A new antigen receptor gene family that undergoes rearrangement and extensive somatic diversification in sharks

Immunoglobulin and T-cell receptor (TCR) molecules are central to the adaptive immune system. Sequence conservation, similarities in domain structure, and usage of similar recombination signal sequences and recombination machinery indicate that there was probably a time during evolution when an ancestral receptor diverged to the modern-day immunoglobulin and TCR. Other molecules that undergo rearrangement have not been described in vertebrates, nor have intermediates been identified that have features of both these gene families. We report here the isolation of a new member of the immunoglobulin superfamily from the nurse shark, Ginglymostoma cirratum, which contains one variable and five constant domains and is found as a dimer in serum.

A quantitative analysis of the cat retinal ganglion cell topography

A retinal ganglion cell distribution map has been prepared for the cresyl violet stained cat retina. It differs from previously published maps in revealing the visual streak to be more substantial and in showing a higher peak density of 9-10,000 ganglion cells/mm2 at the presumed visual pole. The map was used to obtain a minimum estimate of the retinal ganglion cell population as 217,000 cells, more than double the total previously reported. The problem of classifying the cells of the ganglion cell layer is discussed in detail and examples of criterion cells illustrated. The paper also includes an account of retinal mensuration (dimensions, area, etc.) and a discussion of the visual streak orientation.

A pilot study to explore circulating tumour cells in pancreatic cancer as a novel biomarker

Background:

Obtaining tissue for pancreatic carcinoma diagnosis and biomarker assessment to aid drug development is challenging. Circulating tumour cells (CTCs) may represent a potential biomarker to address these unmet needs. We compared prospectively the utility of two platforms for CTC enumeration and characterisation in pancreatic cancer patients in a pilot exploratory study.

Patients and methods:

Blood samples were obtained prospectively from 54 consenting patients and analysed by CellSearch and isolation by size of epithelial tumour cells (ISET). CellSearch exploits immunomagnetic capture of CTCs-expressing epithelial markers, whereas ISET is a marker independent, blood filtration device. Circulating tumour cell expression of epithelial and mesenchymal markers was assessed to explore any discrepancy in CTC number between the two platforms.

Results:

ISET detected CTCs in more patients than CellSearch (93% vs 40%) and in higher numbers (median CTCs/7.5 ml, 9 (range 0–240) vs 0 (range 0–144)). Heterogeneity observed for epithelial cell adhesion molecule, pan-cytokeratin (CK), E-Cadherin, Vimentin and CK 7 expression in CTCs may account for discrepancy in CTC number between platforms.

Conclusion:

ISET detects more CTCs than CellSearch and offers flexible CTC characterisation with potential to investigate CTC biology and develop biomarkers for pancreatic cancer patient management.

Metabonomics, dietary influences and cultural differences: a 1H NMR-based study of urine samples obtained from healthy British and Swedish subjects

The aim of this study was to assess the feasibility and comparability of metabonomic data in clinical studies conducted in different countries without dietary restriction. A (1)H NMR-based metabonomic analysis was performed on urine samples obtained from two separate studies, both including male and female subjects. The first was on a group of healthy British subjects (n = 120), whilst the second was on healthy subjects from two European countries (Britain and Sweden, n = 30). The subjects were asked to provide single, early morning urine samples collected on a single occasion. The (1)H NMR spectra obtained for urine samples were visually inspected and analysed chemometrically using principal components analysis (PCA). These inspections highlighted outliers within the urine samples and displayed interesting differences, revealing characteristic dietary and cultural features between the subjects of both countries, such as high trimethylamine-N-oxide (TMAO)-excretion in the Swedish population and high taurine-excretion, due to the Atkins diet. This study suggests that the endogenous urinary profile is subject to distinct cultural and severe dietary influences and that great care needs to be taken in the interpretation of 'biomarkers of disease and response to drug therapy' for diagnostic purposes.

What clinical features are most useful to distinguish definite multiple system atrophy from Parkinson's disease?

OBJECTIVES

Few studies have attempted to identify what premortem features best differentiate multiple system atrophy (MSA) from Parkinson's disease (PD). These studies are limited by small sample size, clinical heterogeneity, or lack of postmortem validation. We evaluated the sensitivity and specificity of different clinical features in distinguishing pathologically established MSA from PD.

METHODS

One hundred consecutive cases of pathologically confirmed PD and 38 cases of pathologically confirmed MSA in one Parkinson's disease brain bank were included. All cases had their clinical notes reviewed by one observer (AH). Clinical features were divided into two groups: those occurring up to 5 years after onset of disease and those occurring up to death. Statistical analysis comprised multivariate logistic regression analysis to choose and weight key variables for the optimum predictive model.

RESULTS

The selected early features and their weightings were: autonomic features (2), poor initial levodopa response (2), early motor fluctuations (2), and initial rigidity (2). A cut off of 4 or more on the ROC curve resulted in a sensitivity of 87.1% and specificity of 70.5%. A better predictive model occurred if the following features up to death were included: poor response to levodopa (2), autonomic features (2), speech or bulbar dysfunction (3), absence of dementia (2), absence of levodopa induced confusion (4), and falls (4). The resulting ROC curve based on individual scores showed a best cut off score of at least 11 of 17 (sensitivity 90.3%, specificity 92.6%).

CONCLUSIONS

Predictive models may help differentiate MSA and PD premortem. Hitherto poorly recognised features, suggestive of MSA, included preserved cognitive function and absence of psychiatric effects from antiparkinsonian medication. Diagnostic accuracy was higher in those models taking into account all clinical features occurring up to death. Further studies need to be based on new incident cohorts of parkinsonian patients with subsequent neuropathological evaluation.

Homocysteine and cognitive decline in healthy elderly

Serum homocysteine is increased, and correlates inversely with cognitive scores, in Alzheimer's disease (AD), vascular dementia and "age-associated memory impairment". Elevated levels might signal accelerated cognitive decline, although this remains to be established. We therefore repeated Mini-Mental State Examinations, together with additional ADAS-Cog assessments, in 32 healthy elderly individuals to determine whether prior homocysteine levels predicted cognitive changes over a 5-year period. Homocysteine predicted follow-up cognitive scores and rate of decline in cognitive performance independently of age, sex, education, renal function, vitamin B status, smoking and hypertension (p < 0.001). Homocysteine predicted word recall (p = 0.01), orientation (p = 0.02) and constructional praxis scores (p < 0.0001). One subject, with the second highest initial homocysteine, had developed probable AD at follow-up. Fasting total serum homocysteine appears to be an independent predictor of cognitive decline in healthy elderly and exerts a maximal effect on spatial copying skills.

Population magnitudes and distribution of the major modal classes of cat retinal ganglion cell as estimated from HRP filling and a systematic survey of the soma diameter spectra for classical neurones

A survey of diameter spectra in presented for classic neurones of the cat retinal ganglion cell layer. From these, with the aid of retrograde HRP filling for central retina, a set of density distribution maps has been prepared for each of the major modes of the neuronal diameter spectrum. The total population of classical neurones, the presumed ganglion cells of Hughes ('75), confirms published values with a minimum of some 207,000 comprised 5,600 cells in the alpha mode, 80,700 cells in the beta mode, and 120,700 cells in the gamma mode. A proportion of classical neurones in the gamma mode do not fill by retrograde transport of HRP from either optic nerve or superior colliculus. Their morphology is characteristic and includes a conspicuous basophilic nuclear bar or fold; they remain subsequent to ganglion cell retrograde degeneration and resemble some profiles of the amacrine layer. It is presumed that they represent a class of displaced amacrine cells. Estimates based on ganglion cell identification by HRP filling indicate populations of about 80,000 cells in both the gamma and the beta modes and a total count of about 170,000 ganglion cells; a good agreement with Hughes and Wässle's ('76) optic nerve fibre count, but lower than the classic neurone count. It is concluded that the distribution maps for ganglion cells in each of the three modes of the soma diameter spectra are similar in form and resemble that of the total neurone density map. The ganglion cell population of the gamma mode in the visual streak is not found to increase in proportion relative to that of the beta mode, as has been reported elsewhere.

Identification of a novel genetic locus for familial cardiac myxomas and Carney complex

BACKGROUND

Intracardiac myxomas are significant causes of cardiovascular morbidity and mortality through embolic stroke and heart failure. In the autosomal dominant syndrome Carney complex, intracardiac myxomas arise in the setting of lentiginosis and other lesions associated with cutaneous hyperpigmentation, extracardiac myxomas, and nonmyxomatous tumors. Genetic factors that regulate cardiac tumor growth remain unknown.

METHODS AND RESULTS

We used the molecular genetic techniques of linkage analysis to study 4 kindreds affected by Carney complex to determine the genetic basis of this syndrome. Our investigation confirmed genetic heterogeneity of Carney complex. Moreover, genetic linkage analysis with polymorphic short tandem repeats on the long arm of chromosome 17 revealed maximal pairwise LOD scores of 5.9, 1.5, 1.8, and 2.9 for families YA, YB, YC01, and YC11, respectively. Haplotype analysis excluded a founder effect at this locus. These data identify a major 17 cM locus on chromosome 17q2 that contains the Carney complex disease gene.

CONCLUSIONS

The ultimate identification and analysis of the Carney complex disease gene at this human chromosome 17q2 locus will facilitate diagnosis and treatment of cardiac myxomas and will foster new concepts in regulation of cardiac cell growth and differentiation.

CD40L blockade prevents autoimmune diabetes by induction of bitypic NK/DC regulatory cells

Systemic treatment with antibody to CD40 ligand (aCD40L) can prevent autoimmunity and transplant rejection in several animal models and is currently under evaluation in clinical trials. While it is known that aCD40L administration inhibits expansion and effector functions of aggressive T cells, it is still unclear whether additional regulatory mechanisms are operative. Here we demonstrate that a single episode of CD40L blockade during development of the autoaggressive immune response completely prevented autoimmune disease in the RIP-LCMV mouse model for virally induced type 1 diabetes. Interestingly, protection could be transferred by a highly potent, bitypic cell population sharing phenotypic and functional properties of both natural killer (NK) and dendritic cells (DC). Furthermore, protection of prediabetic recipients was autoantigen specific and did not result in generalized immunosuppression. The origin, function, and therapeutic potential of these bitypic NK/DC regulatory cells is discussed.

A controlled study of education about drug treatment in schizophrenia

BACKGROUND

Various problems are associated with schizophrenia which may theoretically lead to impaired educability about treatment.

METHOD

The Understanding of Medication Questionnaire, designed to measure knowledge about treatment in schizophrenia, is described and presented. An educational programme based on a specially designed information booklet was developed. Sixty-four patients with DSM-III-R diagnosis schizophrenia were randomly allocated to groups receiving none (control), one session or three sessions of education.

RESULTS

Pre-intervention low levels of knowledge about illness and treatment increased significantly immediately after a standard education session. Three education sessions led to significantly greater knowledge gain than one session. There was no significant change in the control group. Only the PANSS negative syndrome score independently and consistently explained a significant proportion of the education effect. The influence on educability of attitudes to education, impaired insight, cognitive impairment and other variables were considered. Three sessions of education led to significantly increased insight, but no change in compliance.

CONCLUSIONS

Techniques appropriate for educating schizophrenic patients were discussed, and the value of involving patients in education emphasised. A series of patient education sessions is needed to consolidate learning, rather than a single informing process. The strong association between impaired learning and more severe negative schizophrenic syndrome emphasises the need for responsible prescribing of antipsychotic treatment in schizophrenia.

Deregulation of EIF4E: a novel mechanism for autism

BACKGROUND

Autism is a common childhood onset neurodevelopmental disorder, characterised by severe and sustained impairment of social interaction and social communication, as well as a notably restricted repertoire of activities and interests. Its aetiology is multifactorial with a strong genetic basis. EIF4E is the rate limiting component of eukaryotic translation initiation, and plays a key role in learning and memory through its control of translation within the synapse. EIF4E mediated translation is the final common process modulated by the mammalian target of rapamycin (mTOR), PTEN and fragile X mental retardation protein (FMRP) pathways, which are implicated in autism. Linkage of autism to the EIF4E region on chromosome 4q has been found in genome wide linkage studies.

METHODS AND RESULTS

The authors present evidence that directly implicates EIF4E in autism. In a boy with classic autism, the authors observed a de novo chromosome translocation between 4q and 5q and mapped the breakpoint site to within a proposed alternative transcript of EIF4E. They then screened 120 autism families for mutations and found two unrelated families where in each case both autistic siblings and one of the parents harboured the same single nucleotide insertion at position -25 in the basal element of the EIF4E promoter. Electrophoretic mobility shift assays and reporter gene studies show that this mutation enhances binding of a nuclear factor and EIF4E promoter activity.

CONCLUSIONS

These observations implicate EIF4E, and more specifically control of EIF4E activity, directly in autism. The findings raise the exciting possibility that pharmacological manipulation of EIF4E may provide therapeutic benefit for those with autism caused by disturbance of the converging pathways controlling EIF4E activity.

Nutrition support improves patient outcomes, treatment tolerance and admission characteristics in oesophageal cancer

AIMS

Patients with oesophageal cancer undergoing chemoradiation with curative intent are at high risk of malnutrition and its complications, including increased side effects of treatment. We have developed a nutrition pathway (NP), involving the early then periodic nutrition assessment of all patients presenting to the multidisciplinary oesophageal clinic who were planned to receive definitive chemoradiation.

MATERIALS AND METHODS

Patients were assessed as at 'low', 'moderate' or 'severe' nutrition risk, and were provided with appropriate nutrition intervention ranging from preventative advice (low risk), oral nutrition support (moderate risk) to enteral feeding (severe risk). Outcomes for 24 patients treated before implementation of the NP were compared with those of 24 patients treated using the NP.

RESULTS

Patients managed using the NP experienced less weight loss (mean weight change -4.2 kg +/-6.4 cf. -8.9 kg +/- 5.9, P = 0.03), greater radiotherapy completion rates (92% cf. 50%, P = 0.001), fewer patients had an unplanned hospital admission (46% cf. 75%, P = 0.04), and those that did had a shorter length of stay (3.2 days +/- 5.4 cf. 13.5 days +/- 14.1, P = 0.002).

CONCLUSION

Early and regular nutrition assessment/intervention and a multidisciplinary approach to nutrition care results in improved treatment tolerance for patients with oesophageal cancer receiving chemoradiation.

The rabbit optic nerve: fibre diameter spectrum, fibre count, and comparison with a retinal ganglion cell count

This electron microscopic study indicates that the rabbit optic nerve contains 394,000 +/- 20,000 (p less than 0.05) nerve fibers, of which at least 98% are myelinated. The fibre diameter spectrum of the nerve is unimodal and ranges from 0.25-7 mum with its peak at 0.75 mum. The projection of the visual streak fibres is not apparent in local diameter spectra near the optic nerve head. Integration of a ganglion cell density map of the retina from another rabbit indicates a total ganglion cell count lying between 455,000 and 547,000. The optic nerve fibre and ganglion cell counts are both substantially greater than the maximum fibre count previously reported.

Randomised controlled trial of oral vitamin A supplementation in preterm infants to prevent chronic lung disease

BACKGROUND

Intramuscular supplementation with vitamin A in large doses may reduce the incidence of chronic lung disease.

AIM

To investigate whether oral supplementation with vitamin A would reduce the incidence of chronic lung disease in a group of extremely low birthweight infants.

METHODS

Infants with birth weight < 1000 g were randomised at birth to receive oral vitamin A supplementation (5000 IU/day) or placebo for 28 days. The primary outcome was oxygen dependency at 28 days of age or death.

RESULTS

A total of 154 infants were randomised; 77 received vitamin A (median birth weight (interquartile range) 806 (710-890) g), and 77 received placebo (median birth weight (interquartile range) 782 (662-880) g). Plasma vitamin A concentrations in the supplemented group were significantly higher at 24 hours of age but did not differ significantly at birth, 12 hours of age, 7 days, or 28 days of life. There were no significant differences in the proportion of infants who survived, required oxygen at 28 days, required oxygen at 36 weeks postmenstrual age, survived without chronic lung disease at 36 weeks, survived without significant retinopathy, or who survived without significant intraventricular haemorrhage.

CONCLUSIONS

Oral supplementation with 5000 IU vitamin A in extremely low birthweight infants does not significantly alter the incidence of chronic lung disease. However, this dose may have been inadequate to achieve optimal serum retinol concentrations.

Evaluation of the role of RANK and OPG genes in Paget's disease of bone

Paget's disease of bone (PDB) is one of the most common bone disorders in the western world. PDB is characterized by focal areas of increased osteoclastic bone resorption and bone formation, which leads to the formation of poorly structured bone. These abnormalities of bone turnover and structure predispose affected individuals to various complications including bone pain, deformity, pathological fracture, and an increased risk of osteosarcoma. One of the main mechanisms of osteoclast formation and activation involves the receptor activator of nuclear factor -kappaB (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) pathway, where binding of RANKL to RANK results in the differentiation of osteoclast precursors. OPG, on the other hand, acts as an inhibitor of osteoclastogenesis by serving as a decoy receptor for RANKL. Recently, mutations in the RANK gene have been shown to cause familial expansile osteolysis, a rare bone disorder showing great similarity to PDB. We performed mutation analysis in the RANK and OPG genes in 28 PDB patients to investigate whether mutations in these genes could be responsible for PDB. Our data suggest that RANK is not directly involved in PDB in our set of patients, as no mutations in the RANK coding region could be identified and allele frequencies of RANK polymorphisms did not differ in PDB patients as compared with the random population. Also, in the OPG gene, we could not detect PDB-causing mutations. However, of the several polymorphisms identified, one (400 + 4 C/T in intron 2), showed a statistically significant increased frequency for the C allele in PDB patients, suggesting that individuals harboring this allele may be more susceptible for developing PDB.

Blind and partial sight registration in Avon

All blind and partially sighted registration forms for the county of Avon for a two-year period were analysed, and the findings are presented. Comparisons with the national figure published by Sorsby over 20 years ago show there has been no marked change in the rates of blind registration per 100,000 population with the exception of those for cataract, which show a large reduction. Diabetic registrations have remained similar, but this may represent an encouraging trend in view of the significant increase in the size of the diabetic population. Glaucoma may show some improvement in the future when time has elapsed for beta blockers and trabeculoplasty to be fully assessed. There has been an increase in the rate of registration from aging macular degeneration.

Do published criteria improve clinical diagnostic accuracy in multiple system atrophy?

OBJECTIVE

To assess the accuracy of a clinical diagnosis of multiple system atrophy (MSA) and compare it to the Quinn and Consensus criteria for MSA using neuropathologically examined cases from the Queen Square Brain Bank for Neurological Disorders.

METHODS

Fifty-nine cases with a neurologic diagnosis of MSA when last assessed prior to death were studied.

RESULTS

In 51 (86%) of these cases, the diagnosis of MSA was confirmed pathologically. False positive diagnoses included PD (n = 6), progressive supranuclear palsy (n = 1), and cerebrovascular disease (n = 1). When applying either set of diagnostic criteria, a diagnosis of probable MSA gave lower sensitivity but higher positive predictive value than one of possible MSA. Application of either set of diagnostic criteria was superior to actual clinical diagnosis made early in the disease, but there was little difference by the last clinic visit.

CONCLUSIONS

This study shows a high diagnostic accuracy for the clinical diagnosis of MSA by neurologists, with PD accounting for most of the false positive diagnoses. Application of either Quinn or Consensus criteria was superior to actual clinical diagnosis made early in the disease, but there was little difference by last clinic visit.

The morphology, number, and distribution of a large population of confirmed displaced amacrine cells in the adult cat retina

The presence of a large population of some 730,000 displaced amacrines is confirmed in the ganglion cell layer of the cat retina. These cells correspond to the microneurons of Hughes and Wieniawa-Narkiewicz (Nature 284:468-470, '80) and the bar-cells of Hughes (J. Comp. Neurol. 197:303-339, '81): a population of profiles of which the majority had previously been presumed to be glia (Stone: J. Comp. Neurol. 12:337-352, '65; J. Comp. Neurol 180:753-772, '78; Hughes: J. Comp. Neurol. 163: 107-128, '75). A sample of such nonganglion cells was identified by Nissl criteria in an area of retina subsequently subjected to serial sectioning and electron microscopy. Such cells form synapses with other processes in the inner plexiform layer. Members of each morphological subclass were found to bear synapses. In some instances, synapses occurred both onto and from the soma and processes of a cell, which is strong evidence for their being displaced amacrines, or preferably, "amacrines of the ganglion cell layer." In confirmation of their amacrine nature, it was established that the microneurons and bar-cells survive optic nerve section for up to 2.5 years. Ganglion cells underwent retrograde degeneration and completely disappeared in a much shorter time. Injection of kainic acid, a neurotoxin, into an eye whose optic nerve had been cut over 2 years previously resulted in the pyknosis of all morphologically classified microneurons and bar-cells without influence on conventional glial cells. These results further support the conclusion that microneurons and bar-cells are neurons and that they collectively form the displaced amacrine population of the cat ganglion cell layer. The topographic distribution of the displaced amacrines resembles that of the ganglion cells in form; their density peaks at 4,500-5,000 cells mm-2 in the area centralis and falls to less than 1,000 mm-2 in peripheral retina. A ganglion cell distribution map based on the latest morphological criteria derived from this study confirms that there are 170,000 ganglion cells in the cat retina. Displaced amacrines form some 80% of the total neuron population of the cat ganglion cell layer. The large population magnitude of these confirmed displaced amacrines implies their nonectopic origin and now provides a fresh insight into the ontogeny of the cat retinal ganglion cell layer.

The cat optic nerve: fibre total count and diameter spectrum

An electron microscopic examination of two cat optic nerves indicates a mean total count of 193,000 fibres ranging from 0.5 mu to 13.5 mu in diameter. This count, although nearly double any previously reported, supports recent minimum estimates of the retinal ganglion cell population of the cat eye. A radial gradient of packing density exists across the nerve close to the globe; a high density "core" with a unimodal fibre diameter spectrum may be identified as the area centralis outflow and a peripheral low density region with a trimodal diameter spectrum contains the projection of the peripheral retina. Division of the peripheral fibre spectrum suggests the percentages of alpha, beta and gamma ganglion cells in the peripheral retina to be 5%, 42% and 53% respectively.

Growth and acid production of Candida species in human saliva supplemented with glucose

Growth characteristic and acid production of oral isolates of Candida albicans and Candida glabrata in glucose supplemented and glucose-free, pooled, human whole saliva were examined. Both Candida species exhibited sigmoidal growth curves in batch cultures of mixed saliva, supplemented with glucose. The growth of Candida in saliva was accompanied by a rapid decline in pH from 7.5 to 3.2 over 48 h and the major acidic components initiating and sustaining this pH drop were pyruvates and acetates. These acidic metabolites may play an important role in the pathogenesis of oral Candida infections.

Detection of BRAF mutations in the tumour and serum of patients enrolled in the AZD6244 (ARRY-142886) advanced melanoma phase II study

Background:

This study investigated the potential clinical utility of circulating free DNA (cfDNA) as a source of BRAF mutation detection in patients enrolled into a phase II study of AZD6244, a specific MEK1/2 inhibitor, in patients with advanced melanoma.

Methods:

BRAF mutations were detected using Amplification Refractory Mutation System allele-specific PCR. BRAF mutation status was assessed in serum-derived cfDNA from 126 patients enrolled into the study and from 94 matched tumour samples.

Results:

Of 94 tumour samples, 45 (47.9%) were found to be BRAF mutation positive (BRAF+). Serum-derived cfDNA was BRAF+ in 33 of 126 (26.2%) samples, including in five samples for which tumour data were unavailable. Of BRAF+ tumours, 25 of 45 (55.6%) were BRAF+ in cfDNA. In three cases in which the tumour was negative, cfDNA was BRAF+. Progression-free survival (PFS) of patients with BRAF+ tumour and cfDNA was not significantly different compared with tumour BRAF+ but cfDNA BRAF-negative patients, indicating that cfDNA BRAF detection is not associated with poorer prognosis on PFS in stage III/IV advanced melanoma.

Conclusions:

These data demonstrate the feasibility of BRAF mutation detection in cfDNA of patients with advanced melanoma. Future studies should aim to incorporate BRAF mutation testing in cfDNA to further validate this biomarker for patient selection.