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J Hardy

Publications and source records attributed to J Hardy.

At least 181 records · Page 10Linked to original sources
PubMed1998

Increased Abeta42(43) from cell lines expressing presenilin 1 mutations.

Mutations in the presenilin 1 (PS1) gene on chromosome 14 are a major cause of autosomal dominant, early-onset Alzheimer's disease. Here, we show that transfecting cells with several mutant, but not wild-type, PS1 cDNAs alters the processing of the amyloid precursor protein (APP) such that more Abeta42(43) is produced, confirming and extending several recent reports. The most effective mutation in this regard was the exon 9 splice-out mutation (delta9). The correlation between the size of the effect on APP processing and the age of onset of disease assessed in families with the mutations was not informative, and the possible reasons for this are discussed.

Age of Onset↗
PubMed1998

Low frequency of alpha-synuclein mutations in familial Parkinson's disease.

A mutation in exon 4 of the alpha-synuclein (NACP) gene has been reported to explain the chromosome 4 linkage to autosomal dominant Parkinson's disease. We developed primers and methods for exonic sequencing of this gene and sequenced the entire coding region of the gene in 6 families with autosomal dominant disease and in 2 cases of lytico and bodig from Guam. In addition, we have sequenced exon 4 of this gene in 5 cases of familial disease and have screened for the specific mutation (A53T) in a 40 cases of idiopathic Parkinson's disease, 3 cases of multisystem atrophy, and 15 cases of Lewy body dementia. We have found no genetic variation in the gene. We discuss these findings with respect to both the epidemiology of Parkinson's disease and the possibility that NACP is not the chromosome 4 locus for disease.

Adult↗
PubMed1998

Fatigue in patients with cancer.

This paper reviews current knowledge regarding cancer-related fatigue assessment, prevalence, mechanisms and management. Most quality of life questionnaires contain at least some items pertaining to fatigue and a number of more specific self-assessment tools have now also been developed. As a results, there is a growing body of literature which documents the extent and severity of fatigue in cancer populations. Unfortunately most of these studies are uncontrolled and do not, therefore, provide an accurate estimate of the prevalence or severity of cancer fatigue relative to that found in the general population. Data from controlled studies are limited and the results are conflicting. Cross-sectional studies suggest that fatigue is the result of a combination of physical and psychological causes. Although no one treatment is proven to alleviate cancer-related fatigue a number of strategies show therapeutic promise.

Cachexia↗
PubMed1998

A phase I trial of vinorelbine in combination with mitoxantrone in patients with refractory solid tumors.

Vinorelbine (Navelbine) is a unique semi-synthetic vinca-alkaloid with a favorable safety profile that has demonstrated significant antitumor activity in patients with non-small cell lung cancer, advanced breast cancer, advanced ovarian cancer and Hodgkin's disease. The most common dose-limiting toxicity is neutropenia, while other reported toxicities are minimal. Mitoxantrone (Novantrone) is an anthracene derivative that has demonstrated antitumor activity in patients with breast cancer, ovarian cancer, acute leukemia, and lymphoma. Mitoxantrone also has a very favorable toxicity profile with significantly less nausea and vomiting, alopecia, and stomatitis as compared with anthracyclines. The dose-limiting toxicity for mitoxantrone is leukopenia. The study was designed to determine the safety and maximally tolerated dose of IV vinorelbine used in combination with a fixed dose of mitoxantrone for the treatment of patients with refractory solid tumors. Vinorelbine was administered on days 1 and 8 of the treatment regimen as a short IV infusion. The starting dose was 15 mg/m2. Mitoxantrone was administered as a 20-min infusion on day 1 only at a fixed dose of 10 mg/m2. Seventeen patients with solid malignancies were entered in the study. For personal reasons, one patient decided to discontinue the treatment after day 1 of cycle 1. Therefore, 16 patients were evaluable for toxicity. The main toxicity was myelosuppression which was dose-limiting and resulted in dose reductions and delays. The use of G-CSF had a minimal overall impact on this regimen. Stable disease was observed in three cases. In patients previously treated with chemotherapy, the maximally tolerated dose was defined as vinorelbine 20 mg/m2 on days 1 and 8 and mitoxantrone 10 mg/m2 on day 1 without growth factor support. These doses can be recommended for phase II study of the regimen as salvage treatment.

Adult↗
PubMed1998

Genetic dissection of Alzheimer's disease and related dementias: amyloid and its relationship to tau.

Molecular genetic analysis is revealing the etiologies of Alzheimer's disease (AD) and related dementias. Here we review genetic and molecular biological evidence suggesting that the peptide A beta 42 is central to the etiology of AD. Recent data also suggests that dysfunction in the cytoskeletal protein tau is on the pathway that leads to neurodegeneration and dementia. Tau is produced either indirectly, by A beta 42, or directly, in some forms of frontotemporal dementia by mutations in tau itself. These data support are refine the amyloid cascade hypothesis for AD and suggest that understanding the causes and consequences of tau dysfunction is an important priority for dementia research.

Alzheimer Disease↗
PubMed1998

Accelerated Alzheimer-type phenotype in transgenic mice carrying both mutant amyloid precursor protein and presenilin 1 transgenes.

Genetic causes of Alzheimer's disease (AD) include mutations in the amyloid precursor protein (APP), presenilin 1 (PS1), and presenilin 2 (PS2) genes. The mutant APP(K670N,M671L) transgenic line, Tg2576, shows markedly elevated amyloid beta-protein (A beta) levels at an early age and, by 9-12 months, develops extracellular AD-type A beta deposits in the cortex and hippocampus. Mutant PS1 transgenic mice do not show abnormal pathology, but do display subtly elevated levels of the highly amyloidogenic 42- or 43-amino acid peptide A beta42(43). Here we demonstrate that the doubly transgenic progeny from a cross between line Tg2576 and a mutant PS1M146L transgenic line develop large numbers of fibrillar A beta deposits in cerebral cortex and hippocampus far earlier than their singly transgenic Tg2576 littermates. In the period preceding overt A beta deposition, the doubly transgenic mice show a selective 41% increase in A beta42(43) in their brains. Thus, the development of AD-like pathology is substantially enhanced when a PS1 mutation, which causes a modest increase in A beta42(43), is introduced into Tg2576-derived mice. Remarkably, both doubly and singly transgenic mice showed reduced spontaneous alternation performance in a "Y" maze before substantial A beta deposition was apparent. This suggests that some aspects of the behavioral phenotype in these mice may be related to an event that precedes plaque formation.

Alzheimer Disease↗
PubMed1998

A variant of Alzheimer's disease with spastic paraparesis and unusual plaques due to deletion of exon 9 of presenilin 1.

We describe a novel variant of Alzheimer's disease (AD) in a Finnish pedigree with 17 affected individuals of both sexes in three generations. The disease is characterized by progressive dementia which is, in most cases, preceded by spastic paraparesis. Neuropathological investigations revealed numerous, distinct, large, round and eosinophilic plaques as well as neurofibrillary tangles and amyloid angiopathy throughout the cerebral cortex. The predominant plaques resembled cotton wool balls and were immunoreactive for Abeta but lacked a congophilic dense core or marked plaque-related neuritic pathology. Molecular genetic analysis revealed that the disease was caused by a deletion of exon 9 (delta9) of the presenilin 1 (PS1) gene from the mRNA: unlike previous examples of the delta9 variant, the deletion was not caused by a splice acceptor site mutation.

Age of Onset↗
PubMed1998

Genetics of Alzheimer's disease.

Mutations in any one of three genes can cause autosomal dominant, early-onset Alzheimer's disease: these genes are the amyloid precursor protein (APP) gene on chromosome 21, the presenilin-1 (PS-1) gene on chromosome 14 and the presenilin-2 (PS-2) gene on chromosome 1. Pathogenic mutations at all these loci cause mismetabolism of APP such that more of the peptide A beta 42 is produced. This peptide is deposited in the plaques in the brains of Alzheimer's patients. These facts have led to the dominant hypothesis for the disease process: the 'amyloid cascade hypothesis', which proposes that overproduction or failure to clear the peptide A beta 42 is always central to the disease. Genetic variability at the apoliprotein E locus is a major determinant of late onset Alzheimer's disease. The mechanism by which apoliprotein E is involved in the pathogenesis of Alzheimer's disease is not yet known. There are likely to be other genetic factors which impinge on Alzheimer's disease.

Age of Onset↗
PubMed1998

Structure and technofunctional properties of protein-polysaccharide complexes: a review.

Food proteins and polysaccharides are the two key structural entities in food materials. Generally, interactions between proteins and polysaccharides in aqueous media can lead to one- or two-phase systems, the latter being generally observed. In some cases of protein-polysaccharide net attraction, mainly mediated through electrostatic interactions, complex coacervation or associative phase separation occurs, giving rise to the formation of protein-polysaccharide complexes. Physicochemical factors such as pH, ionic strength, ratio of protein to polysaccharide, polysaccharide and protein charge, and molecular weight affect the formation and stability of such complexes. Additionally, the temperature and mechanical factors (pressure, shearing rate, and time) have an influence on phase separation and time stability of the system. The protein-polysaccharide complexes exhibit better functional properties than that of the proteins and polysaccharides alone. This improvement could be attributed to the simultaneous presence of the two biopolymers, as well as the structure of the complexes. Consequently, the interesting hydration (solubility, viscosity), structuration (aggregation, gelation) and surface (foaming, emulsifying) properties of these complexes can be used in a number of domains. Among others, these could be macromolecular purification, microencapsulation, food formulation (fat replacers, texturing agents), and synthesis of biomaterials (edible films, artificial grafts).

Biopolymers↗
PubMed1998

Estimation of the genetic contribution of presenilin-1 and -2 mutations in a population-based study of presenile Alzheimer disease.

Two closely related genes, the presenilins ( PS ), located at chromosomes 14q24.3 and 1q42.1, have been identified for autosomal dominant Alzheimer disease (AD) with onset age below 65 years (presenile AD). We performed a systematic mutation analysis of all coding and 5'-non-coding exons of PS -1 and PS -2 in a population-based epidemiological series of 101 unrelated familial and sporadic presenile AD cases. The familial cases included 10 patients of autosomal dominant AD families sampled for linkage analysis studies. In all patients mutations in the amyloid precursor protein gene ( APP ) had previously been excluded. Four different PS -1 missense mutations were identified in six familial cases, two of which where autosomal dominant cases. Three mutations resulted in onset ages above 55 years, with one segregating in an autosomal dominant family with mean onset age 64 years (range 50-78 years). One PS -2 mutation was identified in a sporadic case with onset age 62 years. Our mutation data provided estimates for PS -1 and PS -2 mutation frequencies in presenile AD of 6 and 1% respectively. When family history was accounted for mutation frequencies for PS -1 were 9% in familial cases and 18% in autosomal dominant cases. Further, polymorphisms were detected in the promoter and the 5'-non-coding region of PS -1 and in intronic and exonic sequences of PS -2 that will be useful in genetic association studies.

Aged↗
PubMed1998

Sequencing of the alpha-synuclein gene in a large series of cases of familial Parkinson's disease fails to reveal any further mutations. The European Consortium on Genetic Susceptibility in Parkinson's Disease (GSPD).

A mutation in exon 4 of the human alpha-synuclein gene was reported recently in four families with autosomal dominant Parkinson's disease (PD). In order to examine whether mutations in this exon or elsewhere in the gene are common in familial PD, all seven exons of the alpha-synuclein gene were amplified by PCR from index cases of 30 European and American Caucasian kindreds affected with autosomal dominant PD. Each product was sequenced directly and examined for mutations in the open reading frame. No mutations were found in any of the samples examined. We conclude that the A53T change described in the alpha-synuclein gene is a rare cause of PD or may even be a rare variant. Mutations in the regulatory or intronic regions of the gene were not excluded by this study.

Adult↗
PubMed1998

Pronounced impact of Th1/E47cs mutation compared with -491 AT mutation on neural APOE gene expression and risk of developing Alzheimer's disease.

Possession of the apolipoprotein E (APOE) epsilon4 allele is the most frequently associated genetic susceptibility factor for Alzheimer's disease (AD). Recently, new polymorphisms in the regulatory region of the APOE gene have been described. We analysed the effects of three of these mutations (-491 AT, -427 CT and Th1/E47cs) on disease risk in a large case-control study, and tested their impacts on APOE allelic expression in brain tissues. The Th1/E47cs T allele was associated with an increased risk of occurrence of AD, while the -491 T allele was associated with a decreased risk, independently of the APOE epsilon2/epsilon3/epsilon4 polymorphism effect. However, the impact of the Th1/E47cs mutation was the strongest. The -427 CT polymorphism was not associated with the disease. In AD subjects heterozygous for the epsilon4 allele, analysis of allelic expression showed that the relative expression levels of the epsilon4 allele were higher than those of the corresponding controls. Consistent with epidemiological data, the relative level of expression of the epsilon4 allele was modified accordingly to the presence or absence of the two main promoter polymorphisms, indicating, in vivo, the deleterious effect of the Th1/E47cs T allele and the protective effect of the -491 T allele in population. These data indicate that in addition to the qualitative effect of the APOE epsilon2/epsilon3/epsilon4 polymorphisms on the AD occurrence, the quantitative variation of expression of these alleles due to functional APOE promoter mutations, is a key determinant of AD development.

Aged↗
PubMed1998

Chromosome 14 familial Alzheimer's disease: the clinical and neuropathological characteristics of a family with a leucine-->serine (L250S) substitution at codon 250 of the presenilin 1 gene.

BACKGROUND: Seven affected members are described from a kindred with autosomal dominant familial Alzheimer's disease associated with a novel mutation in the presenilin 1 (PS1) gene on chromosome 14 that results in a leucine to serine substitution at codon 250 (L250S). METHOD: Clinical information on the pedigree was collected directly from family members including affected members and their carers and also from hospital records. RESULTS: Detailed clinical information was available on five members. All had an early age at onset with a median age of 52 (95% confidence interval (95% CI) 49.4-54.9). Age at onset varied between 49 and 56 years, with duration of illness varying between six years and 15 years. Myoclonus, depression, and psychosis were features of this pedigree; seizures were not reported. CONCLUSIONS: PS1 L250S familial Alzheimer's disease is an early onset form of Alzheimer's disease with clinical features similar to other reported familial Alzheimer's disease pedigrees, except that seizures were absent.

Age of Onset↗
PubMed1998

Pitfalls in placebo-controlled trials in palliative care: dexamethasone for the palliation of malignant bowel obstruction.

To determine the effect of dexamethasone when treating malignant bowel obstruction, 35 patients were randomized to receive intravenous dexamethasone or a placebo, crossing over to the alternate treatment arm if there had been no resolution of obstruction by day 5. This was done in two consecutive studies. Patients were stratified according to whether or not they had received specific anticancer therapy within 28 days of study. In trial 1, 15 out of 22 patients 'responded' (resolution of obstruction by day 5; 10 on dexamethasone, five on placebo). Eleven out of 15 patients were 'on treatment'. In trial 2, six out of 13 responded (three on dexamethasone, three on placebo); three out of six were 'on treatment'. When both studies are combined, 60% (21/35) patients responded (13 on dexamethasone, eight on placebo). Poor patient accrual terminated both studies. Numbers are too small to allow a combination of studies or formal statistical analysis. We are unable to make any conclusion as to the effectiveness of dexamethasone in the palliation of malignant bowel disease.

Adult↗
PubMed1998

The use of the Edmonton Symptom Assessment Scale (ESAS) within a palliative care unit in the UK.

The Edmonton Symptom Assessment scale (ESAS) was used on 1004 occasions to assess 71 patients with advanced malignant disease admitted to a palliative care unit in the UK over a six-week period. The median length of inpatient stay was eight days (range 1-36) and the median survival from start of ESAS to death was 16 days (range 2-202). Across all patients there was a trend towards worsening symptom scores over the first five days from admission with a significant deterioration in appetite scores. When scores were analysed retrospectively over five days according to outcome (death--group 1, or discharge--group 2) there was a significant improvement in pain scores in group 2 but no change in overall score, and a significant deterioration in activity, drowsiness and appetite in group 1 with no change in overall score. ESAS did not seem an appropriate tool in this group of patients as the total symptom scores were so often biased by the inevitable increase in individual symptom scores immediately prior to death.

Adult↗
PubMed1998

Cell trafficking, mediator release, and articular metabolism in acute inflammation of innervated or denervated isolated equine joints.

OBJECTIVES: To describe the acute cellular response, inflammatory mediator release, and effect on chondrocyte metabolism of interleukin 1 beta (IL-1 beta) in isolated innervated or denervated equine metacarpophalangeal joints. ANIMALS: One metacarpophalangeal joint of 24 adult horses. PROCEDURES: The metacarpophalangeal joint was isolated for 6 hours in a pump-perfused, auto-oxygenated, innervated or denervated metacarpophalangeal joint preparation. Isolated joints were assigned to 4 groups: control, control-denervated, inflamed, and inflamed-denervated, and inflammation was induced by intra-articular injection of IL-1 beta. Synovial fluid was collected for cytologic examination and determination of IL (IL)-1 beta, (IL-6), prostaglandin E2 (PGE2), and substance P (SP) values. Synovial membrane was immunostained with SP and nerve-specific enolase (NSE) antibodies. Cartilage was collected for determination of proteoglycan (PG) synthesis and degradation. RESULTS: IL-1 beta induced significant neutrophilic leukocytosis in synovial and synovial membrane. IL-1 beta concentration and returned to baseline by 5.5 hours, but IL-6 concentration significantly increased throughout the study. Total SP content was significantly higher in inflamed joints. There was a significant increase in 24- and 48-hour PG degradation in inflamed innervated joints. CONCLUSION: Cellular response to IL-1 beta was rapid and sustained; joint clearance of IL-1 beta was rapid, and endogenous production of IL-1 beta did not follow. The IL-6 and PGE2 concentrations significantly increased, and SP content was increased in association with inflammation but not denervation. A degradative response of cartilage of IL-1 beta was observed, and was enhanced by innervation. This model was useful for investigation of the articular response to acute inflammation and the influence of denervation in modulating this response.

Animals↗
PubMed1998

Effect of synovial membrane infection in vitro on equine synoviocytes and chondrocytes.

OBJECTIVE: To determine the functional response of synovium to infection, and the influence of infected synovium on articular cartilage metabolism. SAMPLE POPULATION: Synovium and articular cartilage explants from the midcarpal and tarsocrural joints of adult horses. PROCEDURE: For experiment 1, synovium explants were incubated as follows: control--incubation in standard medium, infected (I)--incubation with Staphylococcus aureus, and infected-filtered (IF)--incubation with medium collected from the infected group and filtered (0.22-micron filter). Daily collected medium was assayed for interleukin 1 beta (IL-1 beta), IL-6, tumor necrosis factor, and hyaluronan (HA) concentrations. For experiment 2, cartilage explants were incubated as follows: control--incubation in standard medium, and IF--incubation in medium collected from infected synovium cultures and filtered. After 48 hours, explant proteoglycan synthesis and endogenous proteoglycan and glycosaminoglycan contents were determined. RESULTS: IL-1 beta and IL-6 values were significantly increased in synovium explants from the I and IF groups. Hyaluronan concentration was lower in I and IF groups. Proteoglycan synthesis and content, and total glycosaminoglycan and chondroitin sulfate concentrations, were significantly decreased in cartilage from the IF group. CONCLUSIONS: Bacterial infection was associated with decreased HA concentration and increased mediator release. These effects were also observed despite elimination of bacteria. Exposure to sterile but previously infected medium decreased articular cartilage matrix synthesis and composition. CLINICAL RELEVANCE: Resident synovial cells may contribute appreciably to articular damage during bacterial infection in the absence of migrant inflammatory cells. This response is prolonged despite elimination of the bacteria.

Animals↗