Honeybee pollination of buckwheat (Fagopyrum esculentum Moench) cv. Manor

The role of honeybees (Apis mellifera) in the pollination of buckwheat cv. Manor was studied in a commercial planting at Smeaton, Victoria. Honeybees comprised 80% of all insect visitors to this crop. Other insects included ladybirds (Coccinella transversalis and C. undecimpunctata), hoverflies (Meangyna viridiceps), drone flies (Eristalis sp.), blowflies (Calliphoridae), cabbage white butterflies (Pieris rapae), small bush flies and native bees. The activity of honeybees and other insects increased seed production from 91.5 g/plot (plots closed to insects) to 180.4 g/plot (plots open to insects).

Serotypes/groups distribution and antimicrobial resistance of invasive pneumococcal isolates: implications for vaccine strategies

Based on the invasive pneumococcal isolates referred to reference laboratories in Scotland in 1988-99, we identified the distribution of serotypes/groups and their antimicrobial resistance patterns in order to evaluate the coverage of polysaccharide and the new pneumococcal conjugate vaccines. A total of 5659 invasive isolates were included. Of these, 5124 (90.5%) were blood isolates, 308 (5.5%) were CSF isolates, 143 (2.5%) were blood and CSF and 84 (1.5%) were other normally sterile isolates. The most prevalent 11 serotypes/groups were 14, 9, 19, 6, 23, 1, 3, 4, 7, 8 and 18, in numerical order. These accounted for 84% of total serotypes/groups. The serotypes/groups included in the 23 and 14-valent polysaccharide vaccines accounted for 96% and 88% of all isolates. Both vaccines accounted for 98% of penicillin non-susceptible and 100% of erythromycin non-susceptible isolates. The 7, 9, and 11-valent conjugate vaccines covered 61, 68 and 80% of invasive isolates respectively. The coverage of these vaccines was substantially higher in youngest age group with 84, 86 and 93% of invasive isolates in children < 2 years included in the 7, 9 and 11-valent conjugate vaccines compared with 58, 64 and 77% in adults > or = 65 years of age. The serotype/group distribution of invasive isolates in Scotland varied from year to year over the period 1993-9. The coverage of the 23-valent vaccine remained above 95% in each year but the coverage of the 7, 9 and 11-valent conjugate vaccines showed more marked fluctuation with coverage as low as 53, 60 and 75% in some years. Continued surveillance of invasive pneumococcal isolates is required to inform the development of appropriate vaccine strategies to prevent pneumococcal disease in Scotland.

Development of an instrument to assess readiness to recover in anorexia nervosa

OBJECTIVE

The degree to which patients with anorexia nervosa demonstrate readiness to recover from their illness has received scant theoretical or empirical attention. Investigating the prevalence and degree of amotivation for recovery in anorexia nervosa, its role in outcome, and the effectiveness of interventions designed to enhance readiness to recover necessitates the existence of a reliable and valid measure of motivational issues relevant to the disorder. The present study aimed to develop and evaluate an instrument for assessing readiness to recover in anorexia nervosa, namely, the Anorexia Nervosa Stages of Change Questionnaire (ANSOCQ), a 23-item self-report questionnaire based on Prochaska and DiClemente's stages of change model.

METHOD

Seventy-one inpatients with anorexia nervosa participated in the study. On several occasions during their admission, participants completed the ANSOCQ as well as questionnaires assessing readiness to recover, anorexic symptomatology, general distress, and social desirability.

RESULTS

The ANSOCQ demonstrated good internal consistency (.90) and 1-week test-retest reliability (.89). Various aspects of validity were also supported, such as significant relationships with other instruments assessing readiness to recover and the prediction of weight gain during different periods of treatment.

DISCUSSION

The results suggest that the ANSOCQ is a psychometrically sound instrument that may prove useful in investigating the role of readiness to recover in anorexia nervosa.

A novel post-translational modification of yeast elongation factor 1A. Methylesterification at the C terminus

Protein methylation reactions can play important roles in cell physiology. After labeling intact Saccharomyces cerevisiae cells with S-adenosyl-l-[methyl-(3)H]methionine, we identified a major methylated 49-kDa polypeptide containing [(3)H]methyl groups in two distinct types of linkages. Peptide sequence analysis of the purified methylated protein revealed that it is eukaryotic elongation factor 1A (eEF1A, formerly EF-1alpha), the protein that forms a complex with GTP and aminoacyl-tRNAs for binding to the ribosomal A site during protein translation. Previous studies have shown that eEF1A is methylated on several internal lysine residues to give mono-, di-, and tri-N-epsilon-methyl-lysine derivatives. We confirm this finding but also detect methylation that is released as volatile methyl groups after base hydrolysis, characteristic of ester linkages. In cycloheximide-treated cells, methyl esterified eEF1A was detected largely in the ribosome and polysome fractions; little or no methylated protein was found in the soluble fraction. Because the base-labile, volatile [methyl-(3)H]radioactivity of eEF1A could be released by trypsin treatment but not by carboxypeptidase Y or chymotrypsin treatment, we suggest that the methyl ester is present on the alpha-carboxyl group of its C-terminal lysine residue. From the results of pulse-chase experiments using radiolabeled intact yeast cells, we find that the N-methylated lysine residues of eEF1A are stable over 4 h, whereas the eEF1A carboxyl methyl ester has a half-life of less than 10 min. The rapid turnover of the methyl ester suggests that the methylation/demethylation of eEF1A at the C-terminal carboxyl group may represent a novel mode of regulation of the activity of this protein in yeast.

Psychiatric symptomatology in borderline and other personality disorders: dissociation and fragmentation as mediators

This study considered the role of dissociation and personality fragmentation as psychological factors that might distinguish borderline and personality disorder (BPD) patients, and that might explain why BPD patients have higher levels of other psychiatric symptomatology than those with other personality disorders. Two groups of personality-disordered patients (personality disorders including BPD; personality disorders other than BPD) completed measures of dissociation, personality fragmentation, and psychiatric disturbance. The BPD group had higher levels of a number of aspects of psychiatric symptomatology. Those differences were mediated by aspects of dissociation. Personality fragmentation differentiated the two groups but was not related to the higher levels of other aspects of psychiatric disturbance. Treating the syndrome of BPD may depend on addressing both dissociation and personality fragmentation. In contrast, reducing the level of comorbid psychiatric disturbance in BPD is likely to be more strongly dependent on reducing levels of different aspects of dissociation. Psychotherapeutic techniques and targets for achieving such change are discussed.

Expression, purification, and characterization of the protein repair l-isoaspartyl methyltransferase from Arabidopsis thaliana

Protein l-isoaspartate (d-aspartate) O-methyltransferase (EC 2.1.1. 77) is a repair enzyme that methylates abnormal l-isoaspartate residues in proteins which arise spontaneously as a result of aging. This enzyme initiates their conversion back into the normal l-aspartate form by a methyl esterification reaction. Previously, partial cDNAs of this enzyme were isolated from the higher plant Arabidopsis thaliana. In this study, we report the cloning and expression of a full-length cDNA of l-isoaspartyl methyltransferase from A. thaliana into Escherichia coli under the P(BAD) promoter, which offers a high level of expression under a tight regulatory control. The enzyme is found largely in the soluble fraction. We purified this recombinant enzyme to homogeneity using a series of steps involving DEAE-cellulose, gel filtration, and hydrophobic interaction chromatographies. The homogeneous enzyme was found to have maximum activity at 45 degrees C and a pH optimum from 7 to 8. The enzyme was found to have a wide range of affinities for l-isoaspartate-containing peptides and displayed relatively poor reactivity toward protein substrates. The best methyl-accepting substrates were KASA-l-isoAsp-LAKY (K(m) = 80 microM) and VYP-l-isoAsp-HA (K(m) = 310 microM). We also expressed the full-length form and a truncated version of this enzyme (lacking the N-terminal 26 amino acid residues) in E. coli under the T7 promoter. Both the full-length and the truncated forms were active, though overexpression of the truncated enzyme led to a complete loss of activity.

PRMT3 is a distinct member of the protein arginine N-methyltransferase family. Conferral of substrate specificity by a zinc-finger domain

S-Adenosyl-l-methionine-dependent protein arginine N-methyltransferases (PRMTs) catalyze the methylation of arginine residues within a variety of proteins. At least four distinct mammalian family members have now been described, including PRMT1, PRMT3, CARM1/PRMT4, and JBP1/PRMT5. To more fully define the physiological role of PRMT3, we characterized its unique putative zinc-finger domain and how it can affect its enzymatic activity. Here we show that PRMT3 does contain a single zinc-finger domain in its amino terminus. Although the zinc-liganded form of this domain is not required for methylation of an artificial substrate such as the glutathione S-transferase-fibrillarin amino-terminal fusion protein (GST-GAR), it is required for the enzyme to recognize RNA-associated substrates in RAT1 cell extracts. The recombinant form of PRMT3 is inhibited by high concentrations of ZnCl(2) as well as N-ethylmaleimide, reagents that can modify cysteine sulfhydryl groups. We found that we could distinguish PRMT family members by their sensitivity to these reagents; JBP1/PRMT5 and Hsl7 methyltransferases were inhibited in a similar manner as PRMT3, whereas Rmt1, PRMT1, and CARM1/PRMT4 were not affected. We were also able to define differences in these enzymes by their sensitivity to inhibition by Tris and free arginine. Finally, we found that the treatment of RAT1 cell extracts with N-ethylmaleimide leads to a loss of the major PRMT1-associated activity that was immune to inhibition under the same conditions as a GST fusion protein. These results suggest that native forms of PRMTs can have different properties than their GST-catalytic chain fusion protein counterparts, which may lack associated noncatalytic subunits.

Do patients with rheumatoid arthritis established on methotrexate and folic acid 5 mg daily need to continue folic acid supplements long term?

BACKGROUND

It is postulated that some aspects of methotrexate toxicity may be related to its action as an anti-folate. Folic acid (FA) is often given as an adjunct to methotrexate therapy, but there is no conclusive proof that it decreases the toxicity of methotrexate and there is a theoretical risk that it may decrease the efficacy of methotrexate.

OBJECTIVES

To look at the effect of stopping FA supplementation in UK rheumatoid arthritis (RA) patients established on methotrexate <20 mg weekly and FA 5 mg daily, to report all toxicity (including absolute changes in haematological and liver enzyme indices) and to report changes in the efficacy of methotrexate.

METHODS

In a prospective, randomized, double-blind, placebo-controlled study, 75 patients who were established on methotrexate <20 mg weekly and FA 5 mg daily were asked to stop their FA and were randomized to one of two groups: placebo or FA 5 mg daily. Patients were evaluated for treatment toxicity and efficacy before entry and then at intervals of 3 months for 1 yr.

RESULTS

Overall, 25 (33%) patients concluded the study early, eight (21%) in the group remaining on FA and 17 (46%) in the placebo group (P = 0.02). Two patients in the placebo group discontinued because of neutropenia. At 9 months there was an increased incidence of nausea in the placebo group (45 vs. 7%, P = 0.001). The placebo group had significantly lower disease activity on a few of the variables measured, but these were probably not of clinical significance.

CONCLUSIONS

It is important to continue FA supplementation over the long term in patients on methotrexate and FA in order to prevent them discontinuing treatment because of mouth ulcers or nausea and vomiting. Our data suggest that FA supplementation is also helpful in preventing neutropenia, with very little loss of efficacy of methotrexate.

Amyloid beta -peptide-binding alcohol dehydrogenase is a component of the cellular response to nutritional stress

Amyloid beta-peptide-binding alcohol dehydrogenase (ABAD) is a member of the family of short chain dehydrogenase/reductases whose distinctive properties include the capacity to bind amyloid beta-peptide and enzymatic activity toward a broad array of substrates including n-isopropanol and beta-estradiol. In view of the wide substrate specificity of ABAD and its high activity on l-beta-hydroxyacyl-CoA derivatives, we asked whether it might also catalyze the oxidation of the ketone body d-3-hydroxybutyrate. This was indeed the case, and oxidation proceeded with K(m) of approximately 4.5 mm and V(max) of approximately 4 nmol/min/mg protein. When placed in medium with d-beta-hydroxybutyrate as the principal energy substrate, COS cells stably transfected to overexpress wild-type ABAD (COS/wtABAD) better maintained 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide reduction, cellular energy charge, and morphologic phenotype compared with COS/vector cells. Using a severe model of metabolic perturbation, transgenic mice with targeted neuronal expression of ABAD subjected to transient middle cerebral artery occlusion showed strokes of smaller volume and lower neurologic deficit scores in parallel with increased brain ATP and decreased lactate, compared with nontransgenic controls. These data suggest that ABAD contributes to the protective response to metabolic stress, especially in the setting of ischemia.

The tolerability of efavirenz after nevirapine-related adverse events

Eight patients who were infected with human immunodeficiency virus, and who had each sustained an adverse drug reaction while following a regimen including nevirapine, were switched to a regimen including efavirenz. None of the patients experienced adverse events identical to that which necessitated discontinuation of nevirapine. This study demonstrates that adverse events related to nevirapine are not a class-specific effect.

Electrophysiological evidence for fast visual processing through the human koniocellular pathway when stimuli move

There is increasing evidence from cellular recordings in primates and behavioral studies in humans that motion can be processed by other than the magnocellular (M) pathway and the cortical dorsal stream. Little is known about cortical processing of moving stimuli when the information is conveyed by the third retinogeniculocortical pathway - the so-called koniocellular (K) pathway. We addressed this issue in humans by studying the spatio-temporal dynamics of the brain electrical fields evoked by tritan (S-cone isolating) and luminance-defined moving stimuli. Tritan and luminance stimuli are presumably carried by the K and M pathways respectively. We found two time intervals where significant stimulus-specific electric fields were evoked: an early period between 40 and 75 ms after stimulus onset, and a later period between 175 and 240 ms. Some of these fields were identical for tritanand luminance-motion, suggesting that the processing of moving stimuli share common cortical substrates when mediated via K and M pathway input. However, tritan-motion stimuli also evoked unique electric fields that appeared earlier in time than the common motion-specific fields, indicating very fast activation of cortical areas specific to input through the K pathway. A distributed source localization procedure revealed simultaneous activation of striate and extrastriate areas even at the early processing stages, strongly suggesting a very fast activation of the visual cerebral network.

Personal constructs of male survivors of childhood sexual abuse receiving cognitive analytic therapy

OBJECTIVE

This study assessed whether male survivors of sexual abuse identified with their abusers rather than their child- or victim-selves and failed to identify with men in general or with their victims, following abusive 'acting out'. Changes in both identification and symptomatology were assessed following cognitive analytic therapy.

DESIGN

A patient series within-participants design was used.

METHOD

A repertory grid methodology examined four male survivors self-construals before and after therapy. Measures of symptomatic distress, depression, self-esteem and distorted beliefs related to childhood sexual abuse were also obtained.

RESULTS

Before therapy, patients showed little identification with the child-selves, men in general and ideal-selves. Two heterosexual patients identified with their abuser(s) whereas another, homosexual, patient negatively identified with his abuser. Patients did not identify with their victims following aggressive 'acting out'. After therapy, identification with the abuser reduced markedly; identification with victim- and ideal-self increased. Depression and distorted beliefs declined.

CONCLUSION

Male survivors tend to identify with abusers and disavow their victim-hood. Sexual orientation may predict identification patterns. Cognitive analytic therapy may be a promising method of enabling survivors to integrate their abuse experience and reduce their commitment to the abuser role.

Arginine methylation inhibits the binding of proline-rich ligands to Src homology 3, but not WW, domains

Src homology 3 (SH3) and WW domains are known to associate with proline-rich motifs within their respective ligands. Here we demonstrate that the proposed adapter protein for Src kinases, Sam68, is a ligand whose proline-rich motifs interact with the SH3 domains of p59(fyn) and phospholipase Cgamma-1 as well as with the WW domains of FBP30 and FBP21. These proline-rich motifs, in turn, are flanked by RG repeats that represent targets for the type I protein arginine N-methyltransferase. The asymmetrical dimethylation of arginine residues within these RG repeats dramatically reduces the binding of the SH3 domains of p59(fyn) and phospholipase Cgamma-1, but has no effect on their binding to the WW domain of FBP30. These results suggest that protein arginine methylation can selectively modulate certain protein-protein interactions and that mechanisms exist for the irreversible regulation of SH3 domain-mediated interactions.

Reconstructing historical radionuclide concentrations along the east coast of Ireland using a compartmental model

A mathematical model is presented that simulates the annually averaged transport of radionuclides, originating from the BNFL reprocessing plant at Sellafield, throughout the Irish Sea. The model, CUMBRIA77, represents the processes of radionuclide transport and dispersion in the marine environment and allows predictions of radionuclide concentration in various environmental media, including biota, to be made throughout the whole of the Irish Sea. In this paper we describe the use of the model to reconstruct the historical activity concentrations of 137Cs and 239+240Pu in a variety of environmental media in the western Irish Sea and along the Irish east coast back to 1950. This reconstruction exercise is of interest because only limited measurements of 137Cs and 239+240Pu activity are available prior to the 1980s. The predictions were compared to the available measured data to validate their accuracy. The results of the reconstruction indicate that activity concentrations of 137Cs in the western Irish Sea follow a similar, though slightly delayed and smoothed, profile to the discharges from the Sellafield site, with concentrations at the time of peak discharge (the mid-1970s) being around an order of magnitude higher than those measured in the 1980s and 1990s. By contrast, the concentrations of 239+240Pu at the time of peak discharges were similar to those presently measured. These differences reflect the distinct marine chemistries of the two nuclides, in particular the higher propensity of plutonium to bind to sediments leading to extended transport times. Despite these differences in behaviour the doses to Irish seafood consumers from 137Cs remain significantly higher than those from 239+240Pu.

Auditory agnosia and auditory spatial deficits following left hemispheric lesions: evidence for distinct processing pathways

Auditory recognition and auditory spatial functions were studied in four patients with circumscribed left hemispheric lesions. Patient FD was severely deficient in recognition of environmental sounds but normal in auditory localisation and auditory motion perception. The lesion included the left superior, middle and inferior temporal gyri and lateral auditory areas (as identified in previous anatomical studies), but spared Heschl's gyrus, the acoustic radiation and the thalamus. Patient SD had the same profile as FD, with deficient recognition of environmental sounds but normal auditory localisation and motion perception. The lesion comprised the postero-inferior part of the frontal convexity and the anterior third of the temporal lobe; data from non-human primates indicate that the latter are interconnected with lateral auditory areas. Patient MA was deficient in recognition of environmental sounds, auditory localisation and auditory motion perception, confirming that auditory spatial functions can be disturbed by left unilateral damage; the lesion involved the supratemporal region as well as the temporal, postero-inferior frontal and antero-inferior parietal convexities. Patient CZ was severely deficient in auditory motion perception and partially deficient in auditory localisation, but normal in recognition of environmental sounds; the lesion involved large parts of the parieto-frontal convexity and the supratemporal region. We propose that auditory information is processed in the human auditory cortex along two distinct pathways, one lateral devoted to auditory recognition and one medial and posterior devoted to auditory spatial functions.

Late onset hepatitis and prolonged deterioration in hepatic function associated with nevirapine therapy

The aetiology of hepatic dysfunction in patients with HIV infection is multifactorial. Re-activation of hepatitis C infection, drug toxicity, and opportunistic infections are all potential causes. Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor used as part of combination antiretroviral therapy for the treatment of HIV infection. It is associated with a significant incidence of hepatotoxicity, usually occurring in the initial month of therapy. We report the case of a 49-year-old man who developed NVP-induced prolonged hepatotoxicity 5 months after commencing antiretroviral therapy.

Interhemispheric transfer of visual motion information after a posterior callosal lesion: a neuropsychological and fMRI study

Interhemispheric transfer of visual information was investigated behaviourally and with functional magnetic resonance imaging (fMRI) 6 months after a lesion of the posterior two-thirds of the corpus callosum. On tachistoscopical left hemifield presentation, the patient was severely impaired in reading letters, words and geographical names and moderately impaired in naming pictures and colours. In contrast, interhemispheric transfer of visual motion information, tested by verbal report of the direction of short sequences of coherent dot motion presented within the left hemifield, was preserved. The pattern of cerebral activation elicited by apparent motion stimuli was studied with fMRI and compared to that of normal subjects. In normal subjects, apparent motion stimuli, as compared to darkness, activated strongly striate and extrastriate cortex. When presented to one hemifield only, the contralateral calcarine region was activated while regions on the occipital convexity, including putative area V5, were activated bilaterally. A similar activation pattern was found in the patient with a posterior callosal lesion; unilateral left or right hemifield stimulation was accompanied by activation in the contralateral and ipsilateral occipital convexity. Ipsilateral hemifield representation in the extrastriate visual cortex is believed to depend on callosal input. Our observation suggests that this is not the case for visual motion representation and that other, probably parallel, pathways may mediate visual motion transfer after posterior callosotomy.

PRMT1 is the predominant type I protein arginine methyltransferase in mammalian cells

Type I protein arginine methyltransferases catalyze the formation of asymmetric omega-N(G),N(G)-dimethylarginine residues by transferring methyl groups from S-adenosyl-L-methionine to guanidino groups of arginine residues in a variety of eucaryotic proteins. The predominant type I enzyme activity is found in mammalian cells as a high molecular weight complex (300-400 kDa). In a previous study, this protein arginine methyltransferase activity was identified as an additional activity of 10-formyltetrahydrofolate dehydrogenase (FDH) protein. However, immunodepletion of FDH activity in RAT1 cells and in murine tissue extracts with antibody to FDH does not diminish type I methyltransferase activity toward the methyl-accepting substrates glutathione S-transferase fibrillarin glycine arginine domain fusion protein or heterogeneous nuclear ribonucleoprotein A1. Similarly, immunodepletion with anti-FDH antibody does not remove the endogenous methylating activity for hypomethylated proteins present in extracts from adenosine dialdehyde-treated RAT1 cells. In contrast, anti-PRMT1 antibody can remove PRMT1 activity from RAT1 extracts, murine tissue extracts, and purified rat liver FDH preparations. Tissue extracts from FDH(+/+), FDH(+/-), and FDH(-/-) mice have similar protein arginine methyltransferase activities but high, intermediate, and undetectable FDH activities, respectively. Recombinant glutathione S-transferase-PRMT1, but not purified FDH, can be cross-linked to the methyl-donor substrate S-adenosyl-L-methionine. We conclude that PRMT1 contributes the major type I protein arginine methyltransferase enzyme activity present in mammalian cells and tissues.

Fibrinogen Longmont: a dysfibrinogenemia that causes prolonged clot-based test results only when using an optical detection method

A new fibrinogen variant was discovered as a result of discrepancies found in routine laboratory screening. The patient, a healthy 37-year-old woman, had a mild bleeding history. Initial coagulation studies on the patient revealed a prolonged prothrombin time (PT) and a normal activated partial thromboplastin time (APTT). Further investigation on the patient and her mother demonstrated both had a PT with no end point using an optical detection method (ACL3000+) and a normal PT using an electromechanical detection method (ST4 Clot Detection System). The APTT for both the patient and her mother were essentially normal with both optical and mechanical detection methods. The patient and her mother also had markedly prolonged thrombin time and reptilase time results on the ACL3000+, but they were normal on the ST4. Coagulation test results on the patient's father were all normal. We believe the fibrinogen defect in this family may affect fibrin polymerization only enough to effect light scatter interpretation, while there is enough polymerization to increase plasma viscosity and yield an end point using an electromechanical analyzer. This report should alert pathologists and clinicians to possible discrepancies between mechanical and spectrophotometric clot testing methods.