A 2-4 keV multilayer mirrored channel for the NIF Dante system

During inertial confinement fusion experiments at the National Ignition Facility (NIF), a capsule filled with deuterium and tritium (DT) gas, surrounded by a DT ice layer and a high-density carbon ablator, is driven to the temperature and densities required to initiate fusion. In the indirect method, 2 MJ of NIF laser light heats the inside of a gold hohlraum to a radiation temperature of 300 eV; thermal x rays from the hohlraum interior couple to the capsule and create a central hotspot at tens of millions degrees Kelvin and a density of 100-200 g/cm³. During the laser interaction with the gold wall, m-band x rays are produced at ∼2.5 keV; these can penetrate into the capsule and preheat the ablator and DT fuel. Preheat can impact instability growth rates in the ablation front and at the fuel-ablator interface. Monitoring the hohlraum x-ray spectrum throughout the implosion is, therefore, critical; for this purpose, a Multilayer Mirror (MLM) with flat response in the 2-4 keV range has been installed in the NIF 37° Dante calorimeter. Precision engineering and x-ray calibration of components mean the channel will report 2-4 keV spectral power with an uncertainty of ±8.7%.

Hot Carrier Dynamics at Ligated Silicon(111) Surfaces: A Computational Study

We provide a case-study for thermal grafting of benzenediazonium bromide onto a hydrogenated Si(111) surface using ab initio molecular dynamics (AIMD) calculations. A sequence of reaction steps is identified in the AIMD trajectory, including the loss of N₂ from the diazonium salt, proton transfer from the surface to the bromide ion that eliminates HBr, and deposition of the phenyl group onto the surface. We next assess the influence of the phenyl groups on photophysics of hydrogen-terminated Si(111) slabs. The nonadiabatic couplings necessary for a description of the excited-state dynamics are calculated by combining ab initio electronic structures and reduced density matrix formalism with Redfield theory. The phenyl-terminated slab shows reduced nonradiative relaxation and recombination rates of hot charge carriers in comparison with the hydrogen-terminated slab. Altogether, our results provide atomistic insights revealing that (i) the diazonium salt thermally decomposes at the surface allowing the formation of covalently bonded phenyl group, and (ii) the coverage of phenyl groups on the surface slows down charge carrier cooling driven by electron-phonon interactions, which increases photoluminescence efficiency at the near-infrared spectral region.

Pharmacokinetics of Netilmicin in CAPO Patients

The pharmacokinetics of netilmicin were studied during 16 episodes of peritonitis in CAPD patients. An initial intraperitoneal dose of 10 mg of netilmicin per litre of dialysate gives a concentration adequate for most cases. This dose may have to be increased according to the respective minimal inhibitory concentrations (MICs) of the infecting organisms.

Massive clonal expansion of medulloblastoma-specific T cells during adoptive cellular therapy

In both human and murine systems, we have developed an adoptive cellular therapy platform against medulloblastoma and glioblastoma that uses dendritic cells pulsed with a tumor RNA transcriptome to expand polyclonal tumor-reactive T cells against a plurality of antigens within heterogeneous brain tumors. We demonstrate that peripheral TCR Vβ repertoire analysis after adoptive cellular therapy reveals that effective response to adoptive cellular therapy is concordant with massive in vivo expansion and persistence of tumor-specific T cell clones within the peripheral blood. In preclinical models of medulloblastoma and glioblastoma, and in a patient with relapsed medulloblastoma receiving adoptive cellular therapy, an early and massive expansion of tumor-reactive lymphocytes, coupled with prolonged persistence in the peripheral blood, is observed during effective therapeutic response to immunotherapy treatment.

A Review of Magnetic Particle Imaging and Perspectives on Neuroimaging

Magnetic particle imaging is an emerging tomographic technique with the potential for simultaneous high-resolution, high-sensitivity, and real-time imaging. Magnetic particle imaging is based on the unique behavior of superparamagnetic iron oxide nanoparticles modeled by the Langevin theory, with the ability to track and quantify nanoparticle concentrations without tissue background noise. It is a promising new imaging technique for multiple applications, including vascular and perfusion imaging, oncology imaging, cell tracking, inflammation imaging, and trauma imaging. In particular, many neuroimaging applications may be enabled and enhanced with magnetic particle imaging. In this review, we will provide an overview of magnetic particle imaging principles and implementation, current applications, promising neuroimaging applications, and practical considerations.

Correction: Menaquinone biosynthesis inhibition: a review of advancements toward a new antibiotic mechanism

[This corrects the article DOI: 10.1039/C7RA12950E.].

Menaquinone biosynthesis inhibition: a review of advancements toward a new antibiotic mechanism

Menaquinone is essential in electron transport and ATP generation in all Gram-positive, and anaerobically respiring Gram-negative bacteria. Inhibition of menaquinone production at different steps of the biosynthesis pathway has shown promising novel antibacterial action.

Laparoscopic Adnexectomy for Ovarian Torsion during Late Pregnancy: Case Report of a Non-Conservative Treatment and Literature Analysis

Diagnosis of adnexial torsion is difficult during pregancy (1). The time of decision and laparoscopy is that of the risk of necrosis of the adnexa and, therefore, of the ovarian prognosis. The loss of an ovary can compromise the following fertility. Even if concerns related to laparoscopy in pregnant patients include a limited surgical field, with a risk of uterine injury and negative fetal effects of CO₂ insufflation. Evidence base suggests that minimally invasive surgery can be safe and better than laparotomy for management of adnexal masses during late pregnancy with good postoperative and obstetric outcomes. If for most authors laparoscopy appears to become the best approach for ovarian torsion during pregnancy (2), nonetheless, the ideal surgical laparoscopic approach of adnexa in late pregnancy remains controversial. Since there is no technical gold standard to overcome surgical difficulties which could make laparoscopic procedures as real challenge in patients in second and third trimester (3); at least, in case of radical and non-conservative treatment, the risk for a first trimester of pregnancy is to remove the corpus luteum (1).

Inter-site and inter-scanner diffusion MRI data harmonization

We propose a novel method to harmonize diffusion MRI data acquired from multiple sites and scanners, which is imperative for joint analysis of the data to significantly increase sample size and statistical power of neuroimaging studies. Our method incorporates the following main novelties: i) we take into account the scanner-dependent spatial variability of the diffusion signal in different parts of the brain; ii) our method is independent of compartmental modeling of diffusion (e.g., tensor, and intra/extra cellular compartments) and the acquired signal itself is corrected for scanner related differences; and iii) inter-subject variability as measured by the coefficient of variation is maintained at each site. We represent the signal in a basis of spherical harmonics and compute several rotation invariant spherical harmonic features to estimate a region and tissue specific linear mapping between the signal from different sites (and scanners). We validate our method on diffusion data acquired from seven different sites (including two GE, three Philips, and two Siemens scanners) on a group of age-matched healthy subjects. Since the extracted rotation invariant spherical harmonic features depend on the accuracy of the brain parcellation provided by Freesurfer, we propose a feature based refinement of the original parcellation such that it better characterizes the anatomy and provides robust linear mappings to harmonize the dMRI data. We demonstrate the efficacy of our method by statistically comparing diffusion measures such as fractional anisotropy, mean diffusivity and generalized fractional anisotropy across multiple sites before and after data harmonization. We also show results using tract-based spatial statistics before and after harmonization for independent validation of the proposed methodology. Our experimental results demonstrate that, for nearly identical acquisition protocol across sites, scanner-specific differences can be accurately removed using the proposed method.

Labelling of cells in the medulla oblongata and the spinal cord of the monkey after injections of horseradish peroxidase in the thalamus

Injections of horseradish peroxidase were performed in macaque monkeys in the intralaminar and the ventroposterior thalamic region, respectively. Following injection in the intralaminar region labelled cells were present in the marginal zone both in the spinal trigeminal nuclues and in the spinal dorsal horn. The same areas contained labelled cells after injections in the ventroposterior thalamic region, but in such experiments labelled cells were also present in the lamina IV-V region of the spinal cord, in the gracile and main cuneate nuclei and in the external cuneate nucleus. Thus, the marginal zone of the spinal cord appears to project to at least two of the thalamic regions receiving spinothalamic fibres in the monkey.

Effect of phytohemagglutinin on the growth of krebs-ii tumor-cells, body metabolism and internal organs of mice

Neoplastic proliferation requires the availability of polyamines. Phytohaemagglutinin (PHA) is a potent growth factor which induces polyamine-dependent growth of the gut. In the hope of directing polyamines and other nutrients away from the tumour to the growing gut, mice fed PHA-containing or lactalbumin diets were injected intraperitoneally with Krebs II ascites cells and the number of tumour cells and the weights of internal organs were followed. PHA-treatment significantly slowed down the proliferation of tumour cells. Changes in the weight and polyamine content of tissues indicated that inter-organ competition between the tumour and vital organs can be used to manipulate the metabolism of tumour-bearing mice.

Early decline and late restoration of spinal cord binding and transganglionic transport of isolectin B4 from Griffonia simplicifolia I after peripheral nerve transection or crush

Isolectin B4 from Griffonia simplicifolia I (B4) has a high binding affinity to a large population of unmyelinated primary sensory neurons (Wang et al., Neuroscience 62 (1994) 539-551). Using immunohistochemical techniques, binding and transganglionic transport of B4 in the spinal cord was investigated, both at short and long survival times, after sciatic nerve transection and ligation or crush in the adult rat. Nerve transection and ligation resulted in nearly complete disappearance of B4 immunolabelling in the sciatic nerve territory of the superficial dorsal horn after B4 binding, as well as after transganglionic transport of B4 by 2 weeks postinjury. Partial recovery of both B4 binding and B4 transport was found by 8 months, and nearly complete recovery by 16 months, indicating that reappearance of B4 binding is not critically dependent on peripheral reinnervation. Crush injury made by jeweller's forceps resulted in partial depletion of binding and transport by 2 weeks and a nearly complete recovery by 10 weeks. The results show that binding and transganglionic transport of B4 can be used to label dorsal horn connections of unmyelinated primary afferents during the process of regeneration after crush injury. Furthermore, as B4 binding and transport recover at long survival times in the absence of reestablished peripheral connections, the same techniques can be used to study central primary afferent connections at long survival times after nerve transection. Binding and transganglionic transport of B4 offer alternatives to the use of previous techniques such as transganglionic transport of wheat germ agglutinin conjugated horseradish peroxidase (WGA-HRP) to study central connections of fine primary afferents after injury.

Expression of heparan sulfate proteoglycans in murine models of experimental colitis

BACKGROUND

Heparan sulfate proteoglycans (HSPGs) are considered important in maintaining physiological homeostasis in many systems. Their expression is altered greatly in several pathophysiological conditions. Herein, we assess the expression and cellular localization of HSPGs in two murine models of human inflammatory bowel disease (IBD).

METHODS

Expression and localization of HSPGs, syndecans, and HS epitopes were examined in the colon of 129SvEv interleukin 10 knockout (IL10(-/-)), C3Bir IL10(-/-), and their genetic control (IL10(+/+)) counterparts (129SvEv; C3H/HeJ). mRNA expression of syndecans and heparan sulfate biosynthesis enzymes were evaluated by real-time polymerase chain reaction (PCR). Localization of HSPGs was determined by immunofluorescence.

RESULTS

mRNA for all syndecans was detected and expression in colonic tissues altered in IL10(-/-) mice. Syndecan-1 protein was expressed in the intestinal epithelium and on lamina propria cells of IL10(-/-) and control mice but was significantly reduced on the intestinal epithelial cells of IL10(-/-), mice particularly with severe colitis. Syndecan-2 was not detected, whereas syndecan-3 immunoreactivity was localized in the lamina propria but did not differ between control and IL10(-/-) mice. Syndecan-4 was present on epithelial cells of all mice but was significantly reduced in IL10(-/-) mice. Differences in the expression of HS epitopes between control and IL10(-/-) mice were also confirmed.

CONCLUSIONS

The study has revealed altered expression of syndecan-1 and -4 and HS epitopes in the gut of mice with an IBD-like gut disorder. The IL10(-/-) mouse is a useful model for further study of the functional role of HSPGs in chronic inflammation and in maintaining healthy gut barrier.

Nurse prescribing in specialist mental health (part 2): the views and experiences of psychiatrists and health professionals

The establishment of working relationships between nurse prescribers and other health professionals, particularly psychiatrists offering supervision, can be a rewarding one. However there remains little guidance in terms of how this can be achieved and the opinions of those from different disciplines in specialist mental health teams. This study aims to look at the views and experiences of psychiatrists and other mental health professionals regarding nurse prescribing. Nine health professionals from a multidisciplinary mental health team attended a focus group; and two psychiatrists were interviewed, both with varying degrees of supervision experience. Psychiatrists reported concerns about prescribing in terms of themselves needing better support and communication, and perhaps having an involvement in the selection process. Nonetheless, the psychiatrist who had experience of supervision reported that this was highly positive. Overall, health professionals stated that nurse prescribing enhanced team working; however, most had limited knowledge about the role. Further training for teams, and the establishment of a good supervisory relationship and an agreed working structure are required to fully integrate this competency into specialist mental health services.

Nurse prescribing in specialist mental health (part 1): the views and experiences of practising and non-practising nurse prescribers and service users

Non-medical prescribing is a relatively new competency that appears to benefit both service users and health professionals alike. However, little is known about its use in mental health settings. This single case study in one UK National Health Service (NHS) Trust aimed to look at these views and consider how the role can be developed further in light of this. Six service users and two nurses trained in nurse prescribing were individually interviewed. One trained nurse had been prescribing for the last 3 years; the other was trained but had never practised. Service users reported that nurse prescribing was more convenient and less anxiety provoking, an issue of particular importance for optimizing mental health services. Offering choice was deemed important; however, for some service users, information about why medication may be beneficial was highlighted as an unmet need in the prescribing process. The practising nurse prescriber described her experiences and credited a good structure of supervision and support from the team. Reasons why trained nurse prescribers may not be practising are discussed, with suggestions for future developments and guidance. This competence appears to work well in a mental health setting when conducted in a supported and structured way.

Depth of brain fissures in normal fetuses by prenatal ultrasound between 19 and 30 weeks of gestation

OBJECTIVE

To establish normal reference ranges for the depth of the insula and Sylvian (SF), parieto-occipital (POF) and calcarine (CF) fissures on prenatal ultrasound between 19 and 30 weeks of gestation.

METHODS

This was a prospective study of 15 consecutive normal fetuses per gestational week between 19 + 0 and 30 + 6 weeks. We measured the depth of the insula and SF in a standard transventricular axial plane of the fetal head; the depth of the POF in a plane above and parallel to that used for the insula; and the depth of the CF in a coronal view of the posterior fossa. All measurements were done transabdominally during the routine second- or third-trimester examination. Reproducibility for each of the parameters was assessed by two operators using stored images from 30 cases.

RESULTS

The depth of the four structures increased with increasing gestational age. The insula and SF could be seen in all cases from 19 weeks onwards, while the POF and CF could be identified in 93.3% and 6.6% of cases, respectively, at 19 weeks. From 20 weeks onwards, the POF could be seen in all examinations, as could the CF from 24 weeks. Intra- and interobserver reproducibility analysis showed good results.

CONCLUSIONS

Assessment of the insula, SF, POF and CF is feasible during prenatal ultrasound examination using standard views of the fetal head. Since the normal ranges increase with gestational age, they could be used to estimate brain development. It is possible that this assessment might be incorporated into the neurosonogram to identify fetuses at risk of maturation disorders or as a complement to other standard evaluations.

Spontaneous intrauterine "ping-pong" fracture: review and case illustration

We report a case of a closed outer-table parietal "ping-pong" skull fracture occurring in a 4 190-gram female infant born at 39 weeks and 5 days gestation after an uneventful Cesarean section (Apgar scores of 9 and 9 at one and five minutes). There was no maternal history of abdominal trauma during pregnancy and there were no complications or difficulties with Cesarean section delivery. Neurological examination was normal. Computed tomography with three-dimensional reconstruction images showed a 4 x 5 cm depression in the right parietal bone with a medial lucency consistent with a fracture of the superior margin of the skull and leftward deviation of the sagittal suture and sinus. Spontaneous resolution did not occur by one month of age and the skull fracture was repaired with excellent cosmetic results. Rarely has a case of spontaneous intrauterine skull fracture been reported in an atraumatic Cesarean delivery. We believe this fracture resulted from a chronic in utero process without associated trauma as evidenced by deviation of the sagittal suture and sinus.

Perceptions of the causes of childhood disability among Pakistani families living in the UK

It has been well documented that South Asian families caring for a child with a disability experience discrimination and disadvantage in accessing health and social care services. This gives increasing cause for concern as the number of South Asian people with severe learning impairments in the UK continues to rise. Mainstream services are ill-equipped to provide individual services to parents who choose to define and address disability differently, and whose concerns and solutions may differ from the majority population, despite the fact that these parents possess many strengths and may present alternative ways of addressing their needs. This study aimed to provide a detailed account of the ways that Pakistani parents living in a northern city in the UK and caring for a child with a disability, account for and understand their child's disability. Sixteen in-depth interviews were carried out between October 2002 and July 2003, with Pakistani parents and one grandparent of children with a disability. All final transcripts were in English, and a thematic analysis was undertaken. Results include a detailed account of parents' understanding of the causes of their child's disability. All parents made reference to theological explanations as to why they had a child with a disability; however, most parents also gave biomedical or other explanations. The relationship between theological and biomedical explanations was explored along with the consequences of the different beliefs for individuals and families. Parents also spoke vividly about the impact of negative and stigmatizing beliefs about causes of disability which they felt were prevalent in the Pakistani community, and they used a biomedical discourse to refute these ideas. The authors suggest that knowledge of individual and family beliefs, and awareness of the impact of these beliefs, can provide a valuable conceptual lens for health and social care practitioners to use when working in family-centred, culturally congruent ways with parents.

Immunological Implications of the use of Plant Lectins for Drug and Vaccine Targeting to the Gastrointestinal Tract

Plant lectins are under consideration as targeting agents to enhance the efficacy of orally administered drugs and vaccines. A significant issue that must be considered is the immunogenicity of these molecules since an immune response to the targeting agent may interfere with its ability to interact with the epithelium. In contrast, the ability of certain lectins to activate the immune system may be exploited in the delivery of vaccines. We previously demonstrated that plant lectins vary widely in their immunogenicity and in particular that mistletoe lectins (ML) I, II and II (MLI, MLII, MLIII) are potent immunogens when administered nasotracheally. Here, we measured immune responses following oral delivery of the MLs and assessed their ability to enhance responses to a co-administered antigen to determine if the molecules possess adjuvant activity. Oral administration of the lectins induced potent lectin-specific systemic and mucosal antibody responses. In addition, each of the three lectins possessed adjuvant activity when delivered orally together with ovalbumin (OVA). The lectins enhanced both serum and mucosal antibody responses to the co-delivered antigen. This shows for the first time that MLI, MLII and MLIII possess adjuvant activity when administered orally and may provide a platform for the generation of effective mucosal adjuvants.

A disattenuated correlation estimate when variables are measured with error: illustration estimating cross-platform correlations

Previous cross-platform reproducibility studies have compared consistency of intensities as well as consistency of fold changes across different platforms using Pearson's correlation coefficient. In this study, we propose the use of measurement error models for estimating gene-specific correlations. Additionally, gene-specific reliability estimates are shown to be useful in prioritizing clones for sequence verification rather than selecting clones using a simple random sample. The proposed 'disattenuated' correlation may prove useful in a wide variety of studies when both X and Y are measured with error, such as in confirmation studies of microarray gene expression values, wherein more reliable laboratory assays such as real-time polymerase chain reaction are used.

Impact of odor from industrial hog operations on daily living activities

Intensive industrial animal production systems worldwide require confinement of large numbers of animals in small spaces and concentration of enormous quantities of waste. Industrial hog operations, in particular, have raised public concerns about their adverse impact on public health and sustainable development. Using a community-based participatory research approach and qualitative interviews, we explored people's perception of the impact of odor from these industries on daily living activities as they relate to the beneficial use of property and enjoyment of life. Our research indicates that hog odor limits several leisure time activities and social interactions which could have adverse public health consequences. The results of this study can assist the communities and other stakeholders in public policy development that addresses these concerns.

Biochemical, molecular and behavioral phenotypes of Rab3A mutations in the mouse

Ras-associated binding (Rab) protein 3A is a neuronal guanosine triphosphate (GTP)-binding protein that binds synaptic vesicles and regulates synaptic transmission. A mouse mutant, earlybird (Ebd), with a point mutation in the GTP-binding domain of Rab3A (D77G), exhibits anomalies in circadian behavior and homeostatic response to sleep loss. Here, we show that the D77G substitution in the Ebd allele causes reduced GTP and GDP binding, whereas GTPase activity remains intact, leading to reduced protein levels of both Rab3A and rabphilin3A. Expression profiling of the cortex and hippocampus of Ebd and Rab3a-deficient mice revealed subtle differences between wild-type and mutant mice. Although mice were backcrossed for three generations to a C57BL/6J background, the most robust changes at the transcriptional level between Rab3a(-/-) and Rab3a(+/+) mice were represented by genes from the 129/Sv-derived chromosomal region surrounding the Rab3a gene. These results showed that differences in genetic background have a stronger effect on gene expression than the mutations in the Rab3a gene. In behavioral tests, the Ebd/Ebd mice showed a more pronounced mutant phenotype than the null mice; Ebd/Ebd have reduced anxiety-like behavior in the elevated zero-maze test, reduced response to stress in the forced swim test and a deficit in cued fear conditioning (FC), whereas Rab3a(-/-) showed only a deficit in cued FC. Our data implicate Rab3A in learning and memory as well as in the regulation of emotion. A combination of forward and reverse genetics has provided multiple alleles of the Rab3a gene; our studies illustrate the power and complexities of the parallel analysis of these alleles at the biochemical, molecular and behavioral levels.

Relationship between dietary-induced changes in intestinal commensal microflora and duodenojejunal myoelectric activity monitored by radiotelemetry in the rat in vivo

Interdigestive intestinal motility, and especially phase III of the migrating myoelectric/motor complex (MMC), is responsible for intestinal clearance and plays an important role in prevention of bacterial overgrowth and translocation in the gut. Yet previous results from gnotobiotic rats have shown that intestinal microflora can themselves affect the characteristics of the myoelectric activity of the gut during the interdigestive state. Given that the composition of the intestinal microflora can be altered by dietary manipulations, we investigated the effect of supplementation of the diet with synbiotics on intestinal microflora structure and the duodenojejunal myoelectric activity in the rat. To reduce animal distress caused by restraint and handling, which can itself affect GI motility, we applied radiotelemetry for duodenojejunal EMG recordings in conscious, freely moving rats. Thirty 16-month-old Spraque-Dawley rats were used. The diet for 15 rats (E group) was supplemented with chicory inulin, Lactobacillus rhamnosus and Bifidobacterium lactis. The remaining 15 rats were fed control diet without supplements (C group). Three rats from each group were implanted with three bipolar electrodes positioned at 2, 14 and 28 cm distal to the pylorus. After recovery, two 6 h recordings of duodenojejunal EMG were carried out on each operated rat. Subsequently, group C rats received feed supplements and group E rats received only control diet for 1 week, and an additional two 6 h recordings were carried out on each of these rats. Non-operated C and E rats were killed and samples of GI tract were collected for microbiological analyses. Supplementation of the diet with the pro- and prebiotics mixture increased the number of bifidobacteria, whereas it decreased the number of enterobacteria in jejunum, ileum, caecum and colon. In both caecum and colon, the dietary supplementation increased the number of total anaerobes and lactobacilli. Treatment with synbiotics increased occurrence of phase III of the MMC at all three levels of the small intestine. The propagation velocity of phase III in the whole recording segment was also increased from 3.7 +/- 0.2 to 4.4 +/- 0.2 cm min(-1) by dietary treatment. Treatment with synbiotics increased the frequency of response potentials of the propagated phase III of the MMC at both levels of the jejunum, but not in the duodenum. In both parts of the jejunum, the supplementation of the diet significantly decreased the duration of phase II of the MMC, while it did not change the duration of phase I and phase III. Using the telemetry technique it was demonstrated that changes in the gastrointestinal microflora exhibited an intestinal motility response and, more importantly, that such changes can be initiated by the addition of synbiotics to the diet.

Effects of age and dietary restriction on oxidative DNA damage, antioxidant protection and DNA repair in rats

BACKGROUND

Experimentally imposed dietary restriction is known to extend the lifespan of rodents, perhaps by slowing the accumulation of oxidative damage that is thought to be one of the causes of aging.

AIM OF THE STUDY

We examined the effects of restricted total food intake, and protein and calorie restriction, on DNA oxidation and related biomarkers in rats.

METHODS

From 1 to 17 months, rats in group 1 received normal diet ad libitum. Group 2 received 70% of the quantity consumed by the first group. Group 3 had the same quantity as group 2, but with a reduction in protein (from 18% to 10% of the diet by weight), and group 4 were further restricted with a 30% decrease in calories. Lymphocytes were isolated from blood samples taken every two months. DNA breaks, oxidised pyrimidines, resistance to H2O2-induced damage, and strand break repair were measured with the comet assay. Organs were isolated from rats killed at 17 months, with 1 month-old rats for comparison; DNA oxidation and antioxidant enzyme activities were measured.

RESULTS

DNA breaks in lymphocytes increased from 1 to 3 months but thereafter declined with age, except in ad libitum fed rats. Oxidised pyrimidines did not change significantly. Resistance to H2O2-induced damage was least at 3 months, and increased with age. Repair of DNA strand breaks was efficient at all ages. Diet had little effect on these endpoints. Diet had no influence on 8-oxo-7.8-dihydroguanine levels in DNA from liver, testis and brain of 17 month old rats. Combining data from all four groups, the levels in brain and liver were significantly higher at 17 months compared with 1 month. Antioxidant enzyme activities tended to increase between 1 and 17 months; effects of diet were not so consistent.

CONCLUSIONS

While DNA damage shows a modest increase with age in some organs, antioxidant status and DNA strand break repair do not decline with age. Restricted diets (including protein and calorie restriction) have no effect on any of these markers of genetic stability.

Proliferation patterns of dorsal root ganglion neurons of cutaneous, muscle and visceral nerves in the rat

In a previous study we provided evidence that dorsal root ganglion (DRG) neurons of different phenotypes have different birthdates. The present study aimed at determining if birthdates of DRG neurons are related to different types of peripheral nerves, namely cutaneous versus muscle, and somatic versus visceral. Pregnant rats were injected intraperitoneally with bromodeoxyuridine (BrdU) to label the neurons on one of the embryonic days E12-E16. When the progeny rats reached adulthood, a mixture of 1% B-fragment of cholera toxin and 1% isolectin B4 from Griffonia simplicifolia I was injected into the peripheral nerves, or a 5% Fluoro-Gold solution was applied to the transected end of the nerves. The saphenous and sural nerves were used as cutaneous nerves, the gastrocnemius nerve as a muscle nerve, the intercostal nerves T9-11 as somatic nerves and the greater splanchnic nerve as a visceral nerve. Cell size measurements were made of DRG neurons labeled from the two cutaneous nerves and the muscle nerve, as well as of neurons of the saphenous and gastrocnemius nerves labeled by BrdU at different embryonic stages. Most of the DRG neurons of the muscle and intercostal nerves were generated early, with peaks at E13, and those of the cutaneous and visceral afferent nerves later, with peaks at E14. The temporal differences were reflected in the cell size spectrum, the muscle nerve having a greater proportion of large neurons compared to the cutaneous nerves. The findings add to previous knowledge regarding the sequence of development of different DRG phenotypes.

Assessment of lectin inactivation by heat and digestion

Proteins/glycoproteins from plants, particularly lectins, are more resistant to heat denaturation than animal proteins (1, 2). With legume seeds, whose lectin content is appreciable, this presents potentially serious problems in nutritional practice. Therefore, before they can be used safely, legume-based food/ feeds usually require thorough and expensive heat processing to inactivate antinutritive components. Indeed, dry or moist heating of seeds at 70°C for several h has little or no effect on their lectin activity (Fig. 1) and treatment at much higher temperatures is needed to inactivate the biological and antinutritional effects of legume lectins (1, 2). The safety aspect is even more serious with some monocot lectins, such as wheatgerm agglutinin or a number of oilseed lectins, such as peanut agglutinin and many others because they are extremely heat stable and normal cooking or other conventional heat treatments may fail to inactivate them (3) Thus, the best way to avoid potential harmful effects of these heat-resistant lectins is to limit their dietary intake to a minimum. Fig. 1. Loss of lectin activity during aqueous heat treatment of soybean at various temperatures.

Oral and intestinal mucositis - causes and possible treatments

Chemotherapy and radiotherapy, whilst highly effective in the treatment of neoplasia, can also cause damage to healthy tissue. In particular, the alimentary tract may be badly affected. Severe inflammation, lesioning and ulceration can occur. Patients may experience intense pain, nausea and gastro-enteritis. They are also highly susceptible to infection. The disorder (mucositis) is a dose-limiting toxicity of therapy and affects around 500 000 patients world-wide annually. Oral and intestinal mucositis is multi-factorial in nature. The disruption or loss of rapidly dividing epithelial progenitor cells is a trigger for the onset of the disorder. However, the actual dysfunction that manifests and its severity and duration are greatly influenced by changes in other cell populations, immune responses and the effects of oral/gut flora. This complexity has hampered the development of effective palliative or preventative measures. Recent studies have concentrated on the use of bioactive/growth factors, hormones or interleukins to modify epithelial metabolism and reduce the susceptibility of the tract to mucositis. Some of these treatments appear to have considerable potential and are at present under clinical evaluation. This overview deals with the cellular changes and host responses that may lead to the development of mucositis of the oral cavity and gastrointestinal tract, and the potential of existing and novel palliative measures to limit or prevent the disorder. Presently available treatments do not prevent mucositis, but can limit its severity if used in combination. Poor oral health and existing epithelial damage predispose patients to mucositis. The elimination of dental problems or the minimization of existing damage to the alimentary tract, prior to the commencement of therapy, lowers their susceptibility. Measures that reduce the flora of the tract, before therapy, can also be helpful. Increased production of free radicals and the induction of inflammation are early events in the onset of mucositis. Prophylactic administration of scavengers or anti-inflammatories can partially counteract or limit some of these therapy-mediated effects, as can the use of cryotherapy. The regular use of mouthwashes, mouth coatings, antibiotics and analgesics is essential, prior to and during loss and ablation of the epithelial layer. Granulocyte-macrophage colony-stimulating factor/granulocyte colony-stimulating factor or the use of laser light therapy may aid restitution and repair. Glutamine supplements may be beneficial in the repair/recovery phase.

Supporting families over the life course: mapping temporality

BACKGROUND

The present paper addresses a rather neglected dimension of family caregiving, its temporality. Many accounts of caregiving assume a state of stasis, and therefore, overlook factors which shape the evolving experience of family caregiving over the life course.

METHODS

The paper begins by offering some reflections on theoretical and methodological issues identified by life-course researchers.

RESULTS

Based both on theoretical propositions and a growing body of empirical evidence, this paper offers a heuristic for thinking about caregiving stages applied to families supporting people with intellectual disability.

CONCLUSIONS

This heuristic is used to suggest further avenues of research and development.