[Interferon-associated retinopathy]

BACKGROUND

Recently interferons have been utilized for hepatitis C or some other tumorous conditions. However, a new interferon-associated retinopathy has been reported. There are to our knowledge, no publications in German-speaking countries.

PATIENTS

Four patients developed after interferon therapy cotton-wool spots combined with splinter hemorrhage.

RESULTS

The retinopathy occurred 5-30 days after the beginning of the therapy. In one case the retinopathy aggravated following dose elevation, whereas in two other cases the cotton-wool spots and hemorrhages disappeared irrespective of continued interferon therapy.

CONCLUSIONS

Interferons cannot be primarily responsible for the development of retinopathy.

Immunohistochemical detection of advanced glycation end products in dialysis-related amyloidosis

beta 2-Microglobulin (beta 2m) isolated from the amyloid deposits in patients with dialysis-related amyloidosis (DRA) has been demonstrated to be modified with advanced glycation end products (AGE). We produced a monoclonal anti-AGE antibody which localized AGE to amyloid deposits in patients with DRA by immunohistochemistry. The connective tissues in the carpal tunnel were obtained from surgical specimens in six patients with DRA. AGE were localized to the beta 2m-positive amyloid deposits in these patients using the monoclonal anti-AGE antibody. AGE were also detected in infiltrating cells surrounding the amyloid deposits. The AGE-positive cells were identified as macrophages, since they showed positive staining with anti-CD68 antibody. In conclusion, AGE were demonstrated by immunohistochemical technique to be present in both beta 2m-positive amyloid deposits and surrounding macrophages in patients with DRA.

[Aerosolization of lactide/glycolide copolymer (PLGA) nanospheres for pulmonary delivery of peptide-drugs]

Lactide/glycolide copolymer (PLGA) nanospheres with nafarelin acetate (NA) used as a model peptide-drug have been developed by the emulsion-phase separation method in an oil phase as reported previously. In the present study, the aerosolization of nanospheres in dry and wet dispersion methods was investigated in vitro to evaluate their applications to pulmonary delivery of peptide-drug. The size distribution of aerosolized nanosphere dispersions and pulmonary deposition behaviors of inhaled particles were investigated using a lazer diffraction light-scattering particle sizer and an artificial model lung (Cascade Impactor: CI), respectively. It was found that the freeze-drying of nanospheres with a hydrophilic surface active agent effectively improved the inhalation behavior. Further, the mixing of nanospheres with lactose led to the reduction of their adhesion to an inhalation device (Spinhaler). It was supposed that the mists of nanosphere-suspension generated from a jet nebulizer might be inhaled into the lower bronchus and alveolus, because their respirable fraction (RF) value, i.e., the deposition percentage on stage 2 to 6 of CI, defined as a pulmonary inhalation index, reached a maximum of over 50%.

Liquid chromatographic-atmospheric pressure chemical ionization mass spectrometric analysis of glycine conjugates and urinary isovalerylglycine in isovaleric acidemia

n-Acetylglycine, n-propionylglycine, n-butyrylglycine, isobutyrylglycine, n-valerylglycine, isovalerylglycine, heptanoylglycine, phenylacetylglycine and isovalerylglucuronide were identified based on their liquid chromatographic-atmospheric pressure chemical ionization mass spectra (LC-APCI-MS). We were able to detect the presence of urinary isovalerylglycine in two cases of isovaleric acidemia using LC-APCI-MS. Membrane-filtered urine samples were injected into the LC-APCI-MS system in the negative-ion mode without any further pretreatment, and large amounts of isovalerylglycine were detected as the [M-H]- ion. The urinary excretion of isovalerylglycine appeared to increase after L-carnitine therapy. This analytical method is quick and easy and it may be a useful tool in understanding dysfunctional conditions in isovaleric acidemia.

Detection of 1-phenyl-N-methyl-1,2,3,4-tetrahydroisoquinoline and 1-phenyl-1,2,3,4-tetrahydroisoquinoline in human brain by gas chromatography-tandem mass spectrometry

1-Phenyl-N-methyl-1,2,3,4-tetrahydroisoquinoline and 1-phenyl-1,2,3,4-tetrahydroisoquinoline were detected for the first time in parkinsonian human brain using gas chromatography-tandem mass spectrometry (GC-MS-MS). Since these compounds are structural analogues of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) that produces parkinsonism in humans, they might be candidates for endogenous MPTP-like neurotoxins.

Improved static compression behaviors and tablettabilities of spherically agglomerated crystals produced by the spherical crystallization technique with a two-solvent system

PURPOSE

Poorly compressible crystals of acebutolol hydrochloride were agglomerated by the spherical crystallization technique with a two-solvent system to improve the compressibility for direct tabletting. The mechanism of improvements in static compression behaviors and tablettabilities of the spherically agglomerated crystals were investigated.

METHODS

The improvement of static compression behaviors of the agglomerated crystals was determined by measuring the stress relaxations and elastic recoveries of compressed powder of original and agglomerated crystals. The improved tablettability of agglomerated crystals was evaluated by the pressure transmission ratio upon compression, the ejection pressure for releasing the tablet from the die and the tablet strength, i.e., tensile strength required for breaking.

RESULTS

The higher relaxation pressure and the lower elastic recovery of the agglomerated crystals than of the original crystals were found. The pressure transmission ratio data showed that the friction pressures of the two crystals were similar during the compression period. The ejection pressure of the agglomerated crystals was lower than that of the original crystals. The tensile strength of the tablet of agglomerated crystals was greater than that of the original crystals.

CONCLUSIONS

The compressibility and tablettability of the spherically agglomerated crystals prepared by the spherical crystallization technique were much improved due to their increased plastic property and reduced adhesive property compared to the original crystals.

Hepatocyte growth factor stimulates liver regeneration and elevates blood protein level in normal and partially hepatectomized rats

The effects of recombinant human hepatocyte growth factor (HGF) on liver growth and function of normal and partially hepatectomized rats have been examined. HGF was continuously administered into the jugular vein because it was rapidly eliminated from the plasma (t1/2 alpha; approximately 4.5 min) and degraded. In normal rats, the labeling index of hepatocytes was increased about 6 times by the administration of HGF. HGF also decreased the prothrombin time and increased the hepaplastin and serum albumin content. In 70%-hepatectomized rats, HGF stimulated liver regeneration and increased the level of blood proteins such as hepaplastin in a dose-dependent manner. The stimulation of serum protein level seemed to result from not only the increase of hepatic cell number but also the direct effect of HGF on the protein production in hepatocytes, because HGF rapidly enhanced the protein synthesis prior to the increase of cell number and increased the mRNA content of albumin in the liver in vivo. In addition, a combination of heparin with HGF further accelerated the effects of HGF described above, possibly due to the decrease of HGF clearance. These findings suggest that HGF accelerates both the hepatic regeneration and function in vivo, and that rhHGF is clinically expected to be a potent therapeutic agent in hepatectomy and liver injury.

[An autopsy case of gliomatosis cerebri with marked swelling of the spinal cord]

We report a 26-year-old male with diffuse infiltration of neoplastic glial cell to the bilateral hemisphere, basal ganglia, cerebellum, brain stem and markedly swollen spinal cord. Initial complaints were general malaise and disturbance of eye movements. The patient died after 30 months. The characteristics of this case included diffuse severe swelling of the brain stem and spinal cord (from the cervical to thoracic levels) shown on MRI without marked change of the hemispheres, cerebellum or basal ganglia. This is a rare case report of spinal swelling that was visually and radiologically apparent, although at present 11 cases of gliomatosis cerebri with histologically proven invasion to the spinal cord. From these facts, it is thought that this case is important from the aspect of the differential diagnosis of the spinal cord lesions.

[A case of near total tracheal obstruction from recurrent esophageal carcinoma]

We have treated a 58-year-old man with almost complete tracheal occlusion arising as a result of recurrence of esophageal cancer. Although laser photoresection using partial cardiopulmonary bypass was desirable, neither laser nor cardiopulmonary bypass was available in our hospital. It was then decided to resect the tumor by forceps. In order to prevent bleeding from tumor during such emergency procedure, intratumoral injection of ethanol was preceded and tracheal lumen could be opened successfully. He was managed by insertion of a Dumon silicone stent seven days after the emergency. The result was satisfactory for maintaining the patency of the airway where the stent was placed. Unfortunately the patient died 113 days after the insertion of Dumon silicone stent from massive hemoptysis, which might resulted from the rupture of vessel feeding the tumor or the perforation of aorta involved by the tumor.

Potential bile acid metabolites. 23. Syntheses of 3-glucosides of nonamidated and glycine- and taurine-amidated bile acids

The 3-glucosides of nonamidated lithocholic, chenodeoxycholic, ursodeoxycholic, deoxycholic, and cholic acids, and their double conjugate forms with glycine and taurine were synthesized. The key reactions used were 1) beta-D- glucosidation at C-3 by the Koenigs-Knorr condensation reaction of 3 alpha-hydroxylated bile acid methyl (or p-nitrophenyl) esters with 1 alpha-bromo-1-deoxy-2, 3, 4, 6-tetra-O-acetyl-D-glucopyranose in the presence of cadmium carbonate in refluxing benzene; 2) indirect and direct amidations at C-24 by the activated p-nitrophenyl ester and by the diethylphosphorylcyanide methods, respectively, using glycinate ester and taurine as coupling agents; and 3) simultaneous alkaline hydrolysis of the hydroxyl-protecting and ester groups in both the sugar and aglycone moieties.

Serum pyridinolines as specific markers of bone resorption in hemodialyzed patients

Serum levels of hydroxylysyl pyridinoline and lysyl pyridinoline were quantified in uremic patients undergoing maintenance hemodialysis and in healthy subjects. Pre-hemodialysis serum levels of hydroxylysyl pyridinoline and lysyl pyridinoline in the hemodialyzed patients were significantly higher than those in healthy subjects. Serum levels of hydroxylysyl pyridinoline and lysyl pyridinoline decreased significantly after hemodialysis with reduction rates of about 40%. Pre-hemodialysis serum levels of hydroxylysyl pyridinoline and lysyl pyridinoline correlated significantly with intact parathyroid hormone, osteocalcin and bone-specific alkaline phosphatase. Lysyl pyridinoline showed better correlations with these parameters than hydroxylysyl pyridinoline. Parathyroidectomy markedly decreased serum levels of hydroxylysyl pyridinoline and lysyl pyridinoline. These results indicate that serum pyridinolines, especially lysyl pyridinoline, may be used as specific biochemical markers of bone resorption in hemodialyzed patients.

Efficient removal of albumin-bound furancarboxylic acid by protein-leaking hemodialysis

Furancarboxylic acid (3-carboxy-4-methyl-5-propyl-2-furanpropionic acid, CMPF), an inhibitor of erythropoiesis, cannot be removed by conventional hemodialysis due to its strong albumin binding, resulting in its accumulation in uremic serum. We used protein-leaking hemodialysis with BK-F dialyzers in 8 uremic patients for 4 months to determine its effect on the serum levels of CMPF. Pre-hemodialysis serum levels of CMPF significantly decreased to about 50% after 4 months by protein-leaking hemodialysis, while those of BUN and serum creatinine did not change significantly. Pre-hemodialysis hematocrit and hemoglobin levels significantly increased by protein-leaking hemodialysis. These results indicate that protein-leaking hemodialysis reduces serum levels of albumin-bound CMPF and improves anemia.

Elevated serum levels of 3-deoxyglucosone, a potent protein-cross-linking intermediate of the Maillard reaction, in uremic patients

3-Deoxyglucosone (3-DG) has been identified as an intermediate of the Maillard reaction in vitro. We measured serum 3-DG levels using gas chromatography/mass spectrometry and found a marked elevation in serum 3-DG levels in uremic patients compared with healthy subjects. The uremic patients with diabetes showed significantly higher serum concentrations of 3-DG than those without diabetes. 3-DG was demonstrated to be a potent protein-cross-linking agent in the reaction with lysozyme, leading to browning, fluorescence formation and polymerization of the protein by formation of advanced glycation end products (AGE). The increase in serum 3-DG levels in the uremic patients suggests that 3-DG may be responsible for the development of uremic complications by promoting the formation of AGE.

Interleukin 8 and biocompatibility of dialysis membranes

To determine whether interleukin 8 (IL-8) can be used as an index of biocompatibility of dialysis membranes, the effects of hemodialysis (HD) on plasma IL-8 levels and the expression of IL-8 mRNA in peripheral blood mononuclear cell (PBMC) were compared among regenerated cellulose (RC), polyacrylonitrile (PAN) and polymethylmethacrylate (PMMA) dialyzers. HD using RC dialysers significantly increased plasma IL-8 levels and induced abundant expression of IL-8 mRNA in PBMC. HD using PMMA dialyzers also increased plasma IL-8 levels and induced slight expression of IL-8 mRNA. In contrast, HD using PAN dialyzers neither increased plasma IL-8 levels nor induced the expression of IL-8 mRNA. In vitro studies demonstrated that IL-8 was considerably adsorbed by PAN membranes and not at all by RC and PMMA. These studies indicate that plasma IL-8 level and expression of PBMC IL-8 mRNA can be used as indices of biocompatibility of dialysis membranes.

Mucoadhesion of polymer-coated liposomes to rat intestine in vitro

Multilamellar liposomes consisting of dipalmitoyl phosphatidylcholine (DPPC) and dicetyl phosphate (DCP) in a molar ratio of 8:2 (DPPC:DCP = 8:2) were coated with three different types of polymers: chitosan, polyvinyl alcohol having a long alkyl chain, and poly(acrylic acid) bearing cholesterols. The existence of polymer layers on the liposome surface was confirmed by measuring the zeta potential of the liposomal particles. The mucoadhesive function of the polymer-coated liposomes was evaluated in vitro using rat intestine. A particle counting method using the Coulter counter was adopted to evaluate the adhesive % of liposomes. Chitosan coated liposomes showed the highest adhesive % among the polymer-coated liposomes tested. No adhesive % was observed for the non-coated liposomes. The adhesion of chitosan-coated liposomes to the intestine wall was confirmed by fluorescence microscopy using pyrene loaded liposomes.

Alterations in estradiol metabolism in MCF-7 cells induced by treatment with indole-3-carbinol and related compounds

In mammals, estradiol (E2) metabolism primarily involves mutually exclusive hydroxylation at either C-2 or C-16 alpha. We have previously reported a consistent increase in the C-16 alpha hydroxylation activity in human breast cancer and in mouse strains with high levels of mammary tumors. Here we show that the dietary compound indole-3-carbinol (I3C) increases C-2 hydroxylation five-fold in MCF-7 cells in culture but has minimal effect on the reaction at C-16 alpha. Because I3C-induced changes in E2 metabolism result in a metabolite ratio inverse to that observed in women with breast cancer we have separately examined whether this shift conferred an anti-tumorigenic advantage to estrogen target cells. The preferential changes induced by I3C on estradiol metabolism in MCF-7 cells parallel its anti-tumorigenicity in mice. These results suggest that changes in the metabolism of estradiol via the C-2 pathway might play a significant role in decreasing risk for breast cancer in women. Indole-2-carbinol is readily available as a chemical and as a dietary component of cruciferous vegetables. Feasible dietary changes show promise of having clinical utility in the prevention of breast cancer and other hormone-dependent cancers.

Isolation and characterization of an alicyclic amine N-sulfotransferase from female rat liver

An alicyclic amine N-sulfotransferase sulfonating 4-phenyl-1,2,3,6-tetrahydropyridine (PTHP) was purified from female rat liver cytosol and showed a homogenous band with a molecular weight of 30500 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme, designated NST-1, catalyzed sulfonation not only of the alicyclic amine but also dehydroepiandrosterone, a typical substrate of hydroxysteroid sulfotransferase (STs), but had little sulfonating activity towards 2-naphthol, a typical substrate of aryl STs. The N-terminal amino acid sequence for the first 24 residues had a high homology with those of rat liver hydroxysteroid STs. Therefore, it is suggested that NST-1 is classified as a member of the hydroxysteroid ST. Immunoblot analysis of male and female rat liver cytosol, carried out by using rabbit antisera raised against NST-1, indicated that the female cytosol contained a higher level of the enzyme than that of male. The marked sex difference in the expression level of NST-1 was in good accordance with the previous demonstration that female rat liver cytosol catalyzed sulfonation of PTHP to a greater extent than that of male.

Analysis of conjugated bile acids in human biological fluids. Synthesis of hyodeoxycholic acid 3- and 6-glycosides and related compounds

The glucuronide, glucoside and N-acetylglucosaminide conjugates of hyodeoxycholic acid were synthesized. In addition, murideoxycholic acid 3-glycosides and some of their C-5 epimeric analogs were also prepared. The principal reactions used are 1) the Koenigs-Knorr condensation reaction of 3-oxo-6 alpha-hydroxy and 6-oxo-3 alpha-hydroxy esters with an appropriate alpha-acetohalosugar catalyzed by cadmium carbonate in benzene under reflux, 2) reduction of the resulting bile acid glycoside methyl ester-acetates with tert-butylamine-borane complex, and 3) subsequent hydrolysis with aqueous lithium hydroxide.

Indoxyl sulfate, a circulating uremic toxin, stimulates the progression of glomerular sclerosis

To determine the role of indoxyl sulfate in the progression of glomerular sclerosis, the serum level of indoxyl sulfate was measured in patients with uremia, and the effect of oral administration of indoxyl sulfate on renal function and renal histology was studied in subtotally nephrectomized uremic rats. Further, the effects of a low-protein diet and oral sorbent (AST-120) administration on the serum and urine levels of indoxyl sulfate were studied in different groups of subtotally nephrectomized uremic rats. We noted a marked elevation of serum level of indoxyl sulfate in the patients with uremia. The oral administration of indoxyl sulfate to the uremic rats increased the serum creatinine and blood urea nitrogen levels and decreased creatinine clearance, inulin clearance, and p-aminohippuric acid clearance. The glomerular sclerosis index in the indoxyl sulfate-administered uremic rats was higher than in the control uremic rats. A low-protein diet and AST-120 administration decreased the serum and urine levels of indoxyl sulfate, the blood urea nitrogen level, the urinary protein level, and the glomerular sclerosis index in the uremic rats as compared with those on a high-protein diet. Thus, indoxyl sulfate, a circulating uremic toxin, stimulated the progression of glomerular sclerosis in the uremic model. A low-protein diet and AST-120 reduced the serum and urine levels of indoxyl sulfate and suppressed the progression of glomerular sclerosis.

In vitro drug release behavior of D,L-lactide/glycolide copolymer (PLGA) nanospheres with nafarelin acetate prepared by a novel spontaneous emulsification solvent diffusion method

Nanospheres with D,L-lactide/glycolide copolymer (PLGA) were prepared as a biodegradable and biocompatible polymeric carrier for peptide drugs by a novel spontaneous emulsification solvent diffusion method. Nafarelin acetate (NA), a luteinizing hormone-releasing hormone analogue, was employed as a model peptide drug to investigate the encapsulation efficiency. The drug and PLGA, dissolved in an acetone-dichloromethane-water mixture, were poured into an aqueous solution of polyvinyl alcohol under moderate stirring at room temperature. Spontaneous emulsification arising from a rapid diffusion of acetone from the organic to the aqueous phase enables preparation of PLGA submicron spheres 200-300 nm in size. The entrapment of NA in nanospheres was improved by blending low molecular weight (Mw = 4500) PLGA with higher molecular weight PLGA due to the synergistic effect of the rapid deposition of PLGA and the ionic interaction between NA and PLGA. By coadmixing a small amount of negatively charged phospholipids such as dipalmitoyl phosphatidylglycerol or dicetyl phosphate, the leakage of water-soluble NA was further prevented. The NA encapsulated in PLGA nanospheres was more stable than native NA in acidic medium (pH = 1.2). The drug-release behavior from nanospheres suspended in the disintegration test solution no. 1 (Japanese Pharmacopeia XII) exhibited a biphasic pattern. It was found tht the initial burst of release might be due to the degradation of the PLGA chain, as monitored by gel permeation chromatography. At a later stage, the drug was released more slowly, the rate of which was determined by the diffusion of the drug in the porous matrix structure.(ABSTRACT TRUNCATED AT 250 WORDS)

Preparation of agglomerated crystals for direct tabletting and microencapsulation by the spherical crystallization technique with a continuous system

Adhesive and cohesive properties of chlorpromazine hydrochloride (CP) crystals were modified to improve their powder processing, e.g., direct tabletting and microencapsulation, by agglomeration. Moreover, sustained-released gelling microcapsules of CP were devised to prolong the pharmacological effect. The spherical crystallization technique was applied to prepare agglomerates for direct tabletting and microencapsulation to use them as core materials. The ethanolic solution dissolving CP was poured into a stirred cyclohexane, yielding spherically agglomerated crystals. The resultant agglomerates were free-flowing and easily packable spheres with average diameters of 200 to 1000 microns. The agglomerates reserved the high compressibility of the original powder having a small particle size (14 microns). The compression behavior represented by Heckel's equation suggested that the agglomerates were disintegrated to individual primary crystals at low compression pressures, and then they were closely repacked and plastically deformed at higher pressures. After agglomeration, microencapsulation was continuously performed in the same batch by a phase separation method. Coacervate droplets produced by pouring cyclohexane into a dichloromethane solution, dissolving polyvinyl acetate as a coating polymer, were added to the crystallization system under stirring, to prepare the microcapsules. By filling the microcapsules in gelatin hard capsules or tabletting them, their drug release rates became retarded compared with the physical mixture treated in the same way, having the same formulation as the microcapsules. This phenomenon was due to the gelation of polyvinyl acetate of the microcapsules in the dissolution medium, whose glass transition temperature is very low. This novel sustained-release dosage form is termed "gelled microcapsules."

Endogenous synthesis of N-methylnorsalsolinol in rat brain during in vivo microdialysis with epinine

The in vivo metabolic pathway for the synthesis of N-methylnorsalsolinol, an analogue of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), was studied in the rat brain. N-Methyldopamine (epinine) was perfused at the striatum of the rat brain by in vivo microdialysis. N-Methylnorsalsolinol (NMNSAL) was identified in the brain dialysate after epinine perfusion using gas chromatography-selected-ion monitoring mass spectrometry (GC-SIM-MS). We demonstrated that NMNSAL could be synthesized from epinine with an aldehyde by the Piclet-Spengler condensation reaction in the rat brain.

Effect of repeated injection of somatomedin C on drug metabolizing enzyme activities in rats

The effect of somatomedin C on the hepatic drug-metabolizing enzyme system in rat liver after sc injection, a clinically applicable dosing route, was studied. Although liver weight was slightly increased after somatomedin C (1 mg/kg) was injected for 7 days, no significant changes were observed in other dosing group (0.1 and 10 mg/kg). There were no significant effects of somatomedin C on cytochrome P-450 and b5 contents, and NADPH-cytochrome c reductase, aminopyrine demethylase, aniline hydroxylase, and ethoxyresorufin deethylase. Additionally, somatomedin C treatment did not affect the activities of 2 alpha-, 2 beta-, 6 beta- and 16 alpha-hydroxytestosterone and androstenedione formation from testosterone. Changes relation to dosing period were also examined with 1 mg/kg of somatomedin C. In this case, hepatic levels of cytochrome P-450 and b5, NADPH-cytochrome c reductase and drug oxidations did not differ significantly among groups treated for 3, 7, or 14 days. These results suggest that somatomedin C has no effect on the hepatic mixed-function oxidase system.

Quantification of serum 1,5-anhydroglucitol in uremic and diabetic patients by liquid chromatography/mass spectrometry

We developed a new method for measuring serum 1,5-anhydroglucitol (1,5-AG), using liquid chromatography/atmospheric pressure chemical-ionization mass spectrometry (LC/MS). With this method we measured serum 1,5-AG concentrations in uremic and diabetic patients and compared these values with those determined by an enzymatic method. Serum 1,5-AG concentrations were significantly less in the undialyzed and dialyzed uremic patients and in diabetic patients; the values in the dialyzed patients decreased after hemodialysis. In uremic patients with high concentrations of serum myo-inositol, the 1,5-AG values determined by LC/MS were significantly lower than those determined enzymatically. There was no significant correlation between 1,5-AG and fructosamine in the uremic patients. These results demonstrate that serum 1,5-AG cannot be used as an index for glycemic control in uremic patients and that the LC/MS method is indicated in uremic patients with high concentrations of myo-inositol.

Quantification of serum 1,5-anhydroglucitol in uremic and diabetic patients by liquid chromatography/mass spectrometry

We developed a new method for measuring serum 1,5-anhydroglucitol (1,5-AG), using liquid chromatography/atmospheric pressure chemical-ionization mass spectrometry (LC/MS). With this method we measured serum 1,5-AG concentrations in uremic and diabetic patients and compared these values with those determined by an enzymatic method. Serum 1,5-AG concentrations were significantly less in the undialyzed and dialyzed uremic patients and in diabetic patients; the values in the dialyzed patients decreased after hemodialysis. In uremic patients with high concentrations of serum myo-inositol, the 1,5-AG values determined by LC/MS were significantly lower than those determined enzymatically. There was no significant correlation between 1,5-AG and fructosamine in the uremic patients. These results demonstrate that serum 1,5-AG cannot be used as an index for glycemic control in uremic patients and that the LC/MS method is indicated in uremic patients with high concentrations of myo-inositol.

Progression of glomerular sclerosis in experimental uremic rats by administration of indole, a precursor of indoxyl sulfate

In uremia there is a marked elevation of serum levels of indoxyl sulfate due to its decreased renal clearance. Indoxyl sulfate is synthesized in the liver from indole which is produced by bacteria in the intestines. To determine the role of indoxyl sulfate in the progression of chronic renal failure, we administered indole, the precursor of indoxyl sulfate, to subtotally nephrectomized uremic rats. The oral administration of indole increased the serum levels of creatinine and blood urea nitrogen and decreased creatinine, inulin, and p-aminohippuric acid clearances. The glomerular sclerosis index in the indole-treated rats was higher than in the control uremic rats. After oral administration, indole could not be detected in the urine, but large amounts of its metabolite, indoxyl sulfate. Thus, indole administration stimulated glomerular sclerosis in a uremic model through the production of indoxyl sulfate.

Novel toxins and Parkinson's disease: N-methylation and oxidation as metabolic bioactivation of neurotoxin

In human brains, a series of monoamine-derived 1,2,3,4-tetrahydroisoquinolines and the 6,7-dihydroxy derivatives has been identified. A tetrahydroisoquinoline was found to cause parkinsonism in monkey, but its toxicity was not so potent as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Two metabolic steps were found to increase cytotoxicity of isoquinolines. N-Methylation by a non-specific N-methyltransferase was proved by in vivo and in vitro experiments. The N-methylated compound was oxidized into N-methylisoquinolinium ion by monoamine oxidase from human brain mitochondria. The oxidation was proved by microdialysis in the rat brain. The isoquinolinium ion was more cytotoxic than the two metabolic precursors. N-Methylation of dopamine-derived 1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinolines was detected by in vivo microdialysis in the rat striatum, and their presence in the human brain was confirmed by GC-MS. The metabolic bioactivation may be a general pathway to produce neurotoxins as the pathogenic agents of Parkinson's disease.

Plasma interleukin 8 levels are increased by hemodialysis

The effects of hemodialysis on plasma interleukin 8 (IL-8) levels and the expression of IL-8 mRNA in peripheral blood mononuclear cells (PBMC) were studied in uremic patients undergoing maintenance hemodialysis (HD) using regenerated cellulose dialyzers. The plasma IL-8 levels in the patients after HD sessions were significantly higher than before HD. Comparison of the IL-8 mRNA levels obtained from PBMC before and after HD indicated that the expression of IL-8 mRNA was increased by HD. The enhancement of production of IL-8 in PBMC during HD may be responsible for inflammatory complications and impaired host defense in HD patients.

Analysis of urinary organic acids by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry

We developed a new method for the rapid determination of urinary organic acids using liquid chromatography-atmospheric pressure chemical ionization mass spectrometry. Mass spectra of authentic organic acids obtained in the negative-ion mode showed intense [M-H]- ions with some fragment ions. Urine samples of patients with methylmalonic aciduria, ornithine transcarbamylase deficiency, and phenylketonuria were extracted using anion-exchange columns. The mass chromatograms of the extracts showed some dominant peaks of abnormal metabolites characteristic of each disorder. This is a useful method for the analysis of urinary organic acids for the diagnosis of organic aciduria, because the sample preparation is simple.

Presence of 3-deoxyglucosone, a potent protein crosslinking intermediate of Maillard reaction, in diabetic serum

3-Deoxyglucosone, a potent protein crosslinking intermediate of the Maillard reaction, was first detected in diabetic serum using gas chromatography/mass spectrometry. Serum concentration of 3-deoxyglucosone was elevated in diabetic patients as compared with healthy subjects. More notably, diabetic patients with nephropathy showed higher serum concentration of 3-deoxyglucosone than those without nephropathy. The increased serum concentration of 3-deoxyglucosone in the diabetic patients suggests that 3-deoxyglucosone may be responsible for the development of diabetic complications such as diabetic nephropathy by promoting the formation of advanced glycation end products.

Potential bile acid metabolites. 20. A new synthetic route to stereoisomeric 3,6-dihydroxy- and 6-hydroxy-5 alpha-cholanoic acids

An improved procedure for the syntheses of stereoisomeric 3,6-dihydroxy- and 6-hydroxy-5 alpha-cholanoic acids (and their methyl esters) is described. The principal reactions employed are those reported in the preceding paper of this series, with the commercially available hyodeoxycholic acid as starting material. The final step in the procedure is the reduction of the key 5 alpha C-6 ketones with either the stereoselective equatorial reagent, Li/NH3/MeOH, or the axial reagent, Zn(BH4)2. The results of analysis of the prepared 6-monohydroxylated and 3,6-dihydroxylated stereoisomers by thin-layer chromatographic, high performance liquid chromatographic and gas-liquid chromatographic mobilities, and 1H and 13C nuclear magnetic resonance spectra are discussed along with the data for the corresponding compounds in the 5 beta-series.

Role of the solvent-diffusion-rate modifier in a new emulsion solvent diffusion method for preparation of ketoprofen microspheres

A new emulsion solvent diffusion method to prepare the microspheres of ketoprofen with an acrylic polymer was developed by utilizing sugar esters as solvent diffusion modifiers. The microspheres were produced via transient o/w emulsion droplets of the polymer, which was formed by the interaction of drug and water-miscible organic solvent, e.g. ethanol. The solvent consisting in oil droplets diffused into the outer aqueous medium. In the droplets, ethanol interacted with ketoprofen via hydrogen bonding between -OH group of ethanol and both -COOH and = CO groups of ketoprofen. These hydrogen bonds made ethanol solution strongly hydrophobic. The sugar ester added in the ethanol could inhibit such intermolecular interaction between ethanol and the = CO group of ketoprofen. Modulation in the binding force of ketoprofen-ethanol by the sugar ester contributed to achieving a desirable initial ethanol diffusion rate from the oil droplets for the formation of ketoprofen microspheres with high yield (> 85 per cent) and drug entrapment ratio (> 90 per cent).

Effect of human serum on the in vitro anti-HIV-1 activity of 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine (HEPT) derivatives as related to their lipophilicity and serum protein binding

Several derivatives of 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine (HEPT) were examined for their inhibitory effects on the replication of human immunodeficiency virus type 1 (HIV-1) in MT-4 cells in the presence of various concentrations (10-50%) of human serum (HS). Although all HEPT derivatives proved to be highly potent inhibitors of HIV-1 in the presence of 10% fetal bovine serum, some of them were less inhibitory to HIV-1 replication in the presence of HS. The HEPT derivatives were found to be highly bound to HS proteins. Both the anti-HIV-1 activity and HS protein binding of the compounds appeared to be related to their lipophilicity.

Spontaneous amyloidosis in senile NSY mice

Senile Nagoya, Shibata, Yasuda (NSY) mice developed amyloidosis and died from renal failure as a result of amyloidosis. NSY mice were first reported as experimental congenital diabetic mice by Shibata et al. in 1980. This study questioned whether NSY mice died from diabetic nephropathy. The authors of the present study investigated the life span and cause of death in these mice. The life span of NSY mice was found to be 618.7 +/- 72.5 days. NSY mice that lived for more than 400 days showed rising blood urea nitrogen and large amounts of amyloid deposits in the glomerulus of the kidneys. NSY mice died of renal amyloidosis. Immunological methods revealed that AApoAII was evident in the amyloid deposits of NSY mice. Apart from the kidneys, amyloid deposition was also found in the tongue, esophagus, stomach, small intestine, large intestine, rectum, lung, heart and adrenal glands. Amyloid deposits were found to a slight degree in the liver and the spleen. The most dominant amyloid deposition in NSY mice was seen in the glomerulus of the kidneys. From the point of view of amyloid depositional distribution, NSY mice were unique compared with other spontaneous amyloid mice.

Potential bile acid metabolites. 19. The epimeric 3 alpha,6,7 beta-trihydroxy- and 3 alpha,6,7 beta,12 alpha-tetrahydroxy-5 alpha-cholanoic acids

Syntheses by a new procedure of the known 3 alpha,6 alpha,7 beta- and 3 alpha,6 beta,7 beta-trihydroxy-5 alpha-cholanoic acids, and of the once-reported analog 3 alpha,6 alpha,7 beta,12 alpha-, as well as the new 3 alpha,6 beta,7 beta,12 alpha-tetrahydroxy-5 alpha-cholanoic acids, are described. Key intermediates of the syntheses are the 6-oxo-7 beta-ols of the respective 5 alpha-cholanoic acids (and their methyl esters) prepared by allomerization at C-5 of appropriate 6-bromo-7-oxo derivatives of the corresponding 5 beta-acids. Successful reduction of the 6,7-ketols to the desired products depended on the proper choice of reagents, either Zn(BH4)2 or Li/NH3/MeOH.

Presence of N-methyldopamine in parkinsonian and normal human brains

N-Methyldopamine (epinine) has been identified for the first time in parkinsonian and normal human brains by gas chromatography-mass spectrometry. N-Methylsalsolinol and N-methylnorsalsolinol, which are analogues of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, which produces parkinsonism in humans, may be synthesized from N-methyldopamine by the Pictet-Spengler condensation reaction as an alternative metabolic pathway.