Disease relevance of PPR

• PPR occurs frequently associated with idiopathic generalized epilepsies (IGEs) [1].
• Only 2 of 20 patients (10%) with PPR remained in CR1 and alive: 6 patients with PPR did not survive after allogeneic bone marrow transplantation (BMT) due to recurring disease (n = 3) and toxicity (n = 3), and 12 nontransplanted patients died due to progression (n = 5) or relapse (n = 7) [2].
• METHODS: Four hundred seventy-five patients with angina pectoris were randomized to double-blind treatment with PPR (physiological pattern release) verapamil hydrochloride, amlodipine besylate, amlodipineatenolol combination, or placebo [3].
• Prognosis of PPR is age-dependent and seems favorable in adults without previous epileptic seizures [4].
• In the patient studied, methaqualone withdrawal was manifested by myoclonic and tonic-clonic seizures, an EEG photoparoxysmal response (PPR), and a high-amplitude visual evoked potential (VEP) to pattern-reversal stimuli [5].

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

• The fast response to VNA stimulation was abolished when the ganglion was treated with the nicotinic antagonist, mecamylamine, leaving a slow, long-lasting depolarization of PPR, which we have called the slow excitatory postsynaptic potential (sEPSP) [11].

Biological context of PPR

• Under these conditions all excitatory postsynaptic potentials in PPR were also blocked, but the depolarizing action of oxo-M was unaffected [12].
• Iox was maximal near the resting potential of PPR (-45 to -40 mV), decreasing slightly with hyperpolarization and strongly with depolarization [12].
• A pivotal role for PPR gamma in innate immune homeostasis [13]?
• PPR (pulse pressure ratio), the ratio of minimum pulse pressure during phase 2 and maximum pulse pressure during phase 1 of the Valsalva manoeuvre, was correlated with PCWP (r=0.63, P<0.001) [14].
• The present association study tested whether genetic variation of BRD2 confers also susceptibility to PPR [15].

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].

References