Proton nuclear magnetic resonance of urine and bile from paracetamol dosed rats.
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Acetaminophen↗
Biomedical subjects
J K Nicholson
Publications and source records attributed to J K Nicholson.
In vitro infection of monocytes with HIVBa-L. Effect on cell surface expression of CD4, CD14, HLA-DR, and HLA-DQ.
Monocytes from healthy blood donors were inoculated in vitro with a monocyte-tropic strain of human immunodeficiency virus type 1 HIVBa-L. HIV replication was first detected at Day 5 postinoculation, with peak virus activity at Day 17. We assessed the kinetics of the expression of four monocyte surface antigens (CD14, CD4, HLA-DR, and HLA-DQ) on HIV-infected and uninfected monocyte/macrophages, (M phi) by flow cytometry. We consistently found a decreased expression of CD4 and CD14 on HIV-infected M phi compared to their expression on M phi of uninfected controls. In contrast, HLA-DR and HLA-DQ expression was unchanged on HIV-infected M phi.
Antigens, Differentiation, Myelomonocytic↗
Comparison of monocyte separation methods using flow cytometric analysis.
We isolated normal, nonactivated human monocytes from peripheral blood by four different methods: (1) rosetting with sheep erythrocytes pretreated with 2-aminoethylisothiouronium bromide hydrobromide (AET) followed by monoclonal antibody (OKT3 (CD3), B1 (CD19), Leu7, Leu11 (CD16] and complement treatment; (2) adherence to gelatin/plasma-coated flasks; (3) adherence to plastic dishes; and (4) separation by the Sepracell technique. We monitored these monocyte separations by determining cell recoveries, OKT4A+ lymphocyte contamination, monocyte binding to human immunodeficiency virus (HIV), number of non-specific esterase-positive cells, and proportion of mononuclear cells reactive with a battery of monoclonal antibodies specific for monocytes. Our results indicate that of the four methods compared, adherence to gelatin/plasma-coated flasks produced the highest purity, recovery, and satisfactory binding to HIV with the fewest contaminating CD4+ T cells.
Antibodies, Monoclonal↗
Down-modulation of MHC-I in a CD4+ T cell line, CEM-E5, after HIV-1 infection.
HIV-1 is capable of infecting many different cell types that express the CD4 molecule. In vivo and in vitro this infection is associated with profound immunologic defects. We have examined the effect of HIV-1 infection on the expression of MHC class I (MHC-I) molecules to explore the possibility that this important immune system molecule is perturbed after HIV-1 infection. Our data show that in vitro, HIV-1 infection of CD4+ PBL, and the CD4+ cell lines, CEM-E5, HT, and U937, results in decreased expression of MHC-I molecules on the cell surface. This down-modulation is transient, occurring 18 h after HIV-1 infection of CD4+ PBL and returning to normal expression by 24 h. In CEM-E5, MHC-I down-modulation occurs over the course of days, reaching its greatest decrease (40%) about the time the cells are producing the most virus. Reversal of MHC-I expression to normal levels occurs as viral production decreases. Down-regulation during the time periods examined appear to be specific for MHC-I and does not occur with other cell-surface Ag nor is it caused by selection of a preexisting cell population with low MHC-I expression. Radioimmunoprecipitation of MHC-I protein from CEM-E5 indicated that the decrease of surface MHC-I is caused by decreased total protein secondary to a decrease in the level of mRNA for MHC-I. These decreased levels of MHC-I are biologically relevant because HIV-1 infected CEM-E5 cells are less susceptible to CTL lysis determined by the use of MHC-I cytolytic T cell clones and with the use of cold target-inhibition assay.
Antigens, CD↗
1H NMR studies on protein binding of histidine, tyrosine and phenylalanine in blood plasma.
The binding of histidine (His), phenylalanine (Phe) and tyrosine (Tyr) to macromolecules in blood plasma and serum has been investigated by high resolution 1H NMR spectroscopy. In single pulse and spin-echo spectra of quality control bovine serum and normal human plasma, there are no resonances in the chemical shift range to high frequency of delta = 5.3 ppm when measured in the pH* (meter reading, uncorrected for the presence of 2H2O) range 3 to 8.5. On acidification of the plasma to pH* less than 2.5, resonances from His and Phe are observable. In plasma from patients with Wilson's disease, weak signals from His and Tyr are seen in spin-echo spectra at pH* 7.6, but increase in strength on acidification and signals from Phe appear at pH* 1.8. Addition of standard solutions containing Tyr, His and especially Phe and Trp to plasma at neutral pH* results in poor recovery of their expected signal intensity in spin-echo spectra. Addition of 2 M urea to bovine plasma at pH* 4.5 results in the appearance of Phe signals. These data are consistent with Phe and Tyr (and to a lesser extent His) being bound in or to a macromolecular structure at neutral pH from which there is relatively slow exchange with the free solution environment. Experiments with model solutions suggest that serum albumin has a high capacity for binding aromatic amino acids (stabilized by hydrophobic interactions) at neutral pH and this is responsible for the NMR-invisibility of Tyr and Phe in blood plasma.
Animals↗
Biochemical characterisation of para-aminophenol-induced nephrotoxic lesions in the F344 rat.
The acute biochemical effects of the nephrotoxin p-aminophenol (PAP) were studied in detail using a combination of conventional bioanalytical and 1H-NMR spectroscopic methods. Dosing PAP (25-100 mg/kg) to male F344 rats resulted in a dose-related proximal nephropathy with consequent elevations in urinary enzymes, glucose, and urine total protein as shown by conventional methodology. 1H-NMR spectroscopy at 400 MHz of urine from PAP-treated rats also revealed a characteristic glycosuria, with concomitant amino aciduria. The increased excretion of these compounds indicates functional defects in the proximal tubule and reduced solute reabsorption efficiency. In addition, 1H-NMR urinalysis and conventional enzymatic analysis showed a dose-related lactic aciduria. Other changes detected by 1H-NMR included a dose-related reduction in the excretion of citrate (confirmed by a conventional biochemical method) and an increase in the excretion of acetate. The degree of abnormalities shown by 1H-NMR urinalysis agreed well with histopathological observations and conventional biochemical indices of nephrotoxicity. 1H-NMR urinalysis therefore serves to highlight changes in the excretion of low MW urine components not routinely studied by conventional biochemical analysis.
Amino Acids↗
Deterioration in immunologic status of human immunodeficiency virus (HIV)-infected homosexual men with lymphadenopathy: prognostic implications.
Changes in immunologic parameters were followed in members of a cohort of human immunodeficiency virus (HIV)-positive homosexual or bisexual men with lymphadenopathy and were analyzed for differences between those who have and those who have not progressed to the acquired immunodeficiency syndrome (AIDS) (progressors, nonprogressors). T helpers and the Th/Ts ratio were lower in progressors than in nonprogressors both at entry into the study and at the latest visit. T suppressors were not different in the two groups at entry but were higher in nonprogressors at the latest visit. Evaluation of the patterns of change over time showed that T helpers and Th/Ts ratios tended to decrease over time in both nonprogressors and progressors, while T suppressors increased in nonprogressors and decreased in progressors. Although progressors had a greater deterioration in immunologic parameters over time, nonprogressors also had significant deterioration when compared with controls. Based on the respective percentages of men with abnormal or normal T helpers or Th/Ts ratio at entry who have already progressed to AIDS, we would conservatively estimate, considering their latest T helpers and Th/Ts ratio, that at least an additional 16 (32%) of our nonprogressors will develop AIDS in the next 5 years.
AIDS-Related Complex↗
Lymphocyte immunophenotyping at the Centers for Disease Control: the program and special studies.
Lymphocyte immunophenotyping has been done at the Centers for Disease Control since 1981. The technology is constantly evolving, and changes have been instituted to keep up with and improve this technology. In the last 7 years we have analyzed approximately 8300 specimens from patients and persons at risk in projects related to the acquired immunodeficiency syndrome. Though several subsets of lymphocytes have been found to be increased or decreased in HIV infection, no lymphocyte determination is more sensitive than CD4 alone in predicting the outcome of human immunodeficiency virus infection.
Acquired Immunodeficiency Syndrome↗
A study of the metabolism of dimethylformamide in the rat by high resolution proton NMR spectroscopy.
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Animals↗
Proton NMR spectroscopy of bile for monitoring the excretion of endogenous and xenobiotic metabolites: application to para-aminophenol.
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Aminophenols↗
Serial determinations of HIV-1 titers in HIV-infected homosexual men: association of rising titers with CD4 T cell depletion and progression to AIDS.
Lymphocyte subset enumerations, antibody titers to specific proteins of human immunodeficiency virus (HIV), and measurement of infectious HIV titers in peripheral blood mononuclear cells were performed on serial blood specimens from 15 HIV-infected homosexual men with chronic lymphadenopathy syndrome (LAS); 6 of these men have subsequently progressed to AIDS (progressors), and 9 have remained clinically stable (nonprogressors). For the earliest samples studied, no test distinguished those who would progress to AIDS from those who have not. The two groups diverged significantly about 1 year before AIDS diagnosis in the progressor group. Virus titers rose in progressors but remained relatively stable in nonprogressors. CD4 T cells and the CD4 T cell subset, 4B4, declined more rapidly in progressors than in nonprogressors. HIV antibody titers tended to decline in progressors, but the differences were significant only for antibody and to the pol-encoded proteins, p51/65, and the gag-encoded polyprotein, p55. Before the onset of clinical AIDS, progressors are distinguished from nonprogressors by markedly different rates of CD4 cell depletion and virus replication, but the elements that control these dynamics remain to be defined.
AIDS-Related Complex↗
Acute renal failure following accidental cutaneous absorption of phenol: application of NMR urinalysis to monitor the disease process.
An unusual case of acute renal failure is reported following accidental cutaneous absorption of phenol and exposure to dichloromethane. Renal function during the onset of the nephrotoxic episode and the subsequent recovery period was monitored using a combination of standard clinical biochemical techniques and high resolution 1H-NMR urinalysis. The initial urine biochemical patterns (up to 2 weeks following exposure) showed amino aciduria, glycosuria and lactic aciduria consistent with renal cortical necrosis. There followed a period of polyuria revealing a biochemical pattern (succinic aciduria, dimethylaminuria and N,N-dimethylglycinuria) consistent with renal papillary damage. Haemodialysis was required for a period of 3 weeks and the patient was discharged 42 days after admission to hospital when renal function was normal by standard clinical chemistry criteria (urea, potassium, sodium, creatinine, calcium, phosphate, urine glucose and protein). 1H-NMR spectroscopic urinalysis revealed residual renal biochemical abnormalities consistent with renal papillary damage that were not detected by conventional analytical techniques. One year after the incident the patient is still polyuric, passing up to 3 l of urine a day.
Acute Kidney Injury↗
CD2 and other surface molecules in the regulation of non-MHC-restricted cytolytic function.
The effect of anti-CD2 and Fc receptor binding molecules on the cytolytic function of a highly enriched population of CD3- large granular lymphocytes (LGL) was studied. These cells could mediate natural killer (NK) activity, antibody-dependent cellular cytotoxicity (ADCC) and lectin-dependent cellular cytotoxicity (LDCC). Both ADCC and LDCC were enhanced by anti-CD2. The enhanced LDCC could also be observed with IL-2-activated LGL. However, NK cell activity was usually slightly diminished or unaffected by anti-CD2 binding. Immune complex and aggregated human IgG had no effect on ADCC but an anti-CD16 showed a dose-dependent inhibition of ADCC, reversible by anti-HLA-ABC and anti-CD2. Cross-linking of LGL surface-bound anti-CD2 caused an almost complete inhibition of LDCC and ADCC but had much less effect on NK activity. These experiments show that ADCC and LDCC mediated by CD3- LGL can be influenced by perturbing the CD2 molecule. NK activity was, however, affected differently, suggesting some basic differences in the pathway of ADCC and NK function.
Antibodies, Monoclonal↗
Use of flow cytometry in the evaluation and diagnosis of primary and secondary immunodeficiency diseases.
With the development of monoclonal antibody and flow cytometry technologies, the identification of cells expressing certain markers (phenotypes) and the association of phenotypes with differentiation state and function have become feasible. Clinicians can more clearly define defects and better understand the cellular responses in immunodeficiency diseases and determine the effects of therapy on these patients. This article addresses aspects of immunophenotyping in primary (genetic or with unknown cause) and secondary (acquired or with a known cause) immunodeficiencies with regard to diagnosis, characterization, and therapy.
Antibodies, Monoclonal↗
Quantitative high resolution 1H NMR urinalysis studies on the biochemical effects of cadmium in the rat.
Quantitative changes in the urinary excretion patterns of low molecular weight compounds were followed for up to 30 days after dosing of adult Sprague-Dawley rats with single intraperitoneal injections of CdCl2 (6-24 mumol/kg), using high resolution 1H NMR multicomponent urinalysis. There was a marked reduction in the rate of urinary excretion of citrate, 2-oxoglutarate, and succinate within 4.5 hr of the administration of 24 mumol/kg Cd2+. This continued for up to 4 days after dosing in male rats and was consistent with a renal tubular acidosis, caused by inhibition of carbonic anhydrase. Histological examination of the kidneys showed no evidence of structural abnormalities at any Cd2+ dose level. Creatinine excretion was not affected by Cd2+ treatment at any dose level but hippurate excretion was significantly reduced. Severe testicular damage was noted within 24 hr of Cd2+ treatment at doses of greater than 9 mumol/kg and the degree of damage appeared to be correlated with the presence of large amounts of creatine (up to 20 mM) in the urine. Analysis of homogenates of healthy testicular material indicated the presence of high concentrations of free creatine. Cadmium-induced creatinuria appears to result from direct release of creatine from the necrotic cells of the seminiferous tubules and, hence, the measurement of creatine excretion rates may provide a useful noninvasive indicator of testicular necrosis. Because NMR is nonselective in terms of metabolite detection, this work has shed new light on the changes in urinary composition arising from Cd toxicity. As such, the technique is potentially very valuable in the search for new metabolic markers of toxicity and organ dysfunction.
Animals↗
Investigations into the biochemical effects of region-specific nephrotoxins.
1H NMR spectroscopy provides a useful initial biochemical screen with which to detect abnormal patterns of metabolites in urine collected from animals with different sites of nephrotoxic lesions. Male Fischer 344 rats were treated with nephrotoxic doses of sodium chromate (pars convoluta of proximal tubule), cisplatin, hexachlorobutadiene, mercury II chloride (pars recta of proximal tubule), propylene imine, and bromoethanamine (renal papilla) in order to induce damage in specific regions of the kidney. Urine was collected for up to 48 hr after dosing and was analyzed by 1H NMR spectroscopy (400 MHz) and conventional biochemical methods to provide biochemical fingerprints of urine in various site-specific nephrotoxic states. Hexachlorobutadiene and HgCl2 produced severe glycosuria and transient enzymuria. 1H NMR urinalysis revealed aminoaciduria, glycosuria, and lactic aciduria after exposure to all proximal tubular toxins except cisplatin, whereas papillary insult resulted in early elevations in urinary trimethylamine N-oxide and dimethylamine, together with later elevations in urinary acetate, succinate, and N,N-dimethylglycine (after propylene imine). Trimethylamine N-oxide and dimethylamine are suggested as novel markers of site-specific renal papillary injury in the rat.
Acetylglucosaminidase↗
Cytofluorometric analyses of human T cell CD2/CD4 inter-molecular interactions.
Incubation of human T lymphocytes with saturating concentrations of combinations of certain anti-CD2 and -CD4 mAb results in reciprocal down-regulation of the cell surface density expression of the respective CD molecules. Such reciprocal down-regulation occurs at 0 degrees C in the presence of sodium azide and appears selective for CD2 and CD4 molecules because mAb identifying various other CD T cell surface molecules (anti-Leu2a, -OK-CLL, -W6/32, -beta 2-microglobulin, -4B4) do not modulate CD2 or CD4 R density, and because anti-CD2 mAb (anti-OKT11 and -D66 clone-1) do not alter CD8 R density (anti-OKT8, -Leu2a) and vice versa. Down-regulation of CD2 by mAb specific to CD4 is epitope-specific but does not vary on the basis of the antibody isotype used. The anti-CD4 mAb, Leu3a, was the strongest CD2 down-regulator examined followed by OKT4F. mAb specific to other CD4 epitopes (B, C, D, and E) caused only slight down-regulation of CD2 expression whereas anti-OKT4 and -OKT4A mAb had no significant regulatory effect. Also, mAb specific to the 9.6 (anti-OKT11) and D66 (anti-D66 clone 1) epitopes of the CD2 molecule down-regulated CD4 density detectable with Leu3a, OKT4, and OKT4A anti-CD4 mAb. Down-regulation of CD2 by anti-CD4 mAb also occurred with the transformed T cell line, KE-37, which demonstrates that such effects can occur without mononuclear phagocytic accessory cells. From these data it can be concluded that important T cell immunoregulatory signals may be transmitted intramembranally between CD2 and CD4 glycoproteins.
Adult↗
Comparative effects of morphine on leukocytic antigenic markers of monkeys and humans.
Knowing the in vitro effects of morphine on monkey leukocytes would be helpful in extending the utility of a monkey model for psychoneuroimmunological investigations. Morphine effects on T11, Leu2a, and Leu3a antigenic markers on leukocytes from rhesus monkeys and humans were assessed by using single- and two-color cytofluorometric analyses. Kinetics of expression of these markers was determined after modulation of the original complement of T11 markers from the surface of T11(+) cells. Percentages of leukocytes detectable by directly staining these markers before modulation were within the expected range for monkey and human cells. Also, as expected, T11 modulation reduced the percentages of cells expressing T11. This reduction was particularly obvious for T11 in the single-color analyses, with reductions being greater for monkey than human cells. Furthermore, in the single-color analyses, the effects of morphine on kinetics of T11 expression were quite similar for both human and monkey cells. In the two-color analyses, the simultaneous expression of T11 and Leu3a markers was uniform for both monkey and human cells. The effects of morphine on kinetics of expression of these markers varied only slightly between species. On the other hand, the distribution of Leu2a on T11 cells was markedly different for monkey and human T-cells. Whereas all human Leu2a(+) cells expressed similar numbers of T11 receptors, monkey cells with high-density Leu2a expressed fewer T11 markers than those with low-density Leu2a. The effects of morphine on kinetics of Leu2a and T11 expression were at obvious variance between species.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗