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M Bellis

Publications and source records attributed to M Bellis.

At least 37 records · Page 2Linked to original sources
PubMed2001

General practice or drug clinic for methadone maintenance? A controlled comparison of treatment outcomes.

The model for management of opiate dependence in the United Kingdom includes long term methadone maintenance. A consequence is either long waiting lists for treatment or that treatment capacity is expanded. General practitioners are encouraged to prescribe methadone for opiate dependent patients, but little is known about the differences between patients or outcomes in primary or secondary care settings. This paper compares patients' characteristics and treatment outcomes in a specialist drug clinic and a general practice operating a shared care policy (with the specialist clinic). We undertook a retrospective review of patient records. All patients prescribed methadone maintenance during a 2 year period in one general practice were compared with one in three patients treated at a drug clinic during the same period. Outcome was determined at the end of a treatment episode or on 30 June 1997 (whichever was sooner). Eighty-nine drug clinic and 36 general practice patients were followed up for a minimum of nine months each. Patient characteristics were similar at the start of treatment. A 'good' outcome (remaining in treatment or becoming drug free) was equally likely in either setting. Patients treated in the general practice setting were significantly more likely to be immunised (or have known natural immunity) against hepatitis B (adjusted odds ratio 6.0). Our findings suggest that with similar patient groups this model of care in general practice can produce results at least as good as those of a drug clinic.

Journal Article↗
PubMed2000

Monitoring cellular responses to Listeria monocytogenes with oligonucleotide arrays.

Listeria monocytogenes is a pathogenic intracellular microorganism whose infection induces pleiotropic biological changes associated with host cell gene expression regulation. Here we define the gene expression profiles of the human promyelocytic THP1 cell line before and after L. monocytogenes infection. Gene expression was measured on a large scale via oligonucleotide microarrays with probe sets corresponding to 6,800 human genes. We assessed and discussed the reproducibility of the hybridization signatures. In addition to oligonucleotide arrays, we also performed the large scale gene expression measurement with two high-density membranes, assaying for 588 and 18,376 human genes, respectively. This work allowed the reproducible identification of 74 up-regulated RNAs and 23 down-regulated RNAs as a consequence of L. monocytogenes infection of THP1. The reliability of these data was reinforced by performing independent infections. Some of these detected RNAs were consistent with previous results, while some newly identified RNAs encode gene products that may play key roles in L. monocytogenes infection. These findings will undoubtedly enhance the understanding of L. monocytogenes molecular physiology and may help identify new therapeutic targets.

Blotting, Northern↗
PubMed1999

AIDS funding. The national lottery.

The government's funding of AIDS and HIV services in England is inequitable. Spending per patient in North Thames is four times that in Manchester. Deaths from AIDS in North Thames are significantly lower than in other parts of England.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Detection of glycopeptide-resistant enterococci in routine diagnostic faeces specimens.

Faeces received in a diagnostic laboratory were screened for glycopeptide-resistant enterococci (GRE) on modified Lewisham medium, with and without enrichment in Enterococcosel broth. Colonization by GRE was detected in 102/838 patients (12.2%). In 74 (73%) of colonized patients GRE were detected by both methods and in 28 (27%) they were detected only after enrichment. The carriage rate in hospitalized patients was 32% (93/289) compared with 2.3% (11/425) in the community (GP patients and food-handlers). Carriage of GRE increased with age. Clostridium difficile isolation was associated with GRE colonization, odds ratio 6.76 (P<0.001). Fifty-nine percent (60/102) of the GRE had the VanA phenotype and 41% (42/102) had the VanB phenotype. In the community VanA predominated (91%), whereas 64% (57/89) of the isolates from hospitalised patients were of the VanB phenotype.

Adolescent↗
PubMed1998

Cloning of the presenilin 2 cDNA and its distribution in brain of the primate, Microcebus murinus: coexpression with betaAPP and Tau proteins.

A 1340-bp cDNA fragment encoding the lemurian presenilin 2 protein (PS2) was isolated from a Microcebus murinus brain cDNA library by PCR using oligonucleotide primers based on the nucleotide sequence of the human gene. Analysis of five isolated clones showed that the sequence encoded a 448-amino-acid open reading frame, 95.5% identical to the human and 93.5% identical to the mouse presenilin 2 sequences. However, neither the localization of the 2 positions in PS2 nor that of the 43 positions in PS1 associated with early onset Alzheimer's disease were changed. Expression of the presenilin 2 was detected by RT-PCR and compared with that of presenilin 1 and betaAPP in the brain and in peripheral tissues (liver, kidney, and spleen). Immunohistochemistry with a specific polyclonal antiserum raised against a synthetic peptide from the N-terminal part of the human PS2 showed that the protein is distributed throughout the microcebe brain, in vascular and nerve structures. In cortical and in subcortical areas, PS2 labeling was weak and granular in appearance and was scattered throughout the cytoplasm of many neurones, extending into neurites. The gene expression of PS2 increased with age but was not affected by the presence of numerous amyloid plaques. Double labeling immunocytochemistry detected very few neurones with combined immunoreactivity PS2 and APP, or PS2 and Tau.

Amino Acid Sequence↗
PubMed1997

Drug misuse services. No quick fixes.

The Department of Health's new funding formula for drug misuse services will reduce funding in districts with the highest demand for services. Some regions will receive up to four times more per reported episode of drug misuse than others. This is due, in part, to the inclusion of numbers in rented accommodation in the funding formula.

Financing, Government↗
PubMed1996

Molecular cloning, sequencing, and brain expression of the presenilin 1 gene in Microcebus murinus.

The cDNA encoding the Microcebus murinus presenilin 1 protein (PSI) was cloned by RT-PCR from a brain cDNA library using various combinations of oligonucleotide primers designed on the basis of the human nucleotide sequence. Analysis of five clones isolated from two positive combinations revealed that the deduced open reading frame encodes two protein isoforms of 467 and 463 amino acid residues. The shorter isoform lacked the four residues VRSQ in the N-terminal region and like the 467 amino acid isoform presented 22 substitutions with its human homologue. The 12 bp nucleotide deletion evidenced in the cDNA encoding the shorter isoform is consistent with the use of an alternative 5' splice donor site identified at the end of the human exon 3. The immunohistochemistry performed with a specific polyclonal antiserum raised against a synthetic peptide located in the human large hydrophilic loop of PS1 revealed that the protein is widely distributed independently of age or of pathology in the microcebe brain. PS1 is found predominantly in neurons of the different cortical layers and hippocampus but also in subcortical structures. The PS1 labelling appeared as thin granulations scattered throughout the cytoplasm of numerous neurons and sometimes in neurites.

Aging↗
PubMed1996

Segregation analysis of Alzheimer pedigrees: rare Mendelian dominant mutation(s) explain a minority of early-onset cases. French Alzheimer Collaborative Group.

Segregation analysis of Alzheimer disease (AD) in 92 families ascertained through early-onset ( < or = age 60 years) AD (EOAD) probands has been carried out, allowing for a mixture in AD inheritance among probands. The goal was to quantify the proportion of probands that could be explained by autosomal inheritance of a rare disease allele "a" at a Mendelian dominant gene (MDG). Our data provide strong evidence for a mixture of two distributions; AD transmission is fully explained by MDG inheritance in < 20% of probands. Male and female age-of-onset distributions are significantly different for "AA" but not for "aA" subjects. For "aA" subjects the estimated penetrance value was close to 1 by age 60. For "AA" subjects, it reaches, by age 90, 10% (males) and 30% (females). We show a clear cutoff in the posterior probability of being an MDG case.

Age Factors↗
PubMed1996

beta-Amyloid protein precursor in Microcebus murinus: genotyping and brain localization.

Senile plaques characterized by beta-amyloid protein (A beta) deposits around dystrophic neurites and glial cells are more abundant in the cerebral cortical parenchyma of Alzheimer's disease (AD) patients than in the aged population. Four different mutations in the amyloid precursor protein (APP) gene have been directly involved in a few cases of familial AD with early onset (before 60 years). Previous studies have shown that Microcebus murinus, a nonhuman primate, also develops analogous deposits of A beta in the cortical parenchyma and blood vessel walls in the brain. Sequence analysis of exons 16 and 17 of the APP gene, encoding for A beta, revealed that even if nucleotide divergences occurred, the resulting peptide is completely homologous with the human A beta. The systematic comparison of the A beta nucleotide sequence in microcebus with or without amyloid deposits revealed that neither the presence of mutations involved in some cases of early onset familial AD nor the presence of a mutational founder effect can explain the amyloidosis observed in some old microcebus of our breeding. Localization of the APP was performed by immunocytochemistry in the brains of adult microcebus (1 to 11 years of age) using two antibodies raised against the C-terminus and N-terminus portions of APP. Microscopic examinations revealed that in the microcebus the APP distribution was similar to that observed in the human: (1) A beta and its precursor were simultaneously observed in amyloid plaques (AP) of the cortical parenchyma; (2) APP was localized in cell bodies and proximal dendrites of neurons, in astrocytes and oligodendrocytes, and in blood vessel and capillary walls; (3) labeling of APP in these structures was correlated with the presence of AP; and (4) labeling of APP increased with the age of the animal.

Amino Acid Sequence↗
PubMed1996

No founder effect in three novel Alzheimer's disease families with APP 717 Val-->Ile mutation. Clerget-darpoux. French Alzheimer's Disease Study Group.

We sequenced exons 16 and 17 of the APP (amyloid precursor protein) gene in 18 unrelated French Alzheimer's disease (AD) patients. These patients had an onset before the age of 60 and belonged to families with autosomal dominant transmission of the disease. We detected the APP 717 Val-->Ile mutation in three out of 18 (16.6%) families. In these three families, all affected subjects had the APOE 3/3 genotype, but their ages of onset ranged from 38 to 60 years, indicating that factors other than the APOE genotype influence age of onset. Analysis of two polymorphic loci adjacent to the APP gene showed that at least two independent mutational events had occurred within these pedigrees, in spite of their origin in the same region of France.

Adult↗
PubMed1996

New approaches to the mapping of chromosomal domains.

Although it is generally accepted that the chromosome is divided into elementary subunits, the structural and functional domains, the organisation of these structures at the molecular level is not well understood. In particular, the domain boundaries are not easily identifiable. Several possible candidates such as MARs/SARs, insulators, LCRs, palindromic sequences, or easily melting sequences have been found in the regions having properties one would except for boundaries. None of these elements, however, has been found in all of the constructs functioning as boundaries in tests in vivo. Recent work suggests that the common denominator might be the presence og GC-rich oligonucleotide stretches and the formation of the chromatin hypersensitive sites. A model is discussed in which "unusual" structures, in particular the four-stranded DNA sequence elements containing unpaired bases, play the role of domain boundaries.

Animals↗
PubMed1995

Loop-size spacings between CGCG clusters in long segments of human DNA.

The CGCG tetranucleotides are clustered inside the CpG islands in the genomes of vertebrates. In order to study the distribution of the islands in the human chromosome we have mapped the loci sensitive to the CGCG specific restriction nuclease, in a 1.5 Mb long DNA segment cloned as Yeast Artificial Chromosome (YAC). The sites most sensitive to Bsh 1236 I nuclease show chromosomal loop-size spacing. This result, as well as the result of nucleotide sequence analysis of long genomic segments, suggests that the CGCG are organised in clusters (not always undermethylated) which are coincident with GC peaks on the sine wave-like curve representing DNA composition along the mammalian chromosome.

Animals↗
PubMed1995

Allelic association at the D14S43 locus in early onset Alzheimer's disease. French Alzheimer's Disease Collaborative Study Group.

The D14S43 marker is closely linked to the major gene for early onset autosomal dominant Alzheimer's disease on chromosome 14. Allelic frequencies at the D14S43 locus were compared in 113 familial and isolated cases of early onset Alzheimer's disease (< 60 years of age at onset) (EOAD) and 109 unaffected individuals of the same geographic origin. Allele 7 was significantly (P = 0.033) more frequent in type 1 EOAD patients (13.2%), defined by the presence of at least another first degree relative with EOAD, than in controls (4.1%). Since an autosomal dominant gene is probably responsible for type 1 patients, allelic association may reflect linkage disequilibrium at the D14S43 locus. This would mean that some patients share a common ancestral mutation. However, since multiple tests were carried out, this result must be interpreted with caution, and needs confirmation in an independent sample.

Adult↗
PubMed1995

Identification of a unique apolipoprotein E allele in Microcebus murinus; ApoE brain distribution and co-localization with beta-amyloid and tau proteins.

This report is devoted to the characterization of the apolipoprotein E (ApoE) in Microcebus murinus. Only one allele homologous to the human ApoE4 allele was evidenced. The distribution of the corresponding ApoE protein in the brain was found in association with the pathological proteins characteristic of Alzheimer's disease (AD). Immunocytochemistry revealed brain deposits of ApoE in: (1) the cortical amyloid plaques; (2) the neurones of the various cortical lobes, the hippocampus and the brainstem; (3) the glial cells, astrocytes of the cortical parenchym and oligodendrocytes of the corpus callosum; and (4) the vessel walls. Most ApoE, beta-amyloid protein, abnormally phosphorylated Tau proteins and gliofilament acid proteins were seen in the same cortical areas. These findings for ApoE report the view that Microcebus murinus, in captivity, presents a pathological profile very similar to that observed in AD.

Alleles↗
PubMed1993

A 37-kb fragment common to the pericentromeric region of human chromosomes 13 and 21 and to the ancestral inactive centromere of chromosome 2.

A YAC clone from a chromosome 21-specific partial library was localized by in situ hybridization to the pericentromeric region of chromosomes 13 and 21 and to the long arm of chromosome 2, where an ancestral inactive centromere is present. Restriction mapping of the insert showed that it may contain tandemly repeated DNA. Probes for alpha-satellite and satellite II and III failed to hybridize with the cloned DNA. Shotgun subcloning might reveal a sequence that seems to be specific for chromosome 21. Alu-PCR was performed to generate probes from the YAC clone to map it more precisely, using a somatic hybrid containing only human chromosome 21. The inter-Alu sequences thus isolated were found to be clustered in an approximately 37-kb-long fragment common to chromosome 2, 13, and 21, which might be involved in the centromeric function of these chromosomes.

Animals↗