Ultrafast photochemistry and electron-diffraction spectra in n → (3s) Rydberg excited cyclobutanone resolved at the multireference perturbative level.

We study the ultrafast time evolution of cyclobutanone excited to the singlet n → Rydberg state through non-adiabatic surface-hopping simulationsperformed at extended multi-state complete active space second-order perturbation (XMS-CASPT2) level of theory. These dynamics predict relaxation to the ground-state with a timescale of 822 ± 45 fs with minimal involvement of the triplets. The major relaxation path to the ground-state involves a three-state degeneracy region and leads to a variety of fragmented photoproducts. We simulate the resulting time-resolved electron-diffraction spectra, which track the relaxation of the excited state and the formation of various photoproducts in the ground state.

Phase III, randomised trial of avelumab versus physician's choice of chemotherapy as third-line treatment of patients with advanced gastric or gastro-oesophageal junction cancer: primary analysis of JAVELIN Gastric 300.

Background: There currently are no internationally recognised treatment guidelines for patients with advanced gastric cancer/gastro-oesophageal junction cancer (GC/GEJC) in whom two prior lines of therapy have failed. The randomised, phase III JAVELIN Gastric 300 trial compared avelumab versus physician's choice of chemotherapy as third-line therapy in patients with advanced GC/GEJC. Patients and methods: Patients with unresectable, recurrent, locally advanced, or metastatic GC/GEJC were recruited at 147 sites globally. All patients were randomised to receive either avelumab 10 mg/kg by intravenous infusion every 2 weeks or physician's choice of chemotherapy (paclitaxel 80 mg/m2 on days 1, 8, and 15 or irinotecan 150 mg/m2 on days 1 and 15, each of a 4-week treatment cycle); patients ineligible for chemotherapy received best supportive care. The primary end point was overall survival (OS). Secondary end points included progression-free survival (PFS), objective response rate (ORR), and safety. Results: A total of 371 patients were randomised. The trial did not meet its primary end point of improving OS {median, 4.6 versus 5.0 months; hazard ratio (HR)=1.1 [95% confidence interval (CI) 0.9-1.4]; P = 0.81} or the secondary end points of PFS [median, 1.4 versus 2.7 months; HR=1.73 (95% CI 1.4-2.2); P > 0.99] or ORR (2.2% versus 4.3%) in the avelumab versus chemotherapy arms, respectively. Treatment-related adverse events (TRAEs) of any grade occurred in 90 patients (48.9%) and 131 patients (74.0%) in the avelumab and chemotherapy arms, respectively. Grade ≥3 TRAEs occurred in 17 patients (9.2%) in the avelumab arm and in 56 patients (31.6%) in the chemotherapy arm. Conclusions: Treatment of patients with GC/GEJC with single-agent avelumab in the third-line setting did not result in an improvement in OS or PFS compared with chemotherapy. Avelumab showed a more manageable safety profile than chemotherapy. Trial registration: ClinicalTrials.gov: NCT02625623.

Primary headaches in children: clinical findings on the association with other conditions.

The aim of the present study is to report on the frequency of some comorbidities in primary headaches in childhood. Two hundred and eighty children (175 males and 105 females; ratio 1.7:1), aged 4 to 14 years, affected by primary headaches were consecutively enrolled in this study. In direct interviews, parents and children gave information about the association of their headaches with different conditions including asthma and allergic disorders, convulsive episodes, sleep disorders and increased body weight, affections some time associated in the literature to headache as comorbidities . In addition, anxiety and depression, attention deficit/hyperactivity disorder, tics, learning disabilities and obsessive-compulsive disorders, using psycho-diagnostic scales were evaluated. Two hundred and eighty children matched for age, sex, race and socio-economic status, were used as controls. No significant association of primary headaches was found with asthma and allergic disorders, convulsive episodes, sleep disorders and increased body weight. Overall behavioral disorders were more common in children who experienced headache than in controls. A significant association of primary headache was found with anxiety and depression (p value < 0.001), but not with the other psychiatric disorders. Primary headaches in children are not associated with most of the psychiatric and systemic conditions herein investigated. On the contrary, there was a significant association with anxiety and depression, as frequently reported in adults.

E2F1 has both oncogenic and tumor-suppressive properties in a transgenic model.

Using a transgenic mouse model expressing the E2F1 gene under the control of a keratin 5 (K5) promoter, we previously demonstrated that increased E2F1 activity can promote tumorigenesis by cooperating with either a v-Ha-ras transgene to induce benign skin papillomas or p53 deficiency to induce spontaneous skin carcinomas. We now report that as K5 E2F1 transgenic mice age, they are predisposed to develop spontaneous tumors in a variety of K5-expressing tissues, including the skin, vagina, forestomach, and odontogenic epithelium. On the other hand, K5 E2F1 transgenic mice are found to be resistant to skin tumor development following a two-stage carcinogenesis protocol. Additional experiments suggest that this tumor-suppressive effect of E2F1 occurs at the promotion stage and may involve the induction of apoptosis. These findings demonstrate that increased E2F1 activity can either promote or inhibit tumorigenesis, dependent upon the experimental context.

Suppression or elevation of cytosolic phospholipase A2 alters keratinocyte prostaglandin synthesis, growth, and apoptosis.

Prostaglandins and other arachidonic acid (AA) metabolites are synthesized by keratinocytes in response to tumor promoters and are produced at very high levels in tumors. After phorbol ester treatment, AA is hydrolyzed from keratinocytes primarily by the cytosolic form of phospholipase A2 (cPLA2), which exhibited a strong substrate preference for phosphatidylcholine over phosphatidylethanolamine and AA over other fatty acids. Phorbol esters increase cPLA2 activity but not the level of expression. To dissociate increased cPLA2 activity from other phorbol ester effects and thus determine the effects of altered AA release on cell growth, the murine keratinocyte cell line, HEL-30, was stably transfected with the sense or antisense cDNA for cPLA2. The resulting cell lines displayed corresponding over- or underexpression and up to 23-fold differences in cPLA2 activity between them. Phorbol ester caused a 15-fold difference in AA release between sense and antisense transfectants. Prostaglandin E2 levels correlated with AA release levels. The sense transfectants showed an enhanced proliferative capacity, based on increased cell number over time and [3H]thymidine incorporation. The antisense transfectants had significantly (>60%) reduced growth rates, compared with both parental cells and sense transfectants. The extent of apoptosis was determined in tumors from cell lines grown in graft chambers in vivo. The number of apoptotic cells was significantly greater in tumors from the sense transfectants, based on terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling staining, compared with the parental or antisense lines. These data are in agreement with a recent study (M. C. Stern et al., Mol. Carcinog., 20: 137-142, 1997) showing a correlation between increased apoptosis and tumor progression in this model system. These results suggest that the elevated eicosanoid synthesis that is observed in skin carcinomas contributes to the growth and progression of these tumors.

Dissociation of sensitivities to tumor promotion and progression in outbred and inbred SENCAR mice.

The sensitivity of outbred SENCAR mice and inbred SENCAR (SSIN) mice to multistage carcinogenesis was studied. Tumors were induced using either 7,12-dimethylbenz[a]anthracene or N-methyl-N'-nitro-N-nitrosoguanidine as initiators and 12-O-tetradecanoylphorbol-13-acetate or benzoyl peroxide as promoting agents. Although the number of papillomas per mouse was higher in SSIN than in outbred SENCAR mice, the number of carcinomas observed in the SSIN strain was significantly lower regardless of the initiator or promoter used. It was also observed that the expression of markers of premalignant progression (i.e., dysplasia, expression of keratin K13, and loss of keratin K1 expression) was markedly suppressed in SSIN papillomas. After 50 wk of promotion with 12-O-tetradecanoylphorbol-13-acetate, the pattern of expression of K13 and K1 in SSIN mice was comparable to the pattern observed in outbred SENCAR mice after 10 to 20 wk of promotion with 12-O-tetradecanoylphorbol-13-acetate. It was also observed that 67% of the tumors induced in SSIN mice by initiation with 7,12-dimethylbenz[a]anthracene exhibited a mutation in codon 61 of the Ha-ras-1 gene. This latter finding suggests that the differences observed in tumor progression between the inbred strain and the outbred stock are not related to a genetic alteration in the Ha-ras-1 gene but rather to an independent event that we have postulated to involve a putative suppressor gene. The data reported here suggest that the putative gene(s) that confers susceptibility to tumor promotion was segregated from the gene(s) involved in tumor progression during selection and inbreeding of the SENCAR mouse stock.

Changes in keratin expression during 7,12-dimethylbenz[a]anthracene-induced hamster cheek pouch carcinogenesis.

This study was undertaken to explore the expression of keratins in the hamster cheek pouch carcinogenesis model, using monospecific keratin antibodies and a technique that allows immunoblotting analysis of tissues embedded in paraffin. Changes in keratin expression were correlated with histopathological changes and with the expression of the enzyme gamma-glutamyl transpeptidase. The right cheek pouch of 20 male golden Syrian hamsters was treated with 0.5% 7,12-dimethylbenz[a]anthracene for 16 weeks. As previously described by other laboratories, this treatment resulted in hyperplastic and dysplastic lesions and benign and malignant tumors. The keratins assayed in this study were K14 (Mr 55,000), K1 (Mr 67,000), and K13 (Mr 47,000). The normal hamster cheek pouch epithelium expressed K14 in the basal layer and K13 in the suprabasal and differentiated layers, whereas K1 was not detected by either immunohistochemistry or immunoblotting. Concomitant with 7,12-dimethylbenz[a]anthracene-induced hyperplasia, there were some topographical alterations in the distribution of K14. In this case, K14 was no longer restricted to the basal layer but was also expressed in differentiated cells. The same pattern was also observed in dysplastic lesions and in squamous cell carcinoma. Furthermore, expression of the K13 differentiation-associated keratin was preserved in this hyperplastic epithelium during all the stages of carcinogenesis, including either anaplastic or differentiated areas. In contrast, after 2 weeks of 7,12-dimethylbenz[a]anthracene treatment, K1 expression started as a weak and patchy pattern in suprabasal cells, becoming stronger and more homogeneous at 8 and 16 weeks of treatment. However, K1 was almost absent in squamous cell carcinoma, where only small very well differentiated areas were stained. We also observed gamma-glutamyl transpeptidase-positive foci in earlier stages of carcinogenesis, concomitant with the expression of the K1 keratin. However, it was not possible to find a perfect topographical correspondence between the two events. Alterations in the pattern of keratin expression appear to be a common feature during the development of squamous cell carcinoma in different systems and could be an excellent tool to study carcinogenesis and chemoprevention.

Overexpression of insulin-like growth factor-1 induces hyperplasia, dermal abnormalities, and spontaneous tumor formation in transgenic mice.

Transgenic animals were developed to assess the role of insulin-like growth factor 1 (IGF-1) in skin growth, differentiation and organization, as well as its importance in tumor formation. Expression of a human IGF-1 cDNA was targeted to the interfollicular epidermis of transgenic mice using a human keratin 1 promoter construct (HK1). Transgenic animals (HK1.IGF-1 mice) could be identified at birth by early ear unfolding and excessive ear and skin growth compared to non-transgenic littermates. Further examination of the skin from these mice showed epidermal hyperplasia and hyperkeratosis, marked thickening of the dermis and hypodermis, and early hair follicle generation in newborns. The severity of this phenotype correlated with transgene expression both of which subsided with age. Adult HK1.IGF-1 mice developed spontaneous tumors following treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA) alone and exhibited an exaggerated epidermal proliferative response following treatment with the tumor promoter compared to non transgenic littermates. Additionally, HK1.IGF-1 transgenic mice developed papillomas faster and in markedly greater numbers compared to non-transgenic littermates in standard initiation-promotion experiments. The data presented suggest an important role for IGF-1 in the process of multistage carcinogenesis in mouse skin.

Deregulated expression of cell-cycle proteins during premalignant progression in SENCAR mouse skin.

It is now evident that several genes encoding regulatory activities that control the mammalian cell cycle, particularly some that control the progression of quiescent cells through G1 and into S phase, are targets for alterations that underlie the development of neoplasms. Here, we made a sequential study of alterations in cell cycle protein expression and complex formation among cyclin, cyclin dependent kinases (CDKs) and CDK inhibitors (CKIs) during premalignant progression in SENCAR mouse skin tumors. Changes in the level of expression were observed in positive (cyclin D1, D2, and E2F family members) and negative regulators (p16Ink4a, p57Kip2) of the cell cycle. Also, we observed the formation of cyclin/CDK/CKI complexes. The amounts of these proteins and complexes increased substantially at specific times during promotion but not during malignant conversion to carcinomas. These data show that deregulation of growth control occurs in benign tumors and that subsequent mutations not involved cell-cycle regulation are probably necessary to induce invasive behavior.

Estrogen and progesterone regulation of proliferation, migration, and loss in different target cells of rabbit uterine epithelium.

We have explored the possibility that estrogens and progesterone could have different target uterine cell populations according to their cell cycle stage and localization in glands vs. lumen. Experiments were carried out in which rabbits were injected with [3H]thymidine for 3 days to label nuclei of dividing cells, then either 17 beta-estradiol, progesterone, or vehicle were administered. 17 beta-Estradiol induced a decrease in the percentage of cells with labeled nuclei or labeling index of either luminal or glandular epithelium. Since this steroid has been shown to have a significant proliferative effect on glands, the data suggest that its effect is exerted on unlabeled quiescent cells, which are then recruited into the cell cycle. Progesterone, on the other hand, was found to induce a significant increase in labeling index of both luminal and glandular epithelium. Therefore, it is concluded that dividing cells are a target for this hormone. Analysis of the number of nuclear grains according to cell location in luminal vs. glandular epithelia and the effect of hormone administration confirmed that each ovarian hormone acts on different target cell populations. Short and long term administration of estrogens resulted in a larger internal circumference of the uterus due to an increase in the number of luminal cells, whereas the number of glands and glandular cells per section did not appear to change. These findings, in combination with previous research, suggest that endometrial gland cells migrate towards the lumen and estrogen administration decreases the rate of cell loss in the luminal epithelium. The concept of cell migration is supported by experiments in which single administration of [3H]thymidine to rabbits was followed by determination at different times of the geographical distribution of cells with labeled nuclei. There was observed, as a function of time, a decrease in the number of labeled cells in the bottom of the glands with a concomitant increase in the same parameter in the upper part of the glands and luminal epithelia. Estradiol administration changed these kinetics.

An animal model for oral cancer.

Human head and neck squamous cell carcinogenesis (SCC) is a common malignancy that appears to be related to continuous exposure to putative carcinogens or promoters such as tobacco and alcohol. To understand the mechanisms of the development of head and neck cancer and to test the efficiency of new therapeutic approaches, the characterization of an animal model system is necessary. The check-pouch carcinogenesis model in Syrian golden hamsters is probably the best known animal system that is most closely comparable with the development of premalignant and malignant lesions in human oral cancer. Furthermore, it is one of the most well-characterized animal system models for SCC. Our first approach to understanding the cellular and molecular changes that occur in the hamster cheek-pouch carcinogenesis process was to compare this model to the mouse-skin system, in which a number of critical events have been well characterized. We examined the sequential expression of hyperplasia, micronucleated cells, ornithine decarboxylase activity, polyamine levels, transglutaminase I activity, epidermal growth factor receptor levels, expression of several keratins, gamma-glutamyl transpeptidase, and nucleolar organizer regions. We suggest that these markers can be used to understand mechanisms of carcinogenesis and, in addition, can serve as alternative shorter end points in studies of chemoprevention. We also present preliminary molecular studies in the experimental oral model. We obtained a partial sequence of exon 2 of the Ha-ras gene and detected an A182----T transversion in codon 61 in hamster cheek-pouch SCC induced by 7,12-dimethylbenz(a)anthracene.

Optimal fluorescence excitation wavelengths for detection of squamous intra-epithelial neoplasia: results from an animal model.

Using the hamster cheek pouch carcinogenesis model, we explore which fluorescence excitation wavelengths are useful for the detection of neoplasia. 42 hamsters were treated with DMBA to induce carcinogenesis, and 20 control animals were treated only with mineral oil. Fluorescence excitation emission matrices were measured from the cheek pouches of the hamsters weekly. Results showed increased fluorescence near 350-370 nm and 410 nm excitation and decreased fluorescence near 450-470 nm excitation with neoplasia. The optimal diagnostic excitation wavelengths identified using this model - 350-370 nm excitation and 400-450 nm excitation - are similar to those identified for detection of human oral cavity neoplasia.

Reproducibility of early and late asthmatic responses to allergen challenge in a large group of asthmatics.

The specific bronchial provocative test (sBPT) coupled with allergen is used to investigate asthma. Very few studies have examined the reproducibility of responses to allergen challenge. The aim of this study was to measure the reproducibility of PD20FEV1 allergen and late asthmatic response (LAR) in 53 asthmatics and to relate the reproducibility to the time interval between two allergen challenges. Fifty-three atopic asthmatics performed two allergen challenges not less than 2 and not more than 26 weeks apart. Randomly, 19 subjects were assigned to a short-interval group (14-35 days between the two tests) and 34 to a long-interval group (40-180 days). In each challenge, the PD20FEV1 was sought for and the maximum % fall in FEV1 from 3 to 7 h after the allergen challenge was evaluated as a measurement of magnitude of the LAR. High intraclass correlation coefficients (R(I)) were found for both PD20FEV1 (R(I) = 0.78) and LAR (R(I) = 0.77) in all subjects. PD20FEV1 allergen showed a high R(I) in the long-interval group (R(I) = 0.80), but a low R(I) in the short-interval group (R(I) = 0.63). In contrast LAR showed a lower R(I) in the long-interval group (R(I) = 0.68) than in the short-interval group (R(I) = 0.77). Moreover, the R(I) for PD20FEV1 was particularly low in subjects with a dual pattern to the allergen challenge and a short interval between the two allergen challenges. Our study confirmed that asthmatic responses induced by allergen challenge have a good reproducibility. Moreover, we have demonstrated that the interval between two allergen challenges can determine a change in reproducibility in asthmatic responses induced by allergen challenge.

Genetic analysis of neoplasia induced by N-nitroso-N-methylurea in Xiphophorus hybrid fish.

Interspecific crosses within the genus Xiphophorus have historically been used to study the genetic aspects of melanoma formation. Melanomas typically occur as a result of deregulation of polymorphic, naturally occurring macromelanophore pigment patterns. Hybrid crosses also have been used to study the inducibility of melanoma by physical sources (such as UV light) and chemicals (such as N-methyl-N-nitrosourea, MNU). We previously defined a genomic region that is implicated in fish melanomagenesis and identified a candidate tumor suppressor gene (CDKN2X) within this genomic area. Highly significant associations between BC(1)-hybrid CDKN2X genotypes and UV-induced melanoma formation exist in a backcross produced from 2 inbred parental lines. However, when BC(1) hybrids are exposed to MNU as the tumor induction agent, a significant association between inheritance of CDKN2X alleles and tumor development is not observed. These data suggest there is mechanistic and genetic heterogeneity in melanomas derived from different etiologies within BC(1) hybrid fish.

A proposed classification scheme for Xiphophorus melanomas based on histopathologic analyses.

We studied the histopathologic characteristics of melanomas induced in the Xiphophorus model. This fish model has been used for several decades to study the molecular and genetic mechanisms underlying its susceptibility to melanoma induction. Numerous distinct interspecific hybrid crosses currently are being used in research on carcinogenesis. We previously reported that tumors were induced in such hybrid crosses after treatment with N-methyl-N-nitrosourea or UV radiation. In this report, we describe the histopathologic features of Xiphophorus melanomas and propose a new classification system. We suggest that melanomas in these fishes can be classified as follows: melanocytic melanomas; melanophorous-macromelanophorous polymorphic melanomas; spindle cell type melanomas; epithelioid cell melanomas; and amelanotic melanomas. The new classification of Xiphophorus melanomas should allow correlations between histopathologic characteristics and carcinogen treatment, and between histopathologic characteristics and the genetic background of the hybrid fish.

Effect of the anticonvulsant denzimol on the disposition of diazepam in the rat.

The influence of denzimol, a new imidazole derivative with anticonvulsant properties, on the disposition of diazepam (1 mg kg-1) was investigated in the rat. Denzimol pretreatment significantly increased plasma and brain concentrations of the benzodiazepine, consistent with reduced total clearance. The results suggest that the increase of diazepam brain concentrations by denzimol may produce enhancement of diazepam activity in the rat.

In-vivo metabolism in the rat and mouse of antrafenine to 1-m-trifluoromethylphenylpiperazine.

The analgesic antrafenine forms 1-m-trifluoromethylphenylpiperazine (mCF3PP) during its biotransformation in the rat and mouse. At least 14 and 3% of an antrafenine dose (25 mg kg-1 p.o.) reaches the systemic circulation as mCF3PP in the mouse and rat respectively. The metabolite easily enters the brain, reaching concentrations several times those in body fluids. This, together with the fact that mCF3PP is known to produce several pharmacological effects compatible with a stimulatory action on 5-hydroxytryptamine postsynaptic receptors, suggests that this metabolite may contribute to the parent drug's pharmacological effects.

Interaction of the anticonvulsants, denzimol and nafimidone, with liver cytochrome P450 in the rat.

The presence of an imidazole moiety in the chemical structure of denzimol and nafimidone suggested that these new anticonvulsants might interfere with cytochrome P450-mediated mixed function monooxygenase activities. We therefore investigated their ability to bind reversibly to rat liver cytochrome P450. Both drugs displayed a type II spectra. The Ks values of binding were 6.66 and 7.00 mM, respectively, for denzimol and nafimidone. In other in-vitro studies the IC50 of the inhibition caused by denzimol and nafimidone was determined on carbamazepine (CBZ) epoxidation and diazepam C3-hydroxylation and N1-dealkylation. The IC50 values for CBZ epoxidation were 4.46 x 10(-7) and 2.95 x 10(-7) M, respectively, in the presence of denzimol and nafimidone. The IC50 values for diazepam C3-hydroxylation were 1.44 x 10(-6) and 1.00 x 10(-6) M, respectively, and those for N1-dealkylation 6.66 x 10(-7) and 5.95 x 10(-7) M. The inhibition of CBZ metabolism was also investigated ex-vivo and in-vivo after single oral doses (15 and/or 60 mg kg-1) of denzimol or nafimidone. Inhibition of CBZ-10,11-epoxidation by the two drugs was time- and dose-dependent. Further studies in-vivo showed that denzimol and nafimidone prolong pentobarbitone sleeping times indicating that both drugs bind to rat liver microsomes and are potent inhibitors in the rat of mixed function monooxygense activities both in-vitro and in-vivo.

Propranolol does not alter flutoprazepam kinetics and metabolism in the rat.

The influence of propranolol on the disposition of flutoprazepam, a benzodiazepine derivative extensively biotransformed by hepatic microsomal oxidation, was evaluated in the rat. Propranolol was infused subcutaneously with osmotic minipumps (5 mg/day) to obtain steady-state concentrations of about 200 ng/ml. Flutoprazepam (5 mg/kg) was given intraperitoneally on the third day of propranolol infusion. There was some variability in flutoprazepam disposition, consistent with the concept of an extensive first-pass metabolism of high-extraction drugs. Propranolol had no significant effects on the kinetics of flutoprazepam or norflutoprazepam, an active metabolite possibly accounting for a substantial part of the parent compound's pharmacological and clinical effects. It was concluded that there is no evidence of any pharmacokinetic interaction between this beta-adrenoceptor blocker and flutoprazepam in the rat.

Analysis of amniotic fluid proteins by isoelectrofocusing (IEF).

Among the most recent methods for investigation of proteins in biological fluids SDS Polyacrylamide-gel-electrophoresis and Isoelectrofocusing (IEF) have recently been introduced into laboratory practice. The present investigation has been performed on 20 samples of amniotic fluid obtained during normal pregnancies in the first and in the third trimester. The obtained results suggest that IEF analysis seems to have a selective advantage in allowing the separation of bands which can not be easily recognized with SDS electrophoresis. These bands detected by IEF and present in amniotic fluid during late pregnancy seem to be related to some low molecular weight lipoprotein fractions and we suggest that they might be used as a possible marker for monitoring fetal lung maturation. In conclusion we think that it would be of great interest to evaluate the usefulness of IEF analysis in examining A.F. obtained during pregnancies complicated by infections.