Static NLO susceptibilities: testing approximation schemes against exact results

The reliability of the approximations commonly adopted in the calculation of static optical (hyper)polarizabilities is tested against exact results obtained for an interesting toy-model. The model accounts for the principal features of typical nonlinear organic materials with mobile electrons strongly coupled to molecular vibrations. The approximations introduced in sum over states and finite field schemes are analyzed in detail. Both the Born-Oppenheimer and the clamped nucleus approximations turn out to be safe for molecules, whereas for donor-acceptor charge transfer complexes deviations from adiabaticity are expected. In the regime of low vibrational frequency, static susceptibilities are strongly dominated by the successive derivatives of the potential energy and large vibrational contributions to hyperpolarizabilities are found. In this regime anharmonic corrections to hyperpolarizabilities are very large, and the harmonic approximation, exact for the linear polarizability, turns out totally inadequate for nonlinear responses. With increasing phonon frequency the role of vibrations smoothly decreases, until, in the antiadiabatic (infinite vibrational frequency) regime, vibrations do not contribute anymore to static susceptibilities, and the purely electronic responses are regained.Comment: 9 pages, including 3 figure

Clinical pharmacokinetics of tramadol and main metabolites in horses undergoing orchiectomy.

Tramadol is a synthetic codeine analogue used as an analgesic in human and veterinary medicine. It is not approved for use in horses, but could represent a valid tool for pain treatment in this species.The serum pharmacokinetic profile and urinary excretion of tramadol and its metabolites (O-desmethyltramadol [M1], N-desmethyltramadol [M2] and N,O-desmethyltramadol [M5]) was investigated in a multidrug anaesthetic and analgesic approach for orchiectomy in horses. The evaluation of the degree of cardiovascular stability, the intraoperative effect and postoperative analgesia obtained by the visual analogue scale are also reported. Animal and methods: Tramadol (4 mg/kg BW) was administered intravenously to eight male yearlings as a bolus over 60 seconds, 5 min after intubation and 15 min prior to surgery. Drug quantification was performed in serum and urine for tramadol, M1, M2 and M5 by high-performance liquid chromatography with fluorimetric detection.Mean tramadol concentration was 14.87 ± 11.14 μg/mL at 0.08 h, and 0.05 ± 0.06 μg/mL at 10 h. Serum concentrations of M1 and M2 metabolites were quite limited. For M1 and M2, median maximum concentration (Cmax) and time to achieve maximum concentration (Tmax) were 0.05 μg/mL and 0.75 h, and 0.08 μg/mL and 2 h, respectively; M5 was never detected. In urine, tramadol was the most recovered compound, followed by M1, M2 and M5.Showing no adverse events and based on the kinetic behaviour, pre-operative tramadol IV at a dose of 4 mg/kg BW might be useful and safe as analgesic in horses undergoing surgery

Neonatal mortality in dogs : prognostic value of Doppler ductus venosus waveform evaluation - Preliminary results

Aim: To define the prognostic value of Doppler ultrasonographic morphology of ductus venosus (DV) waveform on canine neonatal mortality. Materials and Methods: Fifty-four healthy pregnant bitches underwent fetal ultrasonographic assessment. The DV waveforms were classified as diphasic (dDVw) or triphasic (tDVw) and compared with neonatal mortality. Results: Ninety-three fetuses were evaluated. Twenty fetuses belonged to litters with neonatal mortality, in which tDVw was observed. Seven fetuses belonged to litters without neonatal mortality, in which tDVw was observed. Fifty-eight fetuses belonged to litters without neonatal mortality, in which only dDVw was observed. Eight fetuses belonged to litters with neonatal mortality, in which only dDVw was observed. The correlation between tDVw and neonatal mortality was statistically significant (odds ratio [OR], 20.7; p<0.0001). Considering only pregnancies with one or two fetuses with the same DV waveform: Two fetuses with tDVw belonged to litters with neonatal mortality; 1 foetus with tDVw belonged to litter without neonatal mortality and 26 fetuses showed dDVw without neonatal mortality. The correlation between tDVw and neonatal mortality even in litters up to two pups was statistically significant (OR, 88.3; p=0.01). Conclusion: Echo-Doppler assessment of DV is feasible in canine fetuses, and the presence tDVw seems to be related to neonatal mortality

Characterization of a population of unique granular lymphocytes in a bitch deciduoma, using a panel of histo- and immunohistochemical markers

The ovaries and uterus were collected after ovariohysterectomy from a 16-month-old Labrador bitch in diestrus that never mated. Discrete swellings were found in the uterine horns, with the macroscopic appearance of normal early pregnancy. At histologic examination, the endometrium, devoid of any conceptus and chorion, showed a marked proliferation, on the basis of which a diagnosis of deciduoma was made. A remarkable population of stromal eosinophilic granular lymphocytes was present, especially in the axis of the endometrial folds. Periodic acid–Schiff and Dolichos biflorus–lectin histochemical reaction and a panel of 10 immunohistochemical markers were used to characterize eosinophilic granular cells. Our findings allowed us to compare these granular cells with the granulated decidual cells, whose presence was until now described only in primates, rodents, or a few other epitheliochorial species. On the basis of our results, the importance of eosinophilic granular cells in a decidualization process is hypothesized to occur also in the bitch

Asymptomatic unilateral ovarian leiomioma in a German shepherd bitch

This report shows for the first time clinical imaging (ultrasound and computed tomography), histological and immunohistochemical findings of an ovarian leiomyoma, coincidentally diagnosed in an asymptomatic unmated nulliparous ten year-old German shepherd bitch concurrently suffering from multiple mammary tumors. A thorough examination allowed the differentiation of ovarian leiomyoma from other spindle cell tumors. An accurate description of the diagnostic procedures useful in the managing of ovarian leiomyoma could provide valuable information to veterinary practitioners. Indeed, despite its rarity and nonspecific symptoms, ovarian leiomyoma may also affect the dog with an unknown potential risk

A first glance on the epigenome of Capra hircus

DNA methylation and microRNAs (miRNA) are two important forms of epigenetic modifications that play an important role in gene regulation in animals. Methylation at the carbon 5 position of cytosine residues is a fundamental layer of cellular differentiation through the control of transcriptional potential. MiRNA are small noncoding RNA molecules that regulate gene expression. Complete DNA methylomes for several organisms are now available; at the present, methylome of the domestic goat is unexplored. There is also still limited knowledge about miRNAs expression profiles in small ruminant species. Therefore, to contribute information on epigenetic modification in Capra hircus, we analysed the methylome and the miRNA population of three tissues (hypothalamus, pituitary and ovary) from 3 adult Saanen goats. We used Methylated DNA binding domain sequencing with enrichment of methylated DNA fragments and next generation sequencing. We produced least 23 million reads per sample, which were aligned to the goat reference genome. Further analyses were performed to identify peaks corresponding to hyper-methylated regions. We sequenced miRNAs expressed in the three tissues with Illumina high-throughput sequencing. Reads were mapped on the Capra hircus reference genome and both known and novel miRNAs, and miRNA target sites were identified using information collected in miRBase and using specific bioinformatic tools. This study produced a comprehensive miRNA profile related to the biology of goat. Furthermore, this is the first work dealing with methylome in Capra hircus: our preliminary results could provide new information for a deeper comprehension of epigenetic mechanisms of this species

The methylome of the hypothalamus of prepubertal and pubertal goats

Puberty is the fulfillment of fertility, a process involving physiological and morphological development. It is well known that the increased hypothalamic secretion of the gonadotropin-releasing hormone (GnRH) is essential for the activation of this process, even if the elements coordinating the timing of puberty have not been fully identified1,2. Recent studies provide proof that there is an epigenetic regulation of female puberty, and DNA methylation, the most studied epigenetic modification, plays a major role in it3. We analyzed DNA methylation patterns of 5 Alpine goats at their prepubertal stage and 5 that reached puberty in order to highlight differences in their methylome. Detection of methylated regions across the goat genome involved a Methyl Binding Domain (MBD) enrichment followed by deep sequencing (Hiseq2000 Illumina). The software ChIPseeqer4 permitted the identification of peaks corresponding to hyper-methylated regions. We have observed a higher methylation level in prepubertal goats. The distribution of the methylation peaks across the genome and within CpG islands per chromosome per group of animals has been analyzed. Furthermore, we have investigated differential methylation in genes associated with puberty. Specifically, Cbx7, coding for a core component of the Polycomb group silencing complex, and GnRHR, the gene coding for GnRH receptor, showed a higher number of peaks into two intragenic fragments within prepubertal goats. These results, accompanied by transcriptome analysis, provide a foundation for elucidating the role of DNA methylation in the complex mechanisms that drive puberty in goat species

Glioma-associated stem cells: A novel class of tumor-supporting cells able to predict prognosis of human low-grade gliomas.

Background: Translational medicine aims at transferring advances in basic science research into new approaches for diagnosis and treatment of diseases. Low-grade gliomas (LGG) have a heterogeneous clinical behavior that can be only partially predicted employing current state-of-the-art markers, hindering the decision-making process. To deepen our comprehension on tumor heterogeneity, we dissected the mechanism of interaction between tumor cells and relevant components of the neoplastic environment, isolating, from LGG and high-grade gliomas (HGG), proliferating stem cell lines from both the glioma stroma and, where possible, the neoplasm. Methods and Findings: We isolated glioma-associated stem cells (GASC) from LGG (n=40) and HGG (n=73). GASC showed stem cell features, anchorage-independent growth, and supported the malignant properties of both A172 cells and human glioma-stem cells, mainly through the release of exosomes. Finally, starting from GASC obtained from HGG (n=13) and LGG (n=12) we defined a score, based on the expression of 9 GASC surface markers, whose prognostic value was assayed on 40 subsequent LGG-patients. At the multivariate Cox analysis, the GASC-based score was the only independent predictor of overall survival and malignant progression free-survival. Conclusions: The microenvironment of both LGG and HGG hosts non-tumorigenic multipotent stem cells that can increase in vitro the biological aggressiveness of glioma-initiating cells through the release of exosomes. The clinical importance of this finding is supported by the strong prognostic value associated with the characteristics of GASC. This patient-based approach can provide a groundbreaking method to predict prognosis and to exploit novel strategies that target the tumor stroma

De novo unbalanced translocations have a complex history/aetiology

We investigated 52 cases of de novo unbalanced translocations, consisting in a terminally deleted or inverted-duplicated deleted (inv-dup del) 46th chromosome to which the distal portion of another chromosome or its opposite end was transposed. Array CGH, whole-genome sequencing, qPCR, FISH, and trio genotyping were applied. A biparental origin of the deletion and duplication was detected in 6 cases, whereas in 46, both imbalances have the same parental origin. Moreover, the duplicated region was of maternal origin in more than half of the cases, with 25% of them showing two maternal and one paternal haplotype. In all these cases, maternal age was increased. These findings indicate that the primary driver for the occurrence of the de novo unbalanced translocations is a maternal meiotic non-disjunction, followed by partial trisomy rescue of the supernumerary chromosome present in the trisomic zygote. In contrast, asymmetric breakage of a dicentric chromosome, originated either at the meiosis or postzygotically, in which the two resulting chromosomes, one being deleted and the other one inv-dup del, are repaired by telomere capture, appears at the basis of all inv-dup del translocations. Notably, this mechanism also fits with the origin of some simple translocations in which the duplicated region was of paternal origin. In all cases, the signature at the translocation junctions was that of non-homologous end joining (NHEJ) rather than non-allelic homologous recombination (NAHR). Our data imply that there is no risk of recurrence in the following pregnancies for any of the de novo unbalanced translocations we discuss here