Efficacy and Residue Comparisons between Two Slow-release Formulations of Fluridone

Residue profiles and efficacy of Avast and Sonar, two slow release pellet formulations of fluridone {1-methyl-3-phenyl-5- [3-(trifluoromethyl)phenly]-4(1H)-pyridinone}, were compared in outdoor tanks. Hydrilla (Hydrilla verticillata (L.f.) Royle) and southern naiad (Najas guadalupensis (Sprengel) Magnus) were treated with a split application of 6, 12, 18 and 24 μg/l a.i. fluridone and the concentrations of both formulations compared over a 134-day period. Both pellet formulations exhibited very similar residues over time for each respective treatment, resulted in peak concentrations of fluridone 40 to 50 days after application, and effectively and similarly controlled southern naiad and hydrilla at all rates tested by 92 days after initial application. (PDF contains 3 pages.

Basic research on the biology of meta-tetra(hydroxyphenyl) chlorin for photodynamic therapy in gynaecology: Somatic genotoxicity assayed with Drosophila melanogaster

The well-established SMART test, a somatic mutation and recombination assay of Drosophila, was applied to assess the possible genotoxicity of sublethal meta-tetra(hydroxyphenyl) chlorin (mTHPC) photodynamic therapy (PDT) to clonogenic cells in situ. The SMART assay monitors the loss of heterozygosity (LOH) at selected cell-marker loci in clonogenic cells of the larval wing primordia. No evidence of genotoxicity was observed under conditions that killed between 38 and 86% of the exposed test larvae. Since the SMART assay is based on the oral uptake of the suspected genotoxic agent, the uptake kinetics of mTHPC by the assay's specific target cells must be known. Therefore, relevant studies are being carried out at present in order to draw final conclusions from this negative test result for genotoxicit

Photodynamic diagnosis of breast tumours after oral application of aminolevulinic acid

Photodynamic diagnosis is of increasing interest for diagnosis in oncology. It is based on a more intense incorporation of a fluorescent dye in tumours compared to normal tissue. As a feasibility study we investigated the effectiveness of oral application of 5-aminolevulinic acid for photodynamic diagnosis of human primary mammary tumours. The study included 16 patients with palpable breast tumours. Aminolevulinic acid was administered at a concentration of 40 mg kg−1bodyweight 150–420 min prior to tumourectomy. Intraoperatively blue light (405 nm) was applied to the operation site. Sections of the excised tumour and some lymph nodes were prepared and analysed with a fluorescent microscope. All primary mammary tumour tissues showed significantly higher fluorescence intensity than surrounding normal mammary tissue. Fluorescence of the mammary tumours could also be discriminated macroscopically and intraoperatively. Fluorescence intensity in nonmetastatic lymph node tissue was higher in 2 out of 3 patients than in primary tumour tissue. By photodynamic diagnosis using aminolevulinic acid we were able to reliably distinguish primary mammary tumours from normal mammary tissue microscopically and macroscopically in all our patients. We suggest that photodynamic diagnosis with aminolevulinic acid for breast tumours should be further investigated and developed for intraoperative use and may well be a simple tool for better intraoperative diagnosis and recognition of tumour margins. We hypothesize that lymph node metastasis of breast tumours will not be detectable by this method. © 2001 Cancer Research Campaign http://www.bjcancer.co

Stripe phases in the two-dimensional Falicov-Kimball model

The observation of charge stripe order in the doped nickelate and cuprate materials has motivated much theoretical effort to understand the underlying mechanism of the stripe phase. Numerical studies of the Hubbard model show two possibilities: (i) stripe order arises from a tendency toward phase separation and its competition with the long-range Coulomb interaction or (ii) stripe order inherently arises as a compromise between itinerancy and magnetic interactions. Here we determine the restricted phase diagrams of the two-dimensional Falicov-Kimball model and see that it displays rich behavior illustrating both possibilities in different regions of the phase diagram.Comment: (5 pages, 3 figures

Phase separation due to quantum mechanical correlations

Can phase separation be induced by strong electron correlations? We present a theorem that affirmatively answers this question in the Falicov-Kimball model away from half-filling, for any dimension. In the ground state the itinerant electrons are spatially separated from the classical particles.Comment: 4 pages, 1 figure. Note: text and figure unchanged, title was misspelle

Loss of atm sensitises p53-deficient cells to topoisomerase poisons and antimetabolites

Background: Ataxia-telangiectasia is a pleiotropic autosomal recessive disorder caused by mutations in the ATM gene. In addition to a profound cancer predisposition, another hallmark of ataxia-telangiectasia is radiosensitivity. Recently, p53-null mouse fibroblasts have been reported to be radiosensitised by the concurrent loss of ATM. Materials and methods: We compared the sensitivity of atm+/+/p53-/- and atm-/-/p53-/- mouse embryonic fibroblasts to different classes of chemotherapeutic agents using the MTT assay, Trypan Blue exclusion and fluorescence-activated cell sorting for cell cycle and apoptosis analyses. Results: Loss of ATM function in p53-deficient cells resulted in a 2- to 4-fold increase in sensitivity to the topoisomerase I poisons camptothecin and topotecan, to the topoisomerase II poisons doxorubicin, epirubicin and etoposide, and to the antimetabolites 5-fluorouracil and gemcitabine, but not to the platinum compounds cisplatin, carboplatin and oxaliplatin, the taxanes docetaxel and paclitaxel, or to busulfan. Loss of ATM function did not result in increased apoptosis, but resulted in increased Trypan Blue staining in response to epirubicin, suggesting that processes other than apoptosis may mediate cytotoxicity. ATM deficiency did not alter the extent of G1/S or G2/M cell cycle phase accumulation produced by epirubicin, suggesting that enhanced sensitivity was not due to failure of checkpoint activation. Conclusions: We provide further evidence that ATM is involved in regulating cellular defences against some cytotoxic agents in the absence of p53. Tumour-targeted functional inhibition of ATM may be a valuable strategy for increasing the efficacy of anticancer agents in the treatment of p53-mutant cancer

Post-traumatic stress disorder in parturients delivering by caesarean section and the implication of anaesthesia: a prospective cohort study.

Post-traumatic stress disorder (PTSD) occurs in 1-7% of women following childbirth. While having a caesarean section (C-section) is known to be a significant risk factor for postpartum PTSD, it is currently unknown whether coexisting anaesthesia-related factors are also associated to the disorder. The aim of this study was to assess anaesthesia-linked factors in the development of acute postpartum PTSD. We performed a prospective cohort study on women having a C-section in a tertiary hospital in Switzerland. Patients were followed up six weeks postpartum. Patient and procedure characteristics, past morbidity or traumatic events, psychosocial status and stressful perinatal events were measured. Outcome was divided into two categories: full PTSD disease and PTSD profile. This was based on the number of DSM-IV criteria of the Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM-IV) present. The PTSD Checklist Scale and the Clinician Administered PTSD Scale were used for measurement. Of the 280 patients included, 217 (77.5%) answered the questionnaires and 175 (62.5%) answered to an additional phone interview. Twenty (9.2%) had a PTSD profile and six (2.7%) a PTSD. When a full predictive model of risk factors for PTSD profile was built using logistic regression, maternal prepartum and intrapartum complications, anaesthetic complications and dissociative experiences during C-section were found to be the significant predictors for PTSD profile. This is the first study to show in parturients having a C-section that an anaesthesia complication is an independent risk factor for postpartum PTSD and PTSD profile development, in addition to known perinatal and maternal risk factors

Rain, power laws, and advection

Localized rain events have been found to follow power-law size and duration distributions over several decades, suggesting parallels between precipitation and seismic activity [O. Peters et al., PRL 88, 018701 (2002)]. Similar power laws are generated by treating rain as a passive tracer undergoing advection in a velocity field generated by a two-dimensional system of point vortices.Comment: 7 pages, 4 figure

Effect of rofecoxib on platelet aggregation and blood loss in gynaecological and breast surgery compared with diclofenac

Background. Non‐selective cyclooxygenase (COX) inhibitors or non‐steroidal anti‐ inflammatory drugs (NSAIDs) are frequently omitted for perioperative pain relief because of potential side‐effects. COX‐2‐selective inhibitors may have a more favourable side‐effect profile. This study tested the hypothesis that the COX‐2‐selective inhibitor rofecoxib has less influence on platelet function than the NSAID diclofenac in gynaecological surgery. In addition, analgesic efficacy and side‐effects of the two drugs were compared. Methods. In this single‐centre, prospective, double‐blind, active controlled study, women undergoing vaginal hysterectomy (n=25) or breast surgery (n=25) under general anaesthesia received preoperatively 50 mg of rofecoxib p.o. followed 8 and 16 h later by two doses of placebo or three doses of diclofenac 50 mg p.o. at the same time points. We assessed arachidonic acid‐stimulated platelet aggregation before and 4 h after the first dose of study medication, estimated intraoperative blood loss, and haemoglobin loss until the first morning after surgery. Analgesic efficacy, use of rescue analgesics, and side‐effects were also recorded. Results. In the rofecoxib group, stimulated platelet aggregation was disturbed less (P=0.02), and estimated intraoperative blood loss (P=0.01) and the decrease in haemoglobin were lower (P=0.01). At similar pain ratings, the use of anti‐emetic drugs was less in the rofecoxib group (P=0.03). Conclusion. Besides having a smaller effect on platelet aggregation, one oral dose of rofecoxib 50 mg given before surgery provided postoperative analgesia similar to that given by three doses of diclofenac 50 mg and was associated with less use of anti‐emetics and less surgical blood loss in gynaecological surgery compared with diclofenac. Br J Anaesth 2004; 92: 523-3