Effect of buthionine sulfoximine on orthophenylphenol-induced hepato- and nephrotoxic potential in male rats

A single oral administration of orthophenylphenol (OPP, 1400 mg/kg; about half the LD₅₀) to male Fischer 344 rats produced an elevation of serum transaminase activity 24 h later. Pretreatment with l-buthionine-S,R-sulfoximine (BSO, 900 mg/kg) in the OPP-treated rats potentiated the hepatic and renal damage which was accompanied by necrosis. Six hours after the administration of OPP (700 or 1400 mg/kg), hepatic and renal glutathione (GSH) levels decreased with increasing dosage. Hepatic GSH depletion with OPP was enhanced with BSO pretreatment and the recovery of GSH in both organs was slow in the high-dose OPP group. These results suggest that hepatic and renal damage is associated with a serious and prolonged GSH depletion. When either phenyl-p-benzoquinone (PBQ) or phenylhydroquinone (PHQ), which are intermediates of OPP, was administered orally to rats at 700 or 1400 mg/kg, the mortality with the high dose of PBQ was 75% at 24 h. The serum transaminase activity and UN level increased with the low dose of PBQ, accompanied by necrotic hepatocytes. The toxic effects of PHQ on kidney or liver were less than those on PBQ. These observations suggest that the liver and kidney may be target organs for toxic actions of a large dose of OPP and its intermediate, PBQ.Part of this work was presented at IInd International ISSX Meeting Xenobiotic Metabolism and Disposition, May 16–20, 1988, Kobe, Japan     

Nephrotoxicity of 5-(N-phenylcarboxamido)-2-thiobarbituric acid in the Fischer 344 rat

Summary In the present investigation, administration of a single i.p. dose of the anticancer drug merbarone [5-(N-phenylcarboxamido)-2-thiobarbituric acid] produced an acute and reversible decrease in renal function in female but not male Fischer 344 rats. The renal lesion in female rats was biochemically characterized as a decrease inp-aminohippuric acid accumulation by renal slices along with polyuria, glucosuria, proteinuria, and enzymuria. These functional changes were accompanied by histopathologic changes of focal tubular necrosis that was confined to the deep cortex and outer stripe of the outer medulla. The changes in these parameters were dose-dependent and were observed at doses as low as 0.2×MELD¹⁰ (12 mg/kg). This low merbarone dose increased urinary glucose and protein excretion by 26- and 9-fold, respectively, in the initial 16-h urine collection in female rats. This increase was accompanied by a 2- to 15-fold increase in the excretion ofN-acetyl--d-glucosaminidase (NAG), -glutamyl transpeptidase (-GTP), and lactate dehydrogenase (LDH) activities. No significant changes in renal function were observed in male rats apart from mild enzymuria after a high dose of merbarone (36 mg/kg). The drug did not increase urea nitrogen levels in male or female rats, reflecting the focal nature of this tubular lesion. Merbarone produced small elevations in serum transaminase activities [i. e., glutamic-oxalacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT)] at doses that produced marked alterations in renal function in female rats, suggesting only mild hepatotoxicity. The present study establishes the kidney as a possible dose-limiting target organ for merbarone toxicity.     

Human serum albumin incorporating synthetic heme: red blood cell substitute without hypertension by nitric oxide scavenging

The administration of extracellular, hemoglobin-based oxygen carriers often elicits an acute increase in blood pressure by vasoconstriction. This side effect is now recognized to be due to the depletion of nitric oxide (endothelial-derived relaxing factor) by the extravasuated hemoglobins. We have recently found that the administration of a recombinant human serum albumin (rHSA)-based oxygen carrier involving synthetic tetraphenyporphinatoiron(II) derivative (FeP) (rHSA-FeP) does not induce such hypertensive action, because of its low permeability through the vascular endothelium. The heart rate responses after the rHSA-FeP injection were also negligibly small. Visualization of the intestinal microcirculatory changes clearly revealed the widths of the venule and arteriole to be fairly constant. The entirely synthetic rHSA-FeP becomes a promising material as a new type of red blood cell substitute.     

A novel mutation in the FcgammaRIIIA gene (CD16) results in active natural killer cells lacking CD16

We report a novel mutation in FcgammaRIIIA (the transmembrane-form CD16) on natural killer (NK) cells in a patient with polyneuropathy. She had no history of recurrent infections. Her NK cells expressed no detectable CD16; however, her NK cytotoxic activity was normal, suggesting that CD16 expression and cytotoxic activity are independent of one another. Molecular analysis revealed a deletion of a single adenine base in exon 4 of CD16 at nucleotide 550. This deletion generates a STOP codon in an extra-cellular domain of the FcgammaRIIIA gene, thereby truncating the CD16 molecule. The patient's NK cells were not recognized by the anti-CD16 monoclonal antibodies 3G8 and Leu11c. Whether the development of her polyneuropathy is associated with this novel mutation is unclear.     

Mononuclear-cell subsets in human idiopathic crescentic glomerulonephritis (ICGN): Analysis in tissue sections with monoclonal antibodies

Mononuclear inflammatory cells (MIC) were analyzed in renal biopsies from 16 patients with ICGN (7 with glomerular immune complex deposits, 3 with anti-GBM disease, and 6 without immune deposits) by the avidin-biotin-immunoperoxidase technique utilizing monoclonal antibodies to cell surface antigens: T11 (total T), T4 (inducer/helper T), T8 (suppressor/cytotoxic T), B1 (B cells), M1 (monocytes/granulocytes), and Leu 7 [natural killer (NK) cells]. Total MIC were significantly increased in both glomeruli and interstitial tissues of the patients. Interstitial MIC consisted mainly of lymphocytes (80%) and monocytes (19%), with small numbers of B and NK cells present. In contrast, MIC in renal glomeruli of patients with ICGN were composed of monocytes (65%) rather than T lymphocytes (34%). A majority of T lymphocytes found in renal tissues of patients and controls had the helper/inducer phenotype. Tissue T4/T8 ratios were not significantly different in the glomeruli and interstitium. Monocytes and T lymphocytes accumulating in renal tissues of patients with ICGN may mediate glomerular injury in all forms of human ICGN.Presented in part at the 15th Annual Meeting of the American Society of Nephrology, Chicago, Illinois, 1982.     

Compatibility in vitro of albumin-heme (O(2) carrier) with blood cell components

Recombinant human serum albumin including 2-[8-[N-(2-methylimidazolyl)]octanoyloxymethyl]-5,10,15,20-tetrakis(alpha,alpha,alpha,alpha-o-pivaloylamino)phenylporphinatoiron(II) (albumin-heme; rHSA-FeP) is a synthetic hemoprotein that has sufficient capability to reversibly bind and release O(2) under physiological conditions (pH 7.3, 37 degrees C) similar to hemoglobin and myoglobin. In order to use this albumin-based O(2) carrier as a new class of red blood cell substitutes, its compatibility with blood cell components carefully was investigated in vitro. After the addition of the rHSA-FeP solution into whole blood at 10, 20, and 44 vol %, the FeP concentration in the plasma phase remained constant for 6 h at 37 degrees C in each group, and no significant time dependence was observed in the numbers of red blood cells, white blood cells, or platelets. The microscopic observations clearly showed that the shapes of the red blood cells had not been deformed during the measurement period. With respect to the blood coagulation parameters (prothrombin time and activated partial thromboplastin time), the coexistence of rHSA-FeP had only a negligibly small influence. Also the blood compatibility under dynamic flow conditions was evaluated using a microchannel array flow analyzer. All these results suggest that the albumin-heme has no effect on the morphology of blood cell components in vitro.     

Identification of Potential Diagnostic and Vaccine Candidates of Helicobacter pylori by Two-Dimensional Gel Electrophoresis, Sequence Analysis, and Serum Profiling

There is great interest in characterizing the proteins of the gastric pathogen Helicobacter pylori, especially those to which humans respond immunologically, because of the potential importance of such proteins in diagnosis and vaccine development. Two-dimensional gel electrophoresis was used to separate and identify potential antigens of H. pylori ATCC 43504. Over 30 proteins were reactive in Western blots with pooled sera from 14 infected patients. These proteins were analyzed by N-terminal sequence analysis. Fourteen proteins were determined to be distinct from any proteins previously described from H. pylori; the others were previously isolated and characterized proteins. Analysis of eight distinct H. pylori strains showed that most of these antigens were produced by all of the strains. We propose that collection of new antigens such as those recognized here will be useful in serologic tests for detecting and monitoring H. pylori infection and may also serve as potential targets for antimicrobial agent or vaccine development.     

Molecular cloning of hepatitis C virus genome from a single Japanese carrier: sequence variation within the same individual and among infected individuals.

A hepatitis C virus (HCV) genome was isolated and sequenced from a single Japanese patient with chronic non-A, non-B hepatitis. The genome (HCV-JT), which was constructed with 23 cDNA clones, consisted of 9436 nucleotides with a long open reading frame which could encode a sequence of 3010 amino acid residues. To study the sequence variation of the HCV genome in an individual, we analyzed another sequence of the HCV genome (HCV-JT') constructed with different cDNA clones derived from the same patient. The nucleotide variation between HCV-JT and -JT' was less than 1%, and was distributed throughout the genome except in the 5' non-coding region, where no variation was observed. The diversity was higher (1.6%) in the putative envelope protein region than in other regions. The nucleotide and deduced amino acid sequences of HCV-JT showed homologies of about 91 and 95%, respectively, with those of other Japanese HCV isolates. The nucleotide diversity was high in the gp 70 region (corresponding to the NS 1 region of flaviviruses) and low in the 5' non-coding and p22 (putative core protein) regions. A similar pattern of distribution of nucleotide changes was observed on comparison of HCV-JT with an American isolate HCV-US, where the homologies in nucleotide and amino acid sequences were about 79 and 85%, respectively. Base transversions contributed about 50% of the total base exchanges between the Japanese and American HCV sequences, but only 20% or less of those among Japanese HCV or among American HCV sequences. Thus, the Japanese and American HCVs are genetically distinguishable, supporting our earlier prediction that these two HCVs could be classified as different subtypes.     

Pathological analyses of long-term intracoronary Palmaz-Schatz stenting; Is its efficacy permanent?

BACKGROUND: Angiographic regression of luminal narrowing occurs 6 months to 3 years poststenting. However, after 4 years lesions progressed gradually and late restenosis was observed in 28% of 179 Palmaz-Schatz-stented lesions during the past 10 years. Elucidating its pathogenesis is pivotal to developing preventive strategies. METHODS AND RESULTS: Histopathological and immunohistochemical studies were performed in 19 stented coronary arteries obtained from 19 patients autopsied after noncardiac death 2-7 years poststenting. The quality/severity of chronic inflammatory cells (T lymphocytes, macrophages and multinucleated giant cells) infiltration around the stent struts that is observed even in the absence of restenosis depended on the time elapsed from stenting: a) 2 years postprocedure, in spite of angiographic regression during the first year and pathologically expressed as maturation of the neointimal scar, there was chronic inflammatory response evidence: neovascularization and lymphocyte infiltration, b) > or = 3 years: the neointimal smooth muscle cells were sparse with abundant proliferation of collagen fibers. Presence of slight helper/inducer T lymphocytes and mild macrophage infiltration around the stent struts was evident immunohistochemically, c) > or = 4 years: prominent infiltration by lipid-laden macrophages with strong collagen-degrading matrix metalloproteinase immunoreactivity was observed around the struts. In two of these arteries, the surface contacting the stent was focally disrupted and covered by nonocclusive mural thrombi. CONCLUSIONS: Stainless steel stents evoke a remarkable foreign-body inflammatory reaction to the metal. These persistent peri-strut chronic inflammatory cells may accelerate new indolent atherosclerotic changes and consequent plaque vulnerability.     

Effect of inhaled corticosteroid on an immunoreactive thymus and activation-regulated chemokine expression in the bronchial biopsies from asthmatics

BACKGROUND: Bronchial asthma is characterized by airway inflammation, notably because of eosinophils and T cells. Thymus and activation-regulated chemokine (TARC) is known to selectively attract Th2 cells, and is increased in response to interleukin (IL)-4 and IL-13, which share a common receptor, IL-4 receptor alpha (IL-4Ralpha). While corticosteroids have proven, very effective in modifying airway inflammation, the effect of corticosteroids on TARC in asthmatics has been little studied. OBJECTIVE: We examined the effects of inhaled budesonide (BUD) on the expression of TARC and the number of inflammatory cells in bronchial biopsy specimens taken from asthma patients. METHODS: Inhaled BUD 800 mug daily, or placebo was administered for 3 months in a double-blind, parallel-group study, and bronchial biopsies were performed before and after treatment. Biopsy specimens were examined by immunocytochemistry. RESULTS: We observed a significant decrease in the epithelial expression of TARC (P < 0.01) in the BUD group compared with the placebo group. This was accompanied by decreases in the number of eosinophils (P < 0.01), CD3(+) T cells (P < 0.05), and CD4(+) T cells (P < 0.01). A significant correlation was found between changes in epithelial TARC and in IL-4Ralpha immunoreactivity (r(s) = 0.66, P < 0.01). CONCLUSIONS: These findings suggest that corticosteroid asthma treatment can reduce infiltration of the airway by inflammatory cells, an effect modulated by down-regulation of bronchial epithelial TARC expression.