
at baseline and increased further during attacks. Patients had
impaired quality of life and increased health care utilization.
CONCLUSIONS: Patients experienced attacks often requiring treatment in a health care facility and/or with hemin, as
well as chronic symptoms that adversely influenced day-to-day
functioning. In this patient group, the high disease burden
and diminished quality of life highlight the need for novel
therapies. (Hepatology 2020;71:1546-1558)
EXPLORE: A prospective, multinational natural history study of patients with acute hepatic porphyria with recurrent attacks
BACKGROUND AND AIMS: Acute hepatic porphyria
comprises a group of rare genetic diseases caused by mutations in genes involved in heme biosynthesis. Patients can
experience acute neurovisceral attacks, debilitating chronic
symptoms, and long-term complications. There is a lack of
multinational, prospective data characterizing the disease and
current treatment practices in severely affected patients.
APPROACH AND RESULTS: EXPLORE is a prospective,
multinational, natural history study characterizing disease activity and clinical management in patients with acute hepatic
porphyria who experience recurrent attacks. Eligible patients
had a confirmed acute hepatic porphyria diagnosis and had
experienced ≥3 attacks in the prior 12 months or were receiving prophylactic treatment. A total of 112 patients were enrolled and followed for at least 6 months. In the 12 months
before the study, patients reported a median (range) of 6
(0-52) acute attacks, with 52 (46%) patients receiving hemin
prophylaxis. Chronic symptoms were reported by 73 (65%)
patients, with 52 (46%) patients experiencing these daily.
During the study, 98 (88%) patients experienced a total of
483 attacks, 77% of which required treatment at a health
care facility and/or hemin administration (median [range] annualized attack rate 2.0 [0.0-37.0]). Elevated levels of hepatic
δ-aminolevulinic acid synthase 1 messenger ribonucleic acid levels, δ-aminolevulinic acid, and porphobilinogen compared with
the upper limit of normal in healthy individuals were observed
at baseline and increased further during attacks. Patients had
impaired quality of life and increased health care utilization.
CONCLUSIONS: Patients experienced attacks often requiring treatment in a health care facility and/or with hemin, as
well as chronic symptoms that adversely influenced day-to-day
functioning. In this patient group, the high disease burden
and diminished quality of life highlight the need for novel
therapies. (Hepatology 2020;71:1546-1558)
Network structure of vertebrate scavenger assemblages at the global scale: drivers and ecosystem functioning implications
publishedVersio
Trends and outcome of neoadjuvant treatment for rectal cancer: A retrospective analysis and critical assessment of a 10-year prospective national registry on behalf of the Spanish Rectal Cancer Project
Introduction: Preoperative treatment and adequate surgery increase local control in rectal cancer. However, modalities and indications for neoadjuvant treatment may be controversial. Aim of this study was to assess the trends of preoperative treatment and outcomes in patients with rectal cancer included in the Rectal Cancer Registry of the Spanish Associations of Surgeons.
Method: This is a STROBE-compliant retrospective analysis of a prospective database. All patients operated on with curative intention included in the Rectal Cancer Registry were included. Analyses were performed to compare the use of neoadjuvant/adjuvant treatment in three timeframes: I)2006–2009; II)2010–2013; III)2014–2017. Survival analyses were run for 3-year survival in timeframes I-II.
Results: Out of 14, 391 patients, 8871 (61.6%) received neoadjuvant treatment. Long-course chemo/radiotherapy was the most used approach (79.9%), followed by short-course radiotherapy ± chemotherapy (7.6%). The use of neoadjuvant treatment for cancer of the upper third (15-11 cm) increased over time (31.5%vs 34.5%vs 38.6%, p = 0.0018). The complete regression rate slightly increased over time (15.6% vs 16% vs 18.5%; p = 0.0093); the proportion of patients with involved circumferential resection margins (CRM) went down from 8.2% to 7.3%and 5.5% (p = 0.0004). Neoadjuvant treatment significantly decreased positive CRM in lower third tumors (OR 0.71, 0.59–0.87, Cochrane-Mantel-Haenszel P = 0.0008). Most ypN0 patients also received adjuvant therapy. In MR-defined stage III patients, preoperative treatment was associated with significantly longer local-recurrence-free survival (p < 0.0001), and cancer-specific survival (p < 0.0001). The survival benefit was smaller in upper third cancers.
Conclusion: There was an increasing trend and a potential overuse of neoadjuvant treatment in cancer of the upper rectum. Most ypN0 patients received postoperative treatment. Involvement of CRM in lower third tumors was reduced after neoadjuvant treatment. Stage III and MRcN + benefited the most
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