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Prana Biotechnology Limited Message Board

pivalde 175 posts  |  Last Activity: 19 hours ago Member since: Feb 15, 2001
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  • Now 1.967M shorts

  • pivalde pivalde Jul 24, 2014 3:45 PM Flag

    Discussion: ......
    "Recent findings have indicated that decreasing brain tau levels in APP Tg mice uncouples Aß from downstream pathogenic mechanisms and improves cognitive performance (Roberson et al., 2007
    ). While Robertson et al did not differentiate between solution states of brain tau, we found that PBT2 (but not CQ) decreased insoluble and soluble phosphorylated tau in the APP/PS1 mice (Figure 6) and insoluble total tau in the Tg2576 mice (although soluble total tau was also increased in the Tg2576 model [Figure S7]). Therefore, if tau reduction contributes to the cognitive improvements we observed, the mechanism may involve preventing tau (either phosphorylated or nonphosphorylated) from precipitating. The differential effect of CQ and PBT2 may be due to the increased brain penetration of PBT2, or its increased ionophoric activity and ability to impact upon tau phosphorylation, and warrants further investigation".
    So the main thing was that cognition improved with PBT2.

  • pivalde pivalde Jul 24, 2014 2:00 PM Flag

    Yki, 6 years on this board has helped me.

  • pivalde pivalde Jul 24, 2014 12:51 PM Flag

    biotech_inv, read: Adlard et al in Neuron 2008, 10 July p. 44-55, it is a free paper and there is a chapeter how PBT2 works on tau.

  • pivalde pivalde Jul 24, 2014 12:10 PM Flag

    biotech_invest

    Read how PBT2 works on Tau from Neuron 10 July 2008, written by Adlard PA et al. "Rapid restoration of cognition...."

  • Reply to

    Smokers have smaller hippocampus

    by pivalde Jul 22, 2014 2:33 AM
    pivalde pivalde Jul 22, 2014 2:38 AM Flag

    CONCLUSIONS:

    ...... that higher F2 isoprostane levels in smokers were related to smaller hippocampal volume. These findings provide additional novel evidence that a history of chronic smoking during adulthood is associated with adverse effects on the human brain that are potentially enduring even with extended smoking cessation.

  • Drug Alcohol Depend. 2014 Jul 3. pii: S0376-8716(14)00957-0. doi: 10.1016/j.drugalcdep.2014.06.030. [Epub ahead of print]

    History of cigarette smoking in cognitively-normal elders is associated with elevated cerebrospinal fluid biomarkers of oxidative stress.

    Durazzo TC1, Mattsson N2, Weiner MW3, Korecka M4, Trojanowski JQ4, Shaw LM4; for the Alzheimer's Disease Neuroimaging Initiative.

    BACKGROUND:

    Cigarette smoking in adults is associated with abnormalities in brain neurobiology. Smoking-induced central nervous system oxidative stress (OxS) is a potential mechanism associated with these abnormalities. The goal of this study was to compare cognitively-normal elders on cerebrospinal fluid (CSF) levels of F2-isoprostane biomarkers of OxS.

    METHODS:

    Elders with a lifetime history of smoking (smokers; n=50; 75±5 years of age; 34±28 pack-years; approximately 12% were actively smoking at the time of study) were compared to never-smokers (n=61; 76±6 years of age) on CSF iPF2α-III and 8,12, iso-iPF2α-VI F2-isoprostanes levels. F2-isoprostanes levels were quantitated with HPLC-atmospheric pressure chemical ionization-tandem mass spectrometry. Associations between F2-isoprostanes levels, hippocampal volumes, and cigarette exposure measures were also evaluated.

    RESULTS:

    Smokers showed higher iPF2α-III level than never-smokers. An age×smoking status interaction was observed for 8,12, iso-iPF2α-VI, where smokers demonstrate a significantly greater concentration with increasing age than never-smokers. In smokers only, higher 8,12, iso-iPF2α-VI concentration was associated with smaller hippocampal volume, and greater iPF2α-III level was related to greater pack years.

    CONCLUSIONS:

    This is the first study to demonstrate that a history of cigarette smoking in cognitively-normal elders was associated with significantly elevated CSF F2-isoprostane levels and greater age-related increases in F2-isoprostanes, and that higher F2-isop

  • Reply to

    partnership possibilities after Imagine study

    by pivalde Jul 21, 2014 2:32 AM
    pivalde pivalde Jul 21, 2014 11:21 AM Flag

    Safety of PBT2 is a marvellous thing when thinking any partnerships. AD is a brain disoder and a complex one. Brain controls everything. No side effects ( just some minor ones) is a almost a miracle. Think about almost any medicine, they all have side effects. Those treating brain disoders have quite a lot of them but PBT2 seems to have very little of them if any. With this kind of record ( the treated numbers are still quite low) it is not a big risk to big pharma to partner.

  • 6y ago we were waiting a deal with a big pharma after the positive Euro-study results. There were rumors that a deal was very close but all fell apart after the world wide economic turmoil started.
    Before the Imagine study results it was apparent that Prana was also looking possible partners but at this time perhaps the initial poor results have stopped the negotiations, or have they been stopped ???
    Now at least when there is better understanding about the Imagine study results (that they were not so poor at all), I would think there could again be something going on.
    There has been a lot of new information about PBT2 during the past 6 years and independent research about clioquinols ( S Lindquist et al) that at this time there is much more to sell than 6y ago. HD and age related memory loss are totally new possible indications for PBT2.
    We all know that Prana needs a partner to do big AD and age related memory loss studies. I can not understand that " the company remains enthusiastic about the prospects of a large trial powered to demonstrate cognitive benefit" if it would not have something real in it's plans, perhaps a partner IMO.

  • This not very important but may still interest some of us.

    Acta Neuropathol. 2014 Jun;127(6):803-10. doi: 10.1007/s00401-014-1290-2. Epub 2014 May 7.

    Do current therapeutic anti-Aβ antibodies for Alzheimer's disease engage the target?

    Watt AD1, Crespi GA, Down RA, Ascher DB, Gunn A, Perez KA, McLean CA, Villemagne VL, Parker MW, Barnham KJ, Miles LA

    Reducing amyloid-β peptide (Aβ) burden at the pre-symptomatic stages of Alzheimer's disease (AD) is currently the advocated clinical strategy for treating this disease. The most developed method for targeting Aβ is the use of monoclonal antibodies including bapineuzumab, solanezumab and crenezumab. We have synthesized these antibodies and used surface plasmon resonance (SPR) and mass spectrometry to characterize and compare the ability of these antibodies to target Aβ in transgenic mouse tissue as well as human AD tissue. SPR analysis showed that the antibodies were able to bind Aβ with high affinity. All of the antibodies were able to bind Aβ in mouse tissue. However, significant differences were observed in human brain tissue. While bapineuzumab was able to capture a variety of N-terminally truncated Aβ species, the Aβ detected using solanezumab was barely above detection limits while crenezumab did not detect any Aβ. None of the antibodies were able to detect any Aβ species in human blood. Immunoprecipitation experiments using plasma from AD subjects showed that both solanezumab and crenezumab have extensive cross-reactivity with non-Aβ related proteins. Bapineuzumab demonstrated target engagement with brain Aβ, consistent with published clinical data. Solanezumab and crenezumab did not, most likely as a result of a lack of specificity due to cross-reactivity with other proteins containing epitope overlap. This lack of target engagement raises questions as to whether solanezumab and crenezumab are suitable drug candidates for the preventative clinical trials for AD.

  • pivalde pivalde Jul 20, 2014 4:04 AM Flag

    Esoteric, thank you ! IMO Data mining is very essential in research when we try to get forward in unknown territories as in AD research. All big follow-up studies as AIBL etc are all data mining studies, but very valuable when trying to find new solutions. In them lot of data is collected, even irrelevant at the moment of collecting but even irrelevant data can later become valuable.
    AF`s goal is not to find an AD drug. His goal is to play with pps.
    What Masters actually did was that he made a litterature review about drugs designed to lower Abeta. In that PBT2 seems to be the best and even looks like it could lower the hippocampus atrophy rate related to memory. Other drug designers have not yet found that hippocampus vol measure is much better than measuring total Abeta by PET-scan when evaluating drug efficacy. In fact it looks like most of AD researchers believed in that still in last year ( read Canadianhegemony's comment ). Only now we know that PET scan is perhaps only for diagnostics (Ong et al 2014) and that result was made by data mining AIBL data.
    Seems that AF is still talking about Abeta visible by PET and not about much more relevant biomeasure hippocampus vol. The fact that the Imagine study found a clear trend in slowering hippocampus atrophy was not a finding made by data mining and it was IMO the most essential finding of the Imagine study, even still only a statistical trend. The effect of PBT2 on more relevant spinal fluid oligomers has been known for years.

  • pivalde by pivalde Jul 19, 2014 8:45 AM Flag

    He explained different pools of Abeta (unpublished data of Roberts and Ryan) and told ( I think to to Big Pharma) that PBT2 is the only of the developed drugs targetting the toxic abeta oligomers by inhibiting their formation and promoting their clearance and so in the end reducing hippocampal atrophy ( only trend) and improving cognition (Euro study)

    PBT2 seems to have effect on total Abeta (as was the hypothesis in the Imagine study), best effect if Abeta in brain is on very high level. By using historical data ( published about the best drug Bapi reperted to lower Abeta) Masters demonstrates that PBT2 was better than that even in this respect. So PBT2 could have some effect also on a bigger pool of abeta and not only the oligomers (but the most important in AD). But when Bapi does not target the oligomers (only few % of the total Abeta) there is no help in cognition.

    The table of the hippocampus atrophy demonstrates well how the mean atrophy rate in treated is smaller than that of placebo but that the numbers are too small for statistical significance (placebo population). It is evident that genetics has a role both in developing brain atrophy and also when trying to slow down it by a drug, but these numbers were too small for these analyses.

    Now when Masters is a consultant of both Lilly and Prana, I would think that there will be some consultations about co-operation aswell.

  • pivalde pivalde Jul 17, 2014 12:27 PM Flag

    Here is one, it is free on the net:

    PLoS One. 2012;7(3):e33552. doi: 10.1371/journal.pone.0033552. Epub 2012 Mar 23.

    The zinc dyshomeostasis hypothesis of Alzheimer's disease.

    Craddock TJ1, Tuszynski JA, Chopra D, Casey N, Goldstein LE, Hameroff SR, Tanzi RE.

  • Reply to

    ApoE4

    by pivalde Jul 17, 2014 4:45 AM
    pivalde pivalde Jul 17, 2014 5:31 AM Flag

    pjemmet, I think that there is a mistake in the tables. I think the triangles are the ApoE4 carriers, but in any case you are reading the tables right. I think this should be asked from Prana.

  • pivalde by pivalde Jul 17, 2014 4:45 AM Flag

    In the Masters's presentation, there was also APOE presented, but the numbers were very small. 3 ApoE4 cases in the placebo group,( 20%) and 6 in PBT2 treated group (24%). Looks like ApoE4 was not the factor in explaining placebo group amyloid measurements.

  • pivalde pivalde Jul 17, 2014 2:12 AM Flag

    interestingtome, thank you ! The papers you have seen in Copenhagen will be published in some 2 years in various journals. You will be now at least 1y ahead of us who did not travel to the meeting. Thanks for posting !

  • pivalde pivalde Jul 16, 2014 9:48 AM Flag

    Interestingtome, thanks again ! This is a very important paper again explaining also the role of ApoE in iron metabolism of the brain.
    The biggest risk factor of AD is related to metal balance !!! ( Hot copper has all of the abstract posted by interestingto me).

  • pivalde pivalde Jul 16, 2014 9:01 AM Flag

    interestingtome, I am only splitting the title of his talk you gave us few weeks ago. Plenary session talks are not always in the abstract booklet and so they can include even the latest info.

  • pivalde pivalde Jul 16, 2014 8:26 AM Flag

    IMO there will be many different aspects in his talk as is usual in plenary sessions and I do not think the talk will relate directly to Imagine study, but there may be indirect issues as he has been one person supporting small control group (his vdeo on youtube) and also to target amyloid. We are supposed to get answers to:

    - How to change the rate of Abeta accumulation ??
    - How to change the rate of cognitive decline??
    - How to monitore the rate of Abeta accumulation??
    - How to monitore the rate of cognitive decline ??

    I think it is too simplistic to think that he will give an answer we Prana investors would like to get, but if there is also a press release from Prana telling more about the Imagine study results, he perhaps could tell more about hippocampus atrophy as one parameter to monitore and perhaps blood oligomers aswell. The role of ApoE4 will be one issue even without any Imagine study results. We will get the info tomorrow!

  • pivalde pivalde Jul 16, 2014 7:37 AM Flag

    Interestngtome, thank you.

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