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Flublok Quadrivalent Vaccine Adjuvanted with R-DOTAP Elicits a Robust and Multifunctional CD4 T Cell Response That Is of Greater Magnitude and Functional Diversity Than Conventional Adjuvant Systems. Vaccines (Basel) 2024; 12:281. [PMID: 38543915 PMCID: PMC10975948 DOI: 10.3390/vaccines12030281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 02/20/2024] [Accepted: 02/29/2024] [Indexed: 04/01/2024] Open
Abstract
It is clear that new approaches are needed to promote broadly protective immunity to viral pathogens, particularly those that are prone to mutation and escape from antibody-mediated immunity. CD4+ T cells, known to target many viral proteins and highly conserved peptide epitopes, can contribute greatly to protective immunity through multiple mechanisms. Despite this potential, CD4+ T cells are often poorly recruited by current vaccine strategies. Here, we have analyzed a promising new adjuvant (R-DOTAP), as well as conventional adjuvant systems AddaVax with or without an added TLR9 agonist CpG, to promote CD4+ T cell responses to the licensed vaccine Flublok containing H1, H3, and HA-B proteins. Our studies, using a preclinical mouse model of vaccination, revealed that the addition of R-DOTAP to Flublok dramatically enhances the magnitude and functionality of CD4+ T cells specific for HA-derived CD4+ T cell epitopes, far outperforming conventional adjuvant systems based on cytokine EliSpot assays and multiparameter flow cytometry. The elicited CD4+ T cells specific for HA-derived epitopes produce IL-2, IFN-γ, IL-4/5, and granzyme B and have multifunctional potential. Hence, R-DOTAP, which has been verified safe by human studies, can offer exciting opportunities as an immune stimulant for next-generation prophylactic recombinant protein-based vaccines.
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Wildlife health surveillance: gaps, needs and opportunities. REV SCI TECH OIE 2023; 42:161-172. [PMID: 37232308 DOI: 10.20506/rst.42.3359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Disease emergence represents a global threat to public health, economy and biological conservation. Most emerging zoonotic diseases have an animal origin, most commonly from wildlife. To prevent their spread and to support the implementation of control measures, disease surveillance and reporting systems are needed, and due to globalisation, these activities should be carried out at the global level. To define the main gaps affecting the performance of wildlife health surveillance and reporting systems globally, the authors analysed data from a questionnaire sent to National Focal Points of the World Organisation for Animal Health that inquired on structure and limits of wildlife surveillance and reporting systems in their territories. Responses from 103 Members, covering all areas of the globe, revealed that 54.4% have a wildlife disease surveillance programme and 66% have implemented a strategy to manage disease spread. The lack of dedicated budget affected the possibility of outbreak investigations, sample collection and diagnostic testing. Although most Members maintain records relating to wildlife mortality or morbidity events in centralised databases, data analysis and disease risk assessment are reported as priority needs. The authors' evaluation of surveillance capacity found an overall low level, with marked variability among Members that was not restricted to a specific geographical area. Increased wildlife disease surveillance globally would help in understanding and managing risks to animal and public health. Moreover, consideration of the influence of socio-economic, cultural and biodiversity aspects could improve disease surveillance under a One Health approach.
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Development of a Mouse Model to Explore CD4 T Cell Specificity, Phenotype, and Recruitment to the Lung after Influenza B Infection. Pathogens 2022; 11:251. [PMID: 35215193 PMCID: PMC8875387 DOI: 10.3390/pathogens11020251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 02/05/2022] [Accepted: 02/08/2022] [Indexed: 01/30/2023] Open
Abstract
The adaptive T cell response to influenza B virus is understudied, relative to influenza A virus, for which there has been considerable attention and progress for many decades. Here, we have developed and utilized the C57BL/6 mouse model of intranasal infection with influenza B (B/Brisbane/60/2008) virus and, using an iterative peptide discovery strategy, have identified a series of robustly elicited individual CD4 T cell peptide specificities. The CD4 T cell repertoire encompassed at least eleven major epitopes distributed across hemagglutinin, nucleoprotein, neuraminidase, and non-structural protein 1 and are readily detected in the draining lymph node, spleen, and lung. Within the lung, the CD4 T cells are localized to both lung vasculature and tissue but are highly enriched in the lung tissue after infection. When studied by flow cytometry and MHC class II: peptide tetramers, CD4 T cells express prototypical markers of tissue residency including CD69, CD103, and high surface levels of CD11a. Collectively, our studies will enable more sophisticated analyses of influenza B virus infection, where the fate and function of the influenza B-specific CD4 T cells elicited by infection and vaccination can be studied as well as the impact of anti-viral reagents and candidate vaccines on the abundance, functionality, and localization of the elicited CD4 T cells.
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Differences in Influenza-Specific CD4 T-Cell Mediated Immunity Following Acute Infection Versus Inactivated Vaccination in Children. J Infect Dis 2020; 223:2164-2173. [PMID: 33074330 DOI: 10.1093/infdis/jiaa664] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 10/16/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Early childhood influenza infections imprint influenza-specific immune memory, with most studies evaluating antibody specificity. In this study, we examined how infection versus inactivated influenza vaccination (IIV) establish pediatric CD4 T-cell mediated immunity to influenza and whether this poises the immune system to respond differently to IIV the following year. METHODS We tracked influenza-specific CD4 T-cell responses in 16 H3N2 infected and 28 IIV immunized children following both initial exposure and after cohorts were revaccinated with IIV the following fall. PBMCs were stimulated with peptide pools encompassing the translated regions of the H3 HA and NP proteins and were then stained to assess CD4 T-cell specificity and function. RESULTS Compared to IIV, infection primed a greater magnitude CD4 T-cell response specific for the infecting HA and NP proteins, with more robust NP-specific immunity persisting through year 2. Post infection, CD4 T cells preferentially produced combinations of cytokines that included interferon-γ. Interestingly, age-specific patterns in CD4 T-cell reactivity demonstrated the impact of multiple influenza exposures over time. CONCLUSIONS These data indicate that infection and vaccination differentially prime influenza-specific CD4 T-cell responses in early childhood, with these differences contributing to the lasting immunologic imprinting established following early influenza infection. CLINICAL TRIALS REGISTRATION NCT02559505.
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Abstract
Live attenuated influenza vaccine (LAIV), or FluMist, was approved for use in the United States in 2003. This vaccine, administered intranasally, offers the advantage of stimulating immunity at the site of infection in the upper respiratory tract and, by mimicking natural infection, has the potential to elicit a multifaceted immune response. However, the development of immunity following LAIV administration requires viral replication, causing vaccine effectiveness to be impacted by both the replicative fitness of the attenuated viruses being administered and the degree of the host's preexisting immunity. In this review, we discuss the current state of knowledge regarding the mechanisms of protection elicited by LAIV in children, contrast this with immune protection that develops upon vaccination with inactivated influenza vaccines, and briefly discuss both the potential advantages as well as challenges offered by this vaccination platform.
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Abstract
Climate change, habitat fragmentation and pollution, and subsequent loss of biodiversity and degradation of natural environments, threaten the range of ecosystem services that support all life on this planet. These changes, among others, are also driving the emergence of infectious diseases, with negative health outcomes for humans, animals, and our shared environment. Historically, interventions aimed at human and agricultural health issues did not always integrate wildlife or environmental health as part of the solution, which has resulted in unintended consequences. One Health recognises the interdependence of humans, animals and their shared environment, and provides a conceptual framework for developing interventions that optimise outcomes for human, animal and environmental health. However, there is a need to clearly articulate the core values, goals, and objectives of One Health for all relevant sectors in order to maximise synergies for communication, coordination, collaboration and, ultimately, for joint actions on disease control and prevention. The application of systems and harm reduction approaches, focusing on the socio-economic and environmental determinants of health, and ensuring good governance and effective leadership will also maximise the opportunities to develop 'win-win-win' solutions to global health and environmental challenges. These solutions would help propel One Health forward to reach its full potential and truly optimise health outcomes for all.
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Differences in the influenza-specific CD4 T cell immunodominance hierarchy and functional potential between children and young adults. Sci Rep 2019; 9:791. [PMID: 30692574 PMCID: PMC6349841 DOI: 10.1038/s41598-018-37167-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 12/04/2018] [Indexed: 01/31/2023] Open
Abstract
Studies of the B cell repertoire suggest that early childhood influenza infections profoundly shape later reactivity by creating an “imprint” that impacts subsequent vaccine responses and may provide lasting protection against influenza strains within the same viral group. However, there is little known about how these early childhood influenza exposures shape CD4 T cell reactivity later in life. To investigate the effect of age on influenza-specific CD4 T cell specificity and functionality, reactivity in cohorts of 2 year old children and young adult subjects was compared. Intracellular cytokine staining was used to determine the viral antigen specificity and expression levels of various cytokines following stimulation of peripheral blood mononuclear cells with complete peptide pools representing the entire translated sequences of the pH1, H3, HA-B, NP, and M1 proteins. We found that the influenza protein-specific immunodominance pattern in children differs from that in young adults, with much lower reactivity to the NP internal virion protein in young children. Alterations in CD4 T cell functionality were also noted, as responding CD4 T cells from children produced less IFNγ and were less likely to express multiple cytokines. These differences in the repertoire of influenza-specific CD4 T cells available for recall on influenza challenge in early childhood could possibly contribute to early imprinting of influenza-specific immunity as well as the increased susceptibility of children to this viral infection.
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Selective pre-priming of HA-specific CD4 T cells restores immunological reactivity to HA on heterosubtypic influenza infection. PLoS One 2017; 12:e0176407. [PMID: 28493882 PMCID: PMC5426616 DOI: 10.1371/journal.pone.0176407] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 04/09/2017] [Indexed: 01/07/2023] Open
Abstract
A hallmark of the immune response to influenza is repeated encounters with proteins containing both genetically conserved and variable components. Therefore, the B and T cell repertoire is continually being remodeled, with competition between memory and naïve lymphocytes. Our previous work using a mouse model of secondary heterosubtypic influenza infection has shown that this competition results in a focusing of CD4 T cell response specificity towards internal virion proteins with a selective decrease in CD4 T cell reactivity to the novel HA epitopes. Strikingly, this shift in CD4 T cell specificity was associated with a diminished anti-HA antibody response. Here, we sought to determine whether the loss in HA-specific reactivity that occurs as a consequence of immunological memory could be reversed by selectively priming HA-specific CD4 T cells prior to secondary infection. Using a peptide-based priming strategy, we found that selective expansion of the anti-HA CD4 T cell memory repertoire enhanced HA-specific antibody production upon heterosubtypic infection. These results suggest that the potentially deleterious consequences of repeated exposure to conserved influenza internal virion proteins could be reversed by vaccination strategies that selectively arm the HA-specific CD4 T cell compartment. This could be a potentially useful pre-pandemic vaccination strategy to promote accelerated neutralizing antibody production on challenge with a pandemic influenza strain that contains few conserved HA epitopes.
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MESH Headings
- Animals
- Antibodies, Neutralizing/immunology
- Antibodies, Neutralizing/therapeutic use
- Antibodies, Viral/immunology
- Antibodies, Viral/therapeutic use
- CD4-Positive T-Lymphocytes/immunology
- Epitopes/immunology
- Hemagglutinins, Viral/immunology
- Humans
- Immunologic Memory
- Influenza A Virus, H1N1 Subtype/immunology
- Influenza A Virus, H1N1 Subtype/pathogenicity
- Influenza Vaccines/immunology
- Influenza Vaccines/therapeutic use
- Influenza, Human/immunology
- Influenza, Human/prevention & control
- Influenza, Human/virology
- Mice
- Pandemics
- Vaccination
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Natural Infections With Pigeon Paramyxovirus Serotype 1: Pathologic Changes in Eurasian Collared-Doves ( Streptopelia decaocto) and Rock Pigeons ( Columba livia) in the United States. Vet Pathol 2017; 54:695-703. [PMID: 28382855 DOI: 10.1177/0300985817695782] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Pigeon paramyxovirus serotype 1 (PPMV-1) is a globally distributed, virulent member of the avian paramyxovirus serotype 1 serogroup that causes mortality in columbiformes and poultry. Following introduction into the United States in the mid-1980s, PPMV-1 rapidly spread causing numerous mortality events in Eurasian collared-doves ( Streptopelia decaocto) (ECDOs) and rock pigeons ( Columba livia) (ROPIs). The investigators reviewed pathological findings of 70 naturally infected, free-ranging columbiforms from 25 different mortality events in the United States. Immunohistochemistry targeting PPMV-1 nucleoprotein was used to determine the tissue distribution of the virus in a subset of 17 birds from 10 of the studied outbreaks. ECDOs (61 birds) and ROPIs (9 birds) were the only species in which PPMV-1-associated disease was confirmed by viral isolation and presence of histologic lesions. Acute to subacute tubulointerstitial nephritis and necrotizing pancreatitis were the most frequent histologic lesions, with immunolabeling of viral antigen in renal tubular epithelial cells and pancreatic acinar epithelium. Lymphoid depletion of bursa of Fabricius and spleen was common, but the presence of viral antigen in these organs was inconsistent among infected birds. Hepatocellular necrosis was occasionally present with immunolabeling of hypertrophic Kupffer cells, and immunopositive eosinophilic intracytoplasmic inclusion bodies were present in hepatocytes of 1 ECDO. Immunopositive lymphocytic choroiditis was present in 1 ECDO, while lymphocytic meningoencephalitis was frequent in ROPIs in absence of immunolabeling. This study demonstrates widespread presence of PPMV-1 antigen in association with histologic lesions, confirming the lethal potential of this virus in these particular bird species.
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Widespread detection of highly pathogenic H5 influenza viruses in wild birds from the Pacific Flyway of the United States. Sci Rep 2016; 6:28980. [PMID: 27381241 PMCID: PMC4933915 DOI: 10.1038/srep28980] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 06/08/2016] [Indexed: 01/21/2023] Open
Abstract
A novel highly pathogenic avian influenza virus belonging to the H5 clade 2.3.4.4 variant viruses was detected in North America in late 2014. Motivated by the identification of these viruses in domestic poultry in Canada, an intensive study was initiated to conduct highly pathogenic avian influenza surveillance in wild birds in the Pacific Flyway of the United States. A total of 4,729 hunter-harvested wild birds were sampled and highly pathogenic avian influenza virus was detected in 1.3% (n = 63). Three H5 clade 2.3.4.4 subtypes were isolated from wild birds, H5N2, H5N8, and H5N1, representing the wholly Eurasian lineage H5N8 and two novel reassortant viruses. Testing of 150 additional wild birds during avian morbidity and mortality investigations in Washington yielded 10 (6.7%) additional highly pathogenic avian influenza isolates (H5N8 = 3 and H5N2 = 7). The geographically widespread detection of these viruses in apparently healthy wild waterfowl suggest that the H5 clade 2.3.4.4 variant viruses may behave similarly in this taxonomic group whereby many waterfowl species are susceptible to infection but do not demonstrate obvious clinical disease. Despite these findings in wild waterfowl, mortality has been documented for some wild bird species and losses in US domestic poultry during the first half of 2015 were unprecedented.
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Abstract
OBJECTIVES To determine whether TMEM106B single nucleotide polymorphisms (SNPs) are associated with frontotemporal lobar degeneration (FTLD) in patients with and without mutations in progranulin (GRN) and to determine whether TMEM106B modulates GRN expression. METHODS We performed a case-control study of 3 SNPs in TMEM106B in 482 patients with clinical and 80 patients with pathologic FTLD-TAR DNA-binding protein 43 without GRN mutations, 78 patients with FTLD with GRN mutations, and 822 controls. Association analysis of TMEM106B with GRN plasma levels was performed in 1,013 controls and TMEM106B and GRN mRNA expression levels were correlated in peripheral blood samples from 33 patients with FTLD and 150 controls. RESULTS In our complete FTLD patient cohort, nominal significance was identified for 2 TMEM106B SNPs (top SNP rs1990622, p(allelic) = 0.036). However, the most significant association with risk of FTLD was observed in the subgroup of GRN mutation carriers compared to controls (corrected p(allelic) = 0.0009), where there was a highly significant decrease in the frequency of homozygote carriers of the minor alleles of all TMEM106B SNPs (top SNP rs1990622, CC genotype frequency 2.6% vs 19.1%, corrected p(recessive) = 0.009). We further identified a significant association of TMEM106B SNPs with plasma GRN levels in controls (top SNP rs1990622, corrected p = 0.002) and in peripheral blood samples a highly significant correlation was observed between TMEM106B and GRN mRNA expression in patients with FTLD (r = -0.63, p = 7.7 × 10(-5)) and controls (r = -0.49, p = 2.2 × 10(-10)). CONCLUSIONS In our study, TMEM106B SNPs significantly reduced the disease penetrance in patients with GRN mutations, potentially by modulating GRN levels. These findings hold promise for the development of future protective therapies for FTLD.
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A combinatorial approach to screening carbon based materials for respiratory protection. JOURNAL OF HAZARDOUS MATERIALS 2010; 183:677-687. [PMID: 20727674 DOI: 10.1016/j.jhazmat.2010.07.079] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Revised: 07/09/2010] [Accepted: 07/19/2010] [Indexed: 05/29/2023]
Abstract
A combinatorial materials science approach for the discovery of an impregnated activated carbon that can adsorb a wide variety of toxic gases (i.e. a multi-gas carbon) has been developed. This approach presently allows for the parallel preparation and investigation of 64-100 IAC samples at once increasing the rate of discovery of viable multi-gas carbons. Multi-gas carbons were prepared using a solutions handling robot and screened gravimetrically for their effectiveness as gas adsorbents. The method was validated using known gas adsorbent materials such as ZnCl(2), K(2)CO(3) and CuO-impregnated carbons. The calculated adsorption capacities and stoichiometric ratios of reactions for these known gas adsorbent materials, when evaluated using the combinatorial approach, was comparable to the values obtained using traditional methods of analysis. A library of samples prepared by combining various amounts of CuO and ZnO impregnants showed the expected decreasing trend in the calculated stoichiometric ratio of reaction with respect to increasing amount of impregnants added. The method is now ready to use to explore new systems of impregnated activated carbons.
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Inflammatory tumour cell killing by oncolytic reovirus for the treatment of melanoma. Gene Ther 2008; 15:1257-70. [PMID: 18401435 PMCID: PMC4821075 DOI: 10.1038/gt.2008.58] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Revised: 02/21/2008] [Accepted: 02/23/2008] [Indexed: 12/18/2022]
Abstract
Reovirus is a promising unmodified double-stranded RNA (dsRNA) anti-cancer oncolytic virus, which is thought to specifically target cells with activated Ras. Although reovirus has been tested in a wide range of preclinical models and has entered early clinical trials, it has not previously been tested for the treatment of human melanoma. Here, we show that reovirus effectively kills and replicates in both human melanoma cell lines and freshly resected tumour; intratumoural injection also causes regression of melanoma in a xenograft in vivo model. Reovirus-induced melanoma death is blocked by caspase inhibition and is dependent on constituents of the Ras/RalGEF/p38 pathway. Reovirus melanoma killing is more potent than, and distinct from, chemotherapy or radiotherapy-induced cell death; a range of inflammatory cytokines and chemokines are released by infected tumour cells, while IL-10 secretion is abrogated. Furthermore, the inflammatory response generated by reovirus-infected tumour cells causes bystander toxicity against reovirus-resistant tumour cells and activates human myeloid dendritic cells (DC) in vitro. Hence, reovirus is suitable for clinical testing in melanoma, and may provide a useful danger signal to reverse the immunologically suppressive environment characteristic of this tumour.
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Escherichia coli nitroreductase plus CB1954 enhances the effect of radiotherapy in vitro and in vivo. Gene Ther 2007; 15:424-33. [PMID: 18079753 DOI: 10.1038/sj.gt.3303081] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Escherichia coli nitroreductase (NTR) converts the prodrug CB1954 (5-(aziridin-1-yl)-2,4-dinitrobenzamide) into a bifunctional alkylating agent that causes DNA crosslinks. In this study, the ability of NTR to enhance the combined effects of CB1954 and radiation has been tested in vitro and in vivo. Stably transduced ovarian cancer cells (SKOV3-NTR) that are sensitive to CB1954 (IC(50)=0.35 muM) demonstrated enhanced cytotoxicity when treated with CB1954 and single-fraction irradiation. The NTR-CB1954 system mediated a bystander effect in combination with radiation on transfer of conditioned medium from SKOV3-NTR, but not SKOV3, cells to SW480 target cells. The ability of CB1954 to enhance radiation-induced cytotoxicity in SKOV3-NTR (but not SKOV3) cells was also demonstrated by fluorescence-activated cell sorting (FACS) with dual staining for propidium iodide/fluorescein diacetate, 4',6-diamidino-2-phenylindole dichloride staining of apoptotic cells and measurement of double-stranded DNA breaks by FACS and confocal microscopy for gammaH2AX foci. Adenoviral delivery of NTR, under constitutive cytomegalovirus or tissue-specific CTP1 promoters, increased the in vitro cytotoxicity of CB1954 plus radiation in MTT and clonogenic assays. Finally, adenoviral delivery of NTR plus CB1954 enhanced the effect of fractionated radiotherapy (12 Gy in four fractions) in SW480 xenograft tumours in nude mice.
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Probing colloidal forces between a Si3N4 AFM tip and single nanoparticles of silica and alumina. J Colloid Interface Sci 2006; 303:627-38. [PMID: 16942778 DOI: 10.1016/j.jcis.2006.08.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2006] [Revised: 08/07/2006] [Accepted: 08/08/2006] [Indexed: 11/24/2022]
Abstract
The atomic force microscope (AFM) has been used to measure surface forces between silicon nitride AFM tips and individual nanoparticles deposited on substrates in 10(-4) and 10(-2) M KCl solutions. Silica nanoparticles (10 nm diameter) were deposited on an alumina substrate and alumina particles (5 to 80 nm diameter) were deposited on a mica substrate using aqueous suspensions. Ionic concentrations and pH were used to manage attractive substrate-particle electrostatic forces. The AFM tip was located on deposited nanoparticles using an operator controlled offset to achieve stepwise tip movements. Nanoparticles were found to have a negligible effect on long-range tip-substrate interactions, however, the forces between the tip and nanoparticle were detectable at small separations. Exponentially increasing short-range repulsive forces, attributed to the hydration forces, were observed for silica nanoparticles. The effective range of hydration forces was found to be 2-3 nm with the decay length of 0.8-1.3 nm. These parameters are in a good agreement with the results reported for macroscopic surfaces of silica obtained using the surface force apparatus suggesting that hydration forces for the silica nanoparticles are similar to those for flat silica surfaces. Hydration forces were not observed for either alumina substrates or alumina nanoparticles in both 10(-4) M KCl solution at pH 6.5 and 10(-2) M KCl at pH 10.2. Instead, strong attractive forces between the silicon nitride tip and the alumina (nanoparticles and substrate) were observed.
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Effect of a selective OX1R antagonist on food intake and body weight in two strains of rats that differ in susceptibility to dietary-induced obesity. Peptides 2005; 26:2331-8. [PMID: 15893404 DOI: 10.1016/j.peptides.2005.03.042] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Revised: 03/24/2005] [Accepted: 03/24/2005] [Indexed: 11/25/2022]
Abstract
An orexin-1 receptor antagonist decreases food intake whereas orexin-A selectively induces hyperphagia to a high-fat diet. In the present study, we evaluated the effect of an orexin antagonist in two strains of rats that differ in their sensitivity to becoming obese while eating a high-fat diet. Male Osborne-Mendel (OM) and S5B/Pl (S5B) rats were treated acutely with an orexin-1 receptor antagonist (SB-334867), after adaptation to either a high-fat (56% fat energy) diet or a low-fat (10% fat energy) diet that were equicaloric for protein (24% energy). Ad libitum fed rats were injected intraperitoneally with SB-334867 at doses of 3, 10 or 30 mg/kg, or vehicle at the beginning of the dark cycle, and food intake and body weight were measured. Hypothalamic prepro-orexin and orexin-1 receptor mRNA expression were analyzed in OM and S5B rats fed at a high-fat or low-fat diet for two weeks. SB-334867 significantly decreased food intake in both strains of rats eating the high-fat diet but only in the OM rats eating the low fat diet. The effect was greatest at 12 and 24 h. Body weight was also reduced in OM rats 1d after injection of SB-334867 but not in the S5B rats. Prepro-orexin and orexin-1 receptor expression levels did not differ between strains or diets. These experiments demonstrate that an orexin antagonist (SB-334867) reduces food intake and has a greater effect in a rat strain that is susceptible to dietary-induced obesity, than in a resistant strain.
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Abstract
Hippocampal sclerosis dementia (HSD) is a disease of unknown etiology and pathogenesis. To determine whether HSD cases could be reclassified as variants of frontotemporal dementia (FTD), a heterogeneous group of disorders, 18 brain autopsy cases previously diagnosed as HSD were re-evaluated. In 11 cases, ubiquitinated neuronal inclusions, similar to those of motor neuron disease inclusion dementia (MNDID), were found. Brain levels of soluble and insoluble tau were normal. Most patients with pathologic findings of HSD may actually have the MNDID variant of FTD.
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Frontotemporal and motor neurone degeneration with neurofilament inclusion bodies: additional evidence for overlap between FTD and ALS. Neuropathol Appl Neurobiol 2003; 29:239-53. [PMID: 12787321 DOI: 10.1046/j.1365-2990.2003.00466.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We present the case of a patient who had clinical frontal lobe dementia without apparent motor neurone disease (MND), with pathologic findings not typical of any single currently classified frontotemporal degeneration (FTD). At autopsy, the brain had frontal and temporal atrophy with neuronal loss, gliosis, and superficial spongiosis, typical of all FTDs. There were at least three different morphologic types of intracytoplasmic neuronal inclusions in a variety of brain and brainstem regions, including the hippocampal dentate gyrus and pyramidal neurones, the neocortex (in particular, the motor cortex), basal ganglia, thalamus, subthalamic nucleus, basis pontis, and inferior olivary nuclei. Inclusions had the morphologies of Pick-like bodies, pleomorphic inclusions, and hyaline conglomerate (HC)-like inclusions. None of these were positive with tau immunostains. Pick-like bodies in the dentate gyrus were labelled with ubiquitin. The pleomorphic inclusions in the neocortex and dentate gyrus and the HC-like inclusions in the motor and parietal cortex were strongly positive with immunostains for neurofilament. We discuss the differential diagnosis and compare this case with those disorders to which it is most similar. In particular, we compare the unique neurofilament-positive inclusions to the inclusions of FTD-MND, to Pick bodies, and to the basophilic and HC inclusions that are occasionally seen in amytrophic lateral sclerosis (ALS). Although FTD-MND may be found in ALS, the findings in this case may have additional implications for a link between FTD and ALS.
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Synapse loss is greater in presenile than senile onset Alzheimer disease: implications for the cognitive reserve hypothesis. Neuropathol Appl Neurobiol 2002; 28:218-27. [PMID: 12060346 DOI: 10.1046/j.1365-2990.2002.00385.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the past, 'Alzheimer disease' (AD) referred to pathologic AD with clinical onset of dementia in the presenium, while 'senile dementia of the Alzheimer type' (SDAT) referred to senile onset AD. Because AD appears clinically homogeneous regardless of age of onset, the two subtypes in more recent years have not been distinguished. Pathologic differences have been noted, but synapse loss has not previously been compared between the two groups. Hypothesizing that synapse loss would be greater in presenile onset than senile onset AD, we compared synapse loss, as well as Alzheimer pathology in presenile and senile onset AD, using an ELISA method to quantify synaptophysin. Synaptophysin was significantly lower in presenile than senile AD in right frontal and bilateral parietal lobes. Neuritic plaque counts were significantly higher in presenile than senile AD in bilateral frontal and parietal lobes. Semi-quantitative evaluation of neurofibrillary tangles revealed significantly more tangles in bilateral frontal and parietal lobes in presenile than senile AD. Brain weight was significantly lower in presenile than senile AD. The differences in synapse loss and Alzheimer-type pathology in presenile and senile onset AD support the hypothesis that 'cognitive reserve' protects the human brain from neurodegenerative disease.
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Continuity of care for short-stay neurosurgery patients: a quality improvement initiative. AXONE (DARTMOUTH, N.S.) 2001; 23:14-21. [PMID: 14621497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Decreases in the length of hospital stay for patients undergoing spinal surgery prompted this evaluation of the post-discharge needs of patients and the strategies that patients and their families employ to meet these needs. The nature and extent of post-discharge problems experienced by newly discharged patients was required as a baseline for the evaluation and improvement of discharge planning. Forty patients were interviewed following discharge, 20 patients within the first week of discharge, and 20 different patients between three and four weeks after discharge. Most patients reported that they had been well-informed about pain management and the majority of patients reported that pain was well-controlled. There was a subset of patients, however, who continued to report high levels of pain, even at one month after discharge. Less than one in three patients stated that they had received information about wound care and the information received was not consistent among health professionals. Given the limited time to prepare patients for discharge, this project highlights the need for written materials and for systematic follow-up after discharge.
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Contribution of asymmetric synapse loss to lateralizing clinical deficits in frontotemporal dementias. ARCHIVES OF NEUROLOGY 2001; 58:1233-9. [PMID: 11493163 DOI: 10.1001/archneur.58.8.1233] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Synapse loss has been found to be the major correlate of cognitive decline in Alzheimer disease (AD), and prefrontal synapse loss has been found in patients with frontotemporal dementia (FTD). OBJECTIVE To see if our hypothesis that within each FTD case, regional synapse loss would correlate with lateralizing neuropsychologic and neurobehavioral deficits would be correct. DESIGN We analyzed synaptophysin as a marker for synapse loss in snap-frozen brain samples, using an enzyme-linked immunosorbent assay technique. Quantitative results were obtained by comparing patient data with a standard curve made by analyzing serial dilutions of a recombinant synaptophysin protein fragment. A board-certified neuropsychologist and a board-certified neurologist, both unaware of the synaptophysin results, determined areas of primary neuropsychologic and neurobehavioral dysfunction. Relationships between areas of primary dysfunction and synapse loss were analyzed using the binomial test. PATIENTS Six cases of FTD, 28 cases of AD, and 16 nondemented control subjects. RESULTS Five of 6 FTD cases had regional synaptophysins correlating with lateralizing frontal or temporal deficits. Three of 6 correlated in 2 or more regions. Although our results were higher than that expected based on a pure-chance mechanism (50% vs 34%), statistical significance was not attained. CONCLUSIONS We found a trend for an association between synapse loss and lateralizing neuropsychologic and neurobehavioral deficits in FTD. Studies in larger numbers of FTD cases are planned with the goal of attaining statistically significant conclusions.
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SPECT imaging in dementias. J Nucl Med 2001; 42:1131-3. [PMID: 11438640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
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Creatine supplementation. Recipe for victory or recipe for risk? ADVANCE FOR NURSE PRACTITIONERS 2001; 9:55-8. [PMID: 12400261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
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Abstract
Cortical synapse loss, the probable substrate of cognitive impairment in Alzheimer disease (AD), has not previously been evaluated in progressive supranuclear palsy (PSP). Hypothesizing that synapse loss would be greater in demented than non-demented PSP patients, we examined synaptophysin concentrations in 8 cases of PSP (5 demented and 3 nondemented cases). We found a decrease in mean synaptophysin concentration in these 8 cases in frontal, temporal, and parietal lobes, and in cerebellum, compared to the means in corresponding lobes of 16 controls. The decreases were similar to those in 28 cases of AD, but not as great. We determined synaptophysin concentration from motor cortex in only 4 of our PSP cases, 2 demented and 2 non-demented. The average concentrations in these 4 cases were lower than in AD motor cortex; both were lower than controls. When demented and non-demented PSP cases were compared, neocortical synaptophysin concentrations in non-demented PSP cases were lower than in demented cases. There appears to be a link between AD and PSP, in that synapse loss is found in both. However, the basis and significance of the prominent neocortical synapse loss in PSP, especially in non-demented subjects, remain to be explored.
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Frontal lobe dementia with novel tauopathy: sporadic multiple system tauopathy with dementia. J Neuropathol Exp Neurol 2001; 60:328-41. [PMID: 11305868 DOI: 10.1093/jnen/60.4.328] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We present a novel tauopathy in a patient with a 10-yr history of progressive frontal lobe dementia and a negative family history. Autopsy revealed mild atrophy of frontal and parietal lobes and severe atrophy of the temporal lobes. There were occasional filamentous tau-positive inclusions, but more interesting were numerous distinctive globular neuronal and glial tau-positive inclusions in both gray and white matter of the neocortex. Affected subcortical regions included substantia nigra, globus pallidus, subthalamic nucleus, and cerebellar dentate nucleus, in a distribution similar to progressive supranuclear palsy (PSP), but without significant accompanying neuronal loss or gliosis. Predominantly straight filaments were detected by electron microscopy (EM), while other inclusions were similar to fingerprint bodies. No twisted ribbons were detected. Immuno-EM studies revealed that only the filamentous inclusions were composed of tau. Immunoblotting of sarkosyl-insoluble tau revealed 2 major bands of 64 and 68 kDa. Blotting analysis after dephosphorylation revealed predominantly 4-repeat tau. Sequence analysis of tau revealed that there were no mutations in either exons 9-13 or the adjacent intronic sequences. The unique cortical tau pathology in this case of sporadic multiple system tauopathy with dementia adds a new pathologic profile to the spectrum of tauopathies.
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Recurrent (nonfamilial) hemangioblastomas involving spinal nerve roots: case report. Neurosurgery 2000; 47:1443-8. [PMID: 11126917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
OBJECTIVE AND IMPORTANCE Spinal nerve root hemangioblastomas are rare and are reported mainly in patients with von Hippel-Lindau (VHL) syndrome. The pathogenesis of so-called nonfamilial lesions is virtually unknown. We discuss, mainly from a molecular perspective, a unique patient with sporadic, recurrent hemangioblastomas restricted to spinal nerve roots. CLINICAL PRESENTATION A 53-year-old man who had had a surgically corrected lumbosacral meningomyelocele presented on at least three occasions during a 17-year period with multifocal capillary hemangioblastomas involving spinal nerve roots. On each occasion, tumors appeared on a different nerve root, with the majority located in the midcervical segments. The patient had no clinical features or family history of VHL syndrome. TECHNIQUE To obtain a clearer understanding of the pathogenesis of this unusual case and its relationship to VHL syndrome, molecular analysis of the VHL gene was performed by use of complete sequence analysis and loss of heterozygosity studies on deoxyribonucleic acid derived from the patient's blood leukocytes and three separately resected hemangioblastomas. CONCLUSION Germ-line molecular analysis performed on all three exons in the VHL gene coding region did not indicate that any mutations were present. Loss of heterozygosity analysis of deoxyribonucleic acid from the three hemangioblastoma resections showed normal heterozygosity in the 3p25-26 region. Complete VHL gene sequence analysis did not demonstrate a somatic mutation in the coding region of the VHL gene in any of the three tumors, thereby supporting the loss of heterozygosity data that a molecular event directly involving the VHL gene may not be the causative factor in their tumorigenesis.
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Reduced binding of protein phosphatase 2A to tau protein with frontotemporal dementia and parkinsonism linked to chromosome 17 mutations. J Neurochem 2000; 75:2155-62. [PMID: 11032905 DOI: 10.1046/j.1471-4159.2000.0752155.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Coding region and intronic mutations in the tau gene cause frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17). We have previously reported that ABalphaC, a major form of protein phosphatase 2A (PP2A) in brain, binds tightly to tau protein in vitro and is a major tau phosphatase in vivo. Using in vitro assays, we show here that the FTDP-17 mutations G272V, DeltaK280, P301L, P301S, S305N, V337M, G389R, and R406W inhibit by approximately 20-95% the binding of recombinant three-repeat and four-repeat tau isoforms to the ABalphaC holoenzyme and the AC core enzyme of PP2A. Reduction in binding was maximal for tau proteins with the G272V, DeltaK280, and V337M mutations. We also show that tau protein can be specifically coimmunoprecipitated with endogenous PP2A from both rat brain and transfected cell extracts. It is significant that, by using similar coimmunoprecipitation assays, we show that all FTDP-17 mutations tested, including the N279K mutation, alter the ability of tau to associate with cellular PP2A. Taken together, these results indicate that FTDP-17 mutations induce a significant decrease in the binding affinity of tau for PP2A in vivo. We propose that altered protein-protein interactions between PP2A and tau may contribute to FTDP-17 pathogenesis.
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A viral member of the ERV1/ALR protein family participates in a cytoplasmic pathway of disulfide bond formation. Proc Natl Acad Sci U S A 2000; 97:12068-73. [PMID: 11035794 PMCID: PMC17295 DOI: 10.1073/pnas.210397997] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Proteins of the ERV1/ALR family are encoded by all eukaryotes and cytoplasmic DNA viruses for which substantial sequence information is available. Nevertheless, the roles of these proteins are imprecisely known. Multiple alignments of ERV1/ALR proteins indicated an invariant C-X-X-C motif, but no similarity to the thioredoxin fold was revealed by secondary structure predictions. We chose a virus model to investigate the role of these proteins as thiol oxidoreductases. When cells were infected with a mutant vaccinia virus in which the E10R gene encoding an ERV1/ALR family protein was repressed, the disulfide bonds of three other viral proteins-namely, the L1R and F9L proteins and the G4L glutaredoxin-were completely reduced. The same outcome occurred when Cys-43 or Cys-46, the putative redox cysteines of the E10R protein, was mutated to serine. These two cysteines were disulfide bonded during a normal virus infection but not if the synthesis of other viral late proteins was inhibited or the E10R protein was expressed by itself in uninfected cells, suggesting a requirement for an upstream viral thiol oxidoreductase. Remarkably, the cysteine-containing domains of the E10R and L1R viral membrane proteins and the glutaredoxin are in the cytoplasm, in which assembly of vaccinia virions occurs, rather than in the oxidizing environment of the endoplasmic reticulum. These data indicated a viral pathway of disulfide bond formation in which the E10R protein has a central role. By extension, the ERV1/ALR family may represent a ubiquitous class of cellular thiol oxidoreductases that interact with glutaredoxins or thioredoxins.
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Abstract
Vaccinia virus encodes two glutaredoxins, O2L and G4L, both of which exhibit thioltransferase and dehydroascorbate reductase activities in vitro. Although O2L was previously found to be dispensable for virus replication, we now show that G4L is necessary for virion morphogenesis. RNase protection and Western blotting assays indicated that G4L was expressed at late times after infection and was incorporated into mature virus particles. Attempts to isolate a mutant virus with a deleted G4L gene were unsuccessful, suggesting that the protein was required for virus replication. This interpretation was confirmed by the construction and characterization of a conditional lethal recombinant virus with an inducible copy of the G4L gene replacing the original one. Expression of G4L was proportional to the concentration of inducer, and the amount of glutaredoxin could be varied from barely detectable to greater than normal amounts of protein. Immunogold labeling revealed that the induced G4L protein was associated with immature and mature virions and adjacent cytoplasmic depots. In the absence of inducer, the production of infectious virus was severely inhibited, though viral late protein synthesis appeared unaffected except for decreased maturation-dependent proteolytic processing of certain core components. Electron microscopy of cells infected under nonpermissive conditions revealed an accumulation of crescent membranes on the periphery of electron-dense globular masses but few mature particles. We concluded that the two glutaredoxin homologs encoded by vaccinia virus have different functions and that G4L has a role in virion morphogenesis, perhaps by acting as a redox protein.
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Abstract
The current experiments were designed to compare the feeding response to enterostatin and beta-casomorphin(1-7) injected intragastrically. Sprague-Dawley rats with a gastric cannula were allowed to chose from high-fat diet (HF) or low-fat diet (LF) in separate jars. Enterostatin injected intragastrically into overnight fasted rats caused a U-shaped dose-dependent reduction in the intake of the HF diet for the first two hours after infusion but had no effect on the LF intake. beta-Casomorphin(1-7) stimulated the intake of the HF diet but had no effect on the LF diet. Finally, beta-casomorphin(1-7) blocked the inhibitory effect of enterostatin on HF intake in fasted rats.
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Proliferative activity in craniopharyngiomas: clinicopathological correlations in adults and children. SURGICAL NEUROLOGY 2000; 54:241-7; discussion 248. [PMID: 11118571 DOI: 10.1016/s0090-3019(00)00298-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Craniopharyngiomas are slow-growing, locally invasive intracranial tumors that can generate considerable morbidity, and recurrences are often difficult to manage. Because reliable morphologic criteria for accurately predicting the clinical outcome of these tumors are lacking, we evaluated the growth potential of craniopharyngiomas by measuring their proliferative activity based on MIB-1 immunostaining for the Ki-67 antigen, which is expressed during all phases of the cell cycle except G(0.) METHODS Paraffin sections from 37 cases of craniopharyngiomas were immunostained with the monoclonal antibody MIB-1, and a labeling index was derived in each case from an the with the highest labeling. RESULTS MIB-1 immunoreactivity was mainly confined to the peripheral palisaded epithelium of craniopharyngiomas. In adult craniopharyngiomas, MIB-1 labeling indices (MIB-LI) varied from 0.1% to 34.6% (mean 8.9%; SD 9. 8), and in pediatric tumors the indices ranged from 1.8% to 15.0% (mean 6.3%; SD 3.7). MIB-LI was not found to be an independent predictor of recurrence, although in all the pediatric cases that recurred, MIB-LI in the second specimen was greater. CONCLUSIONS The actively proliferating compartment in craniopharyngiomas seems to be the peripheral palisaded epithelium. Low MIB-LI observed in the majority of tumors is in concordance with the slow growth and low-grade invasiveness associated with craniopharyngiomas. However, unlike other intracranial neoplasms, where Ki-67 labeling indices have been useful in predicting tumor behavior, a clear relationship could not be demonstrated between MIB-1 immunoreactivity, morphological features and clinical outcomes in adults or children with craniopharyngiomas.
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Prognostic value of proliferation index and expression of the RNA component of human telomerase (hTR) in papillary meningiomas. J Neurooncol 2000; 45:199-207. [PMID: 10845390 DOI: 10.1023/a:1006353322307] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Papillary meningioma is a rare subtype of meningioma that often behaves aggressively. In order to characterize factors that may influence this behavior, we chose to compare MIB-1 labeling index (LI) and telomerase RNA localization (hTR) in papillary meningiomas, meningiomas, and atypical meningiomas. LI is now often used to supplement histologic grade in the evaluation of these lesions. More recent studies indicate that increased expression of hTR is detected in many neoplastic cells, and may play an essential role in cell immortalization. The study group consisted of five papillary meningiomas (and a recurrence in one case), 11 conventional meningiomas, and eight atypical meningiomas. Conventional meningiomas showed either negative or 1 + hTR. Atypical meningiomas showed 1 + hTR. Papillary meningiomas showed the highest hTR (five of six, including recurrence, 2-3+ and one 1+). Generally, the LI was very low for conventional meningiomas (< 2%). The LI of atypical meningiomas ranged from 3-19%, mean 12%, and from 5.5-17.5%, mean 11.75% for papillary meningiomas. LI differentiated between meningiomas, and papillary or atypical meningiomas. hTR further delineated papillary (moderate to high) from atypical meningiomas (low). The combined variable of LI and hTR expression could be a useful independent prognostic indicator in patients with papillary meningioma.
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Alpha-synuclein expression in central nervous system tumors showing neuronal or mixed neuronal/glial differentiation. J Neuropathol Exp Neurol 2000; 59:490-4. [PMID: 10850861 DOI: 10.1093/jnen/59.6.490] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Alpha-synuclein (alpha-synuclein) is a member of a family of cytoplasmic proteins found predominantly and abundantly in the brain, and concentrated in pre-synaptic nerve terminals, near vesicles. We hypothesized that an antibody to alpha-synuclein could be a useful marker of neuronal differentiation in central nervous system (CNS) tumors. Twenty tumors known to have neuronal or mixed neuronal/glial differentiation ( 11 gangliogliomas, 2 anaplastic gangliogliomas, 5 gangliocytomas, and 2 ganglioneuroblastomas), 5 central neurocytomas, and 1 dysembryoplastic neuroepithelial tumor (DNET) were immunostained with a mouse monoclonal antibody raised against human alpha-synuclein. Intense cytoplasmic staining, in some instances extending into the perikarya, was seen in 6 of 11 gangliogliomas, 2 of 2 anaplastic gangliogliomas, and 2 of 2 ganglioneuroblastomas. Alpha-synuclein-positive cells were usually large in size, resembled dysmorphic neurons, and were variably immunoreactive for anti-neurofilament and/or anti-synaptophysin antibodies. In contrast, central neurocytomas, gangliocytomas, and the DNET were negative for cytoplasmic alpha-synuclein expression. Our findings indicate that alpha-synuclein is expressed within the neuronal component of mixed tumors of the CNS displaying more than 1 histophenotype, and/or showing different degrees of anaplasia. Based on currently available data, we conclude that cytoplasmic alpha-synuclein expression is a marker of maturing neurons in these tumors.
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Abstract
The effect on food intake of 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), a serotonin 1-A agonist, has been evaluated in two strains of rats that differ in their sensitivity to becoming obese while eating a high-fat diet. Male Osborne-Mendel (OM) and S5B/Pl rats were tested at 8 weeks and 16 weeks of age. Both strains were adapted to choose between two diets-a 56% fat energy diet, and a 10% fat energy diet-which were equicaloric for protein (24% energy). Daily food intake was measured for 2 weeks before injection of 8-OH-DPAT. The younger OM rats had no diet preference, while the older OM rats preferred the high-fat diet. The younger S5B/P1 rats preferred the low-fat diet, while the older S5B/P1 rats had no diet preference. Satiated rats were injected subcutaneously with 8-OH-DPAT at doses of 0.3, 1.0, or 3.0 mg/kg or vehicle. During the light phase, subcutaneous 8-OH-DPAT increased the intake of the high-fat diet in the 16-week-old OM rats but not the 8-week-old OM rats. 8-OH-DPAT had no effect on the low-fat diet intake in either age OM rat. The 8-week-old S5B/P1 rats showed a significant decrease in intake of the high-fat diet in response to 8-OH-DPAT, whereas an increase in the intake of the low-fat diet was observed in the older S5B/P1 rats. These data are consistent with the hypothesis that increased fat preference in Osborne-Mendel rats may result in part from altered serotonin activity of 5-HT(1A) receptors.
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Molecular interactions among protein phosphatase 2A, tau, and microtubules. Implications for the regulation of tau phosphorylation and the development of tauopathies. J Biol Chem 1999; 274:25490-8. [PMID: 10464280 DOI: 10.1074/jbc.274.36.25490] [Citation(s) in RCA: 234] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Hyperphosphorylated forms of the neuronal microtubule (MT)-associated protein tau are major components of Alzheimer's disease paired helical filaments. Previously, we reported that ABalphaC, the dominant brain isoform of protein phosphatase 2A (PP2A), is localized on MTs, binds directly to tau, and is a major tau phosphatase in cells. We now describe direct interactions among tau, PP2A, and MTs at the submolecular level. Using tau deletion mutants, we found that ABalphaC binds a domain on tau that is indistinguishable from its MT-binding domain. ABalphaC binds directly to MTs through a site that encompasses its catalytic subunit and is distinct from its binding site for tau, and ABalphaC and tau bind to different domains on MTs. Specific PP2A isoforms bind to MTs with distinct affinities in vitro, and these interactions differentially inhibit the ability of PP2A to dephosphorylate various substrates, including tau and tubulin. Finally, tubulin assembly decreases PP2A activity in vitro, suggesting that PP2A activity can be modulated by MT dynamics in vivo. Taken together, these findings indicate how structural interactions among ABalphaC, tau, and MTs might control the phosphorylation state of tau. Disruption of these normal interactions could contribute significantly to development of tauopathies such as Alzheimer's disease.
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Abstract
Concerns about acute pain management prompted the development of a pain management program. The program, with assessment, intervention, and evaluation components, was introduced by the clinical nurse specialist (CNS) in collaboration with a multidisciplinary team. The assessment phase included a descriptive study of postoperative pain and a baseline audit of nursing documentation related to pain assessment and management. Interventions, including a focused educational program and new routes for postoperative analgesia, were then introduced. Evaluations at 3 months and 2 years indicated improvements in documentation of pain assessments and improved management of pain. Additionally, at each follow-up evaluation, patients reported decreased postoperative pain. The assessment and management of pain is an important domain of nursing practice. The CNS is in a unique position to influence nursing practice and to impact on patient outcomes in this area of pain management.
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Abstract
Patients with progressive supranuclear palsy (PSP) often develop dementia, and cortical pathology has been documented in PSP. However, there are no reports correlating dementia in PSP with cortical pathology. We hypothesized that cases of PSP presenting with cognitive impairment would have more severe cortical tau pathology than those without. We compared 7 cases of PSP presenting with cognitive deficits (group 1) with 4 cases of PSP that did not (group 2). The subcortical tau pathology was almost identical in both groups. The cortical tau pathology was strikingly different in group 1, in which it was on average moderate, compared with group 2, in which it was minimal. The accumulation of cortical neuronoglial tau in PSP cases with dementia suggests that neurofibrillary pathology is central to the cause of dementia in PSP.
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Abstract
Differentiation of recurrent glioma from radiation damage can be a challenge to neurologists, neurosurgeons, neuroradiologists, and even neuropathologists. We hypothesized that by evaluating sections of recurrent lesions with proliferation markers we might objectively differentiate between radiation damage gliosis and recurrent astrocytoma. We compared the labeling indices of radiation damage and recurrent neoplasm immunohistochemically, using an antibody to MIB-1, a monoclonal antibody to the Ki-67 proliferation marker. Five of the six recurrent neoplasms were gliomas; four these were astrocytic tumors. In most cases, the MIB-1 LI of radiation damage was < 1% and the LI of recurrent neoplasm was > 3%, with pertinent exceptions. We discuss our findings and their possible interpretation.
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Neocortical synapse density and Braak stage in the Lewy body variant of Alzheimer disease: a comparison with classic Alzheimer disease and normal aging. J Neuropathol Exp Neurol 1998; 57:955-60. [PMID: 9786245 DOI: 10.1097/00005072-199810000-00007] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Substantial numbers of cortical and subcortical Lewy bodies are seen in approximately one quarter of patients whose brains show sufficient histopathologic changes for a neuropathologic diagnosis of definite Alzheimer disease (AD). This subset of cases has been named the Lewy body variant of AD (LBV). Despite comparable dementia and the presence of neocortical senile plaques in LBV patients, the overall burden of neuropathologic changes, in particular neurofibrillary tangles (NFT), is less than in classic AD. While NFT frequency correlates with dementia severity in classic AD, the cognitive impairment in patients with LBV cannot be completely explained by such changes. Since several studies have suggested a role for synapse loss in relation to dementia severity in classic AD, we decided to investigate the role of synapse loss as a candidate for the cognitive impairment of LBV. The Braak staging method is based upon the distribution and severity of neurofibrillary changes, and one therefore would expect LBV cases to be assigned to lower Braak stages. In the present study we assigned a Braak stage to 14 LBV cases, 31 classic AD cases, and a group of 10 non-demented aged controls. We compared the severity of synapse loss as determined by ELISA immunoassay for synaptophysin and Braak stage among the three diagnostic groups. When compared to normal controls, synaptophysin concentrations were statistically significantly lower in both demented groups. There was comparable synapse loss in LBV and AD despite significantly lower Braak stages in the LBV cases. These results suggest a major role for loss of synapses as the substrate of cognitive impairment in LBV.
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Abstract
The purpose of this study was to evaluate the effectiveness of patient-controlled analgesia (PCA) in patients undergoing spinal surgery. Sixty patients undergoing spinal surgery were randomly assigned to receive PCA or the standard approach to postoperative analgesia (intramuscular injections on an "as needed" basis). Information on pain intensity at rest and with activity, total daily amount of analgesia, presence of adverse effects, length of time to ambulation and length of hospital stay was collected on all patients. Patients in the PCA group reported lower levels of pain, both at rest and with activity, and were ambulating earlier than patients receiving standard analgesia. There were no differences between the groups in total daily analgesic intake, presence of adverse effects and length of hospital stay. These data suggest that PCA is a safe, effective approach to managing pain after spinal surgery.
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Correlation of bcl-2, p53, and MIB-1 expression with ependymoma grade and subtype. Mod Pathol 1998; 11:464-70. [PMID: 9619600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In this study, we report our results on the proliferative activity of ependymomas as determined by MIB-1 (also known as Ki-67) immunohistochemical analysis, and we compare our results with those obtained by immunolabeling with monoclonal antibodies to p53 and bcl-2 proteins to assess whether expression correlated with ependymoma subtype or tumor grade. The study included 4 myxopapillary ependymomas (Grade I of the World Health Organization [WHO] scale), 10 subependymomas (WHO Grade I), 17 ependymomas (WHO Grade II), 2 papillary ependymomas (WHO grade II), and 4 anaplastic ependymomas (WHO Grade III). The MIB-1 proliferation index was significantly higher in tumors diagnosed as anaplastic ependymoma (P < .001), with a moderate level of correlation (Kendall's tau-b = 0.557, asymptotic standard error = 108). In addition, one ependymoma (WHO Grade II) not considered overtly anaplastic by routine histologic criteria showed a high MIB-1 labeling index, suggesting that the MIB-1 proliferation index might be a more objective indicator of tumor grade. The remaining WHO Grade I and Grade II ependymomas showed low proliferative activity. bcl-2 oncoprotein expression was identified in all of the four myxopapillary and in both papillary ependymomas. An additional observation was the correlation of p53 expression with increasing WHO grade. These data suggest that high MIB-1 and p53 immunolabeling might be objective indicators of high grade in ependymomas that do not otherwise meet routine histologic criteria for high-grade ependymoma. Subsequent clinicopathologic analyses will be important in assessing whether these markers are useful as independent predictors of survival.
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Deletion analysis of a defective interfering Semliki Forest virus RNA genome defines a region in the nsP2 sequence that is required for efficient packaging of the genome into virus particles. J Virol 1998; 72:4320-6. [PMID: 9557722 PMCID: PMC109662 DOI: 10.1128/jvi.72.5.4320-4326.1998] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/1997] [Accepted: 02/10/1998] [Indexed: 02/07/2023] Open
Abstract
The 1,244-nucleotide genome of Semliki Forest virus (SFV) defective interfering (DI) RNA 19 (DI-19) is coterminal with the infectious genome and contains two major deletions. One deletion removes the end of the nsP1 gene and the beginning of the nsP2 gene, and the other removes the end of the nsP2 gene, the nsP3 and nsP4 genes, and all of the structural protein genes (M. Thomson and N. J. Dimmock, Virology 199:354-365, 1994). Like all DI SFV RNAs, DI-19 contains three regions that are conserved. Region a comprises the 5' terminus continuous with part of the nsP1 gene, region b comprises a central part of the nsP2 gene, and region c comprises the 3' terminus and the associated untranslated region. A deletion analysis of the 265-nucleotide b region (nucleotides 679 to 943, inclusive) was undertaken to determine its role in genome replication and packaging into DI virus particles. Deleted plasmids were constructed and transcribed, and the resulting DI RNAs were transfected into SFV-infected BHK cells. Putative progeny DI virus particles that had been released into the tissue culture fluid were then serially passaged in new monolayers together with added high-multiplicity SFV, and cells and tissue culture fluids were tested for the presence of DI RNA by reverse transcription-PCR. DI RNA that had all of the b region deleted was replicated well in BHK-21 cells, as shown by the presence of large amounts of negative-sense DI RNA and an increase in the amount of positive-sense RNA in the cytoplasm, but was packaged very inefficiently, as indicated by very low amounts of DI RNA in the tissue culture fluid. The genome of a deletion mutant that retained the 3' 224 nucleotides of region b was packaged successfully, but one that retained only the 5' 41 nucleotides was not detected in the tissue culture fluid. These and other data suggest that nucleotides 720 to 777 of region b are of particular importance in the packaging process. This finding agrees with data obtained with Ross River virus and contrasts with the well-studied Sindbis alphavirus major packaging signal that is located within the nsP1 gene.
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Abstract
OBJECTIVE To describe a case of acute, fatal molybdenum poisoning in feedlot cattle. DESCRIPTION OF THE HERD: In total, 831 Hereford, Hereford x Angus, and Hereford x Simmental steers, aged 8 to 10 months, with an average body weight of 310 kg were fed a diet, to which sodium molybdate at a rate of 1.9% of the total ration had been accidently added. INVESTIGATION The steers lost appetite within 3 days and deaths commenced within 6 days of the diet being first offered. The error was rectified when deaths started to occur, but steers continued to die for up to 7 months afterwards. Of the 831 steers on the feedlot, 90 died and a further 5 remained in poor condition. The cause of death was periacinar to massive hepatic necrosis and acute renal tubular necrosis. Blood and tissue samples were taken from surviving steers for 76 days, by which time plasma molybdenum concentrations had returned to normal concentrations. CONCLUSION Sodium molybdate when fed at a rate of 1.9% of the diet results in acute renal tubular necrosis and periacinar to massive hepatic necrosis.
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Primary epithelioid hemangioendothelioma of the clivus. Clin Neuropathol 1998; 17:110-4. [PMID: 9561333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
We describe the clinical, radiologic, and pathologic features of a primary intracranial hemangioendothelioma arising in the clivus in a 38-year-old female, emphasizing the importance of including this rare entity in the differential diagnosis of tumors arising at the base of the skull. To our knowledge, this is the first reported case of a clival hemangioendothelioma. Aside from its unusual location, this case is also notable for its apparent rapid growth and mixed epithelioid-spindle cell morphology. Appropriate neuroimaging studies may offer crucial information, ensuring that this uncommon entity is included in the differential diagnosis of a clival mass.
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The genomic sequence of defective interfering Semliki Forest virus (SFV) determines its ability to be replicated in mouse brain and to protect against a lethal SFV infection in vivo. Virology 1998; 241:215-23. [PMID: 9499796 DOI: 10.1006/viro.1997.8975] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have recently cloned and sequenced two genomes of defective interfering (DI) Semliki Forest virus (SFV), DI-6 (2146 nt), and DI-19 (1244 nt). These are similar in that both contain two large central deletions (encompassing the 5' part of the nsP1 gene and the 3' part of the nsP2 gene and all of the structural genes), and all the sequence of the latter is represented in the genome of SFV DI-6. RNA was transcribed from both and transfected into SFV-infected BHK-21 cells. RT-PCR analysis of tissue culture fluid harvested 18 h after transfection suggested that SFV DI virions had been rescued from the cloned genomes. Unlike the genomes of noncloned DI SFV, these genomes bred true for at least 7 serial passages. Cloned DI-6 and DI-19 viruses interfered to a similar extent with the multiplication of SFV in cultured cells, but only DI-19 protected mice from a lethal intranasal dose of SFV. Further investigation by RT-PCR analysis showed that DI-19 but not DI-6 genomes were replicated in mouse brain after direct intracerebral injection of DI virus together with an excess of infectious helper SFV. Thus the replication and hence antiviral activity of two closely related DI SFV genomes appears to be exquisitely sequence specific and cell specific. These findings mark a significant step on the way to using DI genomes as antivirals and also may explain why so few animal-protecting DI viruses have been identified.
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Abstract
Detailed neuropathologic examination was performed on a 47.5-year-old man with an unusual adult-onset dementing illness. His initial symptoms were those of depression, memory loss, and personality change. He developed progressive cognitive decline with prominent psychiatric symptoms. Seizures began approximately 11 months prior to death and he died 5.5 years after onset of symptoms. Pathologic examination of the brain at autopsy revealed organizing necrosis of the hippocampi, felt to be the result of his seizures. More significant was the finding of widespread microscopic nodular cortical dysplasia. The dysplastic nodules were composed of clusters of abnormal cells with enlarged, pleomorphic, vesicular nuclei, many of which contained nucleoli and had ballooned cytoplasm. There were no mitoses. Cortical dysplasia is most commonly associated with childhood-onset seizures. It has not, to our knowledge, been reported as a cause of dementia. Whether or not the dysplasia was the basis of the patient's dementia is difficult to say with certainty, but we discuss possible pathoetiologic mechanisms of dementia due to cortical dysplasia.
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Role of glucose, fatty acids and protein in regulation of testicular growth and secretion of gonadotrophin, prolactin, somatotrophin and insulin in the mature ram. Reprod Fertil Dev 1998; 9:515-24. [PMID: 9418981 DOI: 10.1071/r96113] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
This study tested whether the effects of nutrition on gonadotrophin secretion and testicular growth in mature rams are due to increases in the supply of glucose, fatty acids (FA) or amino acids. Responses to protein (casein) and glucose, alone or in combination, were compared with responses to lupin grain and responses to a combination of protein, glucose and FA (acetate, propionate and vegetable oil). Glucose and casein were infused intra-abomasally whereas lupins and FA were added to the diet. Lupin feeding decreased blood growth hormone (GH) concentrations, but increased pulsatile luteinizing hormone (LH) secretion and increased the concentrations of follicle-stimulating hormone (FSH), prolactin, glucose and insulin. These effects were associated with testicular growth. Glucose or casein increased insulin concentrations and decreased GH concentrations, but did not affect gonadotrophins or testicular growth. There was no synergism between casein and glucose. Responses elicited by adding FA to the glucose+casein treatment were similar to those observed with lupins. In conclusion, the reproductive axis does not seem to be closely linked with dietary intakes of amino acids or with circulating concentrations of glucose, insulin or GH. However, the energetic components of the diet, particularly the fatty acids, appear to play a key role in the reproductive responses to changes in nutrition.
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Hormone receptor immunoreactivity in hemangioblastomas and clear cell renal cell carcinomas. Mod Pathol 1998; 11:55-9. [PMID: 9556423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Several primary central nervous system (CNS) neoplasms, including meningiomas, spinal cord ependymomas, and acoustic nerve schwannomas, express hormone receptors. In the present study, we investigated hormone receptor immunoreactivity in hemangioblastomas on the basis of recent reports of these tumors complicating pregnancy. We also evaluated cases of renal cell carcinoma (RCC) metastatic to the CNS, hypothesizing that estrogen receptor (ER), progesterone receptor (PR), or androgen receptor (AR) immunoreactivity might help to distinguish between these histologically similar neoplasms. Immunohistochemical analysis for ERs, PRs, and ARs was performed on paraffin-embedded sections of 27 hemangioblastomas, 12 primary clear cell RCCs, and 5 clear cell RCCs metastatic to the CNS. All of the hemangioblastomas demonstrated PR immunoreactivity, whereas 10 of 12 primary RCCs were negative. In addition, four of the five metastatic RCC were PR positive. All but one primary RCC were ER negative. AR immunoreactivity was seen in three hemangioblastomas, five primary RCCs, and one metastatic RCC. Although hormone receptor immunoreactivity was unable to distinguish between hemangioblastoma and clear cell RCC metastatic to the CNS, the identification of PR immunoreactivity in hemangioblastomas is a new finding that might have adjuvant therapy treatment implications.
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Neuropathologic evidence that the Lewy body variant of Alzheimer disease represents coexistence of Alzheimer disease and idiopathic Parkinson disease. J Neuropathol Exp Neurol 1998; 57:39-46. [PMID: 9600196 DOI: 10.1097/00005072-199801000-00006] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
We undertook this study to investigate the neuropathologic relationships among Alzheimer disease (AD), idiopathic Parkinson disease (PD), and the Lewy body variant of AD (AD/LBV). We retrieved 30 autopsy cases in which Lewy bodies (LB) had been identified in the substantia nigra (SN) in routine hematoxylin-eosin-stained sections. Twenty-two of the cases had a primary clinical diagnosis of dementia and neuropathologic changes of AD; 12 of these demented patients also had clinical parkinsonism. Eight cases had clinical and neuropathologic evidence of PD with minimal or no AD neuropathology, though 6 had clinical dementia. Controls consisted of 6 cases of AD without SN LB by hematoxylin-eosin, and 5 neurologically normal aged controls. Paraffin sections of SN, superior temporal gyrus, and cingulate gyrus from each case were immunostained with rabbit anti-ubiquitin antiserum, randomized, and analyzed individually by light microscopy, and the density of LB-like profiles in each section were graded. None of 5 nondemented aged controls showed any neocortical LB, even though 2 had significant numbers of incidental SN LB by ubiquitin immunostaining. Of 6 AD cases without SN LB by hematoxylin-eosin, 3 had rare SN LB on ubiquitin stain, 1 of which showed rare neocortical Lewy-like profiles. Seven of 8 PD cases showed neocortical LB, including the 6 with dementia. Twenty-one of 22 AD cases with SN LB showed ubiquitin-immunoreactive Lewy-like bodies in the neocortex that were statistically significantly greater in number than in either pure PD or pure AD cases. The frequent occurrence of LB in the neocortex in PD alone suggests that AD/LBV likely represents mixed AD/PD. However, AD neuropathology may favor or promote the formation of neocortical LB in patients who go on to develop mixed AD/PD pathology.
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Frequency of unilateral and bilateral mesial temporal sclerosis in primary and secondary epilepsy: a forensic autopsy study. Am J Forensic Med Pathol 1997; 18:335-41. [PMID: 9430283 DOI: 10.1097/00000433-199712000-00004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Controversy exists regarding the pathogenetic relationship of mesial temporal sclerosis (MTS) to epileptogenesis. Some investigators view hippocampal sclerosis as the primary cause of temporal lobe epilepsy, whereas others interpret the changes to be the result of chronic seizure activity. The present autopsy-based study attempts to clarify the etiologic relationship between mesial temporal sclerosis and epilepsy. To investigate the assumption that bilateral MTS is more likely to be the result of chronic seizure activity associated with a seizure focus outside the hippocampus, two subject groups were identified. The first group comprised 43 patients who had no extrahippocampal pathology and were classified as having primary epilepsy. The second group comprised 35 patients who, had identifiable extrahippocampal pathology and were classified as having secondary epilepsy. Fifteen of the 35 cases of secondary epilepsy also had MTS; seven of these were unilateral and eight were bilateral. Of the 43 cases with primary epilepsy, only one had MTS, and it was unilateral. Significantly more cases of primary epilepsy than secondary epilepsy had no MTS (p < 0.001), suggesting that both unilateral and bilateral forms of MTS occur with greater frequency in subjects with seizure foci outside the hippocampus. These results also suggest that unilaterality of MTS does not exclude an extrahippocampal cause.
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