Effect of High-Dose Trivalent vs Standard-Dose Quadrivalent Influenza Vaccine on Mortality or Cardiopulmonary Hospitalization in Patients With High-risk Cardiovascular Disease: A Randomized Clinical Trial

IMPORTANCE

Influenza is temporally associated with cardiopulmonary morbidity and mortality among those with cardiovascular disease who may mount a less vigorous immune response to vaccination. Higher influenza vaccine dose has been associated with reduced risk of influenza illness.

OBJECTIVE

To evaluate whether high-dose trivalent influenza vaccine compared with standard-dose quadrivalent influenza vaccine would reduce all-cause death or cardiopulmonary hospitalization in high-risk patients with cardiovascular disease.

DESIGN, SETTING, AND PARTICIPANTS

Pragmatic multicenter, double-blind, active comparator randomized clinical trial conducted in 5260 participants vaccinated for up to 3 influenza seasons in 157 sites in the US and Canada between September 21, 2016, and January 31, 2019. Patients with a recent acute myocardial infarction or heart failure hospitalization and at least 1 additional risk factor were eligible.

INTERVENTIONS

Participants were randomly assigned to receive high-dose trivalent (n = 2630) or standard-dose quadrivalent (n = 2630) inactivated influenza vaccine and could be revaccinated for up to 3 seasons.

MAIN OUTCOMES AND MEASURES

The primary outcome was the time to the composite of all-cause death or cardiopulmonary hospitalization during each enrolling season. The final date of follow-up was July 31, 2019. Vaccine-related adverse events were also assessed.

RESULTS

Among 5260 randomized participants (mean [SD] age, 65.5 [12.6] years; 3787 [72%] men; 3289 [63%] with heart failure) over 3 influenza seasons, there were 7154 total vaccinations administered and 5226 (99.4%) participants completed the trial. In the high-dose trivalent vaccine group, there were 975 primary outcome events (883 hospitalizations for cardiovascular or pulmonary causes and 92 deaths from any cause) among 884 participants during 3577 participant-seasons (event rate, 45 per 100 patient-years), whereas in the standard-dose quadrivalent vaccine group, there were 924 primary outcome events (846 hospitalizations for cardiovascular or pulmonary causes and 78 deaths from any cause) among 837 participants during 3577 participant-seasons (event rate, 42 per 100 patient-years) (hazard ratio, 1.06 [95% CI, 0.97-1.17]; P = .21). In the high-dose vs standard-dose groups, vaccine-related adverse reactions occurred in 1449 (40.5%) vs 1229 (34.4%) participants and severe adverse reactions occurred in 55 (2.1%) vs 44 (1.7%) participants.

CONCLUSIONS AND RELEVANCE

In patients with high-risk cardiovascular disease, high-dose trivalent inactivated influenza vaccine, compared with standard-dose quadrivalent inactivated influenza vaccine, did not significantly reduce all-cause mortality or cardiopulmonary hospitalizations. Influenza vaccination remains strongly recommended in this population.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02787044.

Association of Influenza-like Illness Activity With Hospitalizations for Heart Failure: The Atherosclerosis Risk in Communities Study

Importance

Influenza is associated with an increased risk of cardiovascular events, but to our knowledge, few studies have explored the temporal association between influenza activity and hospitalizations, especially those caused by heart failure (HF).

Objective

To explore the temporal association between influenza activity and hospitalizations due to HF and myocardial infarction (MI). We hypothesized that increased influenza activity would be associated with an increase in hospitalizations for HF and MI among adults in the community.

Design, Setting, and Participants

As part of the community surveillance component of the Atherosclerosis Risk in Communities (ARIC) study, a population-based study with hospitalizations sampled from 4 US communities, data were collected from 451 588 adults aged 35 to 84 years residing in the ARIC communities from annual cross-sectional stratified random samples of hospitalizations during October 2010 to September 2014.

Exposures

Monthly influenza activity, defined as the percentage of patient visits to sentinel clinicians for influenza-like illness by state, as reported by the Centers for Disease Control and Prevention Surveillance Network.

Main Outcomes and Measures

The monthly frequency of MI hospitalizations (n = 3541) and HF hospitalizations (n = 4321), collected through community surveillance and adjudicated as part of the ARIC Study.

Results

Between October 2010 and September 2014, 2042 (47.3%) and 1599 (45.1%) of the sampled patients who were hospitalized for HF and MI, respectively, were women and 2391 (53.3%) and 2013 (57.4%) were white, respectively. A 5% monthly absolute increase in influenza activity was associated with a 24% increase in HF hospitalization rates, standardized to the total population in each community, within the same month after adjusting for region, season, race/ethnicity, sex, age, and number of MI/HF hospitalizations from the month before (incidence rate ratio, 1.24; 95% CI, 1.11-1.38; P < .001), while overall influenza activity was not significantly associated with MI hospitalizations (incidence rate ratio, 1.02; 95% CI, 0.90-1.17; P = .72). Influenza activity in the months before hospitalization was not associated with either outcome. Our model suggests that in a month with high influenza activity, approximately 19% of HF hospitalizations (95% CI, 10%-28%) could be attributable to influenza.

Conclusions and Relevance

Influenza activity was temporally associated with an increase in HF hospitalizations across 4 influenza seasons. These data suggest that influenza may contribute to the risk of HF hospitalization in the general population.

Testing the joint health and safety committee assessment tool in the education sector

Joint Health and Safety Committee (JHSC) effectiveness has been identified as an area of concern for Ontario's education sector. The JHSC Assessment Tool has been previously tested in hospitals with positive results. This study assessed the feasibility and usability of the JHSC Assessment Tool in the education sector. Members of multi-workplace JHSCs from Ontario school boards used the tool to assess their committees' effectiveness before, during and after a committee meeting with usability testing conducted pre and post meeting. Results suggested that the JHSC Assessment Tool was feasible to use during a regular JHSC meeting, groups were able to come to consensus on the majority of items, and usability scores were high overall. Participant feedback provided insight that informed the development of a version relevant to multi-workplace committees.

High-dose influenza vaccine to reduce clinical outcomes in high-risk cardiovascular patients: Rationale and design of the INVESTED trial

BACKGROUND

Influenza leads to significant cardiopulmonary morbidity and mortality-particularly in patients with cardiovascular disease-that may be prevented with a standard influenza vaccine. However, patients with cardiovascular conditions have a reduced immune response to influenza vaccine, potentially resulting in reduced effectiveness for preventing clinical events. High-dose vaccine augments immune response in cardiac patients, suggesting that a high-dose influenza vaccination strategy may further reduce morbidity and mortality. Alternatively, broader coverage with an influenza vaccine containing an increased number of viral strains is an alternative strategy without direct evaluation.

RESEARCH DESIGN AND METHODS

INfluenza Vaccine to Effectively Stop Cardio Thoracic Events and Decompensated heart failure (INVESTED) is a pragmatic, randomized, double-blind, parallel-group, active-controlled trial comparing the effectiveness of an annual vaccination strategy of high-dose trivalent versus standard-dose quadrivalent influenza vaccine in patients with a history of recent heart failure or myocardial infarction hospitalization. The trial will enroll approximately 9,300 patients over 4 influenza seasons. The primary hypothesis is that high-dose influenza vaccine will reduce the composite outcome of all-cause mortality and hospitalization from a cardiovascular or pulmonary cause compared with standard-dose influenza vaccine within each enrolling season. Approximately 1,300 primary outcome events will provide >90% power to detect an 18% relative risk reduction at a 2-sided α level of .05.

CONCLUSION

INVESTED is the largest and longest study to assess whether high-dose influenza vaccine is superior to standard-dose influenza vaccine in reducing cardiopulmonary events in a high-risk cardiovascular population (ClinicalTrials.gov Identifier: NCT02787044).

Testing the Hand Dermatitis Screening Tool in the Home Health Care Sector

Workers exposed to wet work are at an increased risk for occupational contact dermatitis and may benefit from screening to detect early disease. The objective of this study was to assess the prevalence of hand dermatitis in home care workers, identify factors that influence presence of disease, and explore feasibility and importance of workplace screening in the home care sector. Following institutional ethics approval, nurses, personal support workers, and rehab therapists at one large home care provider in Ontario, Canada, self-screened for hand dermatitis using the Hand Dermatitis Screening Tool and accompanying photo guide and completed a short feasibility evaluation. Of the 220 participants, 18% had a positive screen for hand dermatitis and 77% reported exposure to wet work. In all, 93% of participants reported using the tool took less than 2 minutes and 84% reported screening for hand dermatitis is important. In conclusion, prevalence of hand dermatitis in home care workers is higher than reported in the general population. Workplace screening for hand dermatitis was deemed important, and the tool was feasible to use in the home care sector.

Attitudes and Practices Regarding Influenza Vaccination Among Healthcare Workers Providing Services to Individuals With Spinal Cord Injuries and Disorders

Objective:

To examine influenza vaccination status and predictors for vaccine receipt among healthcare workers (HCWs) caring for patients with spinal cord injuries and disorders.

Design:

Cross-sectional, nationwide anonymous survey.

Setting:

Twenty-three Veterans Affairs spinal cord injury centers.

Participants:

One thousand five hundred fifty-six HCWs.

Methods:

The primary outcome was staff vaccination status. Independent variables included staff demographic and employment characteristics, health status, attitudes and beliefs about the vaccine, and implications for its use.

Results:

The staff vaccination rate was 51%. Leading motivators of vaccine receipt were self-protection (77%) and patient protection (49%). The most common reasons for nonreceipt were concerns about side effects (49%), preventive quality (20%), and inconvenience (14%). Logistic regression results suggested that age of 50 years or older (OR, 1.47; P = .021), male gender (OR, 2.50; P < .001), strong belief in vaccine effectiveness (OR, 19.03; P = .008), and importance of HCW vaccination (OR, 20.50; P = .005) significantly increased the probability of vaccination. Recommending the vaccine to coworkers, patients, or patients' families was also associated with HCW vaccination (OR, 3.20; P < .001). Providers who did not believe the vaccine was protective (P < .001) or effective P < .001) were less likely to recommend it to patients.

Conclusions:

Strategies to increase vaccination rates among HCWs should address concerns about side effects, effectiveness, and protective value of the vaccine and access to it. The impact of provider recommendations should be stressed. Vaccination and subsequent prevention of illness may limit morbidity and mortality, thus benefiting HCWs, healthcare facilities, and patients.

Cost-effectiveness of a recommendation of universal mass vaccination for seasonal influenza in the United States

OBJECTIVES

We evaluated the cost-effectiveness of universal mass vaccination (UMV) against influenza compared with a targeted vaccine program (TVP) for selected age and risk groups in the United States.

METHODS

We modeled costs and outcomes of seasonal influenza with UMV and TVP, taking a societal perspective. The US population was stratified to model age-specific (< 5, 5-17, 18-49, 50-64, and 65+ years) vaccine coverage and efficacy. Probability of influenza-related illness (ILI) and complications, health-care utilization, costs, and survival were estimated. For a season's intervention, ILI cases in that year, lifetime costs (2008 US$), and quality-adjusted life years (QALYs) lost (both discounted at 3% per annum) were calculated for each policy and used to derive incremental cost-effectiveness ratios. A range of sensitivity and alternative-scenario analyses were conducted.

RESULTS

In base-case analyses, TVP resulted in 63 million ILI cases, 859,000 QALYs lost, and $114.5 billion in direct and indirect costs; corresponding estimates for UMV were 61 million cases, 825,000 QALYs lost, and $111.4 billion. UMV was therefore estimated to dominate TVP, saving $3.1 billion and 34,000 QALYs. In probabilistic sensitivity analyses, UMV was dominant in 82% and dominated in 0% of iterations. In alternative-scenario analyses, UMV dominated TVP when lower estimates of vaccine coverage were used. Lower estimates of ILI risk among unvaccinated, vaccine effectiveness, and risk of complications resulted in ICERs of $2800, $8100, and $15,900 per QALY gained, respectively, for UMV compared with TVP.

CONCLUSIONS

UMV against seasonal influenza is cost saving in the United States under reasonable assumptions for coverage, cost, and efficacy.

The social, political, ethical, and economic aspects of biodefense vaccines

Besides natural disasters and naturally occurring novel infectious diseases, nothing potentially threatens the health and stability of nations and health systems as much as the devastating threat and unfathomability of bioterrorism. Other than attempts at political solutions and interdictive attempts, only antimicrobials and vaccines offer possible means for protection. Of these, vaccines offer the most immediate and definitive of preventive solutions. Limiting the development and use of vaccines however are social, political, ethical, and economic considerations, and this article will provide a brief exploration of each of these issues and the intersection with the need for such vaccines. In this article we define bioterrorism as the deliberate use of naturally occurring or bioengineered microorganisms in order to cause harm to people, animals, or plants.

Benefits and costs of immunizing children against influenza at school: an economic analysis based on a large-cluster controlled clinical trial

Current influenza vaccination recommendations focus on immunizing high-risk people; however, influenza mortality and morbidity remain elevated. U.S. policymakers are considering expansion of flu vaccination recommendations to include school-age children (ages 5-18). Children are at risk for flu and propagate epidemic spread. Immunizing children at school offers an efficient approach to covering this population. This study examines the cost consequences of a large multistate, school-based influenza immunization program. The results show that immunization reduces disease among children and adults and is cost-saving to society. An epidemiologically based influenza immunization policy might be an important supplement to the existing risk-based policy.

Macrolide resistance mechanisms among Streptococcus pneumoniae isolated over 6 years of Canadian Respiratory Organism Susceptibility Study (CROSS) (1998 2004)

BACKGROUND

Resistance to macrolides in Streptococcus pneumoniae arises primarily due to Erm(B) or Mef(A). Erm(B) typically confers high-level resistance to macrolides, lincosamides and streptogramin B (MLS(B) phenotype), whereas Mef(A) confers low-level resistance to macrolides only (M phenotype). The purpose of this study was to investigate the incidence of macrolide resistance mechanisms in Canadian isolates of S. pneumoniae obtained between 1998 and 2004. Furthermore, the genetic relatedness, serotype distribution and antibiotic susceptibility profile among S. pneumoniae isolates with dual erythromycin ribosomal methylase [Erm(B)] and efflux pump [Mef(A)] were analysed.

METHODS

A total of 865 macrolide-resistant (erythromycin MIC > or = 1 mg/L) S. pneumoniae isolates were collected from the Canadian Respiratory Organism Susceptibility Study (CROSS) from 1998 to 2004. The presence of erm(B) and mef(A) was determined for each isolate by PCR; mutations in the genes coding for L4 and L22 ribosomal proteins and for 23S rRNA were identified by DNA sequencing. Each isolate containing both erm(B)- and mef(A)-mediated macrolide resistance was genotyped by PFGE and serotyped using the Quellung reaction with antisera.

RESULTS

Of the 865 isolates studied, 404 (46.7%) were mef(A)-positive, 371 (42.9%) were erm(B)-positive, 50 (5.8%) were positive for both mef(A) and erm(B) and 40 (4.6%) were negative for both mef(A) and erm(B). Of the macrolide-resistant isolates negative for both mef(A) and erm(B), 22 (2.5%) contained 23S rRNA A2058G, A2059G or A2059C mutations, 7 (0.8%) contained 23S rRNA A2058G or A2059G mutations along with an S20N mutation in L4 ribosomal protein, and 1 isolate contained an E30K ribosomal protein mutation alone. Of the macrolide-resistant strains positive for both mef(A) and erm(B), 36 (72%) were multidrug-resistant (macrolide-, penicillin- and trimethoprim/sulfamethoxazole-resistant), 39 (78%) isolates belonged to serotype 19A or 19F and 36 (72%) belonged to one clonal complex (> or =80% genetic relatedness) genetically related to the Taiwan 19F-14 clone.

CONCLUSIONS

The prevalence of efflux-based macrolide resistance in S. pneumoniae in Canada remained steady between 1998 and 2004. Macrolide resistance due to erm(B) decreased over the same time period, with a rapid increase in isolates with both erm(B) and mef(A) macrolide resistance.

Predictors of meningococcal vaccination among university students

Invasive disease secondary to Neisseria meningitidis is a rare but devastating illness among university students. The Advisory Committee on Immunization Practices recommends educating college freshmen about meningococcal disease and vaccinating all college freshmen who live in residence halls. We conducted this survey to gain a better understanding of current immunization rates and factors associated with vaccination.

Genomic context drives SCA7 CAG repeat instability, while expressed SCA7 cDNAs are intergenerationally and somatically stable in transgenic mice

Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant cerebellar ataxia caused by a CAG repeat expansion in the ataxin-7 gene. In humans, SCA7 is characterized by marked anticipation due to intergenerational repeat instability with a bias toward expansion, and is thus regarded as the most unstable of the polyglutamine diseases. To study the molecular basis of CAG/CTG repeat instability and its pathological significance, we generated lines of transgenic mice carrying either a SCA7 cDNA construct or a 13.5 kb SCA7 genomic fragment with 92 CAG repeats. While the cDNA transgenic mice showed little intergenerational repeat instability, the genomic fragment transgenic mice displayed marked intergenerational instability with an obvious expansion bias. We then went on to generate additional lines of genomic fragment transgenic mice, and observed that deletion of the 3' genomic region significantly stabilized intergenerational transmission of the SCA7 CAG92 repeat. These results suggest that cis-information present on the genomic fragment is driving the instability process. As the SCA7 genomic fragment contains a large number of replication-associated motifs, the presence of such sequence elements may make the SCA7 CAG repeat region more susceptible to instability. Small-pool and standard PCR analysis of tissues from genomic fragment mice revealed large repeat expansions in their brains and livers, but no such changes were found in any tissues from cDNA transgenic mice that have been shown to undergo neurodegeneration. As large somatic repeat expansions are absent from the brains of SCA7 cDNA mice, our results indicate that neurodegeneration can occur without marked somatic mosaicism, at least in these mice.

Macrolide-resistant Streptococcus pneumoniae in Canada during 1998-1999: prevalence of mef(A) and erm(B) and susceptibilities to ketolides

In this study (1998-1999), we collected 215 macrolide-resistant Streptococcus pneumoniae isolates from an ongoing Canadian Respiratory Organism Surveillance Study involving 23 centers representing all regions of Canada. The prevalence of erythromycin-resistant S. pneumoniae was 8% (215 of 2,688). Of the 215 isolates, 48.8% (105 of 215) were PCR positive for mef(A) and 46.5% (100 of 215) were PCR positive for erm(B). The ketolides telithromycin and ABT-773 demonstrated excellent activity against both mef(A) (MIC for 90% of strains [MIC(90)], 0.06 and 0.03 microg/ml, respectively) and erm(B) (MIC(90), 0.06 and 0.03 microg/ml, respectively) strains of S. pneumoniae.

Improving residents' compliance with standards of ambulatory care: results from the VA Cooperative Study on Computerized Reminders

CONTEXT

Computerized systems to remind physicians to provide appropriate care have not been widely evaluated in large numbers of patients in multiple clinical settings.

OBJECTIVE

To examine whether a computerized reminder system operating in multiple Veterans Affairs (VA) ambulatory care clinics improves resident physician compliance with standards of ambulatory care.

DESIGN, SETTING, AND PARTICIPANTS

A total of 275 resident physicians at 12 VA medical centers were randomly assigned in firms or half-day clinic blocks to either a reminder group (n = 132) or a control group (n = 143). During a 17-month study period (January 31, 1995-June 30, 1996), the residents cared for 12,989 unique patients for whom at least 1 of the studied standards of care (SOC) was applicable.

MAIN OUTCOME MEASURES

Compliance with 13 SOC, tracked using hospital databases and encounter forms completed by residents, compared between residents in the reminder group vs those in the control group.

RESULTS

Measuring compliance as the proportion of patients in compliance with all applicable SOC by their last visit during the study period, the reminder group had statistically significantly higher rates of compliance than the control group for all standards combined (58.8% vs 53.5%; odds ratio [OR], 1.24; 95% confidence interval [CI], 1.08-1.42; P =.002) and for 5 of the 13 standards examined individually. Measuring compliance as the proportion of all visits for which care was indicated in which residents provided proper care, the reminder group also had statistically significantly higher rates of compliance than the control group for all standards combined (17.9% vs 12.2%; OR, 1.57; 95% CI, 1.45-1.71; P<.001) and for 9 of the 13 standards examined individually. The benefit of reminders, however, declined throughout the course of the study, even though the reminders remained active.

CONCLUSIONS

Our data indicate that reminder systems installed at multiple sites can improve residents' compliance to multiple SOC. The benefits of such systems, however, appear to deteriorate over time. Future research needs to explore methods to better sustain the benefits of reminders. JAMA. 2000;284:1411-1416.

Frequency of p53 mutations in breast carcinomas from Ashkenazi Jewish carriers of BRCA1 mutations

BACKGROUND

Breast carcinomas occurring in carriers of BRCA1 gene mutations may have a distinctly different pathway of molecular pathogenesis from those occurring in noncarriers. Data from murine models implicate loss of p53 (also known as TP53) gene function as a critical early event in the malignant transformation of cells with a BRCA1 mutation. Therefore, breast tumors from BRCA1 mutation carriers might be expected to exhibit a high frequency of p53 mutations. This study examined the frequency of p53 mutations in the breast tumors of Ashkenazi Jewish carriers and noncarriers of BRCA1 mutations.

METHODS

Tumor DNA from carriers and noncarriers of BRCA1 mutations was screened for mutations in exons 4 through 10 of the p53 gene by use of the polymerase chain reaction and single-strand conformation polymorphism (SSCP) analysis of the amplified DNA. Direct sequencing was performed on gene fragments that showed altered mobility in SSCP analysis.

RESULTS

Mutations in the p53 gene were detected in 10 of 13 tumors from BRCA1 mutation carriers versus 10 of 33 tumors from non-carriers (two-sided P = .007). The p53 mutations were distributed throughout exons 4 through 10 and included both protein-truncating and missense mutations in both groups.

CONCLUSIONS

A statistically significantly higher frequency of p53 mutations was found in breast tumors from carriers of BRCA1 mutations than from noncarriers, which adds to the accumulating evidence that loss of p53 function is an important step in the molecular pathogenesis of BRCA1 mutation-associated breast tumors. This finding may have implications for understanding phenotypic differences and potential prognostic differences between BRCA1 mutation-associated hereditary breast cancers and sporadic cancers.

Life without huntingtin: normal differentiation into functional neurons

Huntington disease (HD) is a neurodegenerative disorder associated with polyglutamine expansion in a recently identified protein, huntingtin. Huntingtin is widely expressed and plays a crucial role in development, because gene-targeted HD-/- mouse embryos die early in embryogenesis. To analyze the function of normal huntingtin, we have generated HD-/- embryonic stem (ES) cells and used an in vitro model of ES cell differentiation to analyze their ability to develop into neuronal cells. Expression analysis of wild-type ES cells revealed that huntingtin is expressed at all stages during ES cell differentiation with high expression in neurons. Expression levels increased with the maturation of differentiating neurons, demonstrating that expression of huntingtin is developmentally regulated in cell culture and resembles the pattern of expression observed in differentiating neurons in the mouse brain. It is interesting that HD-/- ES cells could differentiate into mature postmitotic neurons that expressed functional voltage- and neurotransmitter-gated ion channels. Moreover, both excitatory and inhibitory spontaneous postsynaptic currents were observed, indicating the establishment of functional synapses in the absence of huntingtin. These results demonstrate that huntingtin is not required for the generation of functional neurons with features characteristic of postmitotic neurons in the developing mouse brain.

A yeast artificial chromosome-based physical map of the juvenile amyotrophic lateral sclerosis (ALS2) critical region on human chromosome 2q33-q34

The autosomal recessive form of juvenile amyotrophic lateral sclerosis (ALS2; RFALS Type 3) has previously been mapped to the 8-cM interval flanked by D2S115 and D2S155 on human chromosome 2q33-q34. We have established a yeast artificial chromosome (YAC) contig spanning an approximately 8-Mb region of the ALS2 candidate region and mapped 52 transcribed DNA sequences including 13 known genes and 39 expressed sequenced tags within this YAC contig. The establishment of a YAC contig and transcript map that spans the region containing the ALS2 mutation is an essential step in the identification of the ALS2 gene.

Cytotoxicity of advanced glycation endproducts is mediated by oxidative stress

Non-enzymatic glycation of proteins with reducing sugars and subsequent transition metal catalysed oxidations leads to the formation of protein bound "advanced glycation endproducts" (AGEs). They accumulate on long-lived proteins and are for example structural components of the beta-amyloid plaques in Alzheimer's disease. Since the oxidation of glycated proteins as well as the interaction of AGEs with cell surface receptors produces superoxide radicals, it was tested in BHK 21 hamster fibroblast cells and SH-SY5Y human neuroblastoma cells if AGEs can exert cytotoxic effects on cells. Cell viability was assessed with three independent tests: MTT-assay (activity of the mitochondrial respiratory chain), lactate dehydrogenase assay (release of cytoplasmatic enzymes, membrane integrity) and Neutral Red assay (active uptake of a hydrophilic dye). Two model AGEs, chicken egg albumin-AGE and BSA-AGE, both caused significant cell death in a dose-dependent manner. The cytotoxic effects of AGEs could be attenuated by alpha-ketoglutarate and pyruvate, by antioxidants such as thioctic acid and N-acetylcysteine, and by aminoguanidine, an inhibitor of nitric oxide synthase. This suggests that reactive oxygen species as well as reactive nitrogen species contribute to AGE mediated cytotoxicity. Since AGEs accumulate on beta-amyloid plaques in AD over time, they may additionally contribute to oxidative stress, cell damage, functional loss and even neuronal cell death in the Alzheimer's disease brain.

Distribution and characterization of the cell types expressing GALR2 mRNA in brain and pituitary gland

The neuropeptide galanin mediates its activities through G-protein-coupled receptors, and three receptor subtypes have been described with distinctly different patterns of regional tissue expression. GALR1 is predominantly expressed in basal forebrain, hypothalamus, as well as spinal cord. GALR2 has a wider distribution in brain and is also present in the pituitary gland and peripheral tissues. GALR3 has been found to be widely distributed at low abundance. We examined the distribution of GALR2 in rat brain and pituitary by in situ hybridization histochemistry and found it abundant in regions of hippocampus, piriform and entorhinal cortex, basal nucleus of the accessory olfactory tract, amygdala, hypothalamic nuclei, Purkinje cells, and discrete brainstem nuclei. It is also highly expressed in the intermediate and anterior lobes of the pituitary. Using combined in situ hybridization immunohistochemistry we characterized the neurotransmitter and hormonal phenotype of cells expressing GALR2 mRNA in the hypothalamus and pituitary gland. Our findings suggest GALR2 is a receptor mediating important functions of galanin in the hypothalamic-pituitary axis and may also play a role in hippocampal and cerebellar function.

Gene structure and map location of the murine homolog of the Huntington-associated protein, Hap1

Huntington's Disease (HD) is an inherited progressive neurodegenerative disorder associated with a mutation in a gene expressed in both affected and non-affected tissues. The selective neuropathology in HD is thought to be mediated in part through interactions with other proteins including the Huntington Associated Protein, HAP-1, which is predominantly expressed in the brain. We have mapped its murine homolog, Hap1, to mouse Chr 11 (band D), which shares extensive synteny with human Chr 17 including the region 17q21-q22, where the gene for 'frontotemporal dementia and parkinsonism linked to chromosome 17' has bee mapped. In addition, we have sequenced a 21,984 base pair (bp) genomic clone encompassing the entire Hap1 gene. It is organized as 11 exons and flanked by exons from potentially one or more novel genes. At least three Hap1 transcripts (Hap1-A; Hap1-B; Hap1-C) can be formed by alternative splicing at the 3' end of the gene leading to protein isoforms with novel C-termini.

HIP1, a human homologue of S. cerevisiae Sla2p, interacts with membrane-associated huntingtin in the brain

Huntington disease (HD) is associated with the expansion of a polyglutamine tract, greater than 35 repeats, in the HD gene product, huntingtin. Here we describe a novel huntingtin interacting protein, HIP1, which co-localizes with huntingtin and shares sequence homology and biochemical characteristics with Sla2p, a protein essential for function of the cytoskeleton in Saccharomyces cerevisiae. The huntingtin-HIP1 interaction is restricted to the brain and is inversely correlated to the polyglutamine length in huntingtin. This provides the first molecular link between huntingtin and the neuronal cytoskeleton and suggests that, in HD, loss of normal huntingtin-HIP1 interaction may contribute to a defect in membrane-cytoskeletal integrity in the brain.

Contribution of DNA sequence and CAG size to mutation frequencies of intermediate alleles for Huntington disease: evidence from single sperm analyses

New mutations for Huntington disease (HD) arise from intermediate alleles (IAs) with between 29 and 35 CAG repeats that expand on transmission through the paternal germline to 36 CAGs or greater. Using single sperm analysis, we have assessed CAG mutation frequencies for four IAs in families with sporadic HD (IANM) and IAs ascertained from the general population (IAGP) by analyzing 1161 single sperm from three persons. We show that IANM are more unstable than IAGP with identical size and sequence. Furthermore, comparison of different sized IAs and IAs with different sequences between the CAG and the adjacent CCG tracts indicates that DNA sequence is a major influence on CAG stability. These studies provide estimates of the likelihood of expansion of IANM and IAGP to > or = 36 CAG repeats for these individuals. For an IA with a CAG of 35 in this family with sporadic HD, the likelihood for siblings to inherit a recurrent mutation > or = 36 CAG is approximately 10%. For IAGP of a similar size, the risk of inheriting an expanded allele of > or = 36 CAG through the paternal germline is approximately 6%. These risk estimates are higher than previously reported and provide additional information for counselling in these families. Further studies on persons with IAs will be needed to determine whether these results can be generalized to other families.

Somatic mosaicism in sperm is associated with intergenerational (CAG)n changes in Huntington disease

We have analysed the CAG repeat in the Huntington disease (HD) gene in sperm and blood from 20 unrelated HD patients. Although the CAG repeat displayed significant mosaicism in sperm from all individuals, there were marked differences in the degree of repeat instability. Individuals who had either inherited or transmitted an expanded CAG repeat displayed the highest levels of repeat mosaicism, whereas individuals who had inherited or transmitted a contracted repeat had very limited CAG mosaicism in sperm. A strong association between intergenerational change in CAG allele size and the level of sperm repeat mosaicism was determined (P = 0.019). In contrast, neither blood CAG size nor repeat mosaicism in blood, were significantly associated with intergenerational CAG changes. These data suggest the presence of a cis-acting factor, separate from CAG size, that strongly influences the intergenerational behaviour of the CAG repeat. Additional studies are needed to determine whether analysis of CAG mosaicism in sperm is useful for assessing an individual's risk for transmitting large expansions or contractions to his offspring.

Ancestral differences in the distribution of the delta 2642 glutamic acid polymorphism is associated with varying CAG repeat lengths on normal chromosomes: insights into the genetic evolution of Huntington disease

This study addresses genetic factors associated with normal variation of the CAG repeat in the Huntington disease (HD) gene. To achieve this, we have studied patterns of variation of three trinucleotide repeats in the HD gene including the CAG and adjacent CCG repeats as well as a GAG polymorphism at residue 2642 (delta 2642). We have previously demonstrated that variation in the CCG repeat is associated with variation of the CAG repeat length on normal chromosomes. Here we show that differences in the GAG trinucleotide polymorphism at residue 2642 is also significantly correlated with CAG size on normal chromosomes. The B allele which is associated with higher CAG repeat lengths on normal chromosomes is markedly enriched on affected chromosomes. Furthermore, this glutamic acid polymorphism shows significant variation in different ancestries and is absent in chromosomes of Japanese, Black and Chinese descent. Haplotype analysis of both the CCG and delta 2642 polymorphisms have indicated that both are independently associated with differences in CAG length on normal chromosomes. These findings lead to a model for the genetic evolution of new mutations for HD preferentially occurring on normal chromosomes with higher CAG repeat lengths and a CCG repeat length of seven and/or a deletion of the glutamic acid residue at delta 2642. This study also provides additional evidence for genetic contributions to demographic differences in prevalence rates for HD.

DNA haplotype analysis of Huntington disease reveals clues to the origins and mechanisms of CAG expansion and reasons for geographic variations of prevalence

This study of allelic association using three intra- and two extragenic markers within 150 kb of the Huntington disease (HD) mutation has provided evidence for linkage disequilibrium for four of five markers. Haplotype analysis of 67 HD families using markers in strong linkage disequilibrium with HD identified two haplotypes underlying 77.6% of HD chromosomes. Normal chromosomes with these two haplotypes had a mean number of CAG repeats significantly larger than and an altered distribution of CAG repeats compared with other normal chromosomes. Furthermore, haplotype analysis of five new mutation families reveals that HD has arisen on these same two chromosomal haplotypes. These findings suggest that HD arises more frequently on chromosomes with specific DNA haplotypes and higher CAG repeat lengths. We then studied CAG and CCG repeat lengths in the HD gene on 896 control chromosomes from different ancestries to determine whether the markedly reduced frequency of HD in Finland, Japan, China and African Blacks is associated with an altered frequency of DNA haplotypes and subsequently lower CAG lengths on control chromosomes compared to populations of Western European descent. The results show a highly significant inverse relationship between CAG and CCG repeat lengths. In populations with lowered prevalence rates of HD, CAG repeat lengths are smaller and the distribution of CCG alleles is markedly different from Western European populations. These findings suggest that, in addition to European emigration, new mutations make a contribution to geographical variation of prevalence rates and is consistent with a multistep model of HD developing from normal chromosomes with higher CAG repeat lengths.

Implementing a mass influenza vaccination program

A 15-site health maintenance organization (HMO) implemented a mass influenza vaccination program to heighten awareness of the vaccine and immunize more "at-risk" members. Successful interventions conducted over a two-year period included: a direct mail leaflet, pharmacy bag reminders, posters at each medical center, articles in the HMO member newsletter, staff education, standing orders for nursing and, most important, the availability and access to vaccination through walk-in clinics. Immunization rates were examined for patients considered "at-risk." In addition, assessments were made to determine program effectiveness and patient and staff satisfaction.

Hospital-based strategies for improving influenza vaccination rates

BACKGROUND

Patients at highest risk for complications from influenza have the lowest rates of vaccination. Each year there are thousands of deaths related to influenza. Many of those who are hospitalized or who die from influenza-related conditions were hospitalized during the preceding influenza vaccination season but not vaccinated.

METHODS

Six community hospitals in northern Minnesota participated in a pilot project to assess the feasibility and effectiveness of three different community hospital-based influenza vaccination programs during the 1991-1992 immunization season. Records of patients discharged from each institution during November and December 1991 were reviewed for documentation of indications for influenza immunization and to determine whether vaccination was offered and whether vaccination occurred before discharge.

RESULTS

In hospitals choosing to implement standing orders for their nursing staffs to review indications for influenza vaccination and administer if indicated, 95.2% of patients were offered vaccination. In hospitals depending on physician chart reminders, 22% of patients were offered vaccination. In hospitals relying on physician education strategies to promote influenza vaccine, only 11.7% of patients were offered vaccination. Documented immunization rates in these three groups were 40.3%, 17%, and 9.6%, respectively.

CONCLUSIONS

Programs implementing standing orders for nursing staffs were more effective than educational programs or physician reminders in offering and administering influenza vaccine to hospitalized patients. Hospital policies can expand the number of high-risk and elderly persons who receive influenza vaccination each year, but hospitals need to be reimbursed for this service to ensure institutional support.

Adenosine modulation of potassium currents in postganglionic neurones of cultured avian ciliary ganglia

1. Potassium currents in cultured postganglionic neurones of avian ciliary ganglia were analysed under whole-cell voltage clamp and their modulation by adenosine determined. 2. In the presence of tetrodotoxin (200 nM), and with moderate holding potentials (Vh = -40 mV), the steady-state current-voltage (I/V) curve was N-shaped over the range from -70 mV to +155 mV. CsCl (1 M) blocked the current, indicating that it was carried by K+. If Ca2+ influx was blocked by CdCl2 (500 microM) then the outward current was reduced and the N-shaped I-V curve lost, indicating the presence of a calcium-activated potassium current (IK(Ca)); the remaining current, due to the delayed rectifier (IK), increased with depolarization up to about a conductance of 10 nS near + 50 mV. This IK was 50% activated at about +20 mV and 50% inactivated at about -50 mV. Adenosine (10 microM) had similar affects on the N-shaped I/V curve as did CdCl2, indicating that it blocked IK(Ca). However, adenosine had little affect on the steady-state current in the presence of CdCl, indicating that it did not much affect IK. 3. In the presence of tetrodotoxin (200 nM), a large inward current occurred for large hyperpolarizations from a Vh = -50 mV. This inward rectifying current (IIR) had a reversal potential near EK and showed 50% activation at about -130 mV. Adenosine (10 microM) reduced IIR, by as much as 50% at large hyperpolarizations beyond -80 mV. 4. Relaxations of the outward current on hyperpolarization from Vh = -30mV were blocked by carbachol (10 microM), had a reversal potential near EK, and an I/V curve typical of 1M currents. These currents were little affected by adenosine (10 microM). 5. A fast transient outward current, due to depolarizing pulses from a large Vh = -110mV was observed in the presence of tetrodotoxin (200 nM). This had the characteristics of an IA current as it could be blocked with 4-aminopyridine (5 mM) and was 50% activated at about -20 mV and 50% inactivated at about -94 mV. The IA current was reduced by 42% at a depolarization of -20 mV by adenosine (10 microM). 6. Many neurones possessed a fast transient outward current that was blocked by tetrodotoxin (200nM). This current could be blocked with 4-aminopyridine (5mM); it therefore has the characteristics of a sodium-activated potassium current ('K(Na)). This IK(Na) was unaffected by adenosine (1O microM). 7. These results are discussed in relation to the role of adenosine in blocking Ca2 + channels and thereby modifying calcium-dependent components of K+ currents.

Fungal infection associated with intravenous drug abuse: a case of localized cerebral phycomycosis

The authors present a case of confusion and mood disturbance caused by a focal cerebral fungal (phycomycosis) infection in an otherwise healthy intravenous drug addict. A review of the literature found only 9 cases of phycomycosis with localized cerebral involvement. This report describes the sixth occurrence of phycomycosis in an intravenous drug addict (the fifth to localize in the basal ganglia). In addition to the human immunodeficiency virus, unusual infectious causes of confusion and mood disturbance may be increasing as the intravenous drug-using population expands. Recognition of the clinical features of a fungal infection in a high-risk population may lead to earlier diagnosis and more effective treatment of this uniformly fatal disease. The clinician should consider localized cerebral phycomycosis as a cause of confusion and mood disturbance in intravenous drug addicts, especially when there is evidence of basal ganglia involvement.