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Kao J, Houck K, Fan Y, Haehnel I, Libutti S, Kayton M, Grikscheit T, Chabot J, Nowygrod R, Greenberg S. Characterization of a novel tumor-derived cytokine. Endothelial-monocyte activating polypeptide II. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)31505-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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127
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Greenberg S, McGowan C, Xie J, Summer WR. Selective pulmonary and venous smooth muscle relaxation by furosemide: a comparison with morphine. J Pharmacol Exp Ther 1994; 270:1077-85. [PMID: 7932155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Furosemide and morphine reduce pulmonary edema associated with congestive heart failure. It is uncertain whether furosemide or morphine are direct-acting relaxants of arterial and venous smooth muscle. The authors compared the effect of furosemide and morphine on isolated rings of canine pulmonary artery (PA) and vein (PV) and mesenteric, splenic and anterior tibial arteries and their corresponding veins precontracted with norepinephrine or (15S)-hydroxy-11 alpha, 9 alpha-(epoxymethano)prosta-5Z,13E-dienoic acid. Furosemide (10-300 microM) selectively relaxed veins by an endothelium-independent mechanism, with its greatest efficacy on the PV. Morphine (10-1000 microM) relaxed both arteries and veins. The mechanism of relaxation by furosemide and morphine was examined in the PV and PA. Morphine-induced relaxation of the PV and PA was dependent on prostanoid release from endothelium and smooth muscle because it was attenuated in endothelium-rubbed and ibuprofen-treated PV and PA but not in blood vessels treated with inhibitors of nitric oxide system/cyclic GMP system (I-NG-nitroarginine and methylene blue). Furosemide-mediated relaxation of the PV was refractory to each of these interventions. Similarly, furosemide- and morphine-induced relaxation of the PV were unaffected by 4-aminopyridine, tetraethylammonium, glibenclamide, dendrodotoxin and apamin and, thereby, were independent of an action on K+ channels. Reduction of extracellular K+ or Cl- attenuated furosemide-mediated relaxation of, and inhibition of 86Rb+ uptake by, PV even in the presence of ouabain. It was concluded that furosemide relaxes veins by an effect on Na+/K+/Cl- cotransport or chloride-mediated refilling of intracellular calcium stores.
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128
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Greenberg S, Suster B. Metastatic pulmonary calcification: appearance on high resolution CT. J Comput Assist Tomogr 1994; 18:497-9. [PMID: 8188924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Abstract
1. Amplitude modulation (AM) is a pervasive property of acoustic communication systems. In the present study we investigate neural temporal mechanisms in the auditory nerve and cochlear nuclei of the pentobarbital sodium-anesthesized cat associated with the neural coding of 100% AM tones, both in quiet and in the presence of wideband, quasi-flat-spectrum noise. The AM carrier frequency was set to the neuron's characteristic frequency (CF) and the sound pressure level (SPL) of acoustic stimuli was varied over a wide dynamic range of intensities (< or = 40 dB). The temporal AM-encoding capability of auditory neurons was measured by computing the synchronization coefficient (SC) of the neural response to the signal's modulation and carrier frequency. The temporal modulation transfer function (tMTF) of a neuron was then computed by measuring the SC of the response to signals of variable fmod (50-2550 Hz). 2. Neurons in the cochlear nuclei synchronize on average more highly to the modulation frequency than fibers of comparable CF, threshold, and spontaneous rate in the auditory nerve. The disparity in performance is greatest at high SPLs and low signal-to-noise ratios. However, there is a significant degree of diversity in AM-encoding capability among neurons in both the cochlear nuclei and auditory nerve. Among auditory nerve fibers (ANFs), low- and medium-spontaneous-rate (SR) units (SR < 18 spike/s) phase-lock with greater precision than comparable high-SR units at any given frequency, particularly at moderate to high SPLs, consistent with previous studies. 3. The phase-locking capabilities of neurons in the cochlear nucleus are considerably more variable than in the auditory nerve. Moreover, the variability itself depends on two distinct measures of phase-locking performance. Most ANFs are capable of phase-locking to frequencies as high as 3-4 kHz. In the cochlear nucleus many unit types do not phase-lock to modulation frequencies > 1 kHz. As a result, phase-locking performance is measured on the basis of two parameters, maximum synchronization, irrespective of stimulus frequency, and the upper frequency limit for significant phase-locking. 4. Cochlear nucleus neurons may be divided into three distinct groups on the basis of maximum synchronization capability. In group 1 are the primary-like (PL) units of the anteroventral division, whose phase-locking capabilities are comparable with those of high-SR ANFs.(ABSTRACT TRUNCATED AT 400 WORDS)
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Kao J, Fan YG, Haehnel I, Brett J, Greenberg S, Clauss M, Kayton M, Houck K, Kisiel W, Seljelid R. A peptide derived from the amino terminus of endothelial-monocyte-activating polypeptide II modulates mononuclear and polymorphonuclear leukocyte functions, defines an apparently novel cellular interaction site, and induces an acute inflammatory response. J Biol Chem 1994; 269:9774-82. [PMID: 7545917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Endothelial-monocyte-activating polypeptide II (EMAP II) is a novel mediator isolated from conditioned medium of methylcholanthrene A-induced tumor cells which modulates properties of endothelial cells, mononuclear phagocytes (MPs), and polymorphonuclear leukocytes (PMNs) in vitro and induces an acute inflammatory response in vivo. A synthetic peptide comprising 15 residues from the N-terminal region (residues 6-20) was shown to induce directional migration of MPs and PMNs, with half-maximal effect at approximately 200-250 pM, whereas a peptide from the C terminus of EMAP II, as well as other irrelevant peptides, were without effect. Modulation of cellular phenotype by EMAP II-derived peptide was suggested by peptide-induced elevation of cytosolic free calcium concentration in fura-2-loaded MPs and PMNs and by stimulation of peroxidase release in PMNs. Consistent with these in vitro data, EMAP II-derived N-terminal peptide-albumin conjugates injected into the mouse footpad elicited inflammatory cell tissue infiltration, whereas albumin alone or EMAP II-derived C-terminal peptide conjugated to albumin incited little response. Binding of 125I-labeled EMAP II-derived peptide (residues 12-20) to MPs was saturable (Kd approximately 200 pM) and was blocked in a dose-dependent manner by the addition of intact EMAP II and unlabeled EMAP II-derived peptides (residues 6-20 and 12-20), whereas interleukin 1, tumor necrosis factor, formyl-methionyl-leucinyl-phenylalanine, or irrelevant peptides were without effect. Cross-linking of 125I-EMAP II-derived peptide (residues 12-20) by disuccinimidyl suberate to human MPs demonstrated a band, approximately 73 kDa, on reduced sodium dodecyl sulfate-polyacrylamide gel electrophoresis. 125I-EMAP II-derived peptide also demonstrated specific binding to human PMNs and murine RAW cells. These data indicate that the N-terminal region of EMAP II defines a biologically active locus of the molecule which interacts with target cells via a potentially novel cellular receptor.
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Greenberg S, Chang P, Silverstein SC. Tyrosine phosphorylation of the gamma subunit of Fc gamma receptors, p72syk, and paxillin during Fc receptor-mediated phagocytosis in macrophages. J Biol Chem 1994; 269:3897-902. [PMID: 7508923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Fc receptor-mediated phagocytosis in mouse macrophages occurs by a tyrosine kinase-dependent pathway (Greenberg, S., Chang, P., and Silverstein, S.C. (1993) J. Exp. Med. 177, 529-534). To identify proteins that are phosphorylated on tyrosine residues during phagocytosis, we used anti-phosphotyrosine antibodies to perform immunoblotting and immunoprecipitation of lysates derived from Fc receptor-stimulated macrophages. Proteins of 26, 30, 35, 37, 40, 43, 47, 56, 60, 68, 83, 116, and 150 kDa displayed enhanced tyrosine phosphorylation during Fc receptor-mediated phagocytosis. Tyrosine phosphorylation of these proteins was not a consequence of actin polymerization since treatment with cytochalasin D did not alter the pattern of Fc receptor-stimulated protein tyrosine phosphorylation. The 68-kDa tyrosine phosphoprotein was identified as paxillin, a cytoskeletal-associated tyrosine kinase substrate previously identified in fibroblasts and shown to localize to focal adhesions (Turner, C.E., Glenney, J.R., and Burridge, K. (1990) J. Cell Biol. 111, 1059-1068). Paxillin colocalized with F-actin beneath nascent phagosomes. In addition to the above proteins detected by anti-phosphotyrosine immunoblotting, the gamma subunit of FcRI and III was shown to undergo tyrosine phosphorylation during Fc receptor-mediated phagocytosis. Of several candidate tyrosine kinases that may be activated during Fc receptor stimulation, p72syk, but not p125FAK, displayed enhanced tyrosine phosphorylation during Fc receptor aggregation. The coordinated tyrosine phosphorylation of the gamma subunit of macrophage Fc receptors, the tyrosine kinase syk, and the cytoskeletal-associated protein, paxillin, may be important steps in integrating signals between Fc receptors and the underlying cytoskeleton.
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MESH Headings
- Actins/analysis
- Animals
- Chromatography, Affinity
- Cytochalasin D/metabolism
- Cytoskeletal Proteins/analysis
- Cytoskeletal Proteins/isolation & purification
- Cytoskeletal Proteins/metabolism
- Electrophoresis, Polyacrylamide Gel
- Fluorescent Antibody Technique
- Macromolecular Substances
- Macrophages, Peritoneal/immunology
- Macrophages, Peritoneal/metabolism
- Macrophages, Peritoneal/physiology
- Mice
- Mice, Inbred C57BL
- Models, Biological
- Molecular Weight
- Paxillin
- Phagocytosis
- Phosphoproteins/analysis
- Phosphoproteins/isolation & purification
- Phosphoproteins/metabolism
- Phosphorylation
- Phosphotyrosine
- Protein-Tyrosine Kinases/metabolism
- Receptors, IgG/isolation & purification
- Receptors, IgG/metabolism
- Receptors, IgG/physiology
- Tyrosine/analogs & derivatives
- Tyrosine/metabolism
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Rhode WS, Greenberg S. Lateral suppression and inhibition in the cochlear nucleus of the cat. J Neurophysiol 1994; 71:493-514. [PMID: 8176421 DOI: 10.1152/jn.1994.71.2.493] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
1. The ability of cells in the cochlear nucleus (CN) to encode frequency information in the presence of background noise on the basis of "place/rate" information was investigated by measuring the threshold, magnitude, and extent of lateral suppression in the ventral and dorsal CN of the anesthesized cat. The suppression regions were delineated through the use of "masked" response areas (MRAs). The MRA is a family of isointensity curves derived from the average discharge rate in response to a tone of variable frequency and sound pressure level in the presence of a concurrently presented broadband, quasi-flat-spectrum noise. Tonal stimuli of sufficient intensity are often effective in significantly reducing the average discharge rate of CN neurons over a wide frequency range. 2. Most units in the CN exhibit prominent lateral suppressive sidebands, but the variability in threshold, magnitude, and extent of suppression is large. Primary-like and onset units of the ventral CN manifest the least suppression and have the highest suppression thresholds. Pauser/buildup units in the dorsal division and choppers distributed throughout the CN show the largest amount of suppression and have the lowest suppression thresholds. 3. Auditory nerve fibers manifest some degree of lateral suppression, particularly fibers of low and medium spontaneous rate. However, in few instances are the threshold, magnitude, and extent comparable with that observed among the majority of chopper and pauser/buildup units. For this reason the lateral suppression observed among the latter unit types is unlikely to originate entirely from cochlear processes, but rather is likely to reflect largely neural mechanisms intrinsic to the CN. In contrast, the MRAs of most primary-like and onset units suggest that the suppression behavior of most of these cells originates mostly, if not entirely, in the cochlea and auditory nerve. 4. A primary consequence of lateral suppression is to preserve the sharp frequency selectivity of CN neurons at moderate to high sound pressure levels, particularly in background noise. In this fashion lateral suppressive mechanisms potentially enhance the representation of spectral information on the basis of place/rate information relative to that in the auditory nerve under noisy background conditions. 5. Lateral suppressive mechanisms probably underlie the dynamic range shift seen in the presence of a simultaneously presented noise. This mechanism may be crucial for preserving the ability to perceive signals in a noisy background.
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Greenberg S, Chang P, Silverstein S. Tyrosine phosphorylation of the gamma subunit of Fc gamma receptors, p72syk, and paxillin during Fc receptor-mediated phagocytosis in macrophages. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)41945-4] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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134
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Gamus D, Weschler Z, Greenberg S, Romano A. Decreased tear secretion in Chernobyl children: external eye disorders in children subjected to long-term low-dose radiation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1994; 350:513-6. [PMID: 8030526 DOI: 10.1007/978-1-4615-2417-5_85] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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135
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Ulrich J, Probst A, Langui D, Greenberg S, Dukas L, Stähelin HB. Rapidly progressing dementia with filopodia-like cytoskeletal neuritic anomalies, but without Alzheimer changes. Clin Neuropathol 1994; 13:39-45. [PMID: 8033461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
An unusual case of dementia is reported. The patient was a woman who died at the age of 69 years and 6 months after a two years history of organic dementia. Possibly the disease was familial. Examination of the brain at autopsy revealed no atrophy. In routine histology the brain seemed to be normal. However, when the sections were stained with highly sensitive techniques such as an antibody to phosphorylated Tau (PHF-1), widespread neuritic pathology was discovered. Probably both, axons and dendrites were involved. Only few perikarya were reactive with the antibody. In some of them, morphologic alterations were reminiscent of Pick's disease.
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Spolarics Z, Spitzer JJ, Wang JF, Xie J, Kolls J, Greenberg S. Alcohol administration attenuates LPS-induced expression of inducible nitric oxide synthase in Kupffer and hepatic endothelial cells. Biochem Biophys Res Commun 1993; 197:606-11. [PMID: 7505571 DOI: 10.1006/bbrc.1993.2522] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
This study investigates the effects of in vivo ethanol (primed infusion, causing 170-190 mg% plasma alcohol for 12 hours) and/or LPS (12 hours after injection of E. coli LPS 1 mg/kg bw.) on the mRNA expression of inducible nitric oxide synthase (NOS II) in hepatic cells measured by competitive PCR technique, and on hepatic release of reactive nitrogen intermediates (RNI, NO2- + NO3-). Perfused livers from alcohol- or saline-infused animals did not release measurable amounts of RNI. Under these conditions small amounts of NOS II mRNA were expressed in Kupffer and endothelial cells, while it was not detectable in parenchymal cells. LPS treatment along with markedly elevating hepatic RNI release increased NOS II mRNA levels by 35- and 200-fold, in endothelial and Kupffer cells, respectively. LPS injection and alcohol infusion to the same animal decreased hepatic RNI release by about 70% and almost completely inhibited the LPS-induced, elevated NOS II mRNA in Kupffer or endothelial cells. No similar changes were observed in the parenchymal cells. These data suggest that the primary target of in vivo LPS in upregulating hepatic NO release are the nonparenchymal cells. Furthermore, alcohol inhibits the LPS-induced response which may influence immune-related hepatic function.
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137
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Greenberg S, Reiser IW, Chou SY. Hyperkalemia with high-dose trimethoprim-sulfamethoxazole therapy. Am J Kidney Dis 1993; 22:603-6. [PMID: 8213804 DOI: 10.1016/s0272-6386(12)80937-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In a patient with the acquired immunodeficiency syndrome, a progressive increase in the serum potassium concentration occurred with high-dose trimethoprim-sulfamethoxazole (TMP-SMX) therapy for Pneumocystis carinii pneumonia. In this patient, factors known to alter transcellular potassium shifts to induce hyperkalemia were not present. There was no evidence of glucocorticoid or mineralocorticoid insufficiency at the time of hyperkalemia, while the transtubular potassium gradient decreased. The hyperkalemia resolved spontaneously on discontinuation of TMP-SMX therapy, suggesting that this electrolyte abnormality is related to altered renal tubular secretion of potassium as a consequence of the high-dose TMP-SMX therapy.
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138
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Karlan B, Chamorro T, Fowler J, Muderspach L, Greenberg S, Lagasse L. Concurrent interstitial radiotherapy and infusional chemotherapy for recurrent gynecologic malignancies. Int J Gynecol Cancer 1993; 3:304-310. [PMID: 11578362 DOI: 10.1046/j.1525-1438.1993.03050304.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Patients with unresectable locally recurrent gynecologic malignancies pose a difficult therapeutic challenge. Conventional therapies are frequently unsuccessful and offer only marginal palliation. In this study, interstitial 192iridium-needle implants and concomitant infusional 5-fluorouracil (5FU) and cisplatin (CDDP) or carboplatin (CBDCA) chemotherapy were used to treat 14 women with recurrent pelvic tumors. Malignancies of the cervix, endometrium ovary, tube and vulva are represented; all patients were heavily pretreated. Twenty interstitial implants were performed in these 14 patients. Needle distributions and doses were individualized to accommodate the recurrent tumor volumes. Tumor responses were seen in 12 patients (six complete and six partial responses). Four women remain clinically free of disease and four are alive with disease at 18-34 months of follow-up. There were no severe acute toxicities, however, four patients have subsequently developed fistulae associated with tumor progression. Although longer follow-up is required, the high response rate, wide applicability and acceptable toxicity observed in this heavily pretreated patient population warrant further study of combined interstitial radiation and chemotherapy.
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139
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Abstract
OBJECTIVE To determine the effect of trimethoprimsulfamethoxazole (Tmp-Smx) on serum potassium concentration. DESIGN Retrospective cohort study. SETTING An urban teaching hospital. PATIENTS Fifty-one persons hospitalized for symptomatic infection with human immunodeficiency virus (HIV). Twenty-five patients who were taking high-dose Tmp-Smx (trimethoprim 20 mg/kg per day; sulfamethoxazole, 100 mg/kg per day) for Pneumocystis carinii pneumonia were the study group. Twenty-six patients who had not received the drug were the control group. Patients who received potassium supplements, those taking medications known to alter potassium homeostasis or renal function, or those with a serum creatinine level more than 186 mumol/L were excluded. MEASUREMENTS AND MAIN RESULTS Serum potassium concentration in the study group was 4.1 +/- 0.1 mmol/L (mean +/- SE) and increased by 1.1 mmol/L (Cl, 0.8 to 1.5 mmol/L) (P < 0.0001) 9.8 +/- 0.5 days after starting Tmp-Smx therapy. Patients followed longitudinally showed a progressive increase in serum potassium levels during therapy and a progressive decline after discontinuing Tmp-Smx. Blood urea nitrogen and serum creatinine levels increased mildly from 4.3 +/- 0.5 mmol/L and 85 +/- 6 mumol/L to 6.4 +/- 0.7 mmol/L and 113 +/- 8 mumol/L, respectively. The serum potassium level in the control group was 4.3 +/- 0.1 mmol/L and remained unchanged during hospitalization. CONCLUSIONS High-dose Tmp-Smx therapy used for the treatment of P. carinii pneumonia in HIV-infected patients leads to an increase in the serum potassium concentration and may result in life-threatening hyperkalemia. Patients receiving high doses of Tmp-Smx require close monitoring of their serum potassium concentration, particularly 7 to 10 days after the start of therapy.
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Greenberg S, Xie J, Wang Y, Cai B, Kolls J, Nelson S, Hyman A, Summer WR, Lippton H. Tumor necrosis factor-alpha inhibits endothelium-dependent relaxation. J Appl Physiol (1985) 1993; 74:2394-403. [PMID: 8335573 DOI: 10.1152/jappl.1993.74.5.2394] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Tumor necrosis factor-alpha (TNF-alpha) stimulates nitric oxide (NO) in vascular endothelium by induction of the enzyme NO synthase II (NOS II). We examined the effects of TNF-alpha on 1) endothelium-dependent (EDR) and endothelium-independent (EIR) relaxation and 2) contraction of bovine intralobar pulmonary arteries (BPA) and veins (BPV) in vitro. Acetylcholine (ACh), bradykinin (BK), histamine, and A23187 produced EDR of BPA contracted with a 50% effective concentration of U-46619 (15 nM), because relaxation was abolished by endothelium-rubbing and attenuated by L-NG-mono-methylarginine (L-NMMA; 300 microM). TNF-alpha (0.00417, 0.0417, 0.417, and 1.25 micrograms/ml) incubated with BPA for 60 min inhibited EDR of the BPA to ACh, BK, and histamine. The effects of TNF required 30 min for onset. Recovery of EDR occurred 3-4 h after washout of TNF-alpha. Pentoxifylline (1 microM) did not affect ACh-induced EDR but selectively reversed TNF-alpha-mediated inhibition of ACh-induced EDR. TNF-alpha-mediated inhibition of EDR was not reversible by L-NMMA, an inhibitor of NOS I and NOS II, the cyclooxygenase inhibitor ibuprofen, or CV-3908 (1 microM), a platelet-activating factor antagonist. The inhibitory effect of TNF-alpha on EDR was not mediated by nonspecific sensitization of the endothelium to human protein because recombinant human granulocyte colony-stimulating factor (10, 50, and 500 x 10(3) U/ml) did not affect EDR of BPA. The effect of TNF-alpha was specific for release of NO from the endothelium of BPA because TNF-alpha did not affect 1) EDR of BPV to ACh, BK, or ATP; 2) EIR of BPA or BPV to nitroprusside; and 3) contraction of either BPA or BPV to KCl, U-46619, histamine, norepinephrine, or serotonin. Thus TNF-alpha appears to selectively inhibit receptor-mediated EDR and NO release in BPA. TNF-alpha-mediated inhibition of EDR differs from that of L-arginine-based inhibitors and may represent an endogenous physiological mechanism of regulation of NO in the endothelium.
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Greenberg S, Chang P, Silverstein SC. Tyrosine phosphorylation is required for Fc receptor-mediated phagocytosis in mouse macrophages. J Exp Med 1993; 177:529-34. [PMID: 7678851 PMCID: PMC2190886 DOI: 10.1084/jem.177.2.529] [Citation(s) in RCA: 169] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Although Fc receptor-mediated phagocytosis is accompanied by a variety of transmembrane signaling events, not all signaling events are required for particle ingestion. For example, Fc receptor-mediated phagocytosis in mouse inflammatory macrophages (Di Virgilio, F., B. C. Meyer, S. Greenberg, and S. C. Silverstein. 1988. J. Cell Biol. 106:657; Greenberg, S., J. El Khoury, F. Di Virgilio, and S. C. Silverstein. 1991. J. Cell Biol. 113:757) and neutrophils (Della Bianca, V., M. Grzeskowiak, and F. Rossi. 1990. J. Immunol. 144:1411) occurs in the absence of cytosolic calcium transients. We sought to identify transmembrane signaling events that are essential for phagocytosis. Here we show that tyrosine phosphorylation is an early event after Fc receptor ligation in mouse inflammatory macrophages, and that the formation of tyrosine phosphoproteins coincides temporally with the appearance of F-actin beneath phagocytic cups. The distribution of tyrosine phosphoproteins that accumulated beneath phagocytic cups was punctate and corresponded to areas of high ligand density on the surface of the antibody-coated red blood cells, which provided the phagocytic stimulus. A tyrosine kinase inhibitor, genistein, but not several inhibitors of protein kinase C, blocked the appearance of tyrosine phosphoproteins as assessed by immunofluorescence, the focal accumulation of F-actin beneath immunoglobulin G-opsonized particles, and the ingestion of these particles as well. We suggest that tyrosine phosphorylation is a critical signaling event that underlies Fc receptor-mediated phagocytosis in mouse macrophages, and is necessary for the engulfment per se.
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142
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Frishman WH, Nadelmann J, Ooi WL, Greenberg S, Heiman M, Kahn S, Guzik H, Lazar EJ, Aronson M. Cardiomegaly on chest x-ray: prognostic implications from a ten-year cohort study of elderly subjects: a report from the Bronx Longitudinal Aging Study. Am Heart J 1992; 124:1026-30. [PMID: 1388323 DOI: 10.1016/0002-8703(92)90987-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This report is from a 10-year cohort study of community-dwelling elderly men and women. Mean age at the time of entry into the study was 79 years. Annual chest x-ray studies were performed, and data are presented regarding prevalence, incidence, and prognosis of cardiomegaly. Cardiomegaly was defined as a transverse diameter of the cardiac silhouette greater than or equal to 50% of the transverse diameter of the chest (increased cardiothoracic ratio). At the time of entry into the study 110 subjects (23%) had cardiomegaly. After 10 years, 51% of the subjects with cardiomegaly at baseline died compared with 33% of the subjects without cardiomegaly (mortality rate = 9.1 vs 4.8/100 person-years respectively; p = 0.014). Cardiovascular disease incidence was also higher for those with preexisting cardiomegaly at baseline (rate 9.1 vs 6.1/100 person-years; p = 0.0001). According to the Cox proportional hazards regression analysis, age, cardiomegaly, diabetes, and prior evidence of myocardial infarction were independent predictors for death in this cohort. Similarly, the best predictive variables for cardiovascular disease were age, diabetes, prior evidence of myocardial infarction, and cigarette smoking. Of the 359 subjects without cardiomegaly at baseline, 108 (30%) showed evidence of new cardiomegaly, and their risk of cardiovascular disease was 1.8 times that of subjects whose test results were negative for cardiomegaly throughout the study (p = 0.003). Thus cardiomegaly, as defined by an increased cardiothoracic ratio on x-ray films, irrespective of cause, is associated with a poor prognosis in very elderly men and women.
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Guzik HJ, Ooi WL, Frishman WH, Greenberg S, Aronson MK. Hypertension: cardiovascular implications in a cohort of old old. J Am Geriatr Soc 1992; 40:348-53. [PMID: 1556362 DOI: 10.1111/j.1532-5415.1992.tb02133.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE To examine the prevalence and cardiovascular implications of hypertension in advanced age. DESIGN Prospective non-interventional study of a fixed cohort of very elderly subjects. PARTICIPANTS AND SETTING The subjects were 488 community-dwelling volunteers. Mean age at entry was 79 years (range 75-85). All subjects were ambulatory, non-demented, and free of terminal illness at baseline. Participants were evaluated at the gerontology department of an urban medical school. MAIN OUTCOME MEASURES Cardiovascular morbid and mortal events that were followed included fatal and non-fatal myocardial infarction, fatal and non-fatal stroke, and death. Prevalence of unrecognized myocardial infarction defined by electrocardiographic changes was also assessed. RESULTS When hypertension was defined by history, current use of medications, or measured elevations in blood pressure, 78% of the subjects could be considered hypertensive. Univariate analysis showed an increased incidence of strokes in subjects with measured hypertension (P = 0.04). Subjects with elevated blood pressure (untreated) were more likely to develop clinically unrecognized myocardial infarction (P = 0.017). Multivariate survival analysis showed hypertension to be a modest predictor of overall cardiovascular disease (P = 0.067) but not of all-cause mortality. Left ventricular hypertrophy was a predictor of cardiovascular disease (P = 0.013) and all-cause mortality (P = 0.008). Age remained a significant risk factor for these endpoints, even in the very old. Isolated systolic hypertension was analyzed separately and in univariate analysis was a risk factor for stroke but not other cardiovascular morbidity. CONCLUSIONS Hypertension at advanced age remains a modestly important risk factor in the development of cardiovascular disease.
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Damle R, Levine J, Matos J, Greenberg S, Brooks R, Frumkin W, Goldberger J, Kadish AH. Efficacy and risks of moricizine in inducible sustained ventricular tachycardia. Ann Intern Med 1992; 116:375-81. [PMID: 1736770 DOI: 10.7326/0003-4819-116-5-375] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVE To assess the efficacy and toxicity of moricizine in treating patients with serious ventricular arrhythmias and inducible sustained ventricular tachycardia. DESIGN Uncontrolled clinical trial. SETTING The intensive care and telemetry units of Northwestern Memorial Hospital, St. Francis Hospital and Medical Center, and Lenox Hill Hospital. PATIENTS Twenty-six patients with sustained ventricular arrhythmias or hemodynamically significant nonsustained ventricular tachycardia, most of whom failed therapy with at least one class I antiarrhythmic agent. INTERVENTION Patients were treated with moricizine, 400 to 1000 mg/d. MEASUREMENT Efficacy was assessed by the results of programmed ventricular stimulation done during moricizine therapy. MAIN RESULTS Seven of the 26 patients (27%) developed life-threatening ventricular proarrhythmia during moricizine loading. Three patients had incessant sustained ventricular tachycardia, two had incessant nonsustained ventricular tachycardia, one had new sustained ventricular tachycardia, and one had new cardiac arrest. One of these patients died of intractable ventricular fibrillation. No clinical or electrophysiologic variables clearly identified those at risk for proarrhythmia. Only 3 of 26 patients (12%) became noninducible on moricizine. CONCLUSION Moricizine has a low rate of efficacy and carries a considerable risk for life-threatening proarrhythmia in patients with serious ventricular arrhythmias and inducible ventricular tachycardia who have failed therapy with other class I antiarrhythmic agents.
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Newton RC, Limpuangthip P, Greenberg S, Gam A, Neva FA. Strongyloides stercoralis hyperinfection in a carrier of HTLV-I virus with evidence of selective immunosuppression. Am J Med 1992; 92:202-8. [PMID: 1543206 DOI: 10.1016/0002-9343(92)90113-p] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A patient with near fatal Strongyloides hyperinfection syndrome is briefly described. Investigation for possible risk factors for this parasitic infection disclosed that he was a carrier of human T-cell leukemia virus type I (HTLV-I), but without evidence of disease due to this retrovirus. Over the next few years, the patient's serum antibody levels of IgG to S. stercoralis larvae declined and became undetectable despite continued infection with the parasite. Repeated courses of appropriate treatment cleared the parasitic infection only temporarily. The patient was also found to have undetectable total serum IgE and a negative immediate hypersensitivity skin test to S. stercoralis antigens. Five of six other patients with HTLV-I-associated disease and with or without strongyloidiasis were also found to have very low total serum IgE levels. It is postulated that HTLV-I infection in certain individuals may selectively impair immune responses that are critical in controlling strongyloidiasis.
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146
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Cohen M, Merino A, Hawkins L, Greenberg S, Fuster V. Clinical and angiographic characteristics and outcome of patients with rest-unstable angina occurring during regular aspirin use. J Am Coll Cardiol 1991; 18:1458-62. [PMID: 1939946 DOI: 10.1016/0735-1097(91)90675-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Today many patients admitted with an acute coronary syndrome are already taking aspirin. Because they have symptoms despite antithrombotic therapy, these patients are presumed to be at higher risk for subsequent clinical events. In a pilot trial of antithrombotic therapy in patients with unstable angina at rest or non-Q wave infarction, 93 patients admitted within 48 h of pain were prospectively followed up for 12 weeks. On admission, 29 patients (31%) were already taking daily aspirin; 64 (68%) were receiving no antiplatelet agent. After enrollment all patients received antithrombotic therapy with either aspirin or heparin according to protocol regardless of prior aspirin use. The two groups (prior users versus nonusers of aspirin) were similar with regard to age, gender, coronary risk factors, prior antianginal medication, duration of symptomatic coronary disease, presentation with non-Q wave infarction and extent of electrocardiographic changes on admission. Quantitative analysis of coronary arteriograms (on a 0 to 10 scale) showed similar myocardium-in-jeopardy scores (JS). Follow-up events (recurrent ischemia [Isch], infarction [MI] and revascularization [Revasc]) were: (formula: see text) Aspirin users experiencing rest angina are similar to other patients with ischemic rest pain. The "resistant to aspirin" group does not constitute a subgroup that is at higher risk for cardiac events or revascularization.
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147
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O'Neill PG, Rokey R, Greenberg S, Pacifico A. Resolution of ventricular tachycardia and endocardial tuberculoma following antituberculosis therapy. Chest 1991; 100:1467-9. [PMID: 1935318 DOI: 10.1378/chest.100.5.1467] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A 23-year-old woman presented with sustained ventricular tachycardia and was found to have an endocardial mass by echocardiography and by magnetic resonance imaging. The diagnosis of cardiac endocardial tuberculoma was made, and she was treated with antituberculous therapy and an antiarrhythmic drug for one year. After a year, the mass was no longer present, and with all antiarrhythmic medications stopped, ventricular tachycardia could no longer be induced by electrophysiologic study. There has been no clinical recurrence.
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148
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Winters SL, Cohen M, Greenberg S, Stein B, Curwin J, Pe E, Gomes JA. Sustained ventricular tachycardia associated with sarcoidosis: assessment of the underlying cardiac anatomy and the prospective utility of programmed ventricular stimulation, drug therapy and an implantable antitachycardia device. J Am Coll Cardiol 1991; 18:937-43. [PMID: 1894867 DOI: 10.1016/0735-1097(91)90750-4] [Citation(s) in RCA: 154] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The presentation, cardiac anatomy and utility of programmed ventricular stimulation in seven patients with sustained ventricular tachycardia associated with sarcoidosis are described. The mean patient age was 38 +/- 8 years. Pulmonary involvement was apparent in three patients and no systemic manifestations of sarcoidosis were present in one patient. All patients had electrocardiographic abnormalities at rest and six had a left ventricular ejection fraction less than 45%. All seven patients had left ventricular wall motion abnormalities and five had mitral valve dysfunction. Sustained ventricular tachycardia was easily induced in all patients. Spontaneous sustained ventricular tachycardia was not prevented with corticosteroid administration. Despite antiarrhythmic drug therapy, two patients had sudden cardiac death and an additional four had recurrence of ventricular tachycardia. Four patients had an automatic cardioverter-defibrillator implanted and received drug therapy; all four received appropriate shocks. This report represents the largest descriptive series of consecutive patients with sustained ventricular tachycardia associated with sarcoidosis. Antiarrhythmic drug therapy of ventricular tachycardia in patients with sarcoidosis, even when guided with programmed ventricular stimulation, is associated with a high rate of arrhythmia recurrence or sudden death, or both. Thus, implantation of an automatic antitachycardia device (cardioverter-defibrillator) should be considered as primary therapy in such patients. Furthermore, sarcoidosis should be excluded, with Kveim skin testing if necessary, in any patient with sustained ventricular tachycardia of unknown origin.
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Frishman WH, Greenberg S. Angiotensin converting enzyme inhibitors as initial monotherapy in severe hypertension. Quinapril and captopril. Am J Hypertens 1991; 4:827-31. [PMID: 1747216 DOI: 10.1093/ajh/4.10.827] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
This 6-week, double-blind, parallel-group study compared the efficacy and safety of the angiotensin converting enzyme (ACE) inhibitors quinapril and captopril as initial monotherapies in patients with severe hypertension (diastolic blood pressure [DBP] greater than or equal to 115 and less than or equal to 130 mm Hg). A total of 97 patients, aged between 18 and 70 years, were randomized to 5 mg oral quinapril twice daily or 25 mg captopril twice daily with maximum titration to 20 mg quinapril twice daily or 100 mg captopril twice daily. With the morning dose 25 mg hydrochlorothiazide (HCTZ) could be added at week 4 of the double-blind phase or earlier if required for safety considerations. For the monotherapy phase, mean reductions in DBP of 12.1 mm Hg were achieved with both treatments. Clinical response rates (reduction in DBP greater than or equal to 10 mm Hg) were 58% for quinapril and 44% for captopril. At the end of therapy, with optional HCTZ, mean reductions in DBP were 19.0 mm Hg for the quinapril-treated group and 16.2 mm Hg for the captopril-treated group. None of the differences achieved statistical significance. Headache was the most frequently reported adverse event in both treatment groups with 8 reports each. No clinically significant changes in laboratory data were observed in any parameter for either treatment group. Quinapril and captopril provide comparable efficacy and safety in treatment of severe hypertension when used as initial monotherapy and with the addition of optional HCTZ.
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Cohen M, Hawkins L, Greenberg S, Fuster V. Usefulness of ST-segment changes in greater than or equal to 2 leads on the emergency room electrocardiogram in either unstable angina pectoris or non-Q-wave myocardial infarction in predicting outcome. Am J Cardiol 1991; 67:1368-73. [PMID: 2042567 DOI: 10.1016/0002-9149(91)90467-y] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To determine the reliability of the admission electrocardiogram in predicting outcome in patients hospitalized for chest pain at rest, 90 patients were randomized into a trial of aspirin versus heparin in unstable angina or non-Q-wave myocardial infarction, and prospectively followed for 3 months. The emergency room admission electrocardiogram was analyzed for ST-segment deviation greater than or equal to 1 mm/lead and T-wave changes. Unfavorable outcomes were recurrent ischemic pain, myocardial infarction and coronary revascularization with angioplasty or surgery. In patients who underwent coronary arteriography, a myocardium in jeopardy score ranging from 0 to 10 was assigned, based on the number of vessels with a diameter stenosis greater than or equal to 70% and the location of the stenoses. Considering all 90 patients, an admission electrocardiogram with ST-segment deviation in greater than or equal to 2 leads had a positive predictive value for adverse clinical events of 79% and a negative predictive value of 64%. In the subset of patients without left ventricular hypertrophy and whose admission electrocardiograms were recorded during chest pain (62 of 90), the positive predictive value of ST deviation in greater than or equal to 2 leads improved to 89% and the negative value to 72%. Of the 62 patients, 53 underwent coronary arteriography. There was a positive linear correlation between the total number of leads with ST-segment deviation and the myocardium in jeopardy score (r = 0.80, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
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