The genome of black cottonwood, Populus trichocarpa (Torr. & Gray)

We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. More than 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event; about 8000 pairs of duplicated genes from that event survived in the Populus genome. A second, older duplication event is indistinguishably coincident with the divergence of the Populus and Arabidopsis lineages. Nucleotide substitution, tandem gene duplication, and gross chromosomal rearrangement appear to proceed substantially more slowly in Populus than in Arabidopsis. Populus has more protein-coding genes than Arabidopsis, ranging on average from 1.4 to 1.6 putative Populus homologs for each Arabidopsis gene. However, the relative frequency of protein domains in the two genomes is similar. Overrepresented exceptions in Populus include genes associated with lignocellulosic wall biosynthesis, meristem development, disease resistance, and metabolite transport.

Relation of cerebral vasospasm to subarachnoid hemorrhage visualized by computerized tomographic scanning

In 47 cases of verified ruptured saccular aneurysm, we investigated the relationship of the amount and distribution of subarachnoid blood detected by computerized tomography to the later development of cerebral vasospasm. When the subarachnoid blood was not detected or was distributed diffusely, severe vasospasm was almost never encounters (1 of 18 cases). In the presence of subarachnoid blood clots larger than 5 X 3 mm (measured on the reproduced images) or layers of blood 1 mm or more thick in fissures and vertical cisterns, severe spasm followed almost invariably (23 of 24 cases). There was an almost exact correspondence between the site of the major subarachnoid blood clots and the location of severe vasospasm. Every patient with severe vasospasm manifested delayed symptoms and signs. Excellent correlation existed between the particular artery in vasospasm and the delayed clinical syndrome. Severe vasospasm involved the anterior cerebral artery in 20 cases and the middle cerebral artery in only 14. As the grading system used is partly subjective, the findings should be regarded as preliminary. The results, if confirmed, indicate that blood localized in the subarachnoid space in sufficient amount at specific sites is the only important etiological factor in vasospasm. It should be possible to identify patients in jeopardy from vasospasm and institute early preventive measures. (Neurosurgery, 6: 1--9, 1980)

Decrease in reelin and glutamic acid decarboxylase67 (GAD67) expression in schizophrenia and bipolar disorder: a postmortem brain study

BACKGROUND

Reelin (RELN) is a glycoprotein secreted preferentially by cortical gamma-aminobutyric acid-ergic (GABAergic) interneurons (layers I and II) that binds to integrin receptors located on dendritic spines of pyramidal neurons or on GABAergic interneurons of layers III through V expressing the disabled-1 gene product (DAB1), a cytosolic adaptor protein that mediates RELN action. To replicate earlier findings that RELN and glutamic acid decarboxylase (GAD)(67), but not DAB1 expression, are down-regulated in schizophrenic brains, and to verify whether other psychiatric disorders express similar deficits, we analyzed, blind, an entirely new cohort of 60 postmortem brains, including equal numbers of patients matched for schizophrenia, unipolar depression, and bipolar disorder with nonpsychiatric subjects.

METHODS

Reelin, GAD(65), GAD(67), DAB1, and neuron-specific-enolase messenger RNAs (mRNAs) and respective proteins were measured with quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) or Western blot analyses. Reelin-positive neurons were identified by immunohistochemistry using a monoclonal antibody.

RESULTS

Prefrontal cortex and cerebellar expression of RELN mRNA, GAD(67) protein and mRNA, and prefrontal cortex RELN-positive cells was significantly decreased by 30% to 50% in patients with schizophrenia or bipolar disorder with psychosis, but not in those with unipolar depression without psychosis when compared with nonpsychiatric subjects. Group differences were absent for DAB1,GAD(65) and neuron-specific-enolase expression implying that RELN and GAD(67) down-regulations were unrelated to neuronal damage. Reelin and GAD(67) were also unrelated to postmortem intervals, dose, duration, or presence of antipsychotic medication.

CONCLUSIONS

The selective down-regulation of RELN and GAD(67) in prefrontal cortex of patients with schizophrenia and bipolar disorder who have psychosis is consistent with the hypothesis that these parameters are vulnerability factors in psychosis; this plus the loss of the correlation between these 2 parameters that exists in nonpsychotic subjects support the hypothesis that these changes may be liability factors underlying psychosis.

Development of an ASAS-endorsed disease activity score (ASDAS) in patients with ankylosing spondylitis

OBJECTIVES

To develop a new index for disease activity in ankylosing spondylitis (ASDAS) that is truthful, discriminative and feasible, and includes domains/items that are considered relevant by patients and doctors.

METHODS

Eleven candidate variables covering six domains of disease activity, selected by ASAS experts in a Delphi exercise, were tested in a three-step approach, similar to the methodology used for the disease activity score in rheumatoid arthritis. Data on 708 patients included in ISSAS (International Study on Starting tumour necrosis factor blocking agents in Ankylosing Spondylitis) were used. Cross validation was carried out in the OASIS cohort (Outcome in Ankylosing Spondylitis International Study).

RESULTS

Principal component analysis disclosed three factors with eigenvalues >0.75: patient assessments, peripheral joint assessments and acute phase reactants. Discriminant function analysis resulted in a correct classification in approximately 72% of the cases (prior probability approximately 50%). Regression analysis resulted in an index with five variables (total back pain, patient global assessment, duration of morning stiffness, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR)). Three additional candidate indices were designed using similar methodology while omitting either ESR or CRP or patient global assessment. All four scores correlated with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI; r = 0.67-0.80), patient (0.58-0.75) and physician's global assessment (0.41-0.48) of disease activity. All four candidate ASDAS indices performed better than BASDAI or single-item variables in discriminating between high and low disease activity state, according to doctors as well as patients in the OASIS cohort.

CONCLUSION

The first steps in the development of a new assessment tool of disease activity in AS derived four candidate indices with good face and construct validity, and high discriminant capacity.

The development of Assessment of SpondyloArthritis international Society classification criteria for axial spondyloarthritis (part I): classification of paper patients by expert opinion including uncertainty appraisal

OBJECTIVE

Non-radiographic axial spondyloarthritis (SpA) is characterised by a lack of definitive radiographic sacroiliitis and is considered an early stage of ankylosing spondylitis. The objective of this study was to develop candidate classification criteria for axial SpA that include patients with but also without radiographic sacroiliitis.

METHODS

Seventy-one patients with possible axial SpA, most of whom were lacking definite radiographic sacroiliitis, were reviewed as "paper patients" by 20 experts from the Assessment of SpondyloArthritis international Society (ASAS). Unequivocally classifiable patients were identified based on the aggregate expert opinion in conjunction with the expert-reported level of certainty of their judgement. Draft criteria for axial SpA were formulated and tested using classifiable patients.

RESULTS

Active sacroiliitis on magnetic resonance imaging (MRI) (odds ratio 45, 95% CI 5.3 to 383; p<0.001) was strongly associated with the classification of axial SpA. The knowledge of MRI findings led to a change in the classification of 21.1% of patients. According to the first set of candidate criteria (sensitivity 97.1%; specificity 94.7%) a patient with chronic back pain is classified as axial SpA in the presence of sacroiliitis by MRI or x rays in conjunction with one SpA feature or, if sacroilitiis is absent, in the presence of at least three SpA features. In a second set of candidate criteria, inflammatory back pain is obligatory in the clinical arm (sensitivity 86.1%; specificity 94.7%).

CONCLUSION

The ASAS group has developed candidate criteria for the classification of axial SpA that include patients without radiographic sacroiliitis. The candidate criteria need to be validated in an independent international study.

The Altman Self-Rating Mania Scale

We report on the development, reliability, and validity of the Altman Self-Rating Mania Scale (ASRM). The ASRM was completed during medication washout and after treatment by 22 schizophrenic, 13 schizoaffective, 36 depressed, and 34 manic patients. The Clinician-Administered Rating Scale for Mania (CARS-M) and Mania Rating Scale (MRS) were completed at the same time to measure concurrent validity. Test-retest reliability was assessed separately on 20 depressed and 10 manic patients who completed the ASRM twice during washout. Principal components analysis of ASRM items revealed three factors: mania, psychotic symptoms, and irritability. Baseline mania subscale scores were significantly higher for manic patients compared to all other diagnostic groups. Manic patients had significantly decreased posttreatment scores for all three subscales. ASRM mania subscale scores were significantly correlated with MRS total scores (r = .718) and CARS-M mania subscale scores (r = .766). Test-retest reliability for the ASRM was significant for all three subscales. Significant differences in severity levels were found for some symptoms between patient ratings on the ASRM and clinician ratings on the CARS-M. Mania subscale scores of greater than 5 on the ASRM resulted in values of 85.5% for sensitivity and 87.3% for specificity. Advantages of the ASRM over other self-rating mania scales are discussed.

The effects of risperidone on the five dimensions of schizophrenia derived by factor analysis: combined results of the North American trials

BACKGROUND

In two double-blind trials conducted in North America, 513 patients with chronic schizophrenia received risperidone, haloperidol, or placebo. In the present study, combined data from the two trials were analyzed.

METHOD

Patients were randomly assigned to receive placebo, fixed doses of risperidone (2, 6, 10, and 16 mg/day) or 20 mg/day of haloperidol for 8 weeks. Factor analysis of scores on the Positive and Negative Syndrome Scale (PANSS) produced five dimensions (negative symptoms, positive symptoms, disorganized thought, uncontrolled hostility/excitement, and anxiety/depression), similar to the five dimensions of previous factor-analytic studies of PANSS data.

RESULTS

Mean changes (symptom reductions) in PANSS factor scores from baseline to treatment Weeks 6 and 8 were significantly greater in patients receiving 6-16 mg/day of risperidone than in patients receiving placebo or haloperidol. The advantages of risperidone were greatest for negative symptoms, uncontrolled hostility/excitement, and anxiety/depression. Even at the lowest dose, 2 mg/day, risperidone was significantly (p < or = .05) superior to haloperidol in reducing negative symptoms. The differences in outcomes between risperidone and haloperidol on PANSS scores were not related to extrapyramidal symptoms.

CONCLUSION

Risperidone produced significantly (p < or = .05) greater improvements than haloperidol on all five dimensions. The large between-group differences on negative symptoms, hostility/excitement, and anxiety/depression suggest that risperidone and other serotonin/dopamine antagonists have qualitatively different effects from those of conventional antipsychotic agents.

Increase in the cerebrospinal fluid content of neurosteroids in patients with unipolar major depression who are receiving fluoxetine or fluvoxamine

We recently reported that fluoxetine or paroxetine, two selective serotonin reuptake inhibitors (SSRIs), when administered to rats, increase the brain content of the neurosteroid 3alpha-hydroxy-5alpha-pregnane-20-one (3alpha5alpha-ALLO) without altering the brain content of other neurosteroids. ALLO (3alpha5alpha and 3alpha5beta isomers) binds with high affinity to various gamma-aminobutyric acid (GABA) receptor A subtypes and facilitates the action of GABA at these receptors. We hypothesized that the increase of ALLO brain content induced by treatment with SSRIs could contribute to alleviating the anxiety and dysphoria associated with the symptomatology of major unipolar depression. We measured ALLO content in four cisternal-lumbar fractions of cerebrospinal fluid (CSF) before and 8-10 weeks after treatment with fluoxetine or fluvoxamine in 15 patients with unipolar major depression. The concentration of ALLO ( approximately 40 fmol/ml in each CSF fraction of three control subjects) was about 60% lower in patients with major unipolar depression. However, in the same patients, fluoxetine or fluvoxamine treatment normalized the CSF ALLO content. Moreover, a statistically significant correlation (r = 0.58; P < 0.023; n = 15) existed between symptomatology improvement (Hamilton Rating Scale for Depression scores) and the increase in CSF ALLO after fluoxetine or fluvoxamine treatment. The CSF content of PREG and PROG remained unaltered after treatment and failed to correlate with the SSRI-induced increase of CSF ALLO. The normalization of CSF ALLO content in depressed patients appears to be sufficient to mediate the anxiolytic and antidysphoric actions of fluoxetine or fluvoxamine via its positive allosteric modulation of GABA type A receptors.

A decrease of reelin expression as a putative vulnerability factor in schizophrenia

Postmortem prefrontal cortices (PFC) (Brodmann's areas 10 and 46), temporal cortices (Brodmann's area 22), hippocampi, caudate nuclei, and cerebella of schizophrenia patients and their matched nonpsychiatric subjects were compared for reelin (RELN) mRNA and reelin (RELN) protein content. In all of the brain areas studied, RELN and its mRNA were significantly reduced (approximately 50%) in patients with schizophrenia; this decrease was similar in patients affected by undifferentiated or paranoid schizophrenia. To exclude possible artifacts caused by postmortem mRNA degradation, we measured the mRNAs in the same PFC extracts from gamma-aminobutyric acid (GABA)A receptors alpha1 and alpha5 and nicotinic acetylcholine receptor alpha7 subunits. Whereas the expression of the alpha7 nicotinic acetylcholine receptor subunit was normal, that of the alpha1 and alpha5 receptor subunits of GABAA was increased when schizophrenia was present. RELN mRNA was preferentially expressed in GABAergic interneurons of PFC, temporal cortex, hippocampus, and glutamatergic granule cells of cerebellum. A protein putatively functioning as an intracellular target for the signal-transduction cascade triggered by RELN protein released into the extracellular matrix is termed mouse disabled-1 (DAB1) and is expressed at comparable levels in the neuroplasm of the PFC and hippocampal pyramidal neurons, cerebellar Purkinje neurons of schizophrenia patients, and nonpsychiatric subjects; these three types of neurons do not express RELN protein. In the same samples of temporal cortex, we found a decrease in RELN protein of approximately 50% but no changes in DAB1 protein expression. We also observed a large (up to 70%) decrease of GAD67 but only a small decrease of GAD65 protein content. These findings are interpreted within a neurodevelopmental/vulnerability "two-hit" model for the etiology of schizophrenia.

Sapphyrins: versatile anion binding agents

Sapphyrin was the first expanded porphyrin to be reported in the literature and remains among the most extensively studied. Much of the interest in this macrocycle reflects its ability to bind anions, a phenomenon that has been examined in solution and in the solid state by a wide range of experimental techniques. In this Account, we summarize these studies while also outlining strategies that may be used to synthesize sapphyrins.

Vitamin E protects nerve cells from amyloid beta protein toxicity

The amyloid beta protein (ABP) is a 40 to 42 amino acid peptide which accumulates in Alzheimer's disease plaques. It has been demonstrated that this peptide and a fragment derived from it are cytotoxic for cultured cortical nerve cells. It is shown here that ABP and an internal fragment encompassing residues 25 to 35 (beta 25-35) are cytotoxic to a clone of PC12 cells at concentrations above 1 x 10(-9)M and to several other cell lines at higher concentrations. Between 10(-9) and 10(-11) M beta 25-35 protects PC12 cells from glutamate toxicity. The antioxidant and free radical scavenger vitamin E inhibits ABP induced cell death. These results have implications regarding the prevention and treatment of Alzheimer's disease.

Safety and immunogenicity in man of a synthetic peptide malaria vaccine against Plasmodium falciparum sporozoites

A 12 amino-acid synthetic peptide (NANP)3 comprising the immunodominant epitope of Plasmodium falciparum circumsporozoite protein was conjugated to tetanus toxoid (TT), adjuvanted with aluminium hydroxide, and administered intramuscularly in three doses at monthly intervals to 35 healthy males as a malaria vaccine. No significant adverse reactions were noted, with mild soreness at the injection site the only common symptom. Seroconversions against NANP occurred in 53% and 71% of recipients of 100 or 160 micrograms, respectively, measured by enzyme-linked immunosorbent assay (ELISA). Most ELISA-positive sera reacted with sporozoites by indirect immunofluorescence (IFA). Three vaccinees with the highest ELISA and IFA titres and four unimmunized controls were challenged with P. falciparum sporozoites introduced via the bites of infective Anopheles mosquitoes. Blood stage parasites were detected in all controls by 10 days (mean 8.5 days, range 7-10). In contrast, the two vaccinees who became infected did not manifest parasitaemia until day 11 and the third vacinee showed neither parasites nor symptoms during the 29 day observation period. This first synthetic peptide parenteral vaccine against a communicable disease tested in man is safe and stimulates biologically active antibodies. These observations encourage the development of improved vaccine formulations which, by enhancing immunogenicity, may lead to practical vaccines to assist in the control of falciparum malaria.

Visual cortical mechanisms detecting focal orientation discontinuities

Neurons in the primary visual cortex (V1) respond in well defined ways to stimuli within their classical receptive field, but these responses can be modified by stimuli overlying the surrounding area. For example patch-suppressed cells respond to gratings of a specific orientation within their classical receptive field, but the response diminishes if the grating is expanded to cover the surrounding area. We report here more complex effects in many such cells. When stimulated at their optimal orientation, introducing a surrounding field at a significantly different (for example, orthogonal) orientation enhanced their output by both a disinhibitory mechanism and an active facilitatory mechanism producing 'supra-optimal' responses. Importantly, some cells responded well if the orientations of centre and surround stimuli were swapped. The output reflected the discontinuity because neither stimulus component alone was effective. Under these stimulus conditions simultaneously recorded cells with orthogonally oriented receptive fields showed correlated firing consistent with neuronal binding to the configuration. We propose a mechanism integrating orientation-dependent information over adjacent areas of visual space to represent focal orientation discontinuities such as junctions or corners.

Bulimia. Its incidence and clinical importance in patients with anorexia nervosa

Among the various eating patterns encountered in anorexia nervosa, the occurrence of bulimia (rapid consumption of large amounts of food in a short period of time) is a perplexing phenomenon, because its presence contradicts the common belief that patients with anorexia nervosa are always firm in their abstinence from food. We studied the eating habits of 105 hospitalized female patients within the context of a prospective treatment study on anorexia nervosa: 53% had achieved weight loss by consistently fasting, whereas 47% periodically resorted to bulimia. The two groups were contrasted with regard to their developmental and psychosocial history, clinical characteristics, and psychiatric symptomatology. Fasting patients were more introverted, more often denied hunger, and displayed little overt psychic distress. In contrast, bulimic patients were more extroverted, admitted more frequently to a strong appetite and tended to be older. Vomiting was frequent, and kleptomania almost exclusively present in bulimic patients, who manifested greater anxiety, depression, guilt, interpersonal sensitivity, and had more somatic complaints. This association of bulimia with certain personality features and a distinct psychiatric symptomatology suggests that patients with bulimia form a subgroup among patients with anorexia nervosa.

Consensus statement on the live organ donor

OBJECTIVE

To recommend practice guidelines for transplant physicians, primary care providers, health care planners, and all those who are concerned about the well-being of the live organ donor.

PARTICIPANTS

An executive group representing the National Kidney Foundation, and the American Societies of Transplantation, Transplant Surgeons, and Nephrology formed a steering committee of 12 members to evaluate current practices of living donor transplantation of the kidney, pancreas, liver, intestine, and lung. The steering committee subsequently assembled more than 100 representatives of the transplant community (physicians, nurses, ethicists, psychologists, lawyers, scientists, social workers, transplant recipients, and living donors) at a national conference held June 1-2, 2000, in Kansas City, Mo.

CONSENSUS PROCESS

Attendees participated in 7 assigned work groups. Three were organ specific (lung, liver, and kidney) and 4 were focused on social and ethical concerns (informed consent, donor source, psychosocial issues, and live organ donor registry). Work groups' deliberations were structured by a series of questions developed by the steering committee. Each work group presented its deliberations to an open plenary session of all attendees. This information was stored and shaped into a statement circulated electronically to all attendees for their comments, and finally approved by the steering committee for publication. The term consensus is not meant to convey universal agreement of the participants. The statement identifies issues of controversy; however, the wording of the entire statement is a consensus by approval of all attendees.

CONCLUSION

The person who gives consent to be a live organ donor should be competent, willing to donate, free from coercion, medically and psychosocially suitable, fully informed of the risks and benefits as a donor, and fully informed of the risks, benefits, and alternative treatment available to the recipient. The benefits to both donor and recipient must outweigh the risks associated with the donation and transplantation of the living donor organ.

Possible mechanisms of central nervous system fatigue during exercise

Fatigue of voluntary muscular effort is a complex phenomenon. To date, relatively little attention has been placed on the role of the central nervous system (CNS) in fatigue during exercise despite the fact that the unwillingness to generate and maintain adequate CNS drive to the working muscle is the most likely explanation of fatigue for most people during normal activities. Several biological mechanisms have been proposed to explain CNS fatigue. Hypotheses have been developed for several neurotransmitters including serotonin (5-HT; 5-hydroxytryptamine), dopamine, and acetylcholine. The most prominent one involves an increase in 5-HT activity in various brain regions. Good evidence suggests that increases and decreases in brain 5-HT activity during prolonged exercise hasten and delay fatigue, respectively, and nutritional manipulations designed to attenuate brain 5-HT synthesis during prolonged exercise improve endurance performance. Other neuromodulators that may influence fatigue during exercise include cytokines and ammonia. Increases in several cytokines have been associated with reduced exercise tolerance associated with acute viral or bacterial infection. Accumulation of ammonia in the blood and brain during exercise could also negatively effect the CNS function and fatigue. Clearly fatigue during prolonged exercise is influenced by multiple CNS and peripheral factors. Further elucidation of how CNS influences affect fatigue is relevant for achieving optimal muscular performance in athletics as well as everyday life.

How effective are second-generation antipsychotic drugs? A meta-analysis of placebo-controlled trials

We conducted a systematic review and meta-analysis of randomized controlled trials that compared second-generation antipsychotic (SGA) drugs with placebo in schizophrenic patients and which considered 13 different outcome measures. Thirty-eight randomized controlled trials with 7323 participants were included. All SGA drugs were more effective than placebo, but the pooled effect size (ES) for overall symptoms (primary outcome) was moderate (-0.51). The absolute difference (RD) in responder rates was at 18% (41% responded to drug compared with 24% to placebo, number needed to treat=6). Similar ESs were found for the other efficacy parameters: negative symptoms (ES=-0.39), positive symptoms (ES=-0.48), depression (ES=-0.26), relapse (RD 20%) and discontinuation due to inefficacy (RD 17%). Curiously, the efficacy of haloperidol for negative and depressive symptoms was similar to that of the SGA drugs. In contrast to haloperidol, there was no difference in terms of EPS between any SGA drugs and placebo, and there was also no difference in terms of dropouts due to adverse events. Meta-regression showed a decline in treatment response over time, and a funnel plot suggested the possibility of publication bias. We conclude that the drug versus placebo difference of SGA drugs and haloperidol in recent trials was moderate, and that there is much room for more efficacious compounds. Whether methodological issues account in part for the relatively low efficacy ESs and the scarcity of adverse event differences compared with placebo needs to be established.

Ankyrin and spectrin associate with voltage-dependent sodium channels in brain

The segregation of voltage-dependent sodium channels to specialized regions of the neuron is crucial for propagation of an action potential. Studies of their lateral mobility indicate that sodium channels are freely mobile on the neuronal cell body but are immobile at the axon hillock, presynaptic terminal and at focal points along the axon. To elucidate the mechanisms that regulate sodium channel topography and mobility, we searched for specific proteins from the brain that associate with sodium channels. Here we show that sodium channels labelled with 3H-saxitoxin (STX) are precipitated in the presence of exogenous brain ankyrin by anti-ankyrin antibodies and that 125I-labelled ankyrin binds with high affinity to sodium channels reconstituted into lipid vesicles. The cytoplasmic domain of the erythrocyte anion transporter competes for the latter interaction. Neither the neuronal GABA (gamma-aminobutyric acid) receptor channel complex nor the dihydropyridine (DHP) receptor bind brain ankyrin. The results indicate that brain ankyrin links the voltage-dependent sodium channel to the underlying cytoskeleton and may help to maintain axolemmal membrane heterogeneity and control sodium channel mobility.

Comparative doses and costs of antipsychotic medication

It is clinically useful to have a table listing the equivalent doses of the various neuroleptics to a standard, such as chlorpromazine. This article derives such data by reviewing double-blind controlled studies that used a flexible dosage schedule of neuroleptics in treating schizophrenic patients. Each neuroleptic is then converted to 100-mg chlorpromazine equivalents. This empirically derived dosage comparability table is compared with a similar table derived from the opinions of experts. Since these comparable doses produce equivalent amounts of antipsychotic activity, the cost to provide such medication was then calculated, and a table comparing the costs of the different neuroleptics was constructed. In absolute amounts, the cost differences between drugs are small. However, for any drug, large savings accrue when the largest possible capsule or tablet to achieve the desired dose is prescribed.

Brain spectrin, a membrane-associated protein related in structure and function to erythrocyte spectrin

An immunoreactive analogue of erythrocyte spectrin has been purified from brain membranes. This protein co-sediments with and cross-links actin filaments, associates with spectrin-binding sites on erythrocyte membranes, and has been visualized by rotary shadowing as an extended, flexible rod. The brain spectrin comprises 3% of the total membrane protein, and may have a major role in mediating linkage of actin to membranes.

A vector for expressing foreign genes in the brains and hearts of transgenic mice

An expression plasmid (MoPrP.Xho), for use in transgenic mice, was developed from the promoter, 5' intronic, and 3' untranslated sequences of the murine prion protein gene. Analyses of mice harboring the MoPrP.Xho construct with cDNA genes encoding the amyloid precursor protein (APP) and human presenilin 1 demonstrated that this vector provides relatively high levels of transgene-encoded polypeptides in brains and hearts of transgenic mice. The MoPrP.Xho vector should be very useful in strategies designed to overexpress a variety of wild-type and disease related mutant transgenes in the heart and brain.

International ASAS consensus statement for the use of anti-tumour necrosis factor agents in patients with ankylosing spondylitis

OBJECTIVE

To obtain an international consensus about the use of anti-tumour necrosis factor alpha (anti-TNF alpha) for treating patients with ankylosing spondylitis (AS).

METHODS

These recommendations were developed by a review of published reports in combination with expert opinion, including a Delphi exercise, and a consensus meeting of the ASsessments in AS (ASAS) Working Group.

RESULTS

The final consensus comprises the following requirements: (1) For the initiation of anti-TNF alpha therapy: (a) a diagnosis of definitive AS; (b) presence of active disease for at least four weeks as defined by both a sustained Bath AS Disease Activity Index (BASDAI) of at least 4 and an expert opinion based on clinical features, acute phase reactants, and imaging modalities; (c) presence of refractory disease defined by failure of at least two non-steroidal anti-inflammatory drugs during a single three month period, failure of intra-articular steroids if indicated, and failure of sulfasalazine in patients with peripheral arthritis; (d) application and implementation of the usual precautions and contraindications for biological therapy. (2) For the monitoring of anti-TNF alpha therapy: both the BASDAI and the ASAS core set for clinical practice should be followed regularly. (3) For the discontinuation of anti-TNF alpha therapy: in non-responders, consideration should be made after 6-12 weeks' treatment. Response is defined as improvement of (a) at least 50% or 2 units (on a 0-10 scale) of the BASDAI, (b) expert opinion that treatment should be continued.

CONCLUSION

This consensus statement on anti-TNF alpha treatment in AS may be used for guidance in clinical decision making and as the basis for the development of guidelines. Evaluation of the healthcare consequences of this consensus is subject to further research by the ASAS group.

Guidelines for the use of cell lines in biomedical research

Cell-line misidentification and contamination with microorganisms, such as mycoplasma, together with instability, both genetic and phenotypic, are among the problems that continue to affect cell culture. Many of these problems are avoidable with the necessary foresight, and these Guidelines have been prepared to provide those new to the field and others engaged in teaching and instruction with the information necessary to increase their awareness of the problems and to enable them to deal with them effectively. The Guidelines cover areas such as development, acquisition, authentication, cryopreservation, transfer of cell lines between laboratories, microbial contamination, characterisation, instability and misidentification. Advice is also given on complying with current legal and ethical requirements when deriving cell lines from human and animal tissues, the selection and maintenance of equipment and how to deal with problems that may arise.