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Pressure ulcers are a serious national health concern impacting cost of care, reimbursement, and quality of life. National estimates show 1.7 million patients annually develop pressure ulcers with associated health care costs of $8.5 billion. Sixty percent of patients develop these pressure ulcers while in acute care hospitals. Assessment of institution prevalence rates, patient risk profile, standardization of therapy protocols, and increased staff awareness can positively impact the balance between cost and quality patient outcomes. [ABSTRACT FROM AUTHOR]

The Anniston Community Health Survey (ACHS-I) was initially conducted from 2005 to 2007 to assess polychlorinated biphenyl (PCB) exposures in Anniston, Alabama residents. In 2014, a follow-up study (ACHS-II) was conducted to measure the same PCBs as in ACHS-I and additional compounds e.g., polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like non-ortho (cPCBs) substituted PCBs. In this epigenome-wide association study (EWAS), we examined the associations between PCDD, PCDF, and PCB exposures and DNA methylation. Whole blood DNA methylation was measured using Illumina EPIC arrays (n=292). We modeled lipid-adjusted toxic equivalencies (TEQs) for: ΣDioxins (sum of 28 PCDDs, PCDFs, cPCBs, and mPCBs), PCDDs, PCDFs, cPCBs, and mPCBs using robust multivariable linear regression adjusting for age, race, sex, smoking, bisulfite conversion batch, and estimated percentages of six blood cell types. Among all exposures we identified 10 genome-wide (Bonferroni p≤6.74E-08) and 116 FDR (p≤5.00E-02) significant associations representing 10 and 113 unique CpGs, respectively. Of the 10 genome-wide associations, seven (70%) occurred in the PCDDs and four (40%) of these associations had an absolute differential methylation ≥1.00%, based on the methylation difference between the highest and lowest exposure quartiles. Most of the associations (six, 60%) represented hypomethylation changes. Of the 10 unique CpGs, eight (80%) were in genes shown to be associated with dioxins and/or PCBs based on data from the 2019 Comparative Toxicogenomics Database. In this study, we have identified a set of CpGs in blood DNA that may be particularly susceptible to dioxin, furan, and dioxin-like PCB exposures., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: J.R. Olson served as an expert witness for the plaintiffs in legal actions regarding the residents of Anniston, Alabama being exposed to PCBs. The other authors declare that they have no competing interests., (Published by Elsevier B.V.)

Anniston, Alabama was home to a major polychlorinated biphenyl (PCB) production facility from 1929 until 1971. The Anniston Community Health Survey I and II (ACHS-I 2005-2007, ACHS-II 2013-2014) were conducted to explore the effects of PCB exposures. In this report we examined associations between PCB exposure and DNA methylation in whole blood using EPIC arrays (ACHS-I, n = 518; ACHS-II, n = 299). For both cohorts, 35 PCBs were measured in serum. We modelled methylation versus PCB wet-weight concentrations for: the sum of 35 PCBs, mono-ortho substituted PCBs, di-ortho substituted PCBs, tri/tetra-ortho substituted PCBs, oestrogenic PCBs, and antiestrogenic PCBs. Using robust multivariable linear regression, we adjusted for age, race, sex, smoking, total lipids, and six blood cell-type percentages. We carried out a two-stage analysis; discovery in ACHS-I followed by replication in ACHS-II. In ACHS-I, we identified 28 associations (17 unique CpGs) at p ≤ 6.70E-08 and 369 associations (286 unique CpGs) at FDR p ≤ 5.00E-02. A large proportion of the genes have been observed to interact with PCBs or dioxins in model studies. Among the 28 genome-wide significant CpG/PCB associations, 14 displayed replicated directional effects in ACHS-II; however, only one in ACHS-II was statistically significant at p ≤ 1.70E-04. While we identified many novel CpGs significantly associated with PCB exposures in ACHS-I, the differential methylation was modest and the effect was attenuated seven years later in ACHS-II, suggesting a lack of persistence of the associations between PCB exposures and altered DNA methylation in blood cells.

Digital PCR has been promoted as a technique for obtaining absolute measures of the amount of nucleic acid target sequence in a sample, but still lacks standardization in data reporting. The initial method of representing data as copies per microliter produced inconsistent results and made inter-assay comparisons difficult. Normalizing copies to amount of nucleic acid gives more uniform results, but factors influencing the effective concentration of nucleic acid in the final digital PCR assay must be considered. Using droplet digital PCR and previously validated reference genes duplexed with target genes, a method of normalization was developed to estimate the amount of input nucleic acid in individual assays, subsequently reporting the number of copies of target gene relative to this amount. Correcting for the actual amount of amplifiable nucleic acid present demonstrated a higher correlation between various dilutions of sample mRNA and allowed more accurate comparisons of digital PCR results.

Tetrabromobisphenol A (TBBPA) is a brominated flame retardant used globally at high volumes, primarily in the epoxy resin of circuit boards. It has been detected in the environment and in humans. The National Toxicology Program found that chronic oral TBBPA treatment of 250mg/kg and higher caused an increased incidence of uterine lesions in female Wistar Han rats. The present laboratory has previously reported changes in gene expression associated with estrogen homeostasis in liver and uterine tissue of adult female Wistar Han rats after five days of gavage with 250mg/kg of TBBPA. Microarray analysis of tissue from these same TBBPA-treated rats was performed to detect additional pathways perturbed by TBBPA. Microarray analysis of uterine tissue detected downregulation of genes in pathways of the immune response following TBBPA treatment. These results, along with validation of associated gene expression changes using droplet digital PCR, are reported here. Our findings suggest mechanisms that may be related to estrogen-mediated immunosuppression., (Published by Elsevier B.V.)

Chronic oral treatment of tetrabromobisphenol A (TBBPA) to female Wistar Han rats resulted in increased incidence of cell proliferation at 250mg/kg and tumor formation in the uterus at higher doses. The present study was designed to test the hypothesis that disruption of estrogen homeostasis was a major mode-of-action for the observed effects. Biological changes were assessed in serum, liver, and the proximal (nearest the cervix) and distal (nearest the ovaries) sections of the uterine horn of Wistar Han rats 24h following administration of the last of five daily oral doses of 250mg/kg. Expression of genes associated with receptors, biosynthesis, and metabolism of estrogen was altered in the liver and uterus. TBBPA treatment also resulted in changes in expression of genes associated with cell division and growth. Changes were also observed in the concentration of thyroxine in serum and in expression of genes in the liver and uterus associated with thyroid hormone receptors. Differential expression of some genes was tissue-dependent or specific to tissue location in the uterus. The biological responses observed in the present study support the hypothesis that perturbation of estrogen homeostasis is a major mode-of-action for TBBPA-mediated cell proliferation and tumorigenesis previously observed in the uterus of TBBPA-treated Wistar Han rats., (Published by Elsevier Inc.)

The cytochrome P450 (P450) enzymes CYP2C8, CYP2C9, and CYP2J2 metabolize arachidonic acid to epoxyeicosatrienoic acids, which are known to be vital in regulation of vascular tone and cardiovascular homeostasis. Because there is limited information regarding the relative expression of these P450 enzymes in cardiovascular tissues, this study examined the expression of CYP2C8, CYP2C9, and CYP2J2 mRNA and protein in human heart, aorta, and coronary artery samples by real-time polymerase chain reaction, immunoblotting, and immunohistochemistry. CYP2J2 and CYP2C9 mRNA levels were highly variable in human hearts, whereas CYP2C8 mRNA was present in lower abundance. CYP2J2 mRNA was approximately 10(3) times higher than CYP2C9 or CYP2C8 in human heart. However, CYP2C9 mRNA was more abundant than CYP2J2 or CYP2C8 in one ischemic heart. In human aorta, mean CYP2C9 mRNA levels were approximately 50 times higher than that of CYP2J2 and 5-fold higher than that of CYP2C8. In human coronary artery, mean values for CYP2C9 mRNA were approximately 2-fold higher than that of CYP2J2 mRNA and 6-fold higher than that of CYP2C8 mRNA. Immunoblotting results show relatively high levels of CYP2J2 and CYP2C8 protein in human hearts, which was confirmed by immunohistochemistry. CYP2C9 protein was also detected at high levels in one ischemic heart by immunoblotting. CYP2C9 was present at higher levels than CYPJ2 in aorta and coronary artery, whereas CYP2C8 protein was below the limits of detection. The expression of CYP2J2 and CYP2C8 in human heart, and CYPC9 and CYP2J2 in aorta and coronary artery is consistent with a physiological role for these enzymes in these tissues.

Objectives: Retinoic acid (RA) is a critical regulator of gene expression during embryonic development and in the maintenance of adult epithelial tissues. This study was undertaken to identify genetic polymorphisms of CYP26A1 which might affect these processes. We sequenced CYP26A1 in racially diverse individuals and assessed the metabolism of retinoic acid by newly identified coding alleles of CYP26A1 in a recombinant system., Methods: CYP26A1 was sequenced in 24 Caucasians, 24 African-Americans, 24 Asians, and 20 individuals of unknown racial origin. cDNA constructs for wild-type and coding alleles of CYP26A1 were constructed in a pcDNA3.1 expression vector and expressed in Cos-1 cells. A FLAG tag at the C-terminal end of the cDNA was used to quantitate the recombinant CYP26A1 proteins., Results: A total of 13 single nucleotide polymorphisms (SNPs) were identified in CYP26A1. Three SNPs produced coding changes: R173S, F186L, and C358R. These alleles were termed as CYP26A1*2, CYP26A1*3, and CYP26A1*4, respectively, by the Human Cytochrome P450 (CYP) Allele Nomenclature Committee at http://www.cypalleles.ki.se/. Wild type CYP26A1 protein metabolized all-trans-retinoic acid (at-RA) to 4-oxo-RA, 4-OH-RA as well as water-soluble metabolites. CYP26A1.3 (F186L) and CYP26A1.4 (C358R) allelic proteins exhibited significantly lower metabolism (40-80%) of at-RA than wild-type CYP26A1.1 protein., Conclusion: This is the first study to identify coding alleles of CYP26A1. Two coding alleles, CYP26A1*3 and CYP26A1*4, are predicted to be defective based on the metabolism of at-RA by the recombinant proteins. These studies suggest the need for future clinical studies of polymorphisms of CYP26A1 in embryonic development.

CYP2C9 was recently resequenced in 150 Asian subjects from Singapore. Several new coding variants were reported, and these variants are now named CYP2C9*14 (R125H), CYP2C9*15 (S162X), CYP2C9*16 (T299A), CYP2C9*17 (P382S), CYP2C9*18 (D397A), and CYP2C9*19 (Q454H). The CYP2C9*18 variant also contained an I359L change previously associated with the CYP2C9*3 allele. In this study, we assessed the functional consequences of the new coding changes. cDNAs containing each of the new coding changes were constructed by site-directed mutagenesis and expressed in a bacterial cDNA expression system, the allelic proteins were partially purified, and their ability to hydroxylate a prototype CYP2C9 substrate was assayed. Expression of cDNAs in Escherichia coli containing either the D397A change or the S162X (premature stop codon) could not be detected either spectrally or at the apoprotein level. CYP2C9.14 and CYP2C9.16 exhibited 80 to 90% lower catalytic activity toward tolbutamide at two substrate concentrations compared with wild-type CYP2C9.1. Kinetic analysis confirmed that CYP2C9.14 and CYP2C9.16 have a higher Km and a >90% lower intrinsic clearance of tolbutamide compared with wild-type CYP2C9.1. Both CYP2C9.17 and CYP2C9.19 proteins exhibited modest 30 to 40% decreases in catalytic activity toward tolbutamide. Thus, CYP2C9*15 and CYP2C9*18 may represent null alleles, whereas CYP2C9*14 and CYP2C9*16 allelic variants produce proteins that are clearly catalytically defective in vitro, indicating the existence of new defective putative alleles of CYP2C9 in Asians.

Background: Adjustments in intestinal absorption and losses of zinc (Zn) are thought to maintain Zn homeostasis when dietary intake levels are altered. Zn status may also influence efficiency of intestinal Zn absorption., Objectives: To determine the impact of dietary intake and status of some micronutrients on Zn absorption in late middle-aged men., Design and Participants: Dietary intake and status of Zn, Cu, Fe, vitamin A, C and fibre, and absorption of Zn were measured in 48 men, aged 58-68 y, confined to a metabolic unit and consuming a typical French diet. Dietary intake was estimated using 4-day food-intake records (including the weekend) and the GENI program. To assess Zn status, serum, erythrocyte, urine Zn levels and serum alkaline phosphatase activity were determined. Zn absorption was determined using the isotope double-labelling method. Zn stable isotopic ratios were measured in plasma samples collected before and 48 h after isotope administration using ICP/MS., Results: Zn intake within the group of men varied from 5.7 to 20.5 mg/day and averaged 12.9 mg/day. Serum Zn level varied from 10 to 18 micromol/l and averaged 12.9 micromol/l. Zn absorption varied from 12 to 46% and averaged 29.7%. Zn absorption was not significantly (P > 0.05) correlated with Zn intake or with any of the Zn status parameters. Zn absorption was only slightly negatively correlated with serum and erythrocyte Zn levels and with serum Fe and ferritin levels in this study., Conclusion: Zn dietary intake and Zn absorption were satisfactory and led to an adequate Zn status in this population.

Genetic variation in CYP3A activity may influence the rate of the metabolism and elimination of CYP3A substrates in humans. We previously reported four new CYP3A4 coding variants in three different racial groups. In the present study, we examined metabolism of nifedipine by the recombinant forms of these allelic variants. Metabolism of nifedipine by the L293P (CYP3A4*18), M445T (CYP3A4*3), and P467S (CYP3A4*19) allelic variants was not significantly different from wild-type CYP3A4*1. However, F189S (CYP3A4*17) exhibited a >99% decrease in both V(max) and CL(max) of nifedipine compared with CYP3A4*1. Of 72 racially diverse individuals, CYP3A4*17 was identified in 1 of 24 Caucasian samples [1:5 Eastern European (Adygei ethnic group)]. Genotyping of an extended set of 276 genomic DNAs of Caucasians (100 from the Coriell Repository and an additional 176 from the United States) for CYP3A4*17 detected no additional individuals containing the CYP3A4*17 allele. However, additional genotyping of four more Adygei samples available from Coriell detected an additional individual carrying the CYP3A4*17 allele. New specific polymerase chain reaction-restriction fragment length polymorphism genotyping procedures were developed for the major splice variant of CYP3A5 (CYP3A5*3) and CYP3A4*17. Genotyping revealed that the two individuals carrying CYP3A4*17 were either homozygous or heterozygous for the more frequent CYP3A5*3 allele, suggesting that the two alleles may exist on the same chromosome as a new putative CYP3A poor metabolizer haplotype. We predict that individuals who are homozygous for defective alleles of both of these genes would metabolize CYP3A substrates poorly. The new genetic tests will be useful in future clinical studies to investigate genotype/phenotype associations.

The human CYP2Cs have been studied extensively with respect to the metabolism of clinically important drugs and endogenous chemicals such as arachidonic acid (AA). Five members of the mouse CYP2C family have previously been described that metabolize arachidonic acid into regio- and stereospecific epoxyeicosatrienoic acids (EETs) and hydroxyeicosatetraenoic acids, which have many important physiological roles. Herein, we describe the cloning and characterization of a new mouse cytochrome P450 (P450), CYP2C44, which has the lowest homology with other known mouse CYP2Cs. Western blotting and real-time polymerase chain reaction detected CYP2C44 mRNA and protein in liver >> kidney > adrenals. Kidney contained approximately 10% of the CYP2C44 mRNA content of liver. CYP2C44 metabolized AA to unique stereospecific products, 11R,12S-EET and 8R, 9S-EET, which are similar to those produced by rat CYP2C23. CY2C23 is highly expressed in rat kidney and has been suggested to be important in producing compensatory renal artery vasodilation in response to salt-loading in this species. Immunohistochemistry showed the presence of CYP2C44 in hepatocytes, biliary cells of the liver, and the proximal tubules of the kidney. Unlike mouse CYP2C29, CYP2C38, and CYP2C39, CYP2C44 did not metabolize the common CYP2C substrate tolbutamide. CYP2C44 was not induced by phenobarbital or pregnenolone-16alpha-carbonitrile, two prototypical inducers of hepatic P450s. The presence of CYP2C44 in mouse liver, kidney, and adrenals and the unique stereospecificity of its arachidonic acid metabolites are consistent with the possibility that it may have unique physiological roles within these tissues, such as modulation of electrolyte transport or vascular tone.

The CYP2C subfamily has been extensively studied in humans with respect to the metabolism of clinically important drugs, and polymorphisms have been identified in these enzymes. In the present study, a murine model was used to determine the possible physiological functions and extrahepatic distribution of CYP2Cs. Using the reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, and immununohistochemistry, this report demonstrates that the mouse CYP2Cs are extensively distributed in extrahepatic tissues and localized to heart muscle, lung Clara and ciliated cells, kidney collecting ducts, the X-zone of female adrenals, reproductive organs, white blood cells, and eyes (in the optic nerve, rods, and cones). RT-PCR, subcloning, and sequencing of the products indicate that each CYP2C has a unique tissue distribution. Four cDNA fragments representing potentially new CYP2Cs were identified, each with its own organ-specific pattern of expression. Using a bacterial cDNA expression system, we found that recombinant proteins for each of the five full-length murine CYP2Cs metabolize arachidonic acid to different regio- and stereospecific products, including epoxyeicosatrienoic acids and hydroxyeicosatetraenoic acids. Regio- and stereospecific metabolites of arachidonic acid have been reported to affect important physiological functions such as inflammation, neutrophil activation, ion transport, cellular proliferation, and vascular tone. Our results suggest that the presence of CYP2C enzymes in heart muscle, aorta, kidney, lung, adrenals, eyes, and reproductive organs could regulate important physiological and/or pathological processes in these tissues.

Cytochrome P450 (CYP) 2C8 is the principal enzyme responsible for the metabolism of the anti-cancer drug paclitaxel (Taxol). It is also the predominant P450 responsible for the metabolism of arachidonic acid to biologically active epoxyeicosatrienoic acids (EETs) in human liver and kidney. In this study, we describe two new CYP2C8 alleles containing coding changes: CYP2C8*2 has an Ile269Phe substitution in exon 5 and CYP2C8*3 includes both Arg139Lys and Lys399Arg amino acid substitutions in exons 3 and 8. CYP2C8*2 was found only in African-Americans, while CYP2C8*3 occurred primarily in Caucasians. Neither occurred in Asians. The frequency of the CYP2C8*2 allele was 0.18 in African-Americans, and that of CYP2C8*3 was 0.13 in Caucasians. CYP2C8*1 (wild-type), CYP2C8*2 and CYP2C8*3 cDNAs were expressed in Escherichia coli, and the ability of these enzymes to metabolize both paclitaxel and arachidonic acid was assessed. Recombinant CYP2C8*3 was defective in the metabolism of both substrates. The turnover number of CYP2C8*3 for paclitaxel was 15% of CYP2C8*1. CYP2C8*2 had a two-fold higher Km and two-fold lower intrinsic clearance for paclitaxel than CYP2C8*1. CYP2C8*3 was also markedly defective in the metabolism of arachidonic acid to 11,12- and 14,15-EET (turnover numbers 35-40% that of CYP2C8*1). Thus, CYP2C8*3 is defective in the metabolism of two important CYP2C8 substrates: the anticancer drug paclitaxel and the physiologically important compound arachidonic acid. This polymorphism has important clinical and physiological implications in individuals homozygous for this allele.

CYP2C19 is selective for the 4'-hydroxylation of S-mephenytoin while the highly similar CYP2C9 has little activity toward this substrate. To identify critical amino acids determining the specificity of human CYP2C19 for S-mephenytoin 4'-hydroxylation, we constructed chimeras by replacing portions of CYP2C9 containing various proposed substrate recognition sites (SRSs) with those of CYP2C19 and mutating individual residues by site-directed mutagenesis. Only a chimera containing regions encompassing SRSs 1--4 was active (30% of wild-type CYP2C19), indicating that multiple regions are necessary to confer specificity for S-mephenytoin. Mutagenesis studies identified six residues in three topological components of the proteins required to convert CYP2C9 to an S-mephenytoin 4'-hydroxylase (6% of the activity of wild-type CYP2C19). Of these, only the I99H difference located in SRS 1 between helices B and C reflects a change in a side chain that is predicted to be in the substrate-binding cavity formed above the heme prosthetic group. Two additional substitutions, S220P and P221T residing between helices F and G but not in close proximity to the substrate binding site together with five differences in the N-terminal portion of helix I conferred S-mephenytoin 4'-hydroxylation activity with a K(M) similar to that of CYP2C19 but a 3-fold lower K(cat). Three residues in helix I, S286N, V292A, and F295L, were essential for S-mephenytoin 4'-hydroxylation activity. On the basis of the structure of the closely related enzyme CYP2C5, these residues are unlikely to directly contact the substrate during catalysis but are positioned to influence the packing of substrate binding site residues and likely substrate access channels in the enzyme.

We recently identified five different murine CYP2C cDNAs from a murine cDNA library. When expressed in a bacterial cDNA expression system, all five recombinant proteins metabolized arachidonic acid but produced distinctly different profiles. In addition, some CYP2C mRNAs were found in extrahepatic tissues, as well as in liver. Immunoblots with an antibody raised against recombinant CYP2C38, which recognizes all five murine CYP2Cs, demonstrated that among extrahepatic tissues, colon and cecum contained the highest amount of CYP2Cs. The highest concentration of CYP2Cs occurred in cecum and colon (cecum >/= proximal colon >> distal colon), with lower levels in duodenum, jejunum, and ileum. Immunohistochemical studies revealed that CYP2Cs were localized principally in epithelial cells and autonomic ganglia in gut and colon. Polymerase chain reaction amplification of reverse-transcribed mRNA using murine CYP2C-specific primers followed by cloning and sequencing identified CYP2C40 as the major CYP2C isoform expressed in murine intestinal tract. Recombinant CYP2C40 metabolized arachidonic acid in a regio- and stereospecific manner to 16(R)-HETE (hydroxyeicosatetraenoic acid) as the major product. To our knowledge, CYP2C40 is the first enzyme known to produce primarily 16-HETE. We conclude that CYP2C40 is one of the major cytochrome P450 proteins in the mouse intestinal tract. In the light of vasoactive and anti-neutrophilic effects of 16-HETE, we hypothesize that CYP2C40 may play an important role in endogenous biological functions in intestine.

The ligand-induced internalization of beta-adrenergic receptors and the receptor-mediated internalization of epidermal growth factor were blocked, under similar conditions, by phenylarsine oxide (PAO) in human astrocytoma cells (1321N1). The inhibition was not prevented or reversed by monofunctional sulfhydryl agents such as 2-mercaptoethanol or glutathione; however, the inhibitory action of PAO was blocked and reversed by bifunctional thiols such as 2,3-dimercaptoethanol or dithiothreitol. The results are consistent with the interaction of PAO with vicinal sulfhydryl groups to form a stabile ring structure. PAO did not prevent isoproterenol-induced uncoupling (desensitization) of beta-adrenergic receptors even though receptor internalization was completely blocked. The effects of PAO on receptor internalization could not be explained by any action of the trivalent arsenical to lower ATP levels. Ligand binding to both receptors was not detectably altered by PAO under conditions selective for inhibition for endocytosis. The results suggest a common mechanism for internalization of beta-adrenergic receptors and epidermal growth factor by a process that involves vicinal sulfhydryl groups.

Beta-Adrenergic receptors and epidermal growth factor receptors are both expressed on the cell surface of human astrocytoma cells. Incubation with a catecholamine or epidermal growth factor results in rapid internalization of the respective receptor. The internalized receptors co-migrate in light fractions on sucrose gradients. Astrocytoma cells maintain a constant ATP concentration by either glycolytic or mitochondrial ATP production. When cells are incubated in a medium depleted of substrates for glycolysis and gluconeogenesis, addition of inhibitors of mitochondrial ATP synthesis causes a rapid reduction in cellular ATP content. An immediate return to control ATP levels occurs upon addition of an appropriate nutrient, such as glucose. Decreasing the cellular ATP content to less than 10% of control markedly inhibits internalization of beta-adrenergic receptors and epidermal growth factor. The inhibition of endocytosis is reversed as soon as the intracellular ATP content is restored. Previous work by others (Clarke, B.L., and Weigel, P.H. (1985) J. Biol. Chem. 260, 128-133) suggested that ATP is not required for internalization (per se) of asialoglycoprotein in hepatocytes but was required for recycling of the asialoglycoprotein receptor. In contrast, our results indicate that in astrocytoma cells the process of internalization of epidermal growth factor and beta-adrenergic receptors, per se, is highly ATP dependent.

In 4 horses with equine infectious anemia (EIA), the predominant clinical sign was ataxia. Other clinical and laboratory findings often associated with EIA included weight loss, anemia, pyrexia, thrombocytopenia, hemorrhages, hypergammaglobulinemia, and high activity of biliary epithelial enzymes. Neuropathologic findings were nonsuppurative granulomatous ependymitis, meningitis, and encephalomyelitis and plasmacytic-lymphocytic infiltration of the brain and spinal cord. The onset of neurologic signs corresponded to the acute stage of infection in at least 2 horses, and the signs developed at least 18 months after infection in 1 case. Cerebrospinal fluid from 3 of the horses contained high concentration of protein and white cells, although changes in 1 horse may have been associated with a prior traumatic attempt to collect CSF. By comparison, CSF from 3 ponies inapparently infected with EIA was normal. Active production of anti-EIA antibody in the CSF was suspected on the basis of serologic findings.