An indoor air quality study of an alligator (Alligator mississippiensis) holding facility

An environmental microbiologic investigation was conducted in an alligator (Alligator mississippiensis) holding facility in a zoo in the southeastern U.S. The facility had housed five alligators between March 1999 and February 2005. In the exhibit, one alligator died and all experienced poor health. It was hypothesized that environmental microbial contamination was associated with these issues. Samples were collected for fungal identification and quantification, microcystin analysis, and airborne mycotoxins. Analyses of air and water were conducted and an examination of the heating, ventilation, and air-conditioning system (HVAC) for design, maintenance, and operating issues was made. Two control sites, a facility for false gharials (Tomistoma schlegelii) and an off-site alligator breeding facility, were also tested. Morbidity and mortality records were examined for all sites. Results showed that, compared to the control sites, the test alligator facility and its HVAC system were extensively contaminated with a range of fungi. Nearly all sampled surfaces featured fungal growth. There were also significantly higher counts of Penicillium/Aspergillus-like and Chrysosporium-like spores in the air (P < 0.004). The design, maintenance, and operation of the HVAC system were all inadequate, resulting in poorly conditioned and mold-contaminated air being introduced to the facility. Morbidity records revealed solitary pulmonary disorders over time in three alligators, with one dying as a result. The other two alligators suffered from general malaise and a range of nonspecific symptoms. The control facilities had no morbidity or mortality issues. In conclusion, although no causal links could be demonstrated because of the nature of the morbidity data, environmental mold contamination appeared to be associated with the history of morbidity and mortality in the alligator exhibit.

HESS observations of the galactic center region and their possible dark matter interpretation

The detection of gamma rays from the source HESS J1745-290 in the Galactic Center (GC) region with the High Energy Spectroscopic System (HESS) array of Cherenkov telescopes in 2004 is presented. After subtraction of the diffuse gamma-ray emission from the GC ridge, the source is compatible with a point source with spatial extent less than 1.2;{'}(stat) (95% C.L.). The measured energy spectrum above 160 GeV is compatible with a power law with photon index of 2.25+/-0.04(stat)+/-0.10(syst) and no significant flux variation is detected. It is finally found that the bulk of the very high energy emission must have non-dark-matter origin.

Complementation of the pina (null) allele with the wild type Pina sequence restores a soft phenotype in transgenic wheat

The tightly linked puroindoline genes, Pina and Pinb, control grain texture in wheat, with wild type forms of both giving soft, and a sequence alteration affecting protein expression or function in either giving rise to hard wheat. Previous experiments have shown that addition of wild type Pina in the presence of mutated Pinb gave intermediate grain texture but addition of wild type Pinb gave soft grain. This raises questions as to whether Pina may be less functional than Pinb. Our goal here was to develop and characterize wheat lines expressing the wild type Pina-D1a sequence in hard wheat with the null mutation (Pina-D1b) for Pina. Three transgenic lines plus Bobwhite were evaluated in two environments. Grain texture, grain protein, and kernel weight were determined for the transgenic lines and Bobwhite. The three transgenic lines had soft phenotype, and none of the transgenic lines differed from Bobwhite for grain protein or kernel weight. The soft phenotype was accompanied by increases in Pina transcript accumulation. Total Triton X-114 extractable PINA and PINB increased from 2.5 to 5.5 times those from a soft wheat reference sample, and friabilin, PINA and PINB bound to starch, increased from 3.8 to 7.8 times those of the soft wheat reference. Bobwhite showed no starch bound PINA, but transgenic lines had levels from 5.3 to 13.7 times those of the soft wheat reference sample. Starch bound PINB in transgenic lines also increased from 0.9 to 2.5 times that for the soft wheat reference sample. The transgenic expression of wild type Pina sequence in the Pina null genotype gave soft grain with the characteristics of soft wheat including increased starch bound friabilin. The results support the hypothesis that both wild type Pin genes need to be present for friabilin formation and soft grain.

The Epstein-Barr virus-encoded LMP-1 oncoprotein negatively affects Tyk2 phosphorylation and interferon signaling in human B cells

Epstein-Barr virus (EBV) establishes a persistent infection in the human host and is associated with a variety of human cancers. Persistent infection results from a balance between the host immune response and viral immune evasion mechanisms. EBV infection is controlled initially by the innate immune response and later by T-cell-mediated adaptive immunity. EBV has evolved mechanisms to evade the host immune response so that it can persist for the lifetime of the host. Latent membrane protein 1 (LMP-1) is the EBV oncoprotein essential for B-cell immortalization by EBV. We show here that LMP-1 interacts with Tyk2, a signaling intermediate in the alpha interferon (IFN-alpha) signaling pathway, via a previously uncharacterized LMP-1 signaling domain. LMP-1 prevents Tyk2 phosphorylation and inhibits IFN-alpha-stimulated STAT2 nuclear translocation and interferon-stimulated response element transcriptional activity. Long-term culture of EBV+ lymphoblastoid cells in IFN-alpha is associated with outgrowth of a population expressing elevated LMP-1 protein levels, suggesting that cells expressing higher levels of LMP-1 survive the antiproliferative selective pressure imposed by IFN-alpha. These results show that LMP-1 can protect EBV+ cells from the IFN-alpha-stimulated antiviral/antiproliferative response and suggest that chronic IFN-alpha treatment may encourage the outgrowth of cells expressing elevated, and therefore potentially oncogenic, LMP-1 levels in EBV+ individuals.

Increased puroindoline levels slow ruminal digestion of wheat (Triticum aestivum L.) starch by cattle

Starch is the primary nutrient in ruminant diets used to promote high levels of performance. The site of starch digestion alters the nature of digestive end products (VFA in the rumen vs. glucose in the small intestine) and the efficiency of use. Cereal grain endosperm texture plays a major role in the rate and extent of starch degradation in ruminants. Wheat grain texture is regulated by the starch surface protein complex friabilin that consists primarily of puroindoline (PIN) A and B. Soft kernel texture in wheat is a result of both PIN genes being in the wild type active form and bound to starch. The objective of this study was to investigate the effect of varying PIN content in wheat on the rate of starch digestion in the rumen of beef cattle. In Exp. 1, 6 transgenic soft pin a/b isolines created in a hard wheat background, and 2 hard wheat controls were milled to yield a wide range of mean particle sizes across all lines. Milled samples were incubated in situ for 3 h. Increased expression of both PINA and PINB decreased DM digestibility (DMD) by 29.2% (P < 0.05) and decreased starch digestibility by 30.8% (P < 0.05). Experiment 2 separated the effects of particle size and total PIN content on digestion by milling the hardest and softest lines such that the mean particle size was nearly identical. Increased PIN decreased DMD by 21.7% (P < 0.05) and starch digestibility by 19.9% (P < 0.05) across particle sizes smaller than whole kernel. Experiment 3 addressed the time course of PIN effects in the rumen by observing ground samples of the hardest and softest lines over a 12-h in situ period. Increased PIN decreased DMD by 10.4% (P < 0.05) and starch digestibility by 11.0% (P < 0.05) across all time points. Dry matter and starch digestibility results demonstrated that increased expression of PIN was associated with a decreased rate of ruminal digestion independent of particle size. Puroindolines seem to aid in the protection of starch molecules from microbial digestion in the rumen, potentially increasing the amount of starch entering the small intestine.

A low level of extragalactic background light as revealed by γ-rays from blazars

The diffuse extragalactic background light consists of the sum of the starlight emitted by galaxies through the history of the Universe, and it could also have an important contribution from the 'first stars', which may have formed before galaxy formation began. Direct measurements are difficult and not yet conclusive, owing to the large uncertainties caused by the bright foreground emission associated with zodiacal light. An alternative approach is to study the absorption features imprinted on the gamma-ray spectra of distant extragalactic objects by interactions of those photons with the background light photons. Here we report the discovery of gamma-ray emission from the blazars H 2356 - 309 and 1ES 1101 - 232, at redshifts z = 0.165 and z = 0.186, respectively. Their unexpectedly hard spectra provide an upper limit on the background light at optical/near-infrared wavelengths that appears to be very close to the lower limit given by the integrated light of resolved galaxies. The background flux at these wavelengths accordingly seems to be strongly dominated by the direct starlight from galaxies, thus excluding a large contribution from other sources-in particular from the first stars formed. This result also indicates that intergalactic space is more transparent to gamma-rays than previously thought.

CXCR3 chemokine receptor immunoreactivity in primary cutaneous malignant melanoma: correlation with clinicopathological prognostic factors

BACKGROUND

A role for CXCR3, the receptor for chemokines Mig, IP-10 and interferon-inducible T cell alpha-chemoattractant, in tumour cell migration during melanoma progression has been proposed.

AIMS

To analyse CXCR3 expression in primary cutaneous malignant melanomas and its comparison with clinicopathological and prognostic factors.

METHODS

A retrospective immunohistochemical study was carried out on formalin-fixed paraffin-wax-embedded sections from 82 patients with primary invasive cutaneous melanomas, with a monoclonal antibody to CXCR3 (clone 49801.111; R&D Systems). Immunoreactivity was semiquantitatively evaluated: labelling intensity (0, absent; 1, weak; 2, moderate; 3, strong) multiplied by the percentage of cells in each of the four intensity categories. A positive staining was considered when the score was >100. Melanomas were categorised by age, sex, primary site, tumour thickness, growth phase, ulceration, lymphocytic infiltration, recurrence, lymph node and distant metastasis, and survival. Univariate and multivariate statistical analyses were carried out.

RESULTS

Of the 82 patients, a positive CXCR3 staining was found in 26 (31.7%) patients, whereas 56 (68.3%) were negative. In univariate analysis, a significant association of CXCR3-positive tumour cell immunostaining with tumour thickness >1 mm (p = 0.003), absence of lymphocytic infiltration (p = 0.04) and the presence of distant metastasis (p = 0.048) was found. Multivariate analysis found tumour thickness as the only independent factor with considerable association with distant metastases.

CONCLUSIONS

Our findings of a positive correlation of CXCR3 tumour cell immunoreactivity in human primary cutaneous melanoma with tumour thickness >1 mm and absence of intratumoral lymphocytic infiltration support the biological implication of CXCR3 in the tumour progression of cutaneous malignant melanoma.

Discovery of very-high-energy γ-rays from the Galactic Centre ridge

The source of Galactic cosmic rays (with energies up to 10(15) eV) remains unclear, although it is widely believed that they originate in the shock waves of expanding supernova remnants. At present the best way to investigate their acceleration and propagation is by observing the gamma-rays produced when cosmic rays interact with interstellar gas. Here we report observations of an extended region of very-high-energy (> 10(11) eV) gamma-ray emission correlated spatially with a complex of giant molecular clouds in the central 200 parsecs of the Milky Way. The hardness of the gamma-ray spectrum and the conditions in those molecular clouds indicate that the cosmic rays giving rise to the gamma-rays are likely to be protons and nuclei rather than electrons. The energy associated with the cosmic rays could have come from a single supernova explosion around 10(4) years ago.

Detection of airborne Stachybotrys chartarum macrocyclic trichothecene mycotoxins in the indoor environment

The existence of airborne mycotoxins in mold-contaminated buildings has long been hypothesized to be a potential occupant health risk. However, little work has been done to demonstrate the presence of these compounds in such environments. The presence of airborne macrocyclic trichothecene mycotoxins in indoor environments with known Stachybotrys chartarum contamination was therefore investigated. In seven buildings, air was collected using a high-volume liquid impaction bioaerosol sampler (SpinCon PAS 450-10) under static or disturbed conditions. An additional building was sampled using an Andersen GPS-1 PUF sampler modified to separate and collect particulates smaller than conidia. Four control buildings (i.e., no detectable S. chartarum growth or history of water damage) and outdoor air were also tested. Samples were analyzed using a macrocyclic trichothecene-specific enzyme-linked immunosorbent assay (ELISA). ELISA specificity was tested using phosphate-buffered saline extracts of the fungal genera Aspergillus, Chaetomium, Cladosporium, Fusarium, Memnoniella, Penicillium, Rhizopus, and Trichoderma, five Stachybotrys strains, and the indoor air allergens Can f 1, Der p 1, and Fel d 1. For test buildings, the results showed that detectable toxin concentrations increased with the sampling time and short periods of air disturbance. Trichothecene values ranged from <10 to >1,300 pg/m3 of sampled air. The control environments demonstrated statistically significantly (P < 0.001) lower levels of airborne trichothecenes. ELISA specificity experiments demonstrated a high specificity for the trichothecene-producing strain of S. chartarum. Our data indicate that airborne macrocyclic trichothecenes can exist in Stachybotrys-contaminated buildings, and this should be taken into consideration in future indoor air quality investigations.

Effect of chlorine dioxide gas on fungi and mycotoxins associated with sick building syndrome

The growth of indoor molds and their resulting products (e.g., spores and mycotoxins) can present health hazards for human beings. The efficacy of chlorine dioxide gas as a fumigation treatment for inactivating sick building syndrome-related fungi and their mycotoxins was evaluated. Filter papers (15 per organism) featuring growth of Stachybotrys chartarum, Chaetomium globosum, Penicillium chrysogenum, and Cladosporium cladosporioides were placed in gas chambers containing chlorine dioxide gas at either 500 or 1,000 ppm for 24 h. C. globosum was exposed to the gas both as colonies and as ascospores without asci and perithecia. After treatment, all organisms were tested for colony growth using an agar plating technique. Colonies of S. chartarum were also tested for toxicity using a yeast toxicity assay with a high specificity for trichothecene mycotoxins. Results showed that chlorine dioxide gas at both concentrations completely inactivated all organisms except for C. globosum colonies which were inactivated an average of 89%. More than 99% of ascospores of C. globosum were nonculturable. For all ascospore counts, mean test readings were lower than the controls (P < 0.001), indicating that some ascospores may also have been destroyed. Colonies of S. chartarum were still toxic after treatment. These data show that chlorine dioxide gas can be effective to a degree as a fumigant for the inactivation of certain fungal colonies, that the perithecia of C. globosum can play a slightly protective role for the ascospores and that S. chartarum, while affected by the fumigation treatment, still remains toxic.

Increased gastro-oesophageal reflux disease in patients with severe COPD

The prevalence and clinical consequences of gastro-oesophageal reflux disease (GERD) in chronic obstructive pulmonary disease (COPD) are not well characterised. The present study prospectively studied 42 males with COPD (forced expiratory volume in one second % predicted: 35%, range 20-49) and 16 healthy volunteers of similar age without respiratory or gastro-oesophageal symptoms. The diagnosis of GERD was confirmed using oesophageal 24 h pH monitoring. In the current study group, reflux symptoms were measured using the Vigneri score, cough and dyspnoea with the modified Medical Research Council questionnaire, and pulmonary function with bronchodilator response and health status using St George's Respiratory Questionnaire. Pathological reflux was documented in 26 out of 42 patients (62%) and in three volunteers (19%). In patients with GERD, 15 patients (58%) did not report any reflux symptoms. There were no differences in symptoms, health status, bronchodilator treatment and pulmonary function test between patients with and without GERD. Oxygen desaturation coincided with episodes of increased oesophageal acidity in 40% of patients with GERD. Patients with severe chronic obstructive pulmonary disease have a high prevalence of asymptomatic gastro-oesophageal reflux. The association between this reflux and oxygen desaturation deserves further attention.

An investigation into techniques for cleaning mold-contaminated home contents

This study examined the efficacy of the following treatments to reduce selected fungal spore and mycotoxin levels on materials commonly found in home contents: (1) gamma irradiation at a 10-13 kiloGray exposure, (2) a detergent/bleach wash, and (3) a steam cleaning technique. A minimum of six replicates were performed per treatment. Paper, cloth, wood, and carpet were inoculated with either fungal spores (Stachybotrys chartarum, Aspergillus niger, Penicillium chrysogenum, or Chaetomium globosum) at 240,000 spores/2.54 cm2 of material or with the mycotoxins roridin A, T-2, and verrucarin A at 10 microg per 2.54 cm2 of material. Treatments were evaluated with an agar plating technique for fungal spores and a yeast toxicity culture assay for mycotoxins. Results showed that gamma irradiation inactivated fungal spores, but the treatment was not successful in inactivating mycotoxins. The washing technique completely inactivated or removed spores on all materials except for C. globosum, which was reduced on all items except paper (p < 0.05). Washing inactivated all mycotoxins on paper and cloth but not on carpet or untreated wood (p < 0.001). The steam cleaning treatment did not completely eliminate any fungal spores; however, it reduced P. chrysogenum numbers on all materials, C. globosum was reduced on wood and carpet, and S. chartarum was reduced on wood (p < 0.05). Steam cleaning was unsuccessful in inactivating any of the tested mycotoxins. These results show that the bleach/detergent washing technique was more effective overall in reducing spore and mycotoxin levels than gamma irradiation or steam cleaning. However, the other examined techniques were successful in varying degrees.

Clinical Prioritisation for Curative Radiotherapy: A Local Waiting List Initiative

AIMS

Waiting time for radiotherapy is a major problem in radiation oncology practice. The aim of this paper is to present the experience of the Peter MacCallum Cancer Centre in trialling a number of strategies to reduce patient waiting times.

MATERIALS AND METHODS

All patients starting megavoltage radiotherapy with curative intent in three separate 1-week blocks had their waiting times recorded. The cohorts were each 8 weeks apart and were before (September), during (November) and after (January) the introduction of a priority points system.

RESULTS

Median waiting time was 35 days in September, 42 days in November and 31 days in January. The number of extremely long waits (>90 days) decreased to 1 by January. Significantly more patients were pre-booked for treatment in January (27/51) compared with September (17/65; P = 0.003) and November (12/65; P < 0.001). Pre-booked patients had shorter waiting times compared with patients who was not pre-booked (P < 0.0001). Difficulties at one particular treating location contributed to the longer median waiting times in November. Although there had no significant difference in waiting time in non-breast unit patients between the three cohorts, there was a decrease in waiting times in breast unit patients, especially between November and January (P = 0.0008). There was no significant increase in delay to starting treatment in other treating units, resulting in more equitable access across all units.

CONCLUSIONS

A combination of encouraging pre-booking and the introduction of a priority points system has led to a decrease in waiting times, especially among breast unit patients.

Wheat puroindolines interact to form friabilin and control wheat grain hardness

Wheat grain is sold based upon several physiochemical characteristics, one of the most important being grain texture. Grain texture in wheat directly affects many end use qualities such as milling yield, break flour yield, and starch damage. The hardness (Ha) locus located on the short arm of chromosome 5D is known to control grain hardness in wheat. This locus contains the puroindoline A ( pina) and puroindoline B ( pinb) genes. All wheats to date that have mutations in pina or pinb are hard textured, while wheats possessing both the 'soft type' pina-D1a and pinb-D1a sequences are soft. Furthermore, it has been shown that complementation of the pinb-D1b mutation in hard spring wheat can restore a soft phenotype. Here, our objective was to identify and characterize the effect the puroindoline genes have on grain texture independently and together. To accomplish this we transformed a hard red spring wheat possessing a pinb-D1b mutation with 'soft type' pina and pinb, creating transgenic isolines that have added pina, pinb, or pina and pinb. Northern blot analysis of developing control and transgenic lines indicated that grain hardness differences were correlated with the timing of the expression of the native and transgenically added puroindoline genes. The addition of PINA decreased grain hardness less than the reduction seen with added PINB. Seeds from lines having more 'soft type' PINB than PINA were the softest. Friabilin abundance was correlated with the presence of both 'soft type' PINA and PINB and did not correlate well with total puroindoline abundance. The data indicates that PINA and PINB interact to form friabilin and together affect wheat grain texture.

Epstein-Barr virus latent membrane protein-1 (LMP-1) and lytic LMP-1 localization in plasma membrane-derived extracellular vesicles and intracellular virions

Epstein-Barr virus (EBV) is a human herpesvirus associated with a number of malignancies. EBV establishes a latent infection in human B cells in vitro, and infected lymphoblastoid cells proliferate indefinitely as a result of virus activation of cellular signalling pathways. Latently infected cells express a viral oncoprotein called the latent membrane protein-1 (LMP-1). LMP-1 signals both proliferative and survival signals to the infected B cell. The switch from latency to lytic replication is associated with upregulation of an N-terminally truncated LMP-1, called lytic LMP-1 (lyLMP-1). To understand better the relationship between LMP-1 protein function and the virus life cycle, LMP-1 and lyLMP-1 were precisely localized in infected B cells. Immunoelectron microscopy of latently infected cells revealed LMP-1 localized in discrete patches in the plasma membrane. Unexpectedly, immunogold-labelled LMP-1 was found in vesicles budding from the plasma membrane into the extracellular space and in small membrane vesicles accumulating in conditioned medium from infected cells. LyLMP-1 immunolabelling was observed only in B95-8 cells harbouring detectable intracellular virus particles and was abundant in the nuclear membrane early, and in the plasma membrane late, following lytic cycle induction. LyLMP-1 immunoreactivity was also observed at sites of virus budding and associated with intracellular virions, suggesting that lyLMP-1 might be incorporated into cytoplasmic virions when budding through the nuclear membrane.

Age of menarche: the role of some psychosocial factors

BACKGROUND

The goal of this study was to determine associations between the age of first menstrual period (menarche) and adverse childhood experiences in a random community sample of New Zealand women. Previous reports have linked early menarche to absence of a live-in father figure and to family conflict, as well as genetic determination of early puberty and adiposity.

METHOD

Two groups of women randomly selected from the community on their responses to a mailed screening questionnaire on childhood sexual abuse (CSA) were interviewed in detail. Data about their childhood experiences, including age of menarche, were collected on two occasions, 6 years apart. Early menarche was defined as first menstruation occurring before the age of 12 years.

RESULTS

Univariate analyses identified a number of adverse childhood experiences preceded early menarche, which was reported by 20.3% of this sample. These included low family socio-economic status, absence of father, a number of variables showing family conflict, poor relationships between the girl and either/both parents, a self-rated childhood personality style as a loner, childhood physical and sexual abuse. Sequential modelling showed parental rows, being a loner and the duration of CSA to be most important, although lack of a father and any CSA were each also independently associated with early menarche. No variables survived the modelling exercise as predictors of early menarche for those women who did not report childhood sexual abuse.

CONCLUSIONS

The identified variables statistically interacted with each other in a highly complex manner. The attempt to rank their importance was only partially successful, for methodological reasons (half the sample reporting CSA). Chronic or protracted CSA needs to be added to the list of factors associated with early menarche in future studies.

EBNA2 and activated Notch induce expression of BATF

The immortalization of human B lymphocytes by Epstein-Barr virus (EBV) requires the virus-encoded transactivator EBNA2 and the products of both viral and cellular genes which serve as EBNA2 targets. In this study, we identified BATF as a cellular gene that is up-regulated dramatically within 24 h following the infection of established and primary human B cells with EBV. The transactivation of BATF is mediated by EBNA2 in a B-cell-specific manner and is duplicated in non-EBV-infected B cells by the expression of mammalian Notch proteins. In contrast to other target genes activated by EBNA2, the BATF gene encodes a member of the AP-1 family of transcription factors that functions as a negative regulator of AP-1 activity and as an antagonist of cell growth. A potential role for BATF in promoting EBV latency is supported by studies in which BATF was shown to negatively impact the expression of a BZLF1 reporter gene and to reduce the frequency of lytic replication in latently infected cells. The identification of BATF as a cellular target of EBV provides important new information on how programs of viral and cellular gene expression may be coordinated to promote viral latency and control lytic-cycle entry.

Unexpected absence of the Epstein-Barr virus (EBV) lyLMP-1 open reading frame in tumor virus isolates: lack of correlation between Met129 status and EBV strain identity

The lytic cycle-associated lytic latent membrane protein-1 (lyLMP-1) of Epstein-Barr virus (EBV) is an amino-terminally truncated form of the oncogenic LMP-1. Although lyLMP-1 shares none of LMP-1's transforming and signal transducing activities, we recently reported that lyLMP-1 can negatively regulate LMP-1-stimulated NF-kappaB activation. The lyLMP-1 protein encoded by the B95-8 strain of EBV initiates from methionine 129 (Met129) of the LMP-1 open reading frame (ORF). The recent report that Met129 in the B95-8 LMP-1 ORF is not conserved in the Akata strain of EBV prompted us to screen a panel of EBV-positive cell lines for conservation of Met129 and lyLMP-1 expression. We found that 15 out of 16 tumor-associated virus isolates sequenced encoded an ATT or ACC codon in place of ATG in the LMP-1 ORF at position 129, and tumor cell lines harboring isolates lacking an ATG at codon 129 did not express the lyLMP-1 protein. In contrast, we found that EBV DNA from 22 out of 37 healthy seropositive donors retained the Met129 codon. Finally, the lyLMP-1 initiator occurs variably within distinct EBV strains and its presence cannot be predicted by EBV strain identity. Thus, Met129 is not peculiar to the B95-8 strain of EBV, but rather can be found in the background of several evolutionarily distinct EBV strains. Its absence from EBV isolates from tumors raises the possibility of selective pressure on Met129 in EBV-dependent tumors.

Female sexual health care in cystic fibrosis

Fifty five teenage girls with cystic fibrosis and their mothers were interviewed to assess the provision of sexual health information. Parents were the most common source of information for adolescents. The cystic fibrosis doctor was identified as the key resource for parents. Yet few parents had spoken to their doctor about these issues, and 96% requested more information. This information was wanted before puberty by mothers, and from puberty onwards by girls.

Transmembrane domains 1 and 2 of the latent membrane protein 1 of Epstein-Barr virus contain a lipid raft targeting signal and play a critical role in cytostasis

The latent membrane protein 1 (LMP-1) oncoprotein of Epstein-Barr virus (EBV) is a constitutively active, CD40-like cell surface signaling protein essential for EBV-mediated human B-cell immortalization. Like ligand-activated CD40, LMP-1 activates NF-kappaB and Jun kinase signaling pathways via binding, as a constitutive oligomer, to tumor necrosis factor receptor-associated factors (TRAFs). LMP-1's lipid raft association and oligomerization have been linked to its activation of cell signaling pathways. Both oligomerization and lipid raft association require the function of LMP-1's polytopic multispanning transmembrane domain, a domain that is indispensable for LMP-1's growth-regulatory signaling activities. We have begun to address the sequence requirements of the polytopic hydrophobic transmembrane domain for LMP-1's signaling and biochemical activities. Here we report that transmembrane domains 1 and 2 are sufficient for LMP-1's lipid raft association and cytostatic activity. Transmembrane domains 1 and 2 support NF-kappaB activation, albeit less potently than does the entire polytopic transmembrane domain. Interestingly, LMP-1's first two transmembrane domains are not sufficient for oligomerization or TRAF binding. These results suggest that lipid raft association and oligomerization are mediated by distinct and separable activities of LMP-1's polytopic transmembrane domain. Additionally, lipid raft association, mediated by transmembrane domains 1 and 2, plays a significant role in LMP-1 activation, and LMP-1 can activate NF-kappaB via an oligomerization/TRAF binding-independent mechanism. To our knowledge, this is the first demonstration of an activity's being linked to individual membrane-spanning domains within LMP-1's polytopic transmembrane domain.

Isolated primary Langerhans' cell histiocytosis of central nervous system

Solitary eosinophilic granuloma that involves the CNS is an uncommon lesion and most frequently affects the hypothalamus. We report a new and rare case of solitary eosinophilic granuloma of the left temporal lobe in a patient without systemic disease. The diagnosis was confirmed by electron microscopy and immuohistochemical techniques. The treatment of choice is surgical resection. There is a better prognosis in comparison with cases accompanied by systemic disease.

Urinary incontinence in female adolescents with cystic fibrosis

OBJECTIVES

Urinary incontinence is common in healthy women and occurs with increased frequency in adult women with chronic lung disease, including cystic fibrosis (CF). This study aimed to determine the prevalence, severity, and impact on daily life of urinary incontinence in female adolescents with CF.

METHODS

An interviewer-administered questionnaire was conducted with females who were aged 12 years and older and attend the CF Clinic at the Royal Children's Hospital in Melbourne, Australia.

RESULTS

Fifty-five (96%) of 57 eligible adolescents (age: 12-19 years) participated. Twenty-six (47%) reported ever having been incontinent of urine; 12 (22%) reported daytime incontinence twice a month or more. Median age of onset of incontinence was 13 years (range: 7-16 years). No relationship was seen with age, lung function, body mass index, or menarchal status. Coughing and laughing were the most commonly reported precipitants (affecting 84% and 68%, respectively). Of those with incontinence once a year or more, 42% reported that it sometimes prevented them from doing effective physiotherapy. Social life was affected by incontinence in approximately one third of respondents. Nearly half (42%) of affected adolescents had told no one, and only 2 had discussed the problem with their physician.

CONCLUSIONS

Urinary incontinence is common in female adolescents with CF and is not related to illness severity. Urinary incontinence has a negative impact on the performance of chest physiotherapy. Given the lack of adolescent report and knowledge of treatment availability, inquiry about symptoms of urinary incontinence should be part of the routine assessment of female adolescents with CF.

Hordoindolines are associated with a major endosperm-texture QTL in barley (Hordeum vulgare)

Endosperm texture has a tremendous impact on the end-use quality of wheat (Triticum aestivum L.). Cultivars of barley (Hordeum vulgare L.), a close relative of wheat, also vary measurably in grain hardness. However, in contrast to wheat, little is known about the genetic control of barley grain hardness. Puroindolines are endosperm-specific proteins found in wheat and its relatives. In wheat, puroindoline sequence variation controls the majority of wheat grain texture variation. Hordoindolines, the puroindoline homologs of barley, have been identified and mapped. Recently, substantial allelic variation was found for hordoindolines among commercial barley cultivars. Our objective was to determine the influence of hordoindoline allelic variation upon grain hardness and dry matter digestibility in the 'Steptoe' x 'Morex' mapping population. This population is segregating for hordoindoline allele type, which was measured by a HinA/HinB/Gsp composite marker. One-hundred and fifty lines of the 'Steptoe' x 'Morex' population were grown in a replicated field trial. Grain hardness was estimated by near-infrared reflectance (NIR) and measured using the single kernel characterization system (SKCS). Variation attributable to the HinA/HinB/Gsp locus averaged 5.7 SKCS hardness units (SKCS U). QTL analysis revealed the presence of several areas of the genome associated with grain hardness. The largest QTL mapped to the HinA/HinB/Gsp region on the short arm of chomosome 7 (5H). This QTL explains 22% of the SKCS hardness difference observed in this study. The results indicate that the Hardness locus is present in barley and implicates the hordoindolines in endosperm texture control.

Use of the Pediatric Risk of Mortality Score as predictor of death and serious neurologic damage in children after submersion

OBJECTIVE

To evaluate the Pediatric Risk of Mortality score (PRISM score) as a tool to evaluate the vital and neurologic prognosis of patients after submersion.

METHODS

We conducted a retrospective analysis of the clinical histories of patients admitted to a tertiary pediatric hospital, Hospital Sant Joan de Déu, Barcelona, Spain from December 1977 to December 1999 as a consequence of near-drowning. PRISM score was calculated for each patient with data obtained upon arrival at the hospital. The probability of death was calculated using this score.

RESULTS

There were 60 patients, divided into two groups as they were admitted to the Pediatric Intensive Care Unit (PICU group, n = 41) or to the Short Stay Unit (SSU group, n = 19). All patients in the SSU group survived without impairments, with PRISM scores <or=8 and a probability of death of 1.3%. All PICU patients with a PRISM score <or=16 or probability of death <or=16% survived without neurologic impairment. Patients with PRISM scores >or=24 or with probability of death >or=42% either died or had serious neurologic impairment. One third of patients with PRISM scores between 17 and 23 and/or probability of death between 16 and 42% either presented serious neurologic impairment or died.

CONCLUSIONS

PRISM score enables the determination of either absence or presence of serious impairment or death in pediatric patients after submersion, if they present extreme values on this scale. However, in patients with intermediate PRISM scores, it is not possible to establish a reliable prognosis.

The development of multiple domains of child and adolescent self-concept: a cohort sequential longitudinal design

The development of child and adolescent self-concept was examined as a function of the self-concept domain, social/developmental/educational transitions, and gender. In two overlapping age cohorts of public school students (Ns = 936 and 984), five dimensions of self-concept were evaluated every 6 months in a manner that spanned grades 3 through 11 (representing the elementary, middle, and high school years). Domains of self-concept included academic competence, physical appearance, behavioral conduct, social acceptance, and sports competence. Structural equation modeling addressed questions about the stability of individual differences over time. Multilevel modeling addressed questions about mean-level changes in self-concept over time. Significant effects emerged with regard to gender, age, dimension of self-concept, and educational transition.

Comparison of steric and electronic requirements for C-C and C-H bond activation. Chelating vs nonchelating case

C-H bond activation was observed in a novel PCO ligand 1 (C(6)H(CH(3))(3)(CH(2)OCH(3))(CH(2)P(t-Bu)(2))) at room temperature in THF, acetone, and methanol upon reaction with the cationic rhodium precursor, [Rh(coe)(2)(solv)(n)()]BF(4) (solv = solvent; coe = cyclooctene). The products in acetone (complexes 3a and 3b) and methanol (complexes 4a and 4b) were fully characterized spectroscopically. Two products were formed in each case, namely those containing uncoordinated (3a and 4a) and coordinated (3b and 4b) methoxy arms, respectively. Upon heating of the C-H activation products in methanol at 70 degrees C, C-C bond activation takes place. Solvent evaporation under vacuum at room temperature for 3-4 days also results in C-C activation. The C-C activation product, ((CH(3))Rh(C(6)H(CH(3))(2)(CH(2)OCH(3))(CH(2)P(t-Bu)(2))BF(4)), was characterized by X-ray crystallography, which revealed a square pyramidal geometry with the BF(4)(-) anion coordinated to the metal. Comparison to the structurally similar and isoelectronic nonchelating Rh-PC complex system and computational studies provide insight into the reaction mechanism. The reaction mechanism was studied computationally by means of a two-layer ONIOM model, using both the B3LYP and mPW1K exchange-correlation functionals and a variety of basis sets. Polarization functions significantly affect relative energetics, and the mPW1K profile appears to be more reliable than its B3LYP counterpart. The calculations reveal that the electronic requirements for both C-C and C-H activation are essentially the same (14e intermediates are the key ones). On the other hand, the steric requirements differ significantly, and chelation appears to play an important role in C-C bond activation.

The cytoplasmic amino-terminus of the Latent Membrane Protein-1 of Epstein-Barr Virus: relationship between transmembrane orientation and effector functions of the carboxy-terminus and transmembrane domain

The Latent Membrane Protein 1 (LMP-1) protein of Epstein-Barr virus (EBV) is localized in the plasma membrane of the infected cell. LMP-1 possesses a hydrophobic membrane spanning domain, and charged, intracellular amino- and carboxy-termini. Two models have been proposed for the contribution of the amino-terminus to LMP-1's function: (i) as an effector domain, interacting with cellular proteins, or (ii) as a structural domain dictating the correct orientation of transmembrane domains and thereby positioning LMP-1's critical effector domains (i.e. the carboxy-terminus). However, no studies to date have addressed directly the structural contributions of LMP-1's cytoplasmic amino-terminus to function. This study was designed to determine if LMP-1's cytoplasmic amino-terminus (N-terminus) encodes information required solely for maintenance of proper topological orientation. We have constructed LMP-1 chimeras in which the cytoplasmic N-terminus of LMP-1 is replaced with an unrelated domain of similar size and charge, but of different primary sequence. Retention of the charged amino-terminal (N-terminal) cytoplasmic domain and first predicted transmembrane domain was required for correct transmembrane topology. The absolute primary sequence of the cytoplasmic N-terminus was not critical for LMP-1's cytoskeletal association, turnover, plasma membrane patching, oligomerization, Tumor Necrosis Factor Receptor-associated factor (TRAF) binding, NF-kappaB activation, rodent cell transformation and cytostatic activity. Furthermore, our results point to the hydrophobic transmembrane domain, independent of the cytoplasmic domains, as the primary LMP-1 domain mediating oligomerization, patching and cytoskeletal association. The cytoplasmic amino-terminus provides the structural information whereby proper transmembrane orientation is achieved.

Localized non-Hodgkin's lymphoma of Waldeyer's ring: clinical features, management, and prognosis of 130 adult patients

BACKGROUND

Waldeyer's ring (WR) is the primary site of non-Hodgkin's lymphoma (NHL) involvement in approximately 5% to 10% of all lymphoma patients, and it accounts for more than half of all primary extranodal lymphomas of the head and neck. Materials and Methods A retrospective review was performed of 130 adult patients with localized (stages I and II) WR-NHL seen at a single institution over 18 years.

RESULTS

Patients had a median age of 55 years, and the male-female ratio was 1:5:1. Seventy five (58%), 46 (35%), and 9 (7%) patients had primary tonsillar, nasopharyngeal, and base of the tongue lymphoma, respectively. Forty-five (35%) and 85 (65%) had stage I and stage II disease, respectively. Most patients (109 patients, 84%) had diffuse large B-cell NHL (DLC). Chemotherapy (CT) was given to 58 (45%) patients, whereas 26 (20%) received radiation therapy (RTX), and 46 (35%) were managed with a combination of chemotherapy and radiotherapy (CMT). One hundred nine (84%), 16 (12%), and 5 (4%) patients attained complete remission (CR), partial remission (PR), and treatment failure, respectively, with no difference in CR rates between the three therapeutic modalities. Of those patients with DLC, 90 (83%), 15 (14%), and 4 (3%) demonstrated CR, PR, and treatment failure, respectively. In a multivariate analysis, the modified International Prognostic Index (IPI) was found to predict the attainment of CR. Over a median follow-up of 49 months; 76 (58%) of the patients were alive and disease-free, 5 (4%) were alive with evidence of disease, and the remaining 49 (38%) were dead. Most distant relapses were in nongastrointestinal extranodal sites. The median overall survival (OS) has not been reached; however, the projected 5-year OS was 58%. No OS difference was noted between patients with stage I and stage II. Cox proportional hazards model identified primary tonsillar site and a low-risk group as defined by the modified IPI were associated with favorable OS. The median event-free survival was 82.3 months, with the primary tonsillar site, and low-risk modified IPI group were associated with favorable EFS in a multivariate analysis. Probably because of the high frequency of patients with DLC, the outcome and the prognostic factors in those patients were not distinctive from those for the whole group. The CMT was not associated with a superior OS compared with either of the single modality treatments; however, it was associated with more favorable EFS.

CONCLUSIONS

This series characterized the clinicopathologic features and outcome of adult patients with early stage WR-NHLs. No survival difference was noted between stage I and stage II, and the outcome was favorable. Primary tonsillar site and the low-risk group of the modified IPI predicted favorable OS and EFS. CMT is probably superior to single modality treatment; however, prospective studies are warranted.

Primary intestinal diffuse large B-cell non-Hodgkin's lymphoma: clinical features, management, and prognosis of 66 patients

BACKGROUND

In Saudi Arabia, primary gastrointestinal non-Hodgkin's lymphoma (NHL) is common. Recently we have reported one of the largest series of primary gastric (PG) diffuse large B-cell lymphoma (DLCL). This has prompted the analysis of another series of patients with primary intestinal DLCL to depict the clinical features and the outcome of that disease and to compare those with that for PG involvement.

PATIENTS AND METHODS

The data of 66 adult patients with primary intestinal NHL having DLCL histology were retrospectively reviewed.

RESULTS

Patients had a median age of 45 years. Of 64 treated patients, 16% and 84%, received single and multiple modality treatment, respectively. Seventy-six percent, ten percent, and fourteen percent attained complete remission (CR), partial remission (PR), and no response/progressive disease, respectively. Multivariate analysis failed to identify any variable that predict the likelihood of attaining CR. Over a median follow-up of 81 months for all 66 patients, 32 (48%) were alive and disease-free, 5 (8%) were alive with evidence of disease, and the remaining 29 (44%) were dead. The median overall survival (OS) was 101 months and it was 58% (+/- 6%) and 48% (+/- 7%) at 5- and 10-year, respectively. Of the 54 patients who achieved CR or PR, the median event-free survival (EFS) was not reached, but the predicted 5- and 10-year EFS was 61% (+/- 7%) and 52% (+/- 7%), respectively. Only low serum albumin (<30 g/l) was associated with adverse OS and EFS in a univariate analysis, however, multivariate analysis was not possible. Our analysis showed that compared with single-modality management, multi-modality strategy attained significantly higher CR, and advantageous EFS, but without a significant superior effect on OS. In comparison with patients with PG DLCL, those with primary intestinal disease demonstrated more adverse prognostic features, but had an equivalent survival.

CONCLUSIONS

This series characterized the clinico-pathologic features and outcome of patients with primary intestinal DLCL. While surgical resection in primary intestinal NHL seems beneficial, only prospective randomized studies can ascertain its precise role. Compared with patients with PG NHL, patients with primary intestinal disease had more prevalence of adverse prognostic features.

EELS analysis of PMMA at high spatial resolution

We performed the electron energy-loss spectroscopic (EELS) analysis of electron-sensitive polymers in the analytical transmission electron microscope in order to evaluate the possibility to obtain chemical information on polymers at a nanometre scale (i.e. at 2.4nm diameter probe). In the acquired spectra, we propose an identification of the ELNES fine structure to the different chemical bonding in agreement with molecular orbital calculations (EHT) and with previous XANES experiments.The main results confirm that poly(methyl mettacrylate) (PMMA) is very sensitive to electrons when a large probe size is used, with a critical dose of about 10(2)Cm(-2). However a high dose rate in a nanometre diameter electron beam is less destructive and the EELS spectra of far less degraded PMMA could be obtained even at 10(7)Cm(-2). Irradiation damage was however thought to be the main limitation of the field-emission gun microscope, since high electron doses are required to acquire an EELS spectrum. This surprising behaviour was already observed in the case of poly(ethylene terephthalate), which is however more resistant to the electron beam (Varlot et al., 1997. Ultramicroscopy 68 (2), 123-133). Several possible explanations were studied, such as the influence of the accelerating voltage, a wrong calculation of the electron dose, the excitation delocalisation and the electron dose rate.

Computational Study of a New Heck Reaction Mechanism Catalyzed by Palladium(II/IV) Species

In this theoretical study on the Heck reaction we explore the feasibility of an alternative pathway that involves a PdII/PdIV redox system. Usually, the catalytic cycle is formulated based on a Pd0/PdII mechanism. We performed quantum chemical calculations using density functional theory on a model system that consisted of diphosphinoethane (DPE) as a bidentate ligand and the substrates ethylene and phenyl iodide to compare both mechanisms. Accordingly, the PdII/PdIV mechanism is most likely to occur in the equatorial plane of an octahedral PdIV complex. The energy profiles of both reaction pathways under consideration are largely parallel. A major difference is found for the oxidative addition of the C-I bond to the palladium centre. This is a rate-determining step of the PdII/PdIV mechanism, while it is facile for a Pd0 catalyst. The calculations show that intermediate ligand detachment and reattachment is necessary in the course of the oxidative addition to PdII. Therefore, we expect the PdII/PdIV mechanism to be only feasible if a weakly coordinating ligand is present.

A fully ab initio potential curve of near-spectroscopic quality for OH- ion: importance of connected quadruple excitations and scalar relativistic effects

A benchmark study has been carried out on the ground-state potential curve of the hydroxyl anion, OH-, including detailed calibration of both the l-particle and n-particle basis sets. The CCSD(T) basis set limit overestimates omega(e) by about 10 cm(-1), which is only remedied by inclusion of connected quadruple excitations in the coupled cluster expansion--or, equivalently, the inclusion of the 2pi orbitals in the active space of a multireference calculation. Upon inclusion of scalar relativistic effects (-3 cm(-1) on omega(e)), a potential curve of spectroscopic quality (sub-cm(-1) accuracy) is obtained. Our best computed EA(OH), 1.828 eV, agrees to three decimal places with the best available experimental value. Our best computed dissociation energies, D0(OH-) = 4.7796 eV and D0(OH) = 4.4124 eV, suggest that the experimental D0(OH) = 4.392 eV may possibly be about 0.02 eV too low.

Are the discrepancies between self- and others' appraisals of competence predictive or reflective of depressive symptoms in children and adolescents: a longitudinal study, Part II

Two cohorts of children and adolescents (who started 6th grade in 1993 and 1996), parents, teachers, and peers participated in a 4-wave, 2-year, longitudinal study of perceived competence and depressive symptoms. The authors assessed children's tendencies to underestimate their competence (discrepant self-appraisals) relative to the appraisals of significant others. We also assessed the degree to which self-appraisals reflected the evaluations of others (reflective self-appraisals). Domains of competence were academic competence, physical appearance, behavioral conduct, social acceptance, and athletic competence. Cross-sectional analyses indicated that depressive symptoms correlated with reflective and discrepant self-appraisals. Longitudinal analyses revealed that reflective and discrepant self-appraisals predicted subsequent depressive symptoms and that depressive symptoms predicted discrepant but not reflective self-appraisals. Clinical implications of the findings are discussed.

Primary intestinal diffuse large B-cell non-Hodgkin's lymphoma: clinical features, management, and prognosis of 66 patients

BACKGROUND

In Saudi Arabia, primary gastrointestinal non-Hodgkin's lymphoma (NHL) is common. Recently we have reported one of the largest series of primary gastric (PG) diffuse large B-cell lymphoma (DLCL). This has prompted the analysis of another series of patients with primary intestinal DLCL to depict the clinical features and the outcome of that disease and to compare those with that for PG involvement.

PATIENTS AND METHODS

The data of 66 adult patients with primary intestinal NHL having DLCL histology were retrospectively reviewed.

RESULTS

Patients had a median age of 45 years. Of 64 treated patients, 16% and 84%, received single and multiple modality treatment, respectively. Seventy-six percent, ten percent, and fourteen percent attained complete remission (CR), partial remission (PR), and no response/progressive disease, respectively. Multivariate analysis failed to identify any variable that predict the likelihood of attaining CR. Over a median follow-up of 81 months for all 66 patients, 32 (48%) were alive and disease-free, 5 (8%) were alive with evidence of disease, and the remaining 29 (44%) were dead. The median overall survival (OS) was 101 months and it was 58% (+/- 6%) and 48% (+/- 7%) at 5- and 10-year, respectively. Of the 54 patients who achieved CR or PR, the median event-free survival (EFS) was not reached, but the predicted 5- and 10-year EFS was 61% (+/- 7%) and 52% (+/- 7%), respectively. Only low serum albumin (<30 g/l) was associated with adverse OS and EFS in a univariate analysis, however, multivariate analysis was not possible. Our analysis showed that compared with single-modality management, multi-modality strategy attained significantly higher CR, and advantageous EFS, but without a significant superior effect on OS. In comparison with patients with PG DLCL, those with primary intestinal disease demonstrated more adverse prognostic features, but had an equivalent survival.

CONCLUSIONS

This series characterized the clinico-pathologic features and outcome of patients with primary intestinal DLCL. While surgical resection in primary intestinal NHL seems beneficial, only prospective randomized studies can ascertain its precise role. Compared with patients with PG NHL, patients with primary intestinal disease had more prevalence of adverse prognostic features.

Basicity of uranyl oxo ligands upon coordination of alkoxides

Uranium(VI) alkoxide complexes are prepared via metathesis reactions of [UO2Cl2(THF)2]2 with potassium alkoxides in nonaqueous media. The dark red compound U[OCH2C(CH3)3]6, 1, results from redistributive exchange of oxo and neopentoxide ligands between more than one uranium species. Single-crystal X-ray diffraction analysis of 1 reveals a monomer in which the uranium is coordinated in a pseudooctahedral fashion by six neopentoxide ligands. Imposition of steric congestion at the metal center prevents oxo-alkoxide ligand exchange in the reactions using more sterically demanding alkoxides. Simple metathesis between uranyl chloride and alkoxide ligands occurs in the synthesis of golden yellow-orange UO2(OCHPh2)2(THF)2, 2, and yellow UO2[OCH(tBu)Ph]2(THF)2, 3. Single-crystal X-ray diffraction analysis of 2 reveals a monomer in which the uranium is coordinated in a pseudooctahedral fashion by two apical oxo ligands, two diphenylmethoxide ligands occupying trans positions, and two tetrahydrofuran ligands. Coordination of diisopropylmethoxide allows for synthesis of a more complex binary alkoxide system. Single-crystal X-ray diffraction analysis of watermelon red [UO2(OCH(iPr)2)2]4, 4, reveals a tetramer in which each uranium is coordinated in a pseudooctahedral fashion by two apical oxo ligands, one terminal alkoxide, two bridging alkoxide ligands, and one bridging oxo ligand from a neighboring uranyl group. These compounds are characterized by elemental analysis, 1H NMR, infrared spectroscopy, and, for 1, 2, and 4, single-crystal X-ray diffraction analysis. Luminescence spectroscopy is employed to evaluate the extent of aggregation of compounds 2-4 in various solvents. Vibrational spectroscopic measurements of 2-4 imply that, in contrast to the case of uranyl complexes prepared in aqueous environments, coordination of relatively strongly donating alkoxide ligands allows for enhancement of electron density on the uranyl groups such that the uranyl U=O bonds are weakened. Crystal data are as follows. 1: monoclinic space group C2/m, a = 10.6192(8) A, b = 18.36(1) A, c = 10.6151(8) A, beta = 109.637(1) degrees, V = 1949.1(3) A3, Z = 2, dcalc = 1.297 g cm-3. Refinement of 2065 reflections gave R1 = 0.045. 2: monoclinic space group P2(1)/c, a = 6.1796(4) A, b = 15.669(1) A, c = 16.169(1) A, beta = 95.380(1) degrees, V = 1558.7(2) A3, Z = 2, dcalc = 1.664 g cm-3. Refinement of 3048 reflections gave R1 = 0.036. 4: tetragonal space group I4, a = 17.8570(6) A, b = 17.8570(6) A, c = 11.4489(6) A, V = 3650.7(3) A3, Z = 2, dcalc = 1.821 g cm-3. Refinement of 1981 reflections gave R1 = 0.020.

Are the discrepancies between self- and others' appraisals of competence predictive or reflective of depressive symptoms in children and adolescents: a longitudinal study, Part II

Two cohorts of children and adolescents (who started 6th grade in 1993 and 1996), parents, teachers, and peers participated in a 4-wave, 2-year, longitudinal study of perceived competence and depressive symptoms. The authors assessed children's tendencies to underestimate their competence (discrepant self-appraisals) relative to the appraisals of significant others. We also assessed the degree to which self-appraisals reflected the evaluations of others (reflective self-appraisals). Domains of competence were academic competence, physical appearance, behavioral conduct, social acceptance, and athletic competence. Cross-sectional analyses indicated that depressive symptoms correlated with reflective and discrepant self-appraisals. Longitudinal analyses revealed that reflective and discrepant self-appraisals predicted subsequent depressive symptoms and that depressive symptoms predicted discrepant but not reflective self-appraisals. Clinical implications of the findings are discussed.

Activity of primate V1 cortical neurons during blinks

Every time we blink our eyes, the image on the retina goes almost completely dark. And yet we hardly notice these interruptions, even though an external darkening is startling. Intuitively it would seem that if our perception is continuous, then the neuronal activity on which our perceptions are based should also be continuous. To explore this issue, we compared the responses of 63 supragranular V1 neurons recorded from two awake monkeys for four conditions: 1) constant stimulus, 2) during a reflex blink, 3) during a gap in the visual stimulus, and 4) during an external darkening when an electrooptical shutter occluded the entire scene. We show here that the activity of neurons in visual cortical area V1 is essentially shut off during a blink. In the 100-ms epoch starting 70 ms after the stimulus was interrupted, the firing rate was 27.2 +/- 2.7 spikes/s (SE) for a constant stimulus, 8.2 +/- 0.9 spikes/s for a reflex blink, 17.3 +/- 1.9 spikes/s for a gap, and 12.7 +/- 1.4 spikes/s for an external darkening. The responses during a blink are less than during an external darkening (P < 0.05, t-test). However, many of these neurons responded with a transient burst of activity to the onset of an external darkening and not to a blink, suggesting that it is the suppression of this transient which causes us to ignore blinks. This is consistent with other studies where the presence of transient bursts of activity correlates with the perceived visibility of a stimulus.

Sex-related differences in methionine metabolism and plasma homocysteine concentrations

BACKGROUND

Elevated fasting homocysteine concentrations are considered a risk factor for vascular disease. Homocysteine, which is produced by the transmethylation of methionine, can be either remethylated back to methionine or metabolized via transsulfuration to cystathionine. It has been speculated that the lower risk of vascular disease among premenopausal women may be related to lower homocysteine concentrations in women than in men.

OBJECTIVE

This study was designed to determine whether sex-related differences exist in methionine cycle kinetics, which may account for the reportedly lower fasting homocysteine concentrations in premenopausal women.

DESIGN

Eleven healthy young men and 11 premenopausal women without cardiac risk factors were studied by using stable-isotope-labeled L-[methyl-(2)H(3),1-(13)C]methionine and L-[methyl- (2)H(3)]leucine. After 3 h of tracer infusion, 100 mg unlabeled L-methionine/kg body wt was ingested. Blood and breath samples were obtained at timed intervals. Fat-free mass was estimated by dual-energy X-ray absorptiometry and muscle mass by urinary creatinine excretion.

RESULTS

No significant sex-related differences were found in fasting homocysteine concentrations, responses to the oral methionine load, or rates of methionine flux based on carboxyl or methyl labels. However, women had significantly higher remethylation rates than did men (P < 0.005) and a tendency toward higher transmethylation (P < 0.10). Whereas adjustment of remethylation rates for fat-free mass tended to attenuate the sex-related effect (P = 0.08), adjustment for muscle mass did not (P < 0.04). In contrast, significant sex-related differences in leucine flux (P < 0.02) were eliminated after adjustment for either fat-free mass or muscle mass.

CONCLUSION

Reported differences between men and women in homocysteine concentrations may be partially explained by differences in rates of homocysteine remethylation.

Treatment of shigellosis with cefixime: two days vs. five days

BACKGROUND

Although the recommended standard course of therapy for shigellosis is 5 days of oral ampicillin or trimethoprim-sulfamethoxazole therapy, successful outcome has been reported in adults treated with abbreviated courses of antibiotics. The purpose of this study was to compare short course (2-day) vs. 5-day therapy with cefixime for treatment of diarrheal disease caused by Shigella sonnei in children.

METHODS

This was a prospective, randomized, double blind, placebo-controlled study. Patients were eligible if they were at least 6 months of age and presented to the Children's Hospital of Pittsburgh during an outbreak of diarrhea caused by S. sonnei, with (1) a history of fever and diarrhea (at least three loose or watery stools per day), (2) bloody diarrhea or (3) diarrhea and known exposure to an individual with documented shigellosis. Patients were randomized to receive either 2 days of cefixime (8 mg/kg(day) given once daily followed by 3 days of placebo or 5 days of cefixime. Telephone follow-up was performed on Days 3, 7 and 14 after enrollment. Follow-up stool cultures were obtained on Day 7 to assess bacteriologic cure. There were standardized definitions for cure, improvement, failure and relapse.

RESULTS

Forty-seven patients were enrolled. Eleven were eliminated from analysis because their stool cultures were not positive for S. sonnei. There were 36 evaluable patients, 21 in the 2-day group and 15 in the 5-day group. Patients ranged in age from 6 months to 17 years. Forty-four percent of the subjects were male. Symptoms were improved or had resolved by Day 3 of therapy in all patients. There were 8 patients who experienced a clinical relapse: 5 of 21 (24%) patients in the 2-day treatment group and 3 of 15 (20%) in the 5-day group. There were 13 patients who experienced a bacteriologic failure (defined as the occurrence of a positive culture at the Day 7 follow-up visit), 11 of 20 (55%) in the 2-day group and 2 of 14 (14%) in the 5-day group (P < 0.02).

CONCLUSION

Two- and 5-day treatment courses with cefixime for treatment of diarrheal disease caused by S. sonnei result in similar rates of clinical cure and clinical relapses; however, there was a higher rate of bacteriologic failure with shorter course therapy.

Influenza virus immunization effectivity in kidney transplant patients subjected to two different triple-drug therapy immunosuppression protocols: mycophenolate versus azathioprine

BACKGROUND

Due to possible complications and treatment limitations, the prevention of influenza in renal transplant (RT) patients is highly indicated.

METHODS

Forty-nine patients with a 1-year functioning RT subjected to two different immunosuppressive regimens and 37 healthy relatives (HR) were administered the anti-influenza vaccine as recommended for 1996 to 1997. Anti-influenza antibody, creatinine, and immunological markers were estimated at 1 and 3 months after vaccination.

RESULTS

Three months after vaccination, 46.2% of the RT patients and 69% of the HR (P=0.06) showed protective antibody titers to influenza A (relative risk [RR]; 0.67; 95% confidence interval: 0.44-1.02). A total of 20.5% of the RT patients and 44.8% of the HR showed antibodies to influenza B (P=0.03). Despite these differences, the incidence of illness was similar. The immunosuppressive regimen had no effect on the antibody response.

CONCLUSIONS

Although the RT patients showed a reduced antibody response, no negative effects on graft outcome were observed.

Properties of sequence-tagged-site primer sets influencing repeatability

The polymerase chain reaction (PCR) has become a standard procedure in plant genetics, and is the basis for many emerging genomics approaches to mapping and gene identification. One advantage of PCR is that sequence information for primer sets can be exchanged between laboratories, obviating the need for exchange and maintenance of biological materials. Repeatability of primer sets, whereby the same products are amplified in different laboratories using the same primer set, is important to successful exchange and utilization. We have developed several hundred sequence-tagged site (STS) primer sets for wheat and barley. The ability of the primer sets to generate reproducible amplifications in other laboratories has been variable. We wished to empirically determine the properties of the primer sets that most influenced repeatability. A total of 96 primer sets were tested with four genomic DNA samples on each of four thermocyclers. All major bands were repeatable across all four thermocylers for approximately 50% of the primer sets. Characteristics most often associated with differences in repeatability included primer GC content and 3'-end stability of the primers. The propensity for primer-dimer formation was not a factor in repeatability. Our results provide empirical direction for the development of repeatable primer sets.

Properties of sequence-tagged-site primer sets influencing repeatability

The polymerase chain reaction (PCR) has become a standard procedure in plant genetics, and is the basis for many emerging genomics approaches to mapping and gene identification. One advantage of PCR is that sequence information for primer sets can be exchanged between laboratories, obviating the need for exchange and maintenance of biological materials. Repeatability of primer sets, whereby the same products are amplified in different laboratories using the same primer set, is important to successful exchange and utilization. We have developed several hundred sequence-tagged site (STS) primer sets for wheat and barley. The ability of the primer sets to generate reproducible amplifications in other laboratories has been variable. We wished to empirically determine the properties of the primer sets that most influenced repeatability. A total of 96 primer sets were tested with four genomic DNA samples on each of four thermocyclers. All major bands were repeatable across all four thermocyclers for approximately 50% of the primer sets. Characteristics most often associated with differences in repeatability included primer GC content and 3'-end stability of the primers. The propensity for primer-dimer formation was not a factor in repeatability. Our results provide empirical direction for the development of repeatable primer sets. Key words: STS-PCR primers, wheat, barley.

The late lytic LMP-1 protein of Epstein-Barr virus can negatively regulate LMP-1 signaling

The BNLF-1 open reading frame of Epstein-Barr virus (EBV) encodes two related proteins, latent membrane protein-1 (LMP-1) and lytic LMP-1 (lyLMP-1). LMP-1 is a latent protein required for immortalization of human B cells by EBV, whereas lyLMP-1 is expressed during the lytic cycle and is found in the EBV virion. We show here that, in contrast to LMP-1, lyLMP-1 is stable, with a half-life of >20 h in tetradecanoyl phorbol acetate- and butyrate-treated B95-8 cells. Although lyLMP-1 itself has negligible effects on NF-kappaB activity, it inhibits NF-kappaB activation by LMP-1 in a dose-dependent manner. The lyLMP-1 protein does not oligomerize with LMP-1, and the negative effect of lyLMP-1 on NF-kappaB activation by LMP-1 does not result from lyLMP-1-mediated disruption of LMP-1 oligomers. Modulation of LMP-1-activated signaling pathways is the first identified biological activity associated with lyLMP-1, and this activity may contribute to the progression of EBV's lytic cycle.

Conserved polymerase chain reaction primers fail in diagnosis of parasitic infections

We demonstrate that a set of previously described polymerase chain reaction primers used for detection of hemogregarines in reptiles will also amplify the same region of the 18S rRNA gene of reptiles, amphibians, mammals, and insects and thus should not be used for molecular diagnosis. These same primers have also been used to differentiate 2 species of Plasmodium that infect lizards. We provide evidence that the observed variance may have been dependent on parasitemia and not representative of actual molecular differences between the 2 parasite species.