Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.16.2 (PCP)
 3,761 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ubiquitin-histone H2A conjugate, uH2A, of the protozoan Tetrahymena pyriformis was isolated by gel chromatography and octadecylsilyl-silica chromatography, from the fractions on the chromatographic purification of histone H2A [Fusauchi, Y. & Iwai, K. (1983) J. Biochem. 93, 1487-1497]. The uH2A showed an amino acid composition corresponding to the sum of an equimolar mixture of two protozoan H2A variants and protozoan free ubiquitin. N- and C-terminal sequencing of the uH2A, by Edman degradation and carboxypeptidase P digestion, showed a branched structure having two N-terminals, those of the H2A and ubiquitin components, and one C-terminal, that of each H2A variant component. Further structural analyses of the uH2A, by tryptic digestion of citraconylated uH2A and of a ubiquitinated BrCN fragment, showed that the ubiquitin C-terminal Gly-Gly is linked to the epsilon-amino group of either Lys-123, 125, or 126 in the H2A sequence, and that the ubiquitin sequence is similar to that of calf thymus but differs at least in the sequence of residues 12-27. The deducted structure was compared with the only known uH2A structure, that of calf thymus, with special reference to the branched site.
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PMID:Tetrahymena ubiquitin-histone conjugate uH2A. Isolation and structural analysis. 299 68

The effects of technical grade pentachlorophenol (T-PCP) exposure on several immunological parameters were examined in adult C57Bl/6 mice following eight weeks of dietary exposure. Immune function tests included mitogen-induced lymphocyte blastogenesis, mixed lymphocyte reactivity (proliferation and cytotoxicity), spontaneous and boosted levels of natural killer (NK) cytotoxicity, and phagocytic activity of resident, thioglycollate-induced, and P815-tumor activated peritoneal macrophages. Thymic and splenic weights, spleen cellularity, percentages of splenic T and B cells, and bone marrow cellularity were also determined. The only statistically significant functional alteration observed in T-PCP exposed mice in these studies was a reduction in the lymphoproliferative response in mixed lymphocyte culture which occurred in the absence of any apparent effect on the generation of cytotoxic cells. Mitogen responses, NK cytotoxicity and macrophage phagocytosis were unaltered by exposure to T-PCP. No changes were observed in spleen or thymus weights or in spleen or bone marrow cellularity. A dose-responsive trend toward reduced T cell and increased B cell percentages in the spleen of T-PCP exposed mice was noted. The apparent functional resistance of T cells, macrophages, and NK cells to T-PCP is in contrast to the marked sensitivity of the humoral immune response to T-PCP induced suppression. The results are discussed in relation to the dioxin contaminants present in T-PCP.
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PMID:Effects of dietary technical pentachlorophenol exposure on T cell, macrophage and natural killer cell activity in C57Bl/6 mice. 315 92

Newborn Holstein bull calves were fed either analytical pentachlorophenol (aPCP) or technical pentachlorophenol (tPCP) for 6 wk to establish and compare the clinical and pathologic manifestations of toxicity. Four groups of three calves/group were each fed either 1 or 10 mg X (kg body weight)-1 X d-1 of either aPCP or tPCP. A fifth group served as control. Dosages of both PCP preparations were normalized to contain equal concentrations of PCP. Toxic effects were observed only at the 10 mg/kg dose in the tPCP-treated calves. These effects included decreased body weight gain, anorexia, decreased serum protein concentration, elevated serum gamma glutamyl transferase, and decreased triiodothyronine (T3) and thyroxine (T4) concentrations. Histologic lesions included cortical atrophy in the thymus and squamous metaplasia and hyperkeratous changes in the Meibomian gland of the eyelid. Thyroid function, which was assessed in vivo by measuring the rate of T3 and T4 production over 4 h after thyrotropin-releasing hormone (TRH)-challenge, was not impaired suggesting an extrathyroidal site of toxic action. Although serum chemistry indicators were suggestive of hepatic injury there were no discernable lesions. Organ weight analyses were inconclusive but there was a tendency toward enlargement of liver, kidneys and thyroid and decreased weight of lungs, spleen and thymus. A toxic effect clearly related to PCP and not its contaminants was depressed active transport of p-aminohippurate measured in kidney slices in vitro. Steady state concentrations of PCP in serum were about 40 and 90 ppm for the 1 and 10 mg/kg groups, respectively. Concentrations of PCP among the major organs were comparable.
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PMID:Assessment of pentachlorophenol toxicity in newborn calves: clinicopathology and tissue residues. 393 33

Initial acute behavioral studies in mice indicated that phencyclidine (PCP) produced marked motor impairment as measured by the inverted screen technique with an ED50 value of 4.1 muMole/kg (i.v.). Phenylcyclohexene (PC) was considerably less active with an ED50 value of 325 muMole/kg (i.v.). PCP was also shown to be more lethal than PC as acute (24 hr; i.v. injection) LD50 values (muMoles/kg) in males were 57 and 448, and in females were /6 and 425, respectively. A greater acute lethality was also produced by PCP after i.p. and p.o. administration. Subchronic (14-day) exposure (i.p.) to PCP at doses up to approximately 40 percent of the acute LD50 value (123.6 muMole/kg, i.p., daily) was without significant effect on body and organ weights, hematology and clinical chemistry, and humoral and cell-mediated immunity. Higher doses of PCP were not possible because of acute lethality. Subchronic exposure to PC (63.4, 317, and 634.5 muMoles/kg; 4 percent, 20 percent and 40 percent of acute i.p. LD50 value, respectively) produced several marked effects. At the highest dose tested, body weight and thymus weight in both males and females, and liver weight in males were significantly decreased. The spleen weight of males exposed to 317 muMole/kg PC was also significantly decreased. Humoral immunity (production of antibody forming cells) was significantly inhibited in both males and females exposed to PC. In contrast, cell-mediated immunity (development of a delayed-type hypersensitivity response) was only significantly inhibited in females. As PCP has no measurable toxicity under these conditions and PC produced significant effects at relatively high doses, the results suggest that neither chemical is exceptionally toxic following subchronic exposure.
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PMID:Pharmacological activity and toxicity of phencyclidine (PCP) and phenylcyclohexene (PC), a pyrolysis product. 713 80

Animal models of Pneumocystis carinii (Pc) pneumonia (PCP) play a central role in research on the Pc microorganism itself and the disease, especially the pathogenesis and the host defence. The classic rat model with corticosteroid-induced reactivation of a latent infection has been most widely used. In our search for alternative non-rodent models, six 31/2-week-old piglets were injected intramuscularly with methylprednisolone acetate, at 18 mg/kg body weight, once a week for 6 weeks. Six littermate piglets constituted the control group. The principals showed a markedly lower growth rate than the controls. Furthermore, they developed "moon face" and "pot belly", snoring sounds while eating, and pronounced respiratory distress during handling. Significant changes in haematological parameters, including lymphopenia, were observed in the principal group. The Pc antibody titres of the controls increased to high levels, whereas the principals were all low-titred or seronegative for Pc at the last blood sampling. At necropsy, the mean body weight of the principals was about half that of the controls. In addition, they had an extreme reduction of the thymus together with dark red consolidations of the frontal lung lobes and/or atelectatic looking diaphragmatic lobes. Histopathologically, there was a focal interstitial pneumonia. Alveolar walls and interstitia had mononuclear cell infiltrations and the alveolar lumina were occluded by foamy acidophilic honeycomb material with a varying number of Pc cysts. The reduced body weight, the thymus involution, and the lymphopenia, together with the reduced levels of specific Pc antibodies and the histomorphology of the PCP, were consistent parameters of the principal group and comparable to the findings of the classic rat model. Thus, the present study is the first to describe that prolonged administration of high doses of methylprednisolone acetate can induce PCP in piglets.
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PMID:Experimental corticosteroid induction of Pneumocystis carinii pneumonia in piglets. 1054 89