204 research outputs found

    Investigation of paramagnetic saturation in lanthanum manganese nitrate

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    Paramagnetic saturation of lanthanum manganese nitrate, La2Mn3(NO3)12·24H2O, has been investigated at liquid He temperatures in a static as well as a dynamical way. With the aid of the molecular-field theory the Casimir and Du Pré dispersion and absorption curves are adapted explicitly to the phenomenon of saturation. A satisfactory agreement has been observed between theory and experiment

    Pregnancy-related pain in the pelvis ( PPP): Terminology, clinical presentation and prevalence

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    Pregnancy-related lumbopelvic pain has puzzled medicine for a long time. The present systematic review focuses on terminology, clinical presentation, and prevalence. Numerous terms are used, as if they indicated one and the same entity. We propose “pregnancy-related pelvic girdle pain (PPP)”, and “pregnancy-related low back pain (PLBP)”, present evidence that the two add up to “lumbopelvic pain”, and show that they are distinct entities (although underlying mechanisms may be similar). Average pain intensity during pregnancy is 50 mm on a visual analogue scale; postpartum, pain is less. During pregnancy, serious pain occurs in about 25%, and severe disability in about 8% of patients. After pregnancy, problems are serious in about 7%. The mechanisms behind disabilities remain unclear, and constitute an important research priority. Changes in muscle activity, unusual perceptions of the leg when moving it, and altered motor coordination were observed but remain poorly understood. Published prevalence for PPP and/or PLBP varies widely. Quantitative analysis was used to explain the differences. Overall, about 45% of all pregnant women and 25% of all women postpartum suffer from PPP and/or PLBP. These values decrease by about 20% if one excludes mild complaints. Strenuous work, previous low back pain, and previous PPP and/or PLBP are risk factors, and the inclusion/exclusion of high-risk subgroups influences prevalence. Of all patients, about one-half have PPP, one-third PLBP, and one-sixth both conditions combined. Overall, the literature reveals that PPP deserves serious attention from the clinical and research communities, at all times and in all countries

    A critical assessment of SELDI-TOF-MS for biomarker discovery in serum and tissue of patients with an ovarian mass

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    <p>Abstract</p> <p>Background</p> <p>Less than 25% of patients with a pelvic mass who are presented to a gynecologist will eventually be diagnosed with epithelial ovarian cancer. Since there is no reliable test to differentiate between different ovarian tumors, accurate classification could facilitate adequate referral to a gynecological oncologist, improving survival. The goal of our study was to assess the potential value of a SELDI-TOF-MS based classifier for discriminating between patients with a pelvic mass.</p> <p>Methods</p> <p>Our study design included a well-defined patient population, stringent protocols and an independent validation cohort. We compared serum samples of 53 ovarian cancer patients, 18 patients with tumors of low malignant potential, and 57 patients with a benign ovarian tumor on different ProteinChip arrays. In addition, from a subset of 84 patients, tumor tissues were collected and microdissection was used to isolate a pure and homogenous cell population.</p> <p>Results</p> <p>Diagonal Linear Discriminant Analysis (DLDA) and Support Vector Machine (SVM) classification on serum samples comparing cancer versus benign tumors, yielded models with a classification accuracy of 71-81% (cross-validation), and 73-81% on the independent validation set. Cancer and benign tissues could be classified with 95-99% accuracy using cross-validation. Tumors of low malignant potential showed protein expression patterns different from both benign and cancer tissues. Remarkably, none of the peaks differentially expressed in serum samples were found to be differentially expressed in the tissue lysates of those same groups.</p> <p>Conclusion</p> <p>Although SELDI-TOF-MS can produce reliable classification results in serum samples of ovarian cancer patients, it will not be applicable in routine patient care. On the other hand, protein profiling of microdissected tumor tissue may lead to a better understanding of oncogenesis and could still be a source of new serum biomarkers leading to novel methods for differentiating between different histological subtypes.</p

    Differential Expression of Sex-Steroid Receptors in the Choroid Aligns With Central Serous Chorioretinopathy Sex Prevalence Across Different Ages

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    PURPOSE. The purpose of this study was to investigate the presence of sex-steroid receptors in human choroidal tissue across different ages and sex, aiming to better understand the pronounced sex difference in central serous chorioretinopathy (CSC) occurrence. METHODS. Paraffin-embedded enucleated eyes of 14 premenopausal women, 15 postmenopausal women, 10 young men (&lt;45 years), and 10 older men (&gt;60 years) were used. A clinically certified immunostaining was performed to detect the presence of the androgen receptor (AR), progesterone receptor (PR; isoform A and B), and estrogen receptor (ERα). The stained slides were scored in a blinded manner for positive endothelial cells and stromal cells in consecutive sections of the same choroidal region. RESULTS. Our analysis revealed the presence of AR, PR, and ERα in endothelial cells and stromal cells of choroidal tissue. The mean proportion of AR-positive endothelial cells was higher in young men (46% ± 0.15) compared to aged-matched women (29% ± 0.12; P &lt; 0.05, 95% confidence interval [CI]). Premenopausal women showed markedly lower mean proportion of ERα (5% ± 0.02) and PR-positive endothelial cells (2% ± 0.01) compared to postmenopausal women (15% ± 0.07 and 19% ± 0.13; both P &lt; 0.05, 95% CI), young men (13% ± 0.04 and 21% ± 0.10; both P &lt; 0.05, 95% CI), and older men (18% ± 0.09 and 27% ± 0.14; both P &lt; 0.05, 95% CI). Mean PR-positive stromal cells were also less present in premenopausal women (12% ± 0.07) than in other groups. CONCLUSIONS. The number of sex-steroid receptors in the choroidal tissue differs between men and women across different ages, which aligns with the prevalence patterns of CSC in men and postmenopausal women.</p

    Distinct contribution of cone photoreceptor subtypes to the mammalian biological clock

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    Ambient light detection is important for the synchronization of the circadian clock to the external solar cycle. Light signals are sent to the suprachiasmatic nuclei (SCN), the site of the major circadian pacemaker. It has been assumed that cone photoreceptors con-tribute minimally to synchronization. Here, however, we find that cone photoreceptors are sufficient for mediating entrainment and transmitting photic information to the SCN, as evaluated in mice that have only cones as functional photoreceptors. Using in vivo electrophysiological recordings in the SCN of freely moving cone-only mice, we observed light responses in SCN neuronal activity in response to 60-s pulses of both ultraviolet (UV) (lambda(max) 365 nm) and green (lambda(max) 505 nm) light. Higher irradiances of UV light led to irradiance-dependent enhancements in SCN neuronal activity, whereas higher irradiances of green light led to a reduction in the sustained response with only the transient response remain-ing. Responses in SCN neuronal activity decayed with a half-max time of similar to 9 min for UV light and less than a minute for green light, indicating differential input between short-wavelength-sensitive and mid-wavelength-sensitive cones for the SCN responsiveness. Furthermore, we show that UV light is more effective for photo-entrainment than green light. Based on the lack of a full sustained response in cone-only mice, we confirmed that rapidly alternating light levels, rather than slowly alternating light, caused substantial phase shifts. Together, our data provide strong evidence that cone types contribute to photoentrainment and differentially affect the electrical activity levels of the SCN.Circadian clocks in health and diseas

    Analysis of current perioperative management with Haemate® P/Humate P® in von Willebrand disease

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    Introduction: Patients with Von Willebrand disease (VWD) are regularly treated with VWF-containing concentrates in case of acute bleeding, trauma and dental or surgical procedures. Aim: In this multicentre retrospective study, current perioperative management with a von Willebrand factor (VWF)/Factor VIII (FVIII) concentrate (Haemate® P) in patients with VWD was evaluated. Patients/Methods: Patients with VWD undergoing minor or major surgery between 2000 and 2015, requiring treatment with a VWF/FVIII concentrate (Haemate® P), were included. Achieved VWF activity (VWF:Act) and FVIII during FVIII-based treatment regimens were compared to predefined target levels in national guidelines. Results: In total, 103 patients with VWD (148 surgeries) were included: 54 type 1 (73 surgeries), 43 type 2 (67 surgeries) and 6 type 3 (8 surgeries). Overall, treatment resulted in high VWF:Act and FVIII levels, defined as ≥0.20 IU/mL above predefined levels. In patients with type 1 VWD, respectively, 65% and 91% of trough VWF:Act and FVIII levels were higher than target levels. In patients with type 2 and type 3 VWD, respectively, 53% and 57% of trough VWF:Act and 72% and 73% of trough FVIII levels were higher than target level. Furthermore, FVIII accumulation over time was observed, while VWF:Act showed a declining trend, leading to significantly higher levels of FVIII than VWF:Act. Conclusion: High VWF:Act and accumulation of FVIII were observed after perioperative FVIII-based replacement therapy in patients with VWD, both underlining the necessity of personalization of dosing regimens to optimize perioperative treatment
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