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PPR  -  photoparoxysmal response

Homo sapiens

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Disease relevance of PPR


Psychiatry related information on PPR

  • We conclude that the demographic characteristics of the patient group, such as age and gender, the epilepsy type, sleep deprivation, technique of IPS and definition of PPR, greatly influence the prevalence rate of PPR [6].

High impact information on PPR

  • The PPR motif - a TPR-related motif prevalent in plant organellar proteins [7].
  • Our study identified two susceptibility loci for PPR, which may be related to the underlying myoclonic epilepsy phenotype present in the families studied [8].
  • Inclusion criteria were poor response to initial prednisone/intrathecal methotrexate (prednisone-poor response [PPR]), resistance to induction therapy, translocation t(9;22), infants with the t(4;11), or CD10(-) ALL [9].
  • Among PPR patients, those who were PPR-only (60.1%)-that is, they achieved CR and were negative for t(9;22) and t(4;11) translocations-had the best outcomes with this intensive treatment, even when additional adverse features (hyperleukocytosis, T phenotype) were present (4-year EFS, 70.1%; SE, 4.7%) [9].
  • The estimated probability for an event-free survival at 6 years (pEFS) was by far better for PGR compared with PPR, who had a dismal prognosis despite intensified treatment (pEFS, 53% +/- 6% v 15% +/- 7%, P =.0001) [10].

Chemical compound and disease context of PPR


Biological context of PPR


Anatomical context of PPR

  • Infants with PGR, comprising a major subgroup (74%) among infants, might successfully be treated with conventional therapy, whereas PPR require new therapeutic strategies, including early treatment intensification or bone marrow transplantation in first remission [10].
  • PPR accounted for 17.4% (p < 0.01) of the patients with juvenile myoclonic epilepsy, 7.6% (p < 0.01) of those with grand mal on awakening, and 6.1% (p < 0.01) of those with symptomatic occipital lobe epilepsy [16].
  • During such spike blockage, pressure ejection of brief puffs of oxo-M into the neuropil evoked a long-lasting depolarization of PPR that resembled the sEPSP.(ABSTRACT TRUNCATED AT 400 WORDS)[11]
  • 1. Application of the muscarinic agonist oxotremorine-M (oxo-M) to isolated abdominal ganglia of larval Manduca sexta excited an identified proleg retractor motoneuron called PPR [12].
  • These data suggest a new interpretation of wavelength specificity of PPR: Flashing lights containing the wavelength spectrum that does not produce antagonistic cone interactions at the level of retinal ganglion cells can elicit PPR in some photosensitive IGE patients [17].

Associations of PPR with chemical compounds

  • Twenty (35%) of 57 evaluable patients had >/=1,000 leukemic blasts per microliter of blood on day 8 of induction (defined as prednisone-poor-response [PPR]) [2].
  • In addition, 557 hypertensive patients were randomized either to PPR verapamil or nifedipine GITS (gastrointestinal system) [3].
  • 6. Bath application of the muscarinic agonist oxotremorine-M (oxo-M) at concentrations > 3 x 10(-7) M increased the spontaneous spiking activity of PPR and other proleg motoneurons [11].
  • This study examines the relationship between cognitive factors and TDR and PPR to fluoxetine [18].
  • Digital angiograms with ECG-triggered bolus injections of 4 to 8 ml of contrast medium at rest and after stimulation by dipyridamole (0,5 mg/kg i.v.) or papaverine (12,5 mg i.c.) were acquired in a 512 x 512 matrix at 8 bit resolution (ADAC 4100) and stored on a digital disk at 25 frames/sec. or 2 frames/cardiac cycle (PPR-mode) [19].

Regulatory relationships of PPR

  • PURPOSE: To investigate the mode of inheritance of the photoparoxysmal response (PPR) and to obtain more information about the influence of photosensitivity on the seizure risk in siblings of patients with epilepsy [20].

Other interactions of PPR

  • These data were correlated with cell survival, demonstrating a more pronounced induction of apoptosis in cells from patients with PGR as compared with PPR [21].
  • Allelic and haplotypic associations were found between PPR and six BRD2 polymorphisms (P: 0.0075-0.035) [15].
  • Mutation screening of the ALDH5A1 coding sequence of 35IGE/PPR patients and four healthy control subjects identified 17 sequence variants, of which three resulted in an exchange of amino acids (H180Y, P182L, A237S) [22].
  • We also report the first direct identification, to our knowledge, of PPR (pentatricopeptide repeat) proteins in the plant mitochondrial proteome [23].
  • Visual HER-2/neu signal scoring was strongly correlated with IFR (P = 0.0001) and PPR (P = 0.0001) [24].

Analytical, diagnostic and therapeutic context of PPR

  • Photosensitivity or photoparoxysmal response (PPR) is a common and highly heritable electroencephalographic trait characterized by an abnormal visual sensitivity of the brain in reaction to intermittent photic stimulation [1].
  • The identification of genes for PPR would, therefore, aid the dissection of the genetic basis of IGE [8].
  • The overall pathologic response rate (pathologic complete response [PCR] plus partial response [PPR]) in 37 evaluable patients was 62%, and in PCRs was 22% [25].
  • Substance withdrawal should be considered in the differential diagnosis of PPR or of an unusually high-amplitude VEP in a person with no previous history of epilepsy [5].
  • To identify prognostic factors associated with PPR, we performed a case-control study comparing the cohort with 33 age-matched patients who had had epileptic seizures prior to PPR recording [4].


  1. Genetic dissection of photosensitivity and its relation to idiopathic generalized epilepsy. Tauer, U., Lorenz, S., Lenzen, K.P., Heils, A., Muhle, H., Gresch, M., Neubauer, B.A., Waltz, S., Rudolf, G., Mattheisen, M., Strauch, K., Nürnberg, P., Schmitz, B., Stephani, U., Sander, T. Ann. Neurol. (2005) [Pubmed]
  2. Philadelphia chromosome-positive (Ph+) childhood acute lymphoblastic leukemia: good initial steroid response allows early prediction of a favorable treatment outcome. Schrappe, M., Aricò, M., Harbott, J., Biondi, A., Zimmermann, M., Conter, V., Reiter, A., Valsecchi, M.G., Gadner, H., Basso, G., Bartram, C.R., Lampert, F., Riehm, H., Masera, G. Blood (1998) [Pubmed]
  3. Medical therapy, symptoms, and the distress the cause: relation to quality of life in patients with angina pectoris and/or hypertension. Hollenberg, N.K., Williams, G.H., Anderson, R. Arch. Intern. Med. (2000) [Pubmed]
  4. Prognosis of photoparoxysmal response in nonepileptic patients. So, E.L., Ruggles, K.H., Ahmann, P.A., Olson, K.A. Neurology (1993) [Pubmed]
  5. Methaqualone withdrawal syndrome with photoparoxysmal responses and high-amplitude visual evoked potentials. Faught, E. Neurology (1986) [Pubmed]
  6. Prevalence of photoparoxysmal response among South Indian epilepsy patients. Radhakrishnan, K., Nayak, S.D., Nandini, V.S., Venugopal, A. Seizure : the journal of the British Epilepsy Association. (1998) [Pubmed]
  7. The PPR motif - a TPR-related motif prevalent in plant organellar proteins. Small, I.D., Peeters, N. Trends Biochem. Sci. (2000) [Pubmed]
  8. Genome-wide linkage scan of epilepsy-related photoparoxysmal electroencephalographic response: evidence for linkage on chromosomes 7q32 and 16p13. Pinto, D., Westland, B., de Haan, G.J., Rudolf, G., da Silva, B.M., Hirsch, E., Lindhout, D., Trenité, D.G., Koeleman, B.P. Hum. Mol. Genet. (2005) [Pubmed]
  9. Improved outcome in high-risk childhood acute lymphoblastic leukemia defined by prednisone-poor response treated with double Berlin-Frankfurt-Muenster protocol II. Aricò, M., Valsecchi, M.G., Conter, V., Rizzari, C., Pession, A., Messina, C., Barisone, E., Poggi, V., De Rossi, G., Locatelli, F., Micalizzi, M.C., Basso, G., Masera, G. Blood (2002) [Pubmed]
  10. Prednisone response is the strongest predictor of treatment outcome in infant acute lymphoblastic leukemia. Dördelmann, M., Reiter, A., Borkhardt, A., Ludwig, W.D., Götz, N., Viehmann, S., Gadner, H., Riehm, H., Schrappe, M. Blood (1999) [Pubmed]
  11. Muscarinic acetylcholine receptors modulate the excitability of an identified insect motoneuron. Trimmer, B.A., Weeks, J.C. J. Neurophysiol. (1993) [Pubmed]
  12. Characterization of a muscarinic current that regulates excitability of an identified insect motoneuron. Trimmer, B.A. J. Neurophysiol. (1994) [Pubmed]
  13. A pivotal role for PPR gamma in innate immune homeostasis? Pettersson, S. J. Pediatr. Gastroenterol. Nutr. (2005) [Pubmed]
  14. Detection of elevated pulmonary capillary wedge pressure in elderly patients with various cardiac disorders by the Valsalva manoeuvre. Remmen, J.J., Aengevaeren, W.R., Verheugt, F.W., Jansen, R.W. Clin. Sci. (2006) [Pubmed]
  15. Association of BRD2 polymorphisms with photoparoxysmal response. Lorenz, S., Taylor, K.P., Gehrmann, A., Becker, T., Muhle, H., Gresch, M., Tauer, U., Sander, T., Stephani, U. Neurosci. Lett. (2006) [Pubmed]
  16. Photosensitivity in relation to epileptic syndromes: asurvey from an epilepsy center in Japan. Shiraishi, H., Fujiwara, T., Inoue, Y., Yagi, K. Epilepsia (2001) [Pubmed]
  17. Wavelength specificity of photoparoxysmal responses in idiopathic generalized epilepsy. Takahashi, Y., Fujiwara, T., Yagi, K., Seino, M. Epilepsia (1995) [Pubmed]
  18. Differences in cognitive factors between "true drug" versus "placebo pattern" response to fluoxetine as defined by pattern analysis. Farabaugh, A.H., Sonawalla, S.B., Fava, M., Pedrelli, P., Papakostas, G.I., Schwartz, F., Mischoulon, D. Human psychopharmacology. (2006) [Pubmed]
  19. Comparison of three different principles in the assessment of coronary flow reserve from digital angiograms. Simon, R., Herrmann, G., Amende, I. International journal of cardiac imaging. (1990) [Pubmed]
  20. Inheritance of photosensitivity. Waltz, S., Stephani, U. Neuropediatrics. (2000) [Pubmed]
  21. Expression and structural analysis of glucocorticoid receptor isoform gamma in human leukaemia cells using an isoform-specific real-time polymerase chain reaction approach. Beger, C., Gerdes, K., Lauten, M., Tissing, W.J., Fernandez-Munoz, I., Schrappe, M., Welte, K. Br. J. Haematol. (2003) [Pubmed]
  22. Candidate gene analysis of the succinic semialdehyde dehydrogenase gene (ALDH5A1) in patients with idiopathic generalized epilepsy and photosensitivity. Lorenz, S., Heils, A., Taylor, K.P., Gehrmann, A., Muhle, H., Gresch, M., Becker, T., Tauer, U., Stephani, U., Sander, T. Neurosci. Lett. (2006) [Pubmed]
  23. Towards an analysis of the rice mitochondrial proteome. Heazlewood, J.L., Howell, K.A., Whelan, J., Millar, A.H. Plant Physiol. (2003) [Pubmed]
  24. Detection and quantitation by fluorescence in situ hybridization (FISH) and image analysis of HER-2/neu gene amplification in breast cancer fine-needle samples. Klijanienko, J., Couturier, J., Galut, M., El-Naggar, A.K., Maciorowski, Z., Padoy, E., Mosseri, V., Vielh, P. Cancer (1999) [Pubmed]
  25. High-dose platinum consisting of combined carboplatin and cisplatin in previously untreated ovarian cancer patients with residual disease. Lund, B., Hansen, M., Hansen, O.P., Hansen, H.H. J. Clin. Oncol. (1989) [Pubmed]
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