Hepatic stellate cell activation in nonalcoholic steatohepatitis and fatty liver

Factors associated with the development of fibrosis in nonalcoholic steatohepatitis (NASH) are largely unknown, although an association with increased hepatic iron has been suggested. Hepatic stellate cells are the principal collagen-producing cells in many liver diseases and when activated express alpha-smooth muscle actin (alpha-SMA). Hepatic stellate cell activation and association with fibrosis, necroinflammatory activity, steatosis, and stainable iron in 60 cases of NASH and 16 cases of steatosis were evaluated. All 76 patients were obese or had other risk factors for NASH. All biopsy specimens were stained for alpha-smooth muscle actin to evaluate the pattern of hepatic stellate cell activation and were evaluated for inflammatory activity (0 to 3), fibrosis (0 to 4), and stainable iron stores (0 to 4). The zonal location of activated stellate cells was recorded, and the degree of activation was graded as high-grade or low-grade based on the percentage of lobular alpha-SMA+ cells. Activated stellate cells were identified in the hepatic lobule in 74 of 76 biopsy specimens and graded as low-grade in 26 and high-grade in 48. Zone 3 was involved in 72 of 74 positive cases, and in 33 cases, the activated stellate cells were preferentially located in zone 3. The degree of stellate cell activation correlated with fibrosis but not with inflammatory activity, severity of steatosis, or stainable iron. In most cases, the degree of stellate cell activation paralleled the degree of hepatic fibrosis, but in 25 cases, the degree of hepatic stellate cell activation was greater than expected, raising the question of whether such patients are at risk for disease progression.

Death postponement and increased chronic lung disease: the hidden costs of mortality reduction in the post-surfactant era

To determine changes in the morbidity and mortality of ventilated, very low-birth-weight infants before and after the introduction of surfactant therapy in 1990, we retrospectively studied the infants in a tertiary neonatal intensive care unit. All ventilated patients admitted from January 1, 1984, to December 31, 1997, with birth weight of 1500 g or less, excluding 76 transferred to other hospitals, were included in the analysis (N = 1336). The primary outcomes studied included mortality, length of stay, and survival without bronchopulmonary dysplasia. Although post-surfactant mortality and pulmonary air leak for infants with birth weight greater than 750 g decreased more than 50% (P < or = .026), the proportion of infants surviving without bronchopulmonary dysplasia also decreased (P < or = .034). For surviving infants with birth weight of 751 to 1000 g, mean post-surfactant length of stay increased 16 days (P = .008). Postnatal age at death also increased in the post-surfactant period for infants with birth weight of 750 g or less (P = .002). For infants with birth weight of 1000 g or less, post-surfactant increases were seen in the mean duration of assisted ventilation (+22% to 32%, P < or = .005) and the incidence of bronchopulmonary dysplasia at 36 weeks' postmenstrual age (+62% to 162%, P < .001). For all infants, the incidence of bacteremia, duration of supplemental oxygen therapy, and likelihood of discharge on home oxygen were increased in the post-surfactant period (P < or = .011). The implicit benefits of mortality reduction in the post-surfactant era may be offset by increasing respiratory morbidity in some survivors and by an unwelcome prolongation of death for some nonsurvivors. We speculate that the ultimate costs of these undesirable outcomes may greatly surpass the ostensible cost benefits of neonatal surfactant therapy.

Enhanced extracellular production of aspartyl proteinase, a virulence factor, by Candida albicans isolates following growth in subinhibitory concentrations of fluconazole

We examined the production of secreted aspartyl proteinase (Sap), a putative virulence factor of Candida albicans, by a series of 17 isolates representing a single strain obtained from the oral cavity of an AIDS patient before and after the development of clinical and in vitro resistance to fluconazole. Isolates were grown in Sap-inducing yeast carbon base-bovine serum albumin medium containing 0, 0.25, 0.5, or 1 MIC of fluconazole, and cultures were sampled daily for 14 days to determine extracellular Sap activity by enzymatic degradation of bovine serum albumin. Extracellular Sap activity was significantly decreased in a dose-dependent manner for the most fluconazole-susceptible isolate (MIC, 1.0 microg/ml) and significantly increased in a dose-dependent manner for the most fluconazole-resistant isolate (MIC, >64 microg/ml). Enhanced extracellular Sap production could not be attributed to cell death or nonspecific release of Sap, because there was no reduction in the number of CFU and no significant release of enolase, a constitutive enzyme of the glycolytic pathway. Conversely, intracellular Sap concentrations were significantly increased in a dose-dependent manner in the most fluconazole-susceptible isolate and decreased in the most fluconazole-resistant isolate. Enhanced Sap production correlated with the overexpression of a gene encoding a multidrug resistance (MDR1) efflux pump occurring in these isolates. These data indicate that exposure to subinhibitory concentrations of fluconazole can result in enhanced extracellular production of Sap by isolates with the capacity to overexpress MDR1 and imply that patients infected with these isolates and subsequently treated with suboptimal doses of fluconazole may experience enhanced C. albicans virulence in vivo.

Sequence variants of DLC1 in colorectal and ovarian tumours

Loss of heterozygosity occurs frequently on the short arm of chromosome 8 in many neoplasms, including colorectal and ovarian cancer. Monochromosome transfer experiments into colorectal tumour cell lines have provided functional evidence for a tumour suppressor gene located at 8p22-23. One of the genes from this region that is expressed by our suppressed hybrids is a candidate tumour suppressor gene, DLC1 (deleted in liver cancer), which has homology to rat RhoGAP. We have delineated the structure of the DLC1 gene and used single-stranded conformation polymorphism analysis (SSCP) to look for sequence variants in 126 colorectal and 33 ovarian primary tumours and cell lines. One exonic missense mutation and three intronic insertions/deletions were identified in primary colorectal tumours, as well as many polymorphisms present in germline DNAs. The rarity of exonic missense mutations, and the absence of protein-truncating mutations, indicates that DLC1 is not the target of 8p LOH in colorectal or ovarian tumours. The delineation of the gene structure allows mutation analysis of DLC1 in other tumour types for which it remains a candidate tumour suppressor gene based on its location and homology to rhoGAP.

Quality-assessed reviews of health care interventions and the database of abstracts of reviews of effectiveness (DARE). NHS CRD Review, Dissemination, and Information Teams

OBJECTIVES

Database of Abstracts of Reviews of Effectiveness (DARE) (http:@www.york.ac.uk/inst/crd/) at the NHS Centre for Reviews and Dissemination provides a unique international resource of structured summaries of quality-assessed reviews of health care interventions. These reviews have been identified from searches of electronic databases and by hand-searching journals. This paper describes and summarizes the DARE database, including the topic areas covered and the review methods used.

METHODS

The first 480 structured abstracts on the DARE database were summarized. Data were extracted from each database field and coded for analysis.

RESULTS

Most of the systematic reviews investigated the effectiveness of treatments: 54% investigated the effectiveness of medical therapies, and 10% assessed surgical interventions. Around two-thirds used meta-analytic methods to combine primary studies. The quality of the reviews was variable, with just over half of the reviews (52%, n = 251) having systematically assessed the validity of the included primary studies. Narrative reviews were more likely than meta-analyses to reach negative conclusions (42% vs. 25%, p = .0001). The 21 reviews that reported drug company funding were more likely to reach positive conclusions (81% vs. 66%, p = .15).

CONCLUSION

The DARE database is a valuable source of quality-assessed systematic reviews, and is free and easily accessible. It provides a valuable online resource to help in filtering out poorer quality reviews when assessing the effectiveness of health technologies.

Gender differences in subjective distress attributable to anticipation of combat among U.S. Army soldiers deployed to the Persian Gulf during Operation Desert Storm

This study compares perceptions of stress, cohesion, and psychological well-being among 856 male soldiers and 169 female soldiers from combat support and combat service support units deployed to the Persian Gulf during Operation Desert Storm. Three different types of stressors were measured: anticipation of combat, operational stress, and personal stress. Female soldiers scored higher than male soldiers on all three measures of stress but scored lower than males on horizontal and vertical cohesion. In a stepwise discriminant function analysis, anticipation of combat was the most significant discriminator between the genders, followed by horizontal cohesion. Anticipation of combat was a significant predictor of increased psychological symptoms for both genders, but it had a greater effect on the psychological symptoms of female soldiers compared with male soldiers.

beta-catenin mutation and expression analysis in ovarian cancer: exon 3 mutations and nuclear translocation in 16% of endometrioid tumours

The molecular mechanisms involved in the generation of epithelial ovarian cancers are poorly understood, but evidence suggests that the different histological subtypes may arise from independent tumorigenic events. beta-Catenin is emerging as an important oncogene in the transformation of a number of epithelial cancers, and mutations have been reported in a small study of endometrioid ovarian adenocarcinomas. Mutations in the NH(2)-regulatory domain of beta-catenin stabilise the cytoplasmic levels of this protein, which promotes up-regulation of the beta-catenin-T-cell factor-lymphoid enhancer factor transcriptional complex. We report here beta-catenin (CTNNB1) exon 3 mutation analysis in 149 epithelial ovarian carcinomas. This revealed 10/63 (16%) endometrioid ovarian tumours with activating mutations of the beta-catenin gene. All mutations were missense changes within the GSK3beta consensus site, affecting serine residues at codons 33 and 37 and glycine at codon 34. Immuno-histochemical analysis identified cytoplasmic stabilisation and nuclear translocation in those endometrioid tumours with mutations. This phenotypic change was also identified in 3 other endometrioid tumours that did not have somatic mutations within exon 3 of CTNNB1. Stabilisation of the free, monomeric pool of beta-catenin and the probable resulting constitutive activation of its Tcf-associated transcriptional complex appears to be a specific oncogenic event in endometrioid ovarian adenocarcinoma.

beta-catenin mutation and expression analysis in ovarian cancer: exon 3 mutations and nuclear translocation in 16% of endometrioid tumours

The molecular mechanisms involved in the generation of epithelial ovarian cancers are poorly understood, but evidence suggests that the different histological subtypes may arise from independent tumorigenic events. beta-Catenin is emerging as an important oncogene in the transformation of a number of epithelial cancers, and mutations have been reported in a small study of endometrioid ovarian adenocarcinomas. Mutations in the NH(2)-regulatory domain of beta-catenin stabilise the cytoplasmic levels of this protein, which promotes up-regulation of the beta-catenin-T-cell factor-lymphoid enhancer factor transcriptional complex. We report here beta-catenin (CTNNB1) exon 3 mutation analysis in 149 epithelial ovarian carcinomas. This revealed 10/63 (16%) endometrioid ovarian tumours with activating mutations of the beta-catenin gene. All mutations were missense changes within the GSK3beta consensus site, affecting serine residues at codons 33 and 37 and glycine at codon 34. Immuno-histochemical analysis identified cytoplasmic stabilisation and nuclear translocation in those endometrioid tumours with mutations. This phenotypic change was also identified in 3 other endometrioid tumours that did not have somatic mutations within exon 3 of CTNNB1. Stabilisation of the free, monomeric pool of beta-catenin and the probable resulting constitutive activation of its Tcf-associated transcriptional complex appears to be a specific oncogenic event in endometrioid ovarian adenocarcinoma.

Frequent loss of heterozygosity at 1p36 in ovarian adenocarcinomas but the gene encoding p73 is unlikely to be the target

Loss of heterozygosity (LOH) involving the distal part of the short arm of chromosome 1 occurs frequently in ovarian adenocarcinomas but the tumour suppressor gene(s) targeted by this event is unknown. We have used five microsatellite markers in a panel of 56 ovarian adenocarcinomas to determine which part of 1p34 - 36 is the focus of this LOH. LOH was considerably more common at 1p36 (43%) than at 1p34 - 35 (18%), and 11 tumours showed LOH at 1p36 but not at 1p34 - 35. These data strongly suggest the presence of a tumour suppressor gene inactivated in ovarian adenocarcinoma at 1p36. The p53 homologue, p73, has recently been isolated and mapped to 1p36 and therefore is a candidate for this tumour suppressor gene. However, RT - PCR and Western analyses revealed strong expression of p73 in ovarian adenocarcinoma cell lines but very low or undetectable levels in normal ovarian surface epithelial cells. Immunohistochemical analysis of primary ovarian tumours showed that only 3/22 (14%) contained p73 expressing cells. There was no association between 1p36 LOH and p73 expression in ovarian tumours, nor between p73 and p53 expression. These findings strongly suggest that p73 is not the target of 1p36 LOH in ovarian adenocarcinomas but indicate the presence of an, as yet unidentified, tumour suppressor gene in this region that plays an important role in ovarian tumorigenesis.

Cytokine-induced apoptosis in epithelial HT-29 cells is independent of nitric oxide formation. Evidence for an interleukin-13-driven phosphatidylinositol 3-kinase-dependent survival mechanism

A combination of the pro-inflammatory cytokines interleukin (IL)-1alpha, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha induces nitric oxide synthase mRNA expression and nitric oxide (NO) generation in the human colon carcinoma cell line HT-29. This can be inhibited by pretreatment with IL-13 via a phosphatidylinositol (PI) 3-kinase-dependent mechanism (Wright, K., Ward, S. G., Kolios, G., and Westwick, J. (1997) J. Biol. Chem. 272, 12626-12633). Since NO has been implicated in regulating mechanisms leading to cell death, while activation of PI 3-kinase-dependent signaling cascades are thought to be involved with promoting cell survival events, we have investigated the outcome of these cytokine treatments on apoptosis and cell survival of HT-29 cells. Initiation of apoptosis can be achieved by the combinations of IFN-gamma/TNF-alpha, IFN-gamma/CD95, IL-1alpha/IFN-gamma, and IL-1alpha/IFN-gamma/TNF-alpha to varying extents. Induction of apoptotic markers by HT-29 cells in response to cytokine treatment is not dependent on NO production. Pretreatment with IL-13 protects against IL-1alpha/IFN-gamma/TNF-alpha- and IFN-gamma/TNF-alpha- as well as IFN-gamma/CD95-induced (but not IL-1alpha/IFN-gamma-induced) cell death. In addition, IFN-gamma/TNF-alpha and IL-1alpha/IFN-gamma/TNF-alpha stimulate activation of caspase-8 and caspase-3, which IL-13 pretreatment was able to partially inhibit and delay. IL-13 also stimulates activation of the major PI 3-kinase effector, protein kinase B. The PI 3-kinase inhibitors wortmannin and LY294002 inhibit IL-13 stimulation of protein kinase B as well as the cell survival effects of IL-13. These data demonstrate that cytokine-induced apoptosis of HT-29 cells is NO-independent and that the activation of a PI 3-kinase-dependent signaling cascade by IL-13 is a key signal responsible for the inhibition of apoptosis.

Acute behavioral effects and abuse potential of trazodone, zolpidem and triazolam in humans

The present study examined the acute behavioral effects and abuse potential of three drugs commonly used to treat sleep disorders, trazodone, zolpidem and triazolam, and placebo in ten male volunteers with histories of alcohol and drug abuse. Trazodone (100, 200 and 300 mg), a triazolopyridine antidepressant, was included because antidepressants are being used more frequently to treat sleep disorders, but it is unclear whether they have a distinct behavioral pharmacologic profile relative to benzodiazepine hypnotics. Zolpidem (15, 30 and 45 mg), an imidazopyridine hypnotic, was tested because it is the most commonly prescribed hypnotic and purportedly has a unique benzodiazepine-receptor binding profile. Triazolam (0.25, 0.5 and 0.75 mg), a triazolobenzodiazepine hypnotic, was included as the standard component because previous laboratory studies have demonstrated that it has at least some abuse potential. Trazodone, zolpidem and triazolam generally produced comparable dose-related increases in scores on the PCAG scale of the ARCI, which suggests the doses tested were equivalent on some behavioral dimension. The effects of trazodone on subject-rated items thought to measure abuse potential (e.g., subject ratings of Willing to Take Again) were less than those observed with triazolam. Zolpidem and triazolam produced comparable effects on these measures. The highest dose of zolpidem, but not triazolam, increased ratings of Like Drug, Happy, Good Effects, Friendly, Elated, Carefree and Bad Effects. Triazolam and zolpidem produced dose-dependent impairment on all of the performance tasks. Trazodone impaired performance on some, but not all, of these tasks. Consistent with the pharmacokinetics of these compounds, the time-action functions of trazodone, zolpidem and triazolam were similar on these measures. These data suggest that trazodone has less abuse potential than triazolam, and may be a viable alternative to benzodiazepine hypnotics in individuals with histories of alcohol or drug abuse. By contrast, despite its unique neuropharmacological profile, the acute behavioral effects and abuse potential of zolpidem are comparable to those of triazolam.

Acute physiological and behavioral effects of oral cocaine in humans: a dose-response analysis

The present study was designed to assess the acute physiological and behavioral effects of a wide range of doses of oral cocaine HCL (placebo, 50, 100, 200, and 300 mg). Nine volunteers (eight males and one female) with recent histories of cocaine use resided on a general inpatient psychiatry unit while they participated. Drug doses were administered in a double-blind fashion under medical supervision, but for safety purposes, they were administered in ascending order. The physiological, subject-rated, and performance effects of oral cocaine HCL were assessed before drug administration and periodically afterwards for 5 h. Oral cocaine HCL increased heart rate and blood pressure as a graded function of dose, but the magnitude of these effects were not clinically significant. Oral cocaine HCL produced positive subject-rated drug effects (e.g. increased ratings of good effects, like drug, and willing to take again), but did not affect performance. Consistent with the pharmacokinetics of oral cocaine HCL, drug effects were generally discernible from placebo 0.5-1 h after administration, peaked approximately 1 h after administration, and progressively abated during the remainder of the experimental session. The results of this experiment demonstrate that across a six-fold range of doses oral cocaine HCL is well tolerated by individuals with recent histories of cocaine use and can be safely administered under controlled laboratory and medical conditions.

Costs of formal care for frail older people in England: the resource implications study of the MRC cognitive function and ageing study (RIS MRC CFAS)

The aim of this paper is to quantify service use and costs of supporting frail older people at home in the community, using data collected in a longitudinal multicentre stratified randomised study for 1055 mentally frail, physically frail, and mentally and physically frail subjects. Average costs per person per week were found to total 64.45 Pounds Sterling, with a small number of services accounting for a large proportion of the total costs. The level of services offered by the nonstatutory voluntary and private sectors was found to be small. To highlight issues for policy makers, the extent of cost variations between a number of different subgroups were calculated. These bivariate analyses revealed substantial variation in costs, especially according to household structure, type of frailty, whether admission to continuing care accommodation occurred and survival. Multiple regression analysis demonstrated that 26% of the variation in log average weekly costs could be explained by a number of socio-demographic and health status variables. A particularly close relationship was observed between costs and whether admission to continuing care accommodation occurred, highlighting a need for policy-makers to examine the nature and scale of provision of alternative community based care packages. The results demonstrate that descriptive cost data such as those presented can provide information useful to the planning process, enabling more informed choices to be made over the provision of services for particular groups of people.

Estimation of a multiproduct cost function for physically frail older people

Using the theory of multiproduct cost functions, this paper derives a cost function for physically frail older people living in private households, based on data collected between 1991 and 1995, for 472 subjects aged 65 years of age or over in four areas of England. The main characteristic of the cost function is that output categories are classified in terms of movements between different health states. These were measured by changes in activities of daily living (ADL) over 2 years, with 'low' ADL representing better functional ability than 'high' ADL. Empirical application of the approach, using four states defined in terms of worsening progression (stable low ADL; deteriorated or improved ADL; stable high ADL; deceased), indicated more favourable states were associated with lower costs. Multivariate analysis showed that the derived states were significantly related to costs which, when combined with variables indicating presence of particular chronic health conditions (diabetes or previous stroke), admission to continuing care accommodation and household structure, explained one-fifth of the variation in log average costs per week. Variables such as age, sex, carer input, social networks and level of cognitive functioning had no independent impact on costs. These findings could be used as a starting point for those interested in predicting the cost implications associated with the ageing population.

The natural history of infantile esotropia during the first six months of life. Pediatric Eye Disease Investigator Group

PURPOSE

The present study addresses the natural history ocular alignment in infantile esotropia that presents at 2 to 4 months of age.

METHODS

Eye alignment during the first 6 months of life was evaluated in two cohorts of healthy infants who initially had esotropia at 2 to 4 months of age; 80 infants were enrolled in a prospective study at the Retina Foundation of the Southwest (RFSW), and 41 infants were reviewed retrospectively as a pilot study for the Early Surgery for Congenital Esotropia (ESCET) multicenter trial. In addition, 79 of the 80 children in the RFSW cohort were reexamined at 4.5 years of age or older for ocular alignment and stereopsis.

RESULTS

Among infants who initially had constant esotropia > or = 40 PD, 0 of 45 children in the RFSW cohort and 0 of 21 children in the ESCET cohort showed resolution to orthophoria. In addition, only 2 infants showed a reduction in angle of deviation below 40 PD (one to 35 PD and one to 20 PD). Resolution to orthophoria was noted in a few infants who initially had small angle or variable angle esotropia. On follow-up at 4.5 years of age or greater, 91% of the children in the RFSW cohort had alignment within 8 PD of orthoposition and 30% had stereoacuity of 3000" to 60". Children who underwent surgical alignment at 6 months of age had a higher prevalence of coarse stereopsis than children who underwent alignment at 7 to 15 months of age.

CONCLUSIONS

Taken together, these results suggest that infants who present at 2 to 4 months of age with constant esotropia of 40 PD or greater are valid candidates for surgical treatment. In addition, data from long-term follow-up support the hypothesis that early surgical alignment may promote the development of at least coarse stereopsis in these infants.

Frequent loss of heterozygosity and three critical regions on the short arm of chromosome 8 in ovarian adenocarcinomas

Many chromosomal regions undergo loss of heterozygosity (LOH) in ovarian adenocarcinomas but few of the target regions have been finely mapped. One of the chromosome arms likely to harbour one or more tumour suppressor genes inactivated in ovarian cancer is the short arm of chromosome 8 which is frequently deleted in many other solid tumours. We have examined a large panel of microsatellite markers on 8p for LOH in 53 ovarian adenocarcinomas. LOH was observed in 27 tumours (51%), with a significant trend towards a higher frequency of LOH in more advanced tumours. Detailed examination of nine tumours with partial deletions defined three regions of overlap, two in 8p23 and one in 8p22, which suggests that there might be as many as three tumour or metastasis suppressor genes on 8p which are inactivated during ovarian tumorigenesis. LOH on 8p was significantly associated with 9p LOH which suggests that inactivation of target genes on these chromosomes may be cooperative events.

Should fewer premature infants be screened for retinopathy of prematurity in the managed care era?

OBJECTIVE

To determine appropriate upper limits for gestational age and birth weight when screening infants for retinopathy of prematurity (ROP).

DESIGN

Retrospective survey.

SETTING

Tertiary neonatal intensive care nursery.

PATIENTS

Seven hundred seven infants born July 1, 1990 to June 30, 1996 and screened for ROP according to the 1988 to 1996 American Academy of Pediatrics guidelines.

OUTCOME MEASURES

Maximum stage of ROP with respect to birth weight and gestational age.

RESULTS

No ROP more than Stage 1 was observed in infants with gestational ages >/=32 weeks or birth weights >/=1500 g. All cases of threshold and Stage 4 ROP were confined to infants with gestational ages </=30 weeks or birth weights <1200 g.

CONCLUSIONS

The latest American Academy of Pediatrics screening guidelines for ROP are discretionary for infants with birth weights >1500 g or gestational ages >28 weeks. If ROP screening is limited to infants with birth weights of </=1500 g, 34.2% fewer infants would require screening compared with the previous <1800 g recommendation, while missing no cases of ROP more than Stage 1. A gestational age cut-off of </=28 weeks, however, is less desirable, and could potentially miss several infants with more advanced retinopathy (including Stage 4). If ROP screening criteria were instead modified to include infants of gestational ages <32 weeks, the number of patients requiring screening could be reduced 29.1% compared with the previous recommendation of <35 weeks, again without missing any cases of ROP more than Stage 1. Use of such a screening strategy (birth weight <1500 g or gestational age <32 weeks) is predicted to save in excess of 1.5 million dollars annually in the United States, while missing no cases of ROP more than Stage 1.

Voting with their feet: public hospitals, health reform, and patient choices

OBJECTIVES

This study identified public hospital patients' preferences under managed care and health reform.

METHODS

A cross-sectional survey of 348 ambulatory public hospital patients was conducted.

RESULTS

Patients reported a high degree of loyalty to the public hospital given several hypothetical reform scenarios. Those patients who stated they would remain at the hospital increased (from 74.2% to 85.5%) when care elsewhere required copayment for medications and physician visits.

CONCLUSIONS

Patients at one public hospital reported a high likelihood of remaining in the public system, and this likelihood increased when copayment for services was required elsewhere.

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.

Novel liposaccharide conjugates for drug and peptide delivery

Sugar-lipid conjugates with general structure 1-4 were prepared by coupling amino sugars with N-Boc-protected lipoamino acids and oligomers. Conjugates with general structure 5 were also prepared from glucuronic acid and methyl 2-aminohexadecanoate. The physicochemical properties of the conjugates were modified by varying the nature and number of sugars or the number of lipoamino acids or their alkyl chain length. The ability of the liposaccharides to aggregate was examined. These preliminary experiments have demonstrated the ability of the liposaccharides to form particulate systems per se and also their ability to be incorporated into conventional liposomal systems. The structure of the respective liposaccharides and the molar ratio of liposaccharide to dimyristoyl lecithin and cholesterol were found to have a profound effect on the type of colloidal systems produced.

Programme budgeting revisited: special reference to people with learning disabilities

The recent reorganization of community care in the UK removed many of the perverse incentives identified in the previous system. However, the organization of care for many people is still divided across several agencies in the public and independent sectors. As purchasing and providing agencies in both the National Health Service and local authority personal social services attempt to coordinate policy objectives and the means to achieve them, the total resources available and their allocation across different care groups and among people in the same care groups from a consistent focus of attention. The principles and practice of programme budgeting provide important lessons for planning and monitoring expenditure. This paper rehearses such principles in the specialized area of policies for people with learning disabilities and draws on the experience of mapping expenditure on relevant services in a survey over 10 local authorities in England.