Disease relevance of PCN

• In this article, we review our experience with rapid intravenous desensitization for patients who gave a history of PCN allergy and who had hypersensitivity demonstrated by skin tests [1].
• Patients allergic to penicillin (PCN) often require treatment with beta-lactam antibiotics for life-threatening bacterial infections [1].
• A mutation in the psrA gene (Pseudomonas sigma regulator), the gene product of which is a member of the TetR/AcrR family of transcriptional regulators, resulted in increased production of autoinducer molecules and PCN [2].
• Since the substantia nigra pars reticulata (SNpr) seems to have an inhibitory action on the ventro-anterior (VA) and ventro-lateral (VL) thalamic nuclei and thalamic neurones send an excitatory influence to the cortex, we undertook an investigation to study nigral influence on cortical epilepsy induced by PCN [3].
• The results showed that a microinjection of PCN in the AM produced a reliable model of interictal spikes, paroxysms and generalized convulsive seizures [4].

Psychiatry related information on PCN

• The only mild changes recorded in the 23 h following PCN microinjections were an increased latency of the first rapid eye movement (REM) sleep episode, a SWS II total time and percentage increase, and, with the highest PCN doses, a not very significant diminution of REM sleep total time [4].
• The result revealed that pretreatment with MO inhibited PCN-induced seizure and markedly reduced locomotor activity [5].

High impact information on PCN

• The sequence of NF25 is 77% similar to that reported for a rat cytochrome "P-450PCN" cDNA (PCN = pregnenolone-16 alpha-carbonitrile) [6].
• AcCho applied directly to PCN somata depolarizes them, indicating that the PCN soma membrane contains AcCho receptors and induces the FMP in the isolated central nervous system preparation [7].
• Incubation of 4-OH-tam with liver microsomes from PCN-treated rat yielded three detectable metabolites [8].
• Expression of wild type PXR and various mutants as green fluorescent fusion proteins in mouse livers showed that PXR was retained in the cytoplasm from where PCN treatment translocated PXR into the nucleus [9].
• We conclude that the CCRP mediates the retention of PXR in the cytosol and modulates the activation of PXR in response to PCN treatment [9].

Chemical compound and disease context of PCN

• Pseudomonas chlororaphis PCL1391 produces the antifungal secondary metabolite phenazine-1-carboxamide (PCN) that inhibits growth of Fusarium oxysporum f. sp. radius lycopersici the causative agent of tomato foot and root rot [10].
• Pseudomonas chlororaphis PCL1391, a root isolate that produces phenazine-1-carboxamide (PCN), is able to reductively dissolve poorly crystalline iron and manganese oxides, whereas a strain carrying a mutation in one of the phenazine-biosynthetic genes (phzB) is not; the addition of purified PCN restores this ability to the mutant strain [11].
• Given a history of PCN anaphylaxis, no allergists but 11% of nonallergists prescribed a cephalosporin [12].
• Experiments were conducted on encéphale isolé cats in which steady interictal activity was induced by means of parenteral PCN administration (feline generalized PCN epilepsy) [3].
• The human hepatoma cell lines HuH7 and HepG2 were treated with PXR activators including clotrimazole, rifampicin, 17beta-hydroxy-11beta-[4-dimethylamino phenyl]-17alpha-[1-propynyl]estra-4,9-dien-3-one (RU486), metyrapone, nifedipine, lithocholic acid, and 5-pregnen-3beta-ol-20-one-16alpha-carbonitrile (PCN) [13].

Biological context of PCN

• To determine the role of the amide group in biocontrol, the PCN biosynthetic genes of strain PCL1391 were identified and characterized [14].
• CONCLUSION: Overall, one-week combination regimens of PCA and PCN present similar H. pylori eradication efficacy [15].
• Our previous work unraveled a cascade of genes regulating the PCN biosynthesis operon, phzABCDEFGH [10].
• The expression of the PCN biosynthetic gene cluster in PCL1391 is population density-dependent and is regulated by the quorum-sensing genes phzI and phzR via synthesis of the autoinducer N-hexanoyl-L-homoserine lactone (C6-HSL) [2].
• Two PCL1391 mutants lacking production of PCN were defective in the genes phzI and phzR, respectively, the nucleotide sequences of which were determined completely [16].

Anatomical context of PCN

• In experiments on seven cats we tested the hypothesis that the epileptogenic effect of penicillin (PCN) on the spinal cord is mediated by a reduction of presynaptic inhibition [17].
• The authors present a case of papillary and cystic neoplasm of the pancreas (PCN) in which fine-needle aspiration was performed intraoperatively [18].
• The features most helpful in reaching a diagnosis of PCN were a monotonous population of tumor cells, round to oval bland-appearing nuclei, scanty to moderate ill-defined cytoplasm, and the presence of numerous capillaries [18].
• Cellular locations, axonal projections, and synaptic effects of inhibitory vestibulocollic (VC) neurons activated by the ampullary nerve of the posterior semicircular canal (PCN) were studied in anesthetized cats [19].
• PB and PCN treatments increased thyroid weight 80%, and PTU increased thyroid weight 500% [20].

Associations of PCN with other chemical compounds

• Roxatidine acetate 300 mg PCN produced the greatest rise of pH, to 4.9, suggesting that the true potency ratio of the 2 drugs is between 1 and 2 [21].
• The antifungal metabolite phenazine-1-carboxamide (PCN), as well as efficient root colonization, are essential in the mechanism of biocontrol by P. chlororaphis PCL1391 [22].
• Fusaric acid, a secondary metabolite produced by the soilborne Fusarium spp. fungi, also reduced PCN levels [23].
• In RT-PCR assay, aging did not change the induction of Sult2A1 mRNAs by the hormonally active vitamin D(3) and the catatoxic synthetic steroid PCN (pregnenolone-16alpha-carbonitrile) [24].
• The human adult liver microsomal specimens also contained a MAb PCN 2-13-1/C2 identified cytochrome P-450 band [25].

Gene context of PCN

• Chromatin immunoprecipitation (ChIP) from liver nuclei showed that aging had no effect on the activity of an IR0 enhancer in the Sult2A1 chromatin to recruit VDR, RXR-alpha (retinoid X receptor) and PXR in mice injected with D(3) or PCN [24].
• We have used a specific anti-PXR antibody in the Western blotting of mouse liver nuclear extracts to show that PXR is accumulated in the nucleus after treatment with 5-pregnen-3beta-ol-20-one-16alpha-carbonitrile (PCN), followed by an increase in Cyp3a11 mRNA [9].
• FA does not alter expression of the PCN regulators gacS, rpoS and psrA [26].
• Taken together, these results indicated that the inhibition of histone deacetylation was required to SXR-mediated increase in CYP3A4 proximal promoter region when rifampicin, or PCN was treated [27].
• Human fetal and adult liver metabolism of ethylmorphine. Relation to immunodetected cytochrome P-450 PCN and interactions with important fetal corticosteroids [28].

Analytical, diagnostic and therapeutic context of PCN

• Of seven different MAbs used MAb PCN 2-13-1/C2 was the only one that immunodetected a cytochrome P-450 band with Western blot analyses of human fetal liver microsomes [25].
• A combination of a phenotypical characterization of a pip mutant, in trans complementation assays of various mutant strains, and electrophoretic mobility shift assays identified Pip as the fifth DNA-binding protein so far involved in regulation of PCN biosynthesis [10].
• Repeated microinjections of PCN did not produce lasting alterations in sleep onset and organization [4].
• In addition, we have shown that BICUC and PCN produced membrane depolarization of mouse spinal cord neurons in primary dissociated cell culture by blocking a potassium conductance, a non-synaptic direct effect [29].
• A retrospective study of a focused history and PCN skin testing was done in a consecutive sample of a suburban allergy population of 319 patients who had a positive history of PCN allergy [30].

References