Proteomic analysis of simulated occupational jet fuel exposure in the lung.

We analyzed protein expression in the cytosolic fraction prepared from whole lung tissue in male Swiss-Webster mice exposed 1 h/day for seven days to aerosolized JP-8 jet fuel at concentrations of 1000 and 2500 mg/m3, simulating military occupational exposure. Lung cytosol samples were solubilized and separated via large scale, high resolution two-dimensional electrophoresis (2-DE) and gel patterns scanned, digitized and processed for statistical analysis. Significant quantitative and qualitative changes in tissue cytosol proteins resulted from jet fuel exposure. Several of the altered proteins were identified by peptide mass fingerprinting, confirmed by sequence tag analysis, and related to impaired protein synthetic machinery, toxic/metabolic stress and detoxification systems, ultrastructural damage, and functional responses to CO2 handling, acid-base homeostasis and fluid secretion. These results demonstrate a significant but comparatively moderate JP-8 effect on protein expression and corroborate previous morphological and biochemical evidence. Further molecular marker development and mechanistic inferences from these observations await proteomic analysis of whole tissue homogenates and other cell compartment, i.e., mitochondria, microsomes, and nuclei of lung and other targets.

Regional protein alterations in rat kidneys induced by lead exposure.

Lead is a potent neuro- and nephrotoxin in humans and a renal carcinogen in rats. Previous studies have detected lead-induced increases in the activities of specific detoxification enzymes in distinct kidney cell types preceding irreversible renal damage. While preferential susceptibility of the highly vascularized cortex to the effects of lead is clear, lead effects on the medullary region have remained unexplored. The present study was undertaken to investigate the extent to which regional renal protein expression differs and to determine which, if any, regionally distinct protein markers indicative of lead's renotoxic mechanism might be detected in kidney cortical and medullary cytosols. We examined protein expression in these two functionally and anatomically distinct regions, and identified several proteins that are differentially expressed in those regions and were significantly altered by lead. Kidney cytosols from rats injected with lead acetate (114 mg/kg, three consecutive daily injections) were separated by two-dimensional electrophoresis. Lead exposure significantly (P<0.001) altered the abundance (either or) of 76 proteins in the cortex and only 13 in the medulla. Eleven of the proteins altered in the protein patterns were conclusively identified either by matrix-assisted laser desorption/ionization mass spectrometry/electrospray ionization-mass spectrometry (MALDI-MS/ESI-MS) analysis of peptide digests, immunological methods, or by gel matching. Several of the cortical proteins altered by lead were unchanged in the medulla while others underwent similar but lesser alterations. These observations reflect the complexity of lead's nephrotoxicity and endorse the application of proteomics in mechanistic studies as well as biomarker development in a variety of toxicologic paradigms.

Differential expression of cytosolic proteins in the rat kidney cortex and medulla: preliminary proteomics.

The rodent kidney is a target of many xenobiotics and is typified by regionally specific structure and function. This renders distinct regions of the kidney differentially susceptible to toxic exposure and effect. To characterize these differences at the proteome level, protein patterns from male rat kidney cortex and medulla cytosols were examined by two-dimensional electrophoresis (2-DE) and image analysis and prominent proteins identified immunologically or by matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) and electrospray/ionization-tandem mass spectrometry (ESI-MS/MS) sequence tag identification. An average of 727 protein spots were resolved and matched to the cortex cytosol reference pattern, and 716 in the medulla. Of this total, 127 proteins were found to differ in abundance (86 higher in cortex; 41 higher in medulla) (P < 0.001). Of those proteins that were detectable in both cortex and medulla, the abundance of 97 differed significantly while 30 proteins were found to be unique to one region or the other (26 in cortex, 4 in medulla). Twenty protein spots were identified and their regional differences are discussed. These results both confirm and expand our understanding of the molecular heterogeneity characterizing structurally and functionally distinct regions of the kidney and serve as a useful foundation for future nephrotoxicologic studies.

Effects of lead on rat kidney and liver: GST expression and oxidative stress.

The effect of acute exposure to lead acetate on the expression of glutathione S-transferase (GST) subunits and the levels of reduced and oxidized glutathione (GSH) and malondialdehyde (MDA) in rat kidney and liver was determined. The purpose of this study was to determine if GSH depletion and/or oxidative stress were responsible for changes in the expression of some or all GSTs that followed lead exposure. In kidney, all GST subunits increased following injection of lead. The level of kidney GSH was not changed at either 0.5 or 1 h after lead exposure, but increased 3, 6, 12 and 24 h after a single injection of lead. MDA levels (a marker of lipid peroxidation) did not change in kidney following lead injection. Immunohistochemical markers of oxidative stress and nitric oxide production were also unchanged by lead administration. Therefore. we conclude that the increases in GST levels in kidney following lead exposure were not dependent on oxidative stress. In liver, lead injection caused GSH depletion (61% of control 12 h after lead treatment) and increased MDA production (2.5-fold increase 6 h after lead exposure), while GSTA1, GSTA2, GSTM1 and GSTM2 did not increase. Analysis of the effects of lead on GST mRNA and GST cellular localization were performed by Northern blot and immunohistochemical techniques. Immunoperoxidase light microscopy and immunogold electron microscopy revealed that the increase in kidney GSTM1 and GSTP1 occurred in nuclei, cytoplasm and microvilli of proximal tubules. Northern blot analysis of GSTA2 and GSTP1 mRNAs showed that their increase following lead exposure was inhibited by actinomycin D, suggesting transcriptional induction. This study demonstrates that acute lead exposure causes dramatic changes in the subcellular distribution and expression of rat kidney GSTs, and that these changes are not a result of oxidative stress.

Glutathione S-transferases: two-dimensional electrophoretic protein markers of lead exposure.

Glutathione S-transferases (GST) are a family of detoxification isoenzymes that catalyze the conjugation of xenobiotics and their metabolites with reduced glutathione. Lead exposure in rats is known to induce GST isoenzymes in the liver and kidney. These changes in expression have potential use as biomarkers of lead exposure. Because two-dimensional electrophoresis (2-DE) enables one to analyze both protein abundance changes and chemical changes in protein structure, 2-DE was used to determine the effect of in vivo lead exposure on GST isoform expression in rat kidney cytosols. Male Sprague-Dawley rats were exposed to inorganic lead, and proteins were separated by conventional ISO-DALT and NEPHGE-DALT techniques and blotted for immunological identification. Lead exposure caused detectable inductions in both GSTP1 and GSTM1 and quantifiable charge modification in GSTP1. These preliminary data confirm the utility of 2-D electrophoretic GST analysis as indicative of lead exposure and toxicity and support its use for further elaboration of lead's effects on renal protein expression.

Effects of lead on glutathione S-transferase expression in rat kidney: a dose-response study.

Glutathione S-transferases (GST, EC 2.5.1.18) are a family of phase II detoxification enzymes involved in the conjugation of glutathione to a highly diverse group of compounds. The purpose of this study was to evaluate the dose-response effects of lead acetate administration on the expression of rat kidney GST. Sprague-Dawley rats were injected with doses of lead acetate ranging from 0.11 to 114 mg/kg (0.3 to 300 mumol/kg) for three consecutive days and sacrificed 24 h later. Kidney GST activity, GST isoform HPLC profiles, blood lead analysis, and electron microscopy were performed. A dose of 1.1 mg/kg lead acetate resulted in a blood lead level of 26 micrograms/dl and produced a significant increase in GST activity which continued to increase with dose up to 38 mg/kg. Morphological changes were detected at 3.8 mg/kg and increasing severity of cellular damage paralleled dose, blood lead levels, and changes in body weight. Individual GST isoforms exhibited different thresholds and maxima; rGSTP1 and rGSTM1 had thresholds of 1.1 and 3.8 mg/kg, respectively, very similar rates of increase with dose, and a maximum yield that was 450% above control at a dose of 38 mg/kg for both enzymes. rGSTA1 and rGSTA3 showed similar thresholds (1.1 mg/kg) and maximal fold increase (275%) but varied in the relative response to each dose. These results indicate that renal GST increases occur at lead levels which are environmentally significant, that these changes precede cellular damage, and suggest that GST may serve as a tissue biomarker of lead exposure.

Effects of triethyl lead administration on the expression of glutathione S-transferase isoenzymes and quinone reductase in rat kidney and liver.

The effects of triethyl lead chloride (TEL) on the expression of two detoxication enzyme families, glutathione S-transferases (GSTs) and NAD(P)H:quinone oxidoreductase (QR) were determined in rat liver and kidney. Fischer 344 rats were given one intraperitoneal (i.p.) injection of TEL. GST activity, GST isoenzyme levels, mRNA levels of alpha class GST isoenzymes Ya1, Ya2, and Yc1 and activity of QR were determined. Treatment of rats with TEL caused a significant increase in GST activity in kidney. In kidney, the levels of all GST subunits were significantly elevated; the largest increase was a 3.2-fold increase in GST Yb1. The levels of GST Ya1, Ya2, and Yc1 mRNA also increased after injection of TEL. In liver, TEL injection resulted in decreased GST activity and lower levels of hepatic GSTs Yb2, Yb3, Ya1, and Ya2. The largest decrease was a 40% reduction of GST Ya1. In contrast, the level of liver GST Yc1 increased from day 4 through day 14 after injection of 10 mg/kg TEL and Yp was increased 1.4-fold 4 days after injection of 12 mg/kg TEL. The levels of liver mRNAs coding for alpha class GSTs Ya1, Ya2, and Yc1 were reduced 12 h after injection of TEL. The mRNA levels of GST Ya1 and Ya2 returned to basal level while Yc1 message increased to a level higher than controls 24 h after TEL injection. The increase in Yc1 protein between days 4 and 14 is consistent with the increase in the corresponding mRNA. The activity of QR was elevated 1.5-fold in kidney and 2.7-fold in liver 14 days after the injection of TEL. This report demonstrates that administration of organic lead significantly affects GST expression and QR activity in a tissue-specific and isoenzyme-specific manner. These results indicate that GST expression and QR activity are not co-regulated.

Paraneoplastic retinopathy associated with antiretinal bipolar cell antibodies in cutaneous malignant melanoma.

PURPOSE: It has been shown previously that the sera, from patients with visual paraneoplastic syndrome associated with lung cancer, contain immunoglobulins that are reactive with the tumor and with photoreceptor and large retinal ganglion cells. The purpose of this study is to determine the retinal cell population that reacts with immunoglobulins in the sera of patients with melanoma-associated retinopathy. METHODS: Clinical and electrophysiologic studies were used to determine the locus responsible for the visual defect in each patient. Sera from two patients with melanoma-associated retinopathy, from a patient with herpes zoster, and from a patient who had a colon tumor were obtained. The sera were incubated with sections of retina obtained from a healthy 3-year-old child who had died of asphyxiation. The tissue sections subsequently were incubated with biotin-labeled anti-human immunoglobulin G, and then with streptavidin-labeled peroxidase. Finally, the tissue sections were developed to show peroxidase activity in the targeted retinal cells. RESULTS: Clinical and electrophysiologic studies were consistent with a defect in intra-retinal transmission distal to the photoreceptors. The immunoglobulins from the patients with the melanoma-associated retinopathy reacted selectively with the bipolar cells of the retina; approximately 30% of the bipolar cells were immunoreactive. The sera from the other two patients were not reactive with any of the retinal cells examined. CONCLUSIONS: The sera of patients with the paraneoplastic syndrome, melanoma-associated retinopathy, contain high titer immunoglobulins that are reactive only with a subset of the bipolar retinal cells. The clinical, electrophysiologic, and immunologic studies are all consistent with an intra-retinal transmission defect at the level of the bipolar cells.

Glutathione S-transferase isoenzymes in rat brain neurons and glia.

The glutathione S-transferases (GSTs) constitute a family of cytosolic isoenzymes and a structurally unrelated microsomal enzyme that is involved in the detoxication of electrophilic xenobiotics. These enzymes also participate in the intracellular binding and transport of a broad range of lipophilic compounds including bilirubin, and hormones such as the glucocorticoids and thyroid hormones. The present investigation demonstrates that GSTs are present in neurons of the brainstem, forebrain, and cerebellum. An isoenzyme-specific distribution of GSTs was found in cytoplasm, nuclei, and nucleoli. The regional and cellular distribution of cytosolic GSTs in the brain was studied by immunohistochemistry, spectrophotometric enzyme assay, and reverse-phase HPLC. Polyclonal antibody against microsomal GST was strongly reactive with Purkinje cells throughout the cerebellar cortex, and with neurons in the brainstem and hippocampus. Nuclei of Purkinje cells and of neurons in the brainstem, hippocampus, and cerebral cortex were immunopositive for alpha-class GST 1-1 (YaYa), whereas alpha-class GST 2-2 (YcYc) antibody was consistently immunoreactive with the nucleolus, but not with the nucleus or soma. All alpha-class GST antibodies studied were reactive, to various degrees, with astrocytes and choroid plexus; however, ependymal cells of the subventricular zones were immunonegative. alpha-class GST 8-8 (YkYk) immunoreactivity was specifically localized to endothelial cells and/or astrocytic end feet associated with blood vessels. Reverse-phase HPLC indicated that there were also substantial regional differences in the pattern of alpha-, mu-, and pi-class GST subunit expression. For example, the thalamus/hypothalamus had the highest GST activity and greatest concentration of total GST protein and mu-class GST subunit 6 (Yb3), whereas the brainstem had the greatest concentration of pi-class GST subunit (Yp). This regional variation in GST expression may be reflective of regional differences in cell populations. In cerebellar cortex, the concentration of mu-class GST subunit 4 (Yb2) was greatest in the flocculus and lowest in the vermis. This is of clinical interest because the pattern of expression of mu-class GST subunit 4 (Yb2) in the cerebellum coincides with the known regional susceptibility of this structure to degeneration after exposure to toxic or metabolic insults. The vermis is most susceptible to these insults, whereas the lateral lobes and flocculus are most resistant.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of hyperbilirubinaemia on glutathione S-transferase isoenzymes in cerebellar cortex of the Gunn rat.

The glutathione S-transferases (GSTs) are a family of isoenzymes involved in the detoxication of a variety of electrophilic xenobiotics. The present investigation demonstrates that GST activity and the concentration of cytosolic GSTs in cerebellar cortex of Gunn rats were increased in hyperbilirubinaemic animals compared with non-jaundiced controls. Age-dependent and region-specific increases in GST isoenzymes were seen in three regions of the cerebellar cortex of jaundiced Gunn rats, whereas GST concentrations were not altered in the brainstem, thalamus/hypothalamus, cortex or liver. Cytosolic GST activity was increased 1.3-fold in the flocculus and lateral hemispheres of 20-day-old and 1.7-fold in the flocculus, lateral hemispheres and vermis of 60-day-old jaundiced (jj; homozygous) Gunn rats compared with non-jaundiced (Jj; heterozygous) Gunn rats. H.p.l.c. was used to determine the GST subunit protein concentrations in cytosolic fractions isolated from liver and brain regions of jaundiced and non-jaundiced animals. In all regions of the cerebellum from 20-day-old animals, the levels of Alpha-class GST subunits 2 (Yc1; 3.0-fold) and 8 (Yk; 2.0-fold) were increased in jaundiced rats. In 60-day-old animals, the concentrations of Alpha-class GST subunits 2 (Yc1; 5.0-fold) and 8 (Yk; 3.0-fold), Mu-class subunit 11 (Yo; 2.5-fold) and Pi-class subunit 7 (Yp; 2.0-fold) were increased in all regions of cerebellar cortex of jaundiced animals. In cerebellum of 10-, 20- and 60-day-old non-jaundiced and jaundiced Gunn rats, the flocculus had the highest concentration of Mu-class GST subunit 4 (Yb2) and vermis the lowest; hyperbilirubinaemia increased the concentration of subunit 4 (Yb2; 3- to 5-fold) in the flocculus and lateral hemispheres, but not the vermis, of 20- and 60-day-old rats. Intraperitoneal injection of sulphadimethoxine, a long-acting sulphonamide which displaces bilirubin from its albumin-binding sites and increases the bilirubin levels in tissues, further increased the already elevated concentrations of GST subunits in the lateral regions of cerebellar cortex of hyperbilirubinaemic rats. For example, the concentration of subunit 4 (Yb2) was increased 2.2-fold (compared with non-jaundiced controls) in Gunn rats injected with saline and 7.4-fold in rats injected with 100 mg of sulphadimethoxine/kg body weight. In contrast, GSTs in the vermis of jaundiced animals were not affected by sulphadimethoxine injection. Sulphadimethoxine had no effect on GST concentrations in lateral regions and vermis of heterozygous (Jj) Gunn rats.(ABSTRACT TRUNCATED AT 400 WORDS)

Preferential binding of radiolabeled poly-L-lysines to C6 and U87 MG glioblastomas compared with endothelial cells in vitro.

This report describes the preparation of polylysine-diethylene triamine pentaacetic acid (DTPA)-metal ion complexes and of iodinated polylysine derivatives and the preferential binding of these polymers to glioblastomas in culture. Synthetic polylysines (DP88 and DP299) were modified covalently either with the chelator DTPA or with 125I-Bolton Hunter reagent. The polylysine (DP88) was modified initially with fluorescein to permit fluorescence cytological studies and quantitative measurements of polylysine concentrations. The polylysines contained an average of one DTPA per 16 lysyl moieties. The polylysine-DTPA derivatives were then modified with a mixture of 153Gd and stable Gd. A copolymer (DP120) of lysine and tyrosine (4:1) was modified with 125I using chloramine T as catalyst. C6 (rat) and U87 MG (human) glioblastoma cells, in culture, bound six to seven times more polylysine-DTPA-Gd than endothelial cells from either aorta or brain. Each of the tumor cell types bound 10(8) molecules of the modified polylysine per cell when 2.5 x 10(5) cells were reacted with 50 micrograms or greater of the polylysine-DTPA-nuclide complex. The higher molecular weight polylysines delivered more radionuclide to the cells in culture. Although the tumor cells bound more [125I]polylysine and [125I]poly(lysine HBr,tyrosine) than they bound polylysyl-DTPA-Gd, the endothelial cells and the plastic culture dish also bound more of the iodinated polymers. The stoichiometry of polylysine bound per cell suggests that the sialic acid moieties on the cell surface are the primary binding sites for polylysine derivatives. Fluorescence microscopy studies revealed that the fluorescein polylysine (DP88) and the fluorescein polylysine-DTPA nuclide complex bound the tumor cells primarily at branch points along the neuritic processes, at the edge of the perikaryon and at the terminal regions of the outgrowth process. The polylysyl-DTPA-Gd can be used, with magnetic resonance imaging, to provide measurable contrast of the margin between C6 glioblastomas and normal brain in vivo in Wistar Furth rats.

Altered placental morphology associated with murine trisomy 16 and murine trisomy 19.

The morphology of placentas from trisomy 16 and trisomy 19 mouse conceptuses aged 12 to 18 gestational days was studied at the light microscopic level. Comparisons were made with placentas from normal littermate animals. Trisomy 16 placentas showed marked changes from normal: 1) the junctional zone showed little indication of normal morphologic differentiation throughout gestation; 2) clusters of germinal trophoblast cells persisted in the labyrinth throughout gestation, whereas these cells disappeared by gestational day 16 in the normal littermate placentas; 3) the labyrinth was reduced in size in the trisomic placentas, and the differentiation of the interhemal membranes was delayed. The size of the labyrinths from trisomy 19 placentas appeared to be decreased, but otherwise the placentas appeared to have normal morphology. These observations and others from the literature show that placental development is affected by the presence of a trisomic genome, and that different trisomies influence the development of the placenta differently. For trisomy 16, we propose that the striking changes of the junctional zone may be associated with the trisomy 16-related gene dosage effect for alpha- and beta-interferon cell surface receptors. Because of the homology for this and other genes on mouse chromosome 16 with genes on human chromosome 21, findings related to the altered development of the trisomy 16 mouse may be relevant to understanding some of the phenotypic variations associated with human trisomy 21, the Down syndrome.

Delayed immune response in chorea-amyotrophy with spherocytosis.

Progressive CSF lymphocytic pleocytosis and intrathecal IgG-synthesis occurred late in familial amyotrophy, neuropathy, chorea, and dementia with spherocytosis. Immunoblotting showed a serum and CSF antibody apparently directed against glial fibrillary acidic protein. A secondary autoimmune response was probably triggered during the evolution of the neurodegenerative process.

Antineurofilament antibody evaluation in neuropsychiatric systemic lupus erythematosus. Combination with anticardiolipin antibody assay and magnetic resonance imaging.

We used Western blot analysis to examine the occurrence and titer of antibody to cytoskeletal neurofilament protein antigens in patients with neuropsychiatric manifestations of systemic lupus erythematosus (SLE) and in controls. Twenty-two patients with neuropsychiatric SLE (NPSLE) had an increased incidence of antineurofilament antibody (ANFA) compared with 34 patients with SLE without neuropsychiatric symptoms, 78 patients with other disease processes, and 22 healthy controls. ANFA were found to be directed against the 205,000- and 160,000-dalton proteins of the neurofilament triplet. Patients with a diffuse NPSLE clinical presentation had the greatest frequency of serum ANFA (7 of 12, 58%) compared with all other groups examined. Magnetic resonance imaging and serum anticardiolipin antibody testing were also performed in selected patients with NPSLE. Patients with a focal clinical presentation of NPSLE, positive magnetic resonance imaging findings, and negative serum ANFA had significantly elevated levels of anticardiolipin antibody.

Autoimmune basis for visual paraneoplastic syndrome in patients with small cell lung carcinoma. Retinal immune deposits and ablation of retinal ganglion cells.

Recently, patients with visual paraneoplastic syndrome (VPS) were described, a binocular loss of vision found in patients with small cell carcinoma of the lung (SCCL). The patients have serum antibodies against a small number of discrete antigens which are shared by the retina and small cell carcinoma cells, and which are associated with cells and processes of the ganglion cell layer of the retina. Pathologic findings are presented with regard to the presence of immunoglobulins in, and the nature of the lesions in, the central nervous system of a VPS patient. The patient's blood-brain barrier was shown to be compromised, as demonstrated by the finding of high immunoglobulin levels in the cerebrospinal fluid and immune deposits in the retina. It is further shown that within the central nervous system only the retina and optic nerve show any tissue damage with the specific loss of retinal ganglion cells and their processes. The findings support the hypothesis of an autoimmune cause for this remote effect of cancer.

Effects of antibodies to large retinal ganglion cells on developing retinogeniculate pathways in the cat.

We investigated the effects of polyclonal antibodies, produced against ox large retinal ganglion cells, on the developing retinogeniculate pathways of cats. Four-week-old kittens were given an intraocular injection of either a low or a high concentration of the antibodies and effects were assessed 35-69 weeks later. After a low concentration (110 micrograms/33 microliter volume) injection, the density of retinal alpha-cells (the morphological counterpart of Y-cells) was reduced 44% in area centralis and 37% in peripheral retina. After a high concentration (333 micrograms/33 microliter volume) injection, alpha-cell density was reduced 76% in area centralis and 91% in peripheral retina. The same concentration of antibodies had no consistent effect on the numbers of medium- or small-size retinal ganglion cells. Electrophysiological recordings from single neurons in layers A and A1 of the lateral geniculate nucleus (LGN) revealed a 53% decrease in the percentage of Y-cells after a low-concentration injection and an 82% decrease after a high-concentration injection. There was a concomitant increase in the percentage of LGN cells that were non-responsive to light or that responded too poorly to be classified. No change was observed in the percentages of LGN X-cells or cells with mixed response properties. The reduced encounter rate of LGN Y-cells was not accompanied by significant changes in LGN cell-body size. Together, the results indicate that the immunoablation technique produces a large and apparently selective reduction of the Y-cell retinogeniculate pathway in developing kittens.

Effects of reduced numbers of lateral geniculate Y-cells on development of ocular dominance in cat striate cortex.

In the companion study (Dev. Brain Res., 34 (1987) 223-233), we showed that a monocular injection of antibodies against ox large retinal ganglion cells produces a 53% (low concentration) to 82% (high concentration) loss of Y-cells in lateral geniculate nucleus (LGN) layers A and A1 that receive inputs from the antibody-injected eye. At the same time, the percentage of LGN X-cells is unaffected. In the present study, we investigated the effect of this monocular antibody-induced reduction of LGN Y-cells on the development of ocular dominance in striate cortex. Four-week-old kittens were given an intraocular injection of either a low (110 micrograms/33 microliter volume) or a high (333 micrograms/33 microliter volume) concentration of antibodies and single-cell recordings were carried out in striate cortex 33-65 weeks later. Following an injection of either antibody concentration, we found only slight abnormalities in striate cortex ocular dominance compared to normal adult cats. There was a small, but significant, decrease in the percentage of binocularly driven cells and a concomitant increase in the percentage of cells driven exclusively by the normal or control-injected eye. No ocular dominance abnormalities were found in kittens injected monocularly with control gamma-globulins, indicating that the changes are due to effects of the antibodies. The changes in cortical ocular dominance produced by early antibody treatment are very different from those produced by rearing with monocular deprivation (MD) despite a similar loss of LGN Y-cells in the two conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Magnetic resonance imaging of gadolinium-labeled monoclonal antibody polymers directed at human T lymphocytes implanted in canine brain.

Two different murine monoclonal anti-human T cell antibodies, that were coupled to gadolinium (Gd), bind specifically to human T lymphocyte cells implanted in canine brain. This binding was at a concentration of Gd sufficient to detect the implanted cells and to distinguish them from the surrounding brain tissue with magnetic resonance imaging (MRI) at a field strength of 1.5 Tesla. These Gd-labeled immunoglobulin preparations did not bind bovine T cells at a concentration sufficient to be detected on MRI. A protein solution containing the immunoglobulins (100 micrograms), gelatin (2 mg), and bovine serum albumin (2.5 mg) was reacted with the dianhydride of diethylenetriaminepentaacetic acid (DTPA); the DTPA serves as a metal chelator and as a protein crosslinking agent. The DTPA-protein complex was reacted with Gd chloride. There were approximately 10 DTPA residues per protein molecule in the modified protein mixture. Isolated human or bovine monocytes (approximately 12 million cells) were implanted in the brains of anesthetized dogs in a volume of 40 microliters. The blood-brain barrier was then disrupted by the intra-arterial injection of hyperosmotic mannitol, and the Gd-labeled antibodies were injected through a catheter placed at the branch of the internal and external carotid arteries. The brains were imaged 48 to 72 hours later. The MRI scans revealed a markedly decreased T1 relaxation time with a high signal intensity (TE = 25 msec, TR = 200 msec) related to the human T cell implants. There was no evidence of decreased T1 at the site of the bovine T cells. Neither control murine gamma globulin coupled to Gd-DTPA nor anti-human T cell antibodies uncoupled to Gd modified the MRI contrast of the human T cells in the brain.

The electronic spectra of porphyrin-like cobalt-tetracarboxy-phthalocyanines as modified by polylysine and polyglycols.

The effect of poly-L-lysine and polyglycols on the electronic spectral properties of cobalt-tetracarboxy-phthalocyanine, compound (I), was studied in order to determine the effect of the polymers on the molecular stacking properties of compound (I). In the present study we have coupled, both covalently and electrostatically, the poly-L-lysine to compound (I). The electrostatic interaction with the polylysine resulted in a bathochromic shift of absorbance by compound (I) from 680 to 695 nm, and the generation of shoulders in the 590 and 580 nm region. The bathochromic shift indicates that the polylysine either misaligns the units of compound (I) in the molecular stack or alters the angular relationship of the planar compound (I) molecules. The covalent linkage with the polylysine resulted in stabilization of the monomeric form of compound (I) with no hypochromism in the 680 nm region. The reaction of the polyglycols, dextran and DEAE dextran with compound (I) prior to the addition of the polylysine, stabilized the polymeric stacked form of compound (I) in the presence of the polylysine. Ammonium ion and ethanolamine resulted in the appearance of peaks in the 730-760 nm region; a trihydroxy containing primary amine and monomeric lysine generated no such peak at wavelengths above 700 nm. The polyglycol binding capacity of compound (I) facilitated the separation of the unbound compound (I) from the polymeric complexes.