Magnetic resonance imaging prognostic factors for survival and relapse in dogs with meningoencephalitis of unknown origin.

IntroductionCanine meningoencephalitis of unknown origin (MUO) is a debilitating disease associated with high mortality. The prognostic value of magnetic resonance imaging (MRI) findings for predicting survival at 12 months and long-term relapse remains uncertain.MethodsThis was a retrospective cohort study evaluating the prognostic value of different MRI variables using multivariable logistic regression and Cox proportional hazards analysis.ResultsIn total, 138 dogs were presumptively diagnosed with MUO. The most common location for lesions identified on MRI were the white matter tracts of the corona radiata and corpus callosum, followed by the frontal, sensorimotor and temporal cortices. Lower T2 lesion load (p = 0.006, OR = 0.942, CI = 0.902-0.983) was associated with longer survival and higher T1 post-contrast lesion load (p = 0.023, OR = 1.162, CI = 1.021-1.322) was associated with relapse.DiscussionThis study has identified prognostic factors that may help identify dogs at higher risk of death and relapse and therefore guide treatment recommendations

Lyapunov spectral analysis of a nonequilibrium Ising-like transition

By simulating a nonequilibrium coupled map lattice that undergoes an Ising-like phase transition, we show that the Lyapunov spectrum and related dynamical quantities such as the dimension correlation length~$\xi_\delta$ are insensitive to the onset of long-range ferromagnetic order. As a function of lattice coupling constant~$g$ and for certain lattice maps, the Lyapunov dimension density and other dynamical order parameters go through a minimum. The occurrence of this minimum as a function of~$g$ depends on the number of nearest neighbors of a lattice point but not on the lattice symmetry, on the lattice dimensionality or on the position of the Ising-like transition. In one-space dimension, the spatial correlation length associated with magnitude fluctuations and the length~$\xi_\delta$ are approximately equal, with both varying linearly with the radius of the lattice coupling.Comment: 29 pages of text plus 15 figures, uses REVTeX macros. Submitted to Phys. Rev. E

Borderline ovarian tumor frozen section diagnoses with features suspicious of invasive cancer:a retrospective study

Abstract Background A frozen section diagnosis of a borderline ovarian tumor with suspicious features of invasive carcinoma (“at least borderline” or synonymous descriptions) presents us with the dilemma of whether or not to perform a full ovarian cancer staging procedure. Quantification of this dilemma may help us with the issue of this clinical decision. The present study assessed and compared both the prevalence of straightforward borderline and “at least borderline” frozen section diagnoses and the proportion of these women with a final histopathological diagnosis of invasive carcinoma, with a special interest in histologic subtypes. Methods A retrospective cohort study was performed in three hospitals in The Netherlands. All women that underwent ovarian surgery with perioperative frozen section evaluation in one of these hospitals between January 2007 and July 2018 were identified and included in case of a borderline or “at least borderline” frozen section diagnosis and a borderline ovarian tumor or invasive carcinoma as a final diagnosis. Results A total of 223 women were included, of which 41 women (18.4%) were diagnosed with “at least borderline” at frozen section. Thirteen of forty-one women (31.7%) following “at least borderline” frozen section diagnosis and 14 of 182 women (7.7%) following a straightforward borderline frozen section diagnosis were diagnosed with invasive carcinoma at paraffin section evaluation (p < 0.001). When compared to straightforward borderline frozen section diagnoses, the proportion of women diagnosed with invasive carcinoma increased from 3.1 to 35.7% for serous tumors (p = 0.001), 10.0 to 21.7% for mucinous tumors (p = 0.129) and 50.0 to 75.0% (p = 0.452) in case of other histologic subtypes following an “at least borderline” frozen section diagnosis. Conclusions Overall, when compared to women with a decisive borderline frozen section diagnosis, women diagnosed with “at least borderline” frozen section diagnoses were found to have a higher chance of carcinoma upon final diagnosis (7.7% vs 31.7%). Especially in the serous subtype, full staging during initial surgery might be considered after preoperative consent to prevent a second surgical procedure or chemotherapy in unstaged women. Further studies are needed to evaluate whether additional sampling in case of an “at least borderline” diagnosis may decrease the risk of surgical over-treatment

Frozen section diagnosis of borderline ovarian tumors with suspicious features of invasive cancer is a devil's dilemma for the surgeon:A systematic review and meta-analysis

Introduction Frozen section diagnoses of borderline ovarian tumors are not always straightforward and a borderline frozen section diagnosis with suspicious features of invasive carcinoma (reported as "at least borderline" or synonymous descriptions) presents us with the dilemma of whether or not to perform a full surgical staging procedure. By performing a systematic review and meta-analysis, the prevalence of straightforward borderline and "at least borderline" frozen section diagnoses, as well as proportion of patients with a final diagnosis of invasive carcinoma in these cases, were assessed and compared, as quantification of this dilemma may help us with the issue of this clinical decision. Material and methods PubMed, EMBASE and Cochrane library databases were searched and studies discussing "at least borderline" frozen section diagnoses were included in the review. Numbers of specific frozen section diagnoses and subsequent final histological diagnoses were extracted and pooled analysis was performed to compare the proportion of patients diagnosed with invasive carcinoma following borderline and "at least borderline" frozen section diagnoses, presented as risk ratio and risk difference with 95% confidence intervals (95% CI). Results Of 4940 screened records, eight studies were considered eligible for quantitative analysis. A total of 921 women was identified and 230 (25.0%) of these women were diagnosed with "at least borderline" ovarian tumor at the time of frozen section. Final histological diagnoses were reported in five studies, including 61 women with an "at least borderline" diagnosis and 290 women with a straightforward borderline frozen section diagnosis. Twenty-five of 61 women (41.0%) of the "at least borderline" group had invasive cancer at final diagnosis, compared with 28 of 290 women (9.7%) of the straightforward borderline frozen section group (risk difference -0.34, 95% CI -0.53 to -0.15; relative risk 0.25, 95% CI 0.13-0.50). Conclusions Women diagnosed with "at least borderline" frozen section diagnoses were found to have a higher chance of carcinoma upon final diagnosis when compared with women with a straightforward borderline frozen section diagnosis (41.0% vs 9.7%). Especially in the serous subtype, and after preoperative consent, full staging during initial surgery might be considered in these cases to prevent a second surgical procedure

Versatile Coordination of Cyclopentadienyl-Arene Ligands and Its Role in Titanium-Catalyzed Ethylene Trimerization

Cationic titanium(IV) complexes with ansa-(η5-cyclopentadienyl,η6-arene) ligands were synthesized and characterized by X-ray crystallography. The strength of the metal-arene interaction in these systems was studied by variable-temperature NMR spectroscopy. Complexes with a C1 bridge between the cyclopentadienyl and arene moieties feature hemilabile coordination behavior of the ligand and consequently are active ethylene trimerization catalysts. Reaction of the titanium(IV) dimethyl cations with CO results in conversion to the analogous cationic titanium(II) dicarbonyl species. Metal-to-ligand backdonation in these formally low-valent complexes gives rise to a strongly bonded, partially reduced arene moiety. In contrast to the η6-arene coordination mode observed for titanium, the more electron-rich vanadium(V) cations [cyclopentadienyl-arene]V(NiPr2)(NC6H4-4-Me)+ feature η1-arene binding, as determined by a crystallographic study. The three different metal-arene coordination modes that we experimentally observed model intermediates in the cycle for titanium-catalyzed ethylene trimerization. The nature of the metal-arene interaction in these systems was studied by DFT calculations.

Dynamical Fermions with Fat Links

We present and test a new method for simulating dynamical fermions with fat links. Our construction is based on the introduction of auxiliary but dynamical gauge fields and works with any fermionic action and can be combined with any fermionic updating. In our simulation we use an over-relaxation step which makes it effective. For four flavors of staggered fermions first results indicate that flavor symmetry at a lattice spacing a~0.2 fm is restored to a few percent. With the standard action this amount of flavor symmetry restoration is achieved at a~0.07 fm. We estimate that the overall computational cost is reduced by at least a factor 10.Comment: 11 pages, 4 figures, detailed description of over-relaxation and references added, figures with more statistic

Borderline tumours of the ovary:Common practice in the Netherlands

Objectives: Discordance between frozen section diagnosis and the definite histopathological diagnosis and the fact that the frozen section result is not always unambiguous, may contribute to differences in clinical practice regarding perioperative treatment and follow-up of borderline ovarian tumours (BOTs) patients amongst gynaecologic oncologists, which may lead to over- and undertreatment. The aim of the study was to map the Dutch gynaecologists' preferred treatment and follow-up strategy in case of BOTs. Methods: A questionnaire was sent to all Dutch gynaecologists involved in ovarian surgery with perioperative frozen section analysis, and the outcomes were assessed using descriptive statistics. Results: Nearly half of the respondents (41.0%) would not perform a staging procedure in case of a BOT. In case of an ambiguous frozen section diagnosis, tending towards invasive carcinoma, a considerable number (sBOT 56.4%; mBOT 30.8%) would perform a lymph node sampling as part of the staging procedure. A relaparotomy/relaparoscopy, to perform a lymph node sampling in case of a serous or mucinous carcinoma after a BOT frozen section diagnosis, would be performed by 97.4% and 48.7% of the respondents, respectively. Conclusions: A considerable number of gynaecologists would perform a staging procedure that is recommended for ovarian cancer in case of an ambiguous BOT frozen section diagnosis, especially for serous tumours. In addition, nearly all gynaecologists would perform a second procedure including a lymph node sampling in case of a serous invasive carcinoma after a BOT frozen section diagnosis, which applies to half of the gynaecologists in case of a mucinous carcinoma. Keywords: Borderline tumours of the ovary, Staging procedure, Frozen section analysis, Questionnaire, Gynaecologic oncologist, Semi-specialized gynaecologist