Developmental and growth controls of tillering and water-soluble carbohydrate accumulation in contrasting wheat (Triticum aestivum L.) genotypes: can we dissect them?

In wheat, tillering and water-soluble carbohydrates (WSCs) in the stem are potential traits for adaptation to different environments and are of interest as targets for selective breeding. This study investigated the observation that a high stem WSC concentration (WSCc) is often related to low tillering. The proposition tested was that stem WSC accumulation is plant density dependent and could be an emergent property of tillering, whether driven by genotype or by environment. A small subset of recombinant inbred lines (RILs) contrasting for tillering was grown at different plant densities or on different sowing dates in multiple field experiments. Both tillering and WSCc were highly influenced by the environment, with a smaller, distinct genotypic component; the genotype × environment range covered 350-750 stems m(-2) and 25-210 mg g(-1) WSCc. Stem WSCc was inversely related to stem number m(-2), but genotypic rankings for stem WSCc persisted when RILs were compared at similar stem density. Low tillering-high WSCc RILs had similar leaf area index, larger individual leaves, and stems with larger internode cross-section and wall area when compared with high tillering-low WSCc RILs. The maximum number of stems per plant was positively associated with growth and relative growth rate per plant, tillering rate and duration, and also, in some treatments, with leaf appearance rate and final leaf number. A common threshold of the red:far red ratio (0.39-0.44; standard error of the difference=0.055) coincided with the maximum stem number per plant across genotypes and plant densities, and could be effectively used in crop simulation modelling as a 'cut-off' rule for tillering. The relationship between tillering, WSCc, and their component traits, as well as the possible implications for crop simulation and breeding, is discussed.

Adenosine A2A and A2B receptor expression in neuroendocrine tumours: potential targets for therapy

The clinical management of neuroendocrine tumours is complex. Such tumours are highly vascular suggesting tumour-related angiogenesis. Adenosine, released during cellular stress, damage and hypoxia, is a major regulator of angiogenesis. Herein, we describe the expression and function of adenosine receptors (A(1), A(2A), A(2B) and A(3)) in neuroendocrine tumours. Expression of adenosine receptors was investigated in archival human neuroendocrine tumour sections and in two human tumour cell lines, BON-1 (pancreatic) and KRJ-I (intestinal). Their function, with respect to growth and chromogranin A secretion was carried out in vitro. Immunocytochemical data showed that A(2A) and A(2B) receptors were strongly expressed in 15/15 and 13/18 archival tumour sections. Staining for A(1) (4/18) and A(3) (6/18) receptors was either very weak or absent. In vitro data showed that adenosine stimulated a three- to fourfold increase in cAMP levels in BON-1 and KRJ-1 cells. The non-selective adenosine receptor agonist (adenosine-5'N-ethylcarboxamide, NECA) and the A(2A)R agonist (CGS21680) stimulated cell proliferation by up to 20-40% which was attenuated by A(2B) (PSB603 and MRS1754) and A(2A) (SCH442416) receptor selective antagonists but not by the A(1) receptor antagonist (PSB36). Adenosine and NECA stimulated a twofold increase in chromogranin A secretion in BON-1 cells. Our data suggest that neuroendocrine tumours predominantly express A(2A) and A(2B) adenosine receptors; their activation leads to increased proliferation and secretion of chromogranin A. Targeting adenosine signal pathways, specifically inhibition of A(2) receptors, may thus be a useful addition to the therapeutic management of neuroendocrine tumours.

Optimal choice of dairy forages in eastern Australia

Although several forage species such as perennial ryegrass are predominant, there is a wide range of forage species that could be grown in subtropical and temperate regions in Australia as dairy pastures. These species have differing seasonal patterns of growth, nutrient quality, and water-use efficiency, as demonstrated in a large experiment evaluating over 30 species at the University of Sydney (Camden, New South Wales, Australia). Some species can be grazed, whereas others require mechanical harvesting, which incurs a further cost. Previous comparisons of species that relied on yield of dry matter per unit of some input (typically land or water) did not simultaneously take into account the season in which forage is produced, or other factors related to the costs of production and delivery to the cows. To effectively compare the profitability of individual species, or combinations of species, requires the use of a whole-farm, multiperiod model. Linear programming was used to find the most profitable mix of forage species for an irrigated dairy farm in a warm temperate irrigation region of New South Wales, Australia. It was concluded that for a typical farmer facing the prevailing milk and purchased feed prices with average milk production per cow, the most profitable mix of species would include a large proportion of perennial ryegrass (Lolium perenne) and prairie grass (Bromus willdenowii). The result was robust to changes in seasonal milk pricing and a move from year-round to a more seasonal calving pattern.

Environment. Sustainable development of the agricultural bio-economy

A U.S. farm policy shift to joint production of commodities and ecological services will advance sustainable agriculture.

Digital pulse shape discrimination

Pulse-shape discrimination (PSD) has been utilised for about 40 years as a method to obtain estimates for dose in mixed neutron and photon fields. Digitizers that operate close to GHz are currently available at a reasonable cost, and they can be used to directly sample signals from photomultiplier tubes. This permits one to perform digital PSD rather than the traditional, and well-established, analogoue techniques. One issue that complicates PSD for neutrons in mixed fields is that the light output characteristics of typical scintillators available for PSD, such as BC501A, vary as a function of energy deposited in the detector. This behaviour is more easily accommodated with digital processing of signals than with analogoue signal processing. Results illustrate the effectiveness of digital PSD.

Transsphenoidal surgery for acromegaly in wales: results based on stringent criteria of remission

We retrospectively analyzed 90 patients who underwent transsphenoidal surgery (performed by three surgeons) in our center as initial therapy for acromegaly. We used a combination of modern, evidence-based remission criteria including mean day curve GH less than 2.5 micro g/liter (5 mU/liter), a nadir GH less than 1.0 micro g/liter (2 mU/liter) after an oral glucose tolerance test, and normal age-related IGF-I levels (where available). Fifty-seven of 90 (63%) patients remained in remission after surgery. Seventy-nine percent of patients with microadenomas but only 56% of patients with macroadenomas achieved remission (P < 0.001). Eighty-six percent of patients with preoperative GH levels below 10 micro g/liter (day profile or after oral glucose tolerance test) went into remission, compared with 51% of patients with GH levels above 25 micro g/liter at diagnosis (P < 0.002). The remission rate was also related to the period of surgery that was significantly higher in 1998-2001 (76%; P < 0.05) compared with 1990-1997 (54%) and 1980-1989 (63%). There were no recurrences or perioperative deaths. Meningitis occurred in 3% of patients, cerebrospinal fluid rhinorrhea in 7%, and permanent diabetes insipidus in 15%. The proportion of patients who developed new anterior pituitary hormone deficiencies and panhypopituitarism was significantly less in the period 1998-2001 (P < 0.001) when compared with the periods from 1990-1997 and 1980-1989. Transsphenoidal surgery is a safe and effective treatment for acromegaly, and our results compare favorably with those from published series. The presence of an intrasellar lesion and low preoperative GH levels is a good predictor of remission in the long term, but historically in our center this can only be achieved in a significant proportion of patients at the expense of some degree of hypopituitarism. However, surgical outcome in our center, including a reduced frequency of hypopituitarism, has improved significantly over time, coincident with the arrival of a dedicated pituitary neurosurgeon and the use of selective adenomectomy as the preferred surgical approach wherever possible.

Polylactide-poly(ethylene glycol) micellar-like particles as potential drug carriers: production, colloidal properties and biological performance

The micellar-like particle systems produced from poly-D,L-lactide-poly(ethylene glycol) (PLA-PEG) copolymers have been assessed using a range of physicochemical characterisation methods, followed by in vivo studies of their biodistribution after intravenous administration to the rat. The size of the PEG chain was kept constant at 5 or 2 kDa, while the PLA size increased within a series from 2 to 25 kDa. The results obtained reveal, that in an aqueous medium the copolymers assembled into micellar-like structures, with the PLA segments forming the core and the PEG segments the surrounding corona. The size of the PLA segments dominated the process of assembly of the molecules and the characteristics of the resultant micellar-like particles. The PLA-PEG micellar particles were found to be less dynamic than those obtained from conventional surfactants. Particles formed from the lower molecular weight PLA polymers allowed a level of chain mobility while the cores of the micellar particles formed from higher molecular weight PLA appeared to be solid-like in nature. The size of the micellar particles was dependent on the copolymer molecular weight and the z-average diameter increased from 25 to 76 nm as the molecular weight of the PLA moiety increased. This provides an ability to control the particle size by adjusting the molecular weight of the PLA moiety. Following intravenous administration to the rat model, micellar-like particles smaller than approximately 70 nm accumulated in the liver, despite the fact that the PEG corona provided an effective steric stabilization effect. Micellar-like particles with a diameter of more than approximately 70 nm exhibited prolonged systemic circulation and reduced liver uptake, although the steric stabilisation of these particles was shown to be less effective. These findings agree with recent observations from other research groups; that indicate a possibility that very small particulates can pass through the sinusoidal fenestrations in the liver and gain access to the parenchymal cells of the liver.

Metabolism of sulfinpyrazone sulfide and sulfinpyrazone by human liver microsomes and cDNA-expressed cytochrome P450s

Human liver microsomes catalyze the oxidation of sulfinpyrazone sulfide (SPZS) to a variable mixture of sulfinpyrazone (SPZ) enantiomers and two minor phenolic metabolites. In one, the thiophenyl ring is hydroxylated, whereas in the second an N-phenyl ring is hydroxylated. SPZ is further oxidized to sulfinpyrazone sulfone (SPZO) and a minor polar metabolite that also has an N-phenyl ring hydroxylated. Determination of the metabolism of SPZ and SPZS under modified incubation conditions of prior heat treatment, higher pH, and the presence of detergent indicated that the formation of SPZ was cytochrome P450 (P450)- but not flavin monooxygenase-dependent. Specific P450 inhibitors (sulfaphenazole, quinidine sulfate, coumarin, diethyldithiocarbamic acid, troleandomycin, and furafylline) and specific cDNA-expressed P450s were used to identify the major isoforms responsible for the oxidation of SPZS to SPZ and SPZ to SPZO. Both P450 2C9 and P450 3A4 were responsible for the oxidation of SPZS to SPZ, whereas P450 3A4 alone catalyzed the further oxidation of SPZ to SPZO. SPZS was found to be metabolized by P450 2C9 to SPZ with a high degree of enantiomeric selectivity (9:1) and a K(m) comparable with its previously determined K(i) for inhibition of the P450 2C9-dependent 7-hydroxylation of (S)-warfarin (WARF). In contrast, the P450 3A4-catalyzed oxidation of SPZS to SPZ proceeded with the same enantioselectivity but to a much lesser degree (58:42). These results provide evidence that the metabolism of both (S)-WARF and SPZS is mediated by a common enzyme, P450 2C9, which is central to understanding the WARF-SPZ interaction and SPZS-mediated drug interactions in general.

Eating habits of children with autism

Autism is a developmental disorder characterized by severe deficits in social interaction and communication, as well as by stereotyped and repetitive behaviors. Children with autism frequently have significant eating difficulties with highly restricted range of food choices. Eating habits and patterns are often unusual and have an impact on family life. The purpose of this article was to review pertinent information regarding this complex developmental disorder and describe a recent study based on a parent survey of feeding patterns in children with autism to give a new perspective for both parents and professionals.

Implementation of a case coordinator role: a focused ethnographic study

This study was a focused ethnography of a 21-bed, inpatient psychiatric unit. Patient care was provided by a multidisciplinary team, and a case coordinator role was developed to coordinate the team's efforts. The purpose of the study was to describe perceptions of the implementation of the case coordinator role. Data collection methods included document review, participant and nonparticipant observation, and personal interviews of key informants. Field notes and transcriptions were analyzed throughout data collection. Three themes were identified: role development, role confusion, and role expectation. Role development was defined as the process of recognizing the need for and instituting the position of case coordinator. Role confusion was defined as the lack of a clear distinction between the role of the case coordinator and the role of the staff nurse. Role expectation was defined as the process of directing the development of the role based on individuals' perceptions of the role. Although the role as implemented had not met initial expectations, team members were confident the role would evolve to fulfill the unit's needs.

Pituitary apoplexy following metastasis of bronchogenic adenocarcinoma to a prolactinoma

A 42-year-old house wife presented with worsening headaches over 6 months in the absence of visual symptoms or symptoms suggestive of focal neurology. She was a life-long smoker. Systems review was unremarkable apart from secondary amenorrhoea and galactorrhoea of 6 months duration. Her serum prolactin was found to be 620 mU/l (60-400), FT4 12.6 nmol/l (9.8-23.1), TSH 1.38 mU/l (0.35-5.5), oestradiol < 73 pmol/l, LH and FSH of 4.4 and 12.6 mIU/l, respectively. She was on bromocriptine. A presumptive diagnosis of pneumonia, based on pyrexia and CXR findings, was made and she was started on IV antibiotics. Two days later she developed meningism and deterioration of conscious level. (Lumbar puncture results: no organisms, 312 neutrophils and 164 lymphocytes). CT scan revealed a 2.5-cm pituitary adenoma, with suprasellar extension. A repeat hormonal profile revealed FSH 1.4, LH < 0.3 mU/l, oestradiol < 73 pmol/l, prolactin 488 mU/l (60-400), and low random cortisol at 29 nmol/l. T1-weighted MRI revealed a large pituitary mass with evidence of haemorrhage. The patient subsequently underwent a transsphenoidal exploration with resection of the pituitary lesion. Whilst awaiting the histopathology results, CT of chest revealed a 1. 5-cm diameter rounded well defined density in the right lower lobe associated with hilar, pre- and right para-tracheal lymphadenopathy. The histopathology of the pituitary lesion, obtained piecemeal, revealed fragments of fibrous tissue infiltrated by sheets of acidophilic prolactin-positive cells, in keeping with a prolactinoma. In addition, other fragments with blood clot included highly atypical epithelial cells with mitotic figures. These were negative for prolactin but showed HMFG-and CEA-positivity, excluding them from a pituitary lineage. Transbronchial biopsy revealed moderately differentiated adenocarcinoma, with evidence of lymphatic spread. The overall conclusion was of bronchogenic adenocarcinoma, metastasizing to a prolactinoma and complicated by apoplexy.

Examination of low-incidence brain tumor responses in F344 rats following chemical exposures in National Toxicology Program carcinogenicity studies

Neoplasms in the brain are uncommon in control Fischer 344 (F344) rats; they occur at a rate of less than 1% in 2-yr toxicity/carcinogenicity studies. Furthermore, only 10 of nearly 500 studies conducted by the National Toxicology Program (NTP) showed any evidence of chemically related neoplastic effects in the brain. Generally, the brain tumor responses were considered equivocal, because the characteristics of potential neurocarcinogenic agents (such as statistically significant increased incidences, decreased latency and/or survival, and demonstration of dose-response relationships) were not observed. A thorough examination, including comparisons with a well-established historical database, is often critical in evaluating rare brain tumors. Chemicals that gave equivocal evidence of brain tumor responses were generally associated with carcinogenicity at other sites, and many chemicals were mutagenic when incubated with metabolic activating enzymes. Other factors that were supportive of the theory that marginal increases in brain tumor incidence were related to chemical exposure were that (a) some of the tumors were malignant, (b) no brain neoplasms were observed in concurrent controls from some studies, and/or (c) brain tumors were also seen following exposure to structurally related chemicals. In 2-yr studies in F344 rats (studies conducted by the NTP), equivocal evidence of carcinogenicity was observed for the following 9 chemicals: isoprene, bromoethane, chloroethane, 3,3'-dimethylbenzidine dihydrochloride, 3,3'-dimethoxybenzidine dihydrochloride, furosemide, C.I. direct blue 15, diphenhydramine hydrochloride, and 1-H-benzotriazole. Glycidol was the only chemical evaluated by the NTP with which there was clear evidence of brain tumor induction in F344 rats. Clarification of the potential neurocarcinogenic risks of chemicals that produce equivocal evidence of a brain tumor response in conventional 2-yr rodent studies may be aided by the use of transgenic mouse models that exhibit genetic alterations that reflect those present in human brain tumors as well as by the use of in utero exposures.

Plateletpheresis efficiency: a comparison of the spectra LRS and AMICUS separators

BACKGROUND

Optimizing the yields of plateletpheresis by increasing collection efficiencies may provide several benefits: to patients, by increasing the dose in single-donor platelet (SDP) units; to the collection center, by increasing the percentage of components that may be split into double units; and/or to the donor, by reducing the duration of donation.

STUDY DESIGN AND METHODS

A prospective, randomized study was undertaken to compare the efficiency of platelet collection in paired donations by 21 donors on two cell separators (Spectra LRS, version [v] 5.1; and AMICUS, v2.37). The order of donation was randomly assigned; donations were performed at least 2 weeks apart. A fixed blood volume (4000 mL) was processed by utilizing standard protocols. Findings were confirmed in a retrospective, matched study that compared the two separators by using fixed collection times (90 min).

RESULTS

The AMICUS and Spectra LRS separators consistently produced white cell-reduced (<1 x 10(6) white cells) components. The AMICUS harvested 32 percent more platelets on average (median, 4.9 x 10(11); range, 1.5-8.7 x 10(11)) than the Spectra LRS (median, 3.7 x 10(11); range, 2.1-7.7 x 10(11)) (p = 0.03), with mean times of 71.5 and 66.0 minutes (p = 0.03), respectively, to process 4000 mL. Mild donor reactions tended to be more common on the AMICUS separator, which used significantly more ACD (median 482 mL vs. 389 mL; p<0.0001) than on the Spectra LRS.

CONCLUSIONS

The AMICUS separator harvested more platelets per unit of blood volume processed than the Spectra LRS. Possible benefits include increased dose in each single-donor unit, increased double-unit harvests, and/or shorter donation time.

Posterior fossa epithelial cyst: case report and review of the literature

A 49-year old woman with progressive cranial nerve signs and hemiparesis was found at MR imaging and at surgery to have a cyst at the foramen magnum. Immunohistochemistry and electron microscopy showed an epithelial cyst of endodermal origin. MR findings were of an extraaxial mass, with short T1 and T2 times. Unless immunohistochemistry and electron microscopy are used in the final diagnosis of such cysts, all posterior fossa cysts lined by a single layer of epithelium should be described simply as epithelial cysts.

The butyrylcholinesterase K variant and susceptibility to Alzheimer's disease

Previous work has shown an association between the K variant of the butyrylcholinesterase (BCHE) gene and Alzheimer's disease (AD) in patients carrying the epsilon4 allele of ApoE. We attempted to replicate this finding in 181 UK white AD cases and 71 controls. No difference was found in BCHE-K genotypes (p=0.75) or alleles (p=0.70) between patients and controls. Moreover, despite a significant excess of ApoE epsilon4 in patients versus controls (p<0.0001), we found no evidence to support previous reports of an interaction between ApoE and BCHE-K (chi2=1.49, df=4, p=0.83).