Interlaboratory validation of a CD71-based flow cytometric method (Microflow) for the scoring of micronucleated reticulocytes in mouse peripheral blood

An interlaboratory study was performed to validate an anti-CD71/flow cytometry-based technique for enumerating micronucleated reticulocytes (MN-RETs) in mouse peripheral blood. These experiments were designed to address International Workshop on Genotoxicity Test Procedures validation criteria by evaluating the degree of correspondence between MN-RET measurements generated by flow cytometry (FCM) with those obtained using traditional microscopy-based methods. In addition to these cross-methods data, flow cytometric MN-RET measurements for each blood sample were performed at two separate sites in order to evaluate the reproducibility of data between laboratories. In these studies, groups of male CD-1 mice were treated with vehicle (saline or vegetable oil), a negative control (saline or vegetable oil), or four dose levels of five known genotoxicants (clastogens: cyclophosphamide, benzo[a]pyrene, 5-fluorouracil, methotrexate; aneugen: vincristine sulfate). Exposure occurred on 3 consecutive days via intraperitoneal injection, and blood samples were obtained approximately 24 hr after the final treatment. MN-RET frequencies were determined for each sample based on the analysis of 2,000 (microscopy) and 20,000 (FCM) reticulocytes. Regardless of the method utilized, each genotoxic agent was observed to cause statistically significant increases in the frequency of MN-RETs, and each response occurred in a dose-dependent manner. Spearman's correlation coefficient (rs) for FCM versus microscopy-based MN-RET measurements (nine experiments, 252 paired measurements) was 0.740, indicating a high degree of correspondence between methods. The rs value for all flow cytometric MN-RET measurements performed at the two independent sites was 0.857 (n = 248), suggesting that the automated method is highly transferable between laboratories. Additionally, the flow cytometric system offered advantages relative to microscopy-based scoring, including a greater number of cells analyzed, much faster analysis times, and a greater degree of objectivity. Collectively, data presented in this report suggest that the overall performance of mouse peripheral blood micronucleus tests is enhanced by the use of the flow cytometric scoring procedure.     

Magnetic resonance imaging measurements of the response of murine and human tumors to the vascular-targeting agent ZD6126.

PURPOSE: ZD6126 is a novel vascular targeting agent currently undergoing clinical evaluation. It acts by destabilizing the microtubulin of fragile and proliferating neoendothelial cells in tumors. The drug leads to blood vessel congestion, the selective destruction of the vasculature, and extensive necrosis in experimental tumors. The aim of the study reported here was to assess the ability of dynamic contrast enhanced magnetic resonance imaging (MRI) to measure the antivascular effects of ZD6126 in tumors. EXPERIMENTAL DESIGN: The work was carried out in mice bearing C38 colon adenocarcinoma and in patients with advanced cancers. MRI was performed before and 6 h (human tumors) or 24 h (C38 tumors) after i.v. drug administration. Contrast agent (gadolinium diethylenetriaminepentaacetate) enhancement was characterized by the initial area under the gadolinium diethylenetriaminepentaacetate uptake versus time curve (IAUC). IAUC reflects blood flow, vascular permeability, and the fraction of interstitial space. RESULTS: The median IAUC was reduced in all C38 tumors after ZD6126 administration [by 6-48% at 50 mg/kg (n = 3)], 58-91% at 100 mg/kg (n = 4), and 11-93% at 200 mg/kg (n = 6). In contrast, the administration of vehicle only led to no consistent change in median IAUC (n = 4). The ZD6126-induced changes in median IAUC appeared to be dose dependent (P = 0.045). No ZD6126-induced changes were apparent in murine muscle. Similar effects were seen in preliminary data from human tumors (11 tumors studied, 9 patients). At doses of 80 mg/m(2) and higher, the median IAUC post-ZD6126 treatment was reduced in all of the tumors studied (8 tumors, 6 patients) to 36-72% from the baseline value. There was a significant trend of increasing reductions with increasing exposure (P < 0.01). No drug-induced changes in human muscle or spleen IAUC were apparent. The reproducibility of the median IAUC parameter was investigated in patients. In 19 human tumors (measured in 19 patients) inter- and intratumor coefficients of variation were 64 and 18%. CONCLUSIONS: The contrast enhanced-MRI measured median IAUC is a useful end point for quantifying ZD6126 antivascular effects in human tumors.     

Changes in practice of breast cancer radiotherapy 1998–2002: An Australasian survey

In order to assess the impact on radiation oncology practice of the publication of evidence-based guidelines for technical aspects of therapeutic radiation for breast cancer, the Radiation Oncology Expert Advisory Group of the National Breast Cancer Centre conducted two postal surveys of radiation oncologists practising in Australia and New Zealand. Results from a survey conducted in 1998, prior to distribution of the guidelines, have been published previously. This article reports on results from a survey undertaken in 2002 and contains data from 102 respondents who manage women with breast cancer. The results show several important changes in practice since 1998, including increased use of CT scanning in breast cancer treatment planning and increased use of immobilization devices for patient treatment. There is also evidence of increased attention to technical aspects of treatment planning that reduce the potential risk of treatment toxicity. The influence of the guidelines, the wider availability of modern equipment and results from landmark clinical trials on change in radiation therapy practice is discussed.     

Post‐traumatic stress disorder,social support and cognitive status in community‐based older veterans

Objective: The present study investigated the relationships between structural and qualitative aspects of social support, combat‐related post‐traumatic stress disorder (PTSD) and cognitive status in a New Zealand veterans sample. Methods: A random sample of 232 New Zealand veterans completed a self‐report questionnaire and participated in a face‐to‐face interview. Results: Regression analysis showed that when controlling for age, income, education, depression and general health, PTSD scores had a negative relationship with cognitive status. Those who reported having private, restricted social networks had poorer cognitive functioning. These relationships were independent of each other. Conclusions: The findings suggest that while social support might be a potential target for interventions in at‐risk older adults, health professionals need to be aware of the concomitant possible influence of past trauma when dealing with this specific population.     

New-generation azaindole-adamantyl-derived synthetic cannabinoids

Purpose

This work reports the synthesis and pharmacological and analytical data for a new series of recently identified azaindole-adamantyl-derived synthetic cannabinoids (SCs).

Methods

Each SC was synthesised using an efficient and divergent synthesis, and assessed by electron ionisation mass spectrometry (EIMS). The cannabimimetic activity of each compound was conducted using a fluorometric imaging plate reader (FLIPR) assay.

Results

The described EIMS method and retention time by gas chromatography were able to effectively differentiate each of the analogues regardless of the bicyclic core. For the first time in these SC structures, the bicyclic ring system was shown to have an impact on the cannabimimetic activities in the fluorometric assay of membrane potential. Analogues ranged from moderately potent at both CB₁ and CB₂ (e.g., AP4AIC EC₅₀?=?160 nM and EC₅₀?=?64 nM, respectively) to not active at either cannabinoid receptor (AP4AICA, AP5AICA, and APIC).

Conclusions

Further investigation into receptor selectivity surrounding these bicyclic cores could prove useful for future therapeutic applications.

     

Sex Education Workshops for Parents of Children with Learning Disabilities

This paper presents an evaluation of the experience of parents of children with learning disabilities who took part in workshops focusing on the sex education needs of parents. Parents' concerns prior to the workshops related particularly to dealing with menstruation and masturbation, and to protecting their children from sexual abuse. The workshop experience gave parents greater awareness of their children's sexual needs and feelings, as well as new and relevant information. A major benefit of attendance at the workshops was the support which parents gained from each other. Issues which need to be addressed to maximise the impact of such workshops include increasing the numbers of parents who attend; ensuring that emotive and painful topics are sensitively facilitated; and the production of suitable sex education resources for parents to use with young people with learning disabilities.     

Enteric colonization in sporadic neonatal necrotizing enterocolitis

Microflora of the gut was studied close to the onset of sporadic necrotizing enterocolitis (NEC) in neonates. Enteric flora in 25 babies with NEC differed from that in 23 matched controls. Bacteroides spp and lactobacilli were less common in babies with NEC compared with controls: 32 versus 61% (p = 0.03) and 12 versus 48% (p = 0.006), respectively. Clostridium perfringens was isolated from 40% of babies with NEC compared with 13% of controls (p = 0.03). It was present in 33% of babies with NEC aged less than 14 days but was not detected in control babies of the same age. The incidences of C. butyricum and C. difficile were similar in patients and controls. Colonization with C. perfringens in the absence of a protective barrier flora may be crucial in the pathogenesis of severe sudden onset NEC. Two potentially valuable marker factors to predict onset of this form of sporadic NEC are the use of fecal smears and estimation of fecal tryptic activity.