Increased very long-chain fatty acids in erythrocyte membranes of patients with aceruloplasminemia

Aceruloplasminemia is a newly recognized autosomal recessive disorder of iron metabolism that causes neurodegeneration of the retina and basal ganglia as well as diabetes mellitus. Our previous studies suggested that increased susceptibility to plasma lipid peroxidation secondary to iron accumulation may contribute to the pathogenesis in this disease. We now have identified increases in the very long-chain fatty acids cis-17-hexacosenoic (C26:1) and hexacosanoic (C26:0) acid in the erythrocyte membranes of three family members affected with aceruloplasminemia. All of them had elevated C26:1/C22:0 and C26:0/C22:0 ratios. These findings suggest that free radicals generated in persons with aceruloplasminemia may interrupt the peroxisomal beta-oxidation of fatty acids.

Fluorometric determination of serum and urinary aluminium with 8-quinolinol by kinetic-differentiation-mode micellar chromatography

A new fluorometric method has been developed for the determination of aluminium with 8-quinolinol by kinetic-differentiation-mode micellar chromatography. The proposed method enabled the determination of aluminium down to 1 microgram/l in human serum and urine without preliminary deproteinization. The most remarkable point of this method is that only aluminium ion selectively responds among metal ions. The complex formation of aluminium in serum with 8-quinolinol was completed within a few minutes at room temperature. The serum matrix and aluminium chelate were separated on a reversed-phase column with an eluent containing acetonitrile, sodium dodecylsulfate, and Triton X-100, and aluminium chelate was detected at Ex 370 nm, Em 504 nm. The values obtained by this method were in good agreement with those of Zeeman graphite-furnace atomic absorption spectrometry. The proposed method will provide a simple and rapid technique for the determination aluminium in medical fields.

Immunosuppressive properties of MX-68, a novel unpolyglutamatable antifolate

MX-68 is a novel unpolyglutamatable antifolate. We here reported the in vitro and in vivo immunosuppressive properties of MX-68 compared with a polyglutamatable antifolate, methotrexate (MTX). MX-68 showed potent suppressive effects on mitogen-induced mouse splenic lymphocyte proliferation as well as immunoglobulin production from LPS-stimulated mouse splenic B cells. In in vivo studies, MX-68 significantly suppressed antigen-specific antibody production of both T cell-dependent antigen and T cell-independent antigen. Moreover, MX-68 inhibited a sheep red blood cell (SRBC)-induced delayed-type hypersensitivity (DTH) reaction by administration starting from the day of antigen immunization, but did not suppress the effector phase of the DTH reaction. MTX showed suppressive activities similar to MX-68 in all experiments. Interestingly, although MX-68 demonstrated somewhat stronger suppressive effects than MTX in vivo, the results from in vitro studies were reversed. These results suggest that polyglutamation is not always required to suppress immune responses and that MX-68 is a slightly stronger immunosuppressive drug than MTX in mice.

Mitochondrial trifunctional protein deficiency associated with recurrent myoglobinuria in adolescence

A 23-year-old man with recurrent myoglobinuria had low muscle-free carnitine levels and deficient fasting ketogenesis. Urinary organic acid analysis showed large amounts of C6-C14 3-hydroxydicarboxylic acids. Mitochondrial trifunctional protein (TP), harboring long-chain enoyl-coenzyme A (CoA) hydratase, long-chain 3-hydroxyacyl-CoA dehydrogenase, and long-chain 3-ketoacyl-CoA thiolase showed markedly decreased activity in fibroblasts. On immunoblot analysis, the TP content of his fibroblasts was less than 2% that of the control cells. TP deficiency can be a life-threatening disorder with early infantile onset, but it can also present in adolescence with recurrent myoglobinuria.

Regulation of epidermal induction by BMP2 and BMP7 signaling

The specification of neural fate in Xenopus embryos has been shown to be under regulation by negative factors. The secreted protein bone morphogenetic protein-4 (BMP4) has been identified as one of these factors: in the early gastrula ectoderm, BMP4 can both inhibit neural fate and induce epidermis. In this study, we show that two other Xenopus BMP genes, BMP2 and BMP7, are endowed with the same types of activities. First, we show that expression of a dominant negative form of the BMP2 ligand, which blocks normal processing of the wild-type ligand, causes neuralization of Xenopus ectoderm. Second, we have isolated the Xenopus BMP2/7 receptor (XALK2) and generated a constitutively active mutant that signals in a ligand-independent manner. We show that signals from the activated BMP2/7 receptor also inhibit neuralization and induce epidermis in dissociated ectoderm cells. Consistent with both findings we show that secreted BMP2 and BMP7 ligands can also mediate neural inhibition and epidermal induction. These results suggest that both BMP2 and BMP7 may be involved independently or together with BMP4 in the inhibition of the neural fate and the onset of the epidermal induction pathway in vivo. This further supports the idea that epidermal induction is due to the effects of multiple signals from heterogeneous BMP genes.

Telomere length and telomerase activity in carcinogenesis of the stomach

Telomerase activity is generally absent in primary cell cultures and normal tissues. Telomerase is known to be induced upon immortalization or malignant transformation of human cells. In the present study, we analyzed both telomere length and telomerase activity in biopsy samples from mucosa undergoing metaplasia, adenoma and cancer of the stomach. We attempted to estimate the correlation between telomerase activity and telomere length in these tissues. Telomerase activity was estimated using the telomeric repeat amplification protocol and telomere length by Southern blot analysis. Extracts were defined as telomerase-negative when the signals were less intense than those for 10(2) KATO-III cells (positive control). We detected telomerase activity in 15%, 45% and 89% of the examined cases of intestinal metaplasia, adenoma and gastric cancer respectively. However, telomere length in the gastric mucosa became reduced as the mucosa underwent metaplasia and developed into adenoma. Gastric cancers showed a broad range of telomere length among cases. However, gastric adenomas showed the shortest telomere length. These results suggest that telomerase is expressed during the early phase (intestinal metaplasia through adenoma) of gastric carcinogenesis, although the activity at that stage is not high enough to fully restore the reduced telomeric DNA.

Adenoma of the common human bile duct in Gardner's syndrome may cause relapsing acute pancreatitis

Familial adenomatous polyposis of the colon, or Gardner's syndrome, is often accompanied by adenomas of the stomach and duodenum. We experienced a rare case of Gardner's syndrome, with adenomas of the common bile duct, in a patient who presented with relapsing acute pancreatitis. Our findings indicate that adenoma in the common bile duct or pancreatic duct should be considered as a possible etiology when patients with familial polyposis or Gardner's syndrome present with pancreatitis, particularly relapsing acute pancreatitis.

Long-term effects of water-soluble corn bran hemicellulose on glucose tolerance in obese and non-obese patients: improved insulin sensitivity and glucose metabolism in obese subjects

We examined the effect of soluble corn bran hemicellulose (CBH, 10 g/day) on glucose control and serum insulin in three groups: patients with impaired glucose tolerance (IGT) with (20 subjects) or without (8 subjects) obesity and with healthy non-obese controls (10 subjects). Long-term supplementation (6 months) with CBH decreased the post oGTT curve for patients with impaired mild Type II diabetes, but not that for the controls. Hemoglobin A1c decreased significantly during CBH supplementation in the obese patients, while the fasting glucose level decreased in all three groups, although not significantly. A decreased serum insulin response by oGTT was found in those patients with IGT. The improved oGTT result was associated with improved insulin release and perhaps with peripheral insulin sensitivity. These findings suggest that CBH at a low dose might contribute to glycemic control and would play a useful role in treating Type II diabetes patients.

Study of transmission routes of Helicobacter pylori in relation to seroprevalence of hepatitis A virus

The seroprevalence of Helicobacter pylori in a group of 1,043 healthy Japanese people was compared with that of hepatitis A virus (HAV), which was used as a marker of fecal-oral exposure. No statistically significant relationship was observed between seropositivity for HAV and that for H. pylori. Therefore, the fecal-oral spread of H. pylori is of limited relevance in Japan.

Expression of muscarinic receptor subtypes in rat gastric smooth muscle: effect of M3 selective antagonist on gastric motility and emptying

Expression of muscarinic receptor subtypes in rat gastric smooth muscle was examined with reverse transcriptase-polymerase chain reaction (RT-PCR). Under the condition for detecting the messages of m1-m4 subtypes in brain, atrium, and gastric mucosa, only the fragments of m2 and m3 subtypes were amplified with RNA prepared from rat gastric smooth muscles. Furthermore, the amplified fragments were digested by restriction enzymes, reconfirming that the predicted size products of m2 and m3 contain the partial DNA sequences of m2 and m3 subtypes, respectively. We measured gastric motility in rats with a pressure transducer system under the continuous venous infusion of the muscarinic antagonists atropine and butylscopolamine (nonselective), AF-DX 116 (M2), zamifenacine (M3), and glucagon. Heart rate was monitored simultaneously in the tail. Gastric motility was inhibited in the presence of glucagon and zamifenacine without alteration of heart rate, whereas there was no inhibition in the presence of AF-DX 116 even after the augmentation of heart rate was observed. Gastric emptying was also suppressed in the presence of zamifenacine, which had an effect comparable with that of atropine, butylscopolamine, and glucagon. These results indicate that the activation of the M3 subtype in gastric smooth muscle causes its contraction, and the M3 selective antagonist could be a potentially useful drug without an adverse effect on the heart for radiological and endoscopic examination in the upper gastrointestinal tract.

Mesoderm induction by BMP-4 and -7 heterodimers

Bone morphogenetic proteins (BMPs) are peptide growth factors belonging to the TGF-beta superfamily. A large number of these ligands, including BMP-2, -4 and -7 is expressed during early embryogenesis in the vertebrate embryo. In this study, we demonstrate that BMP-7 has ventralizing activity both in ectodermal explants as well as in whole embryos. As it was the case for BMP-2 and BMP-4, BMP-7 is a very poor inducer when provided as a homodimer protein. Because of this weak mesoderm inducing activity, it has been suggested that mesoderm induction by BMPs might represent an artifact of overexpression. We provide evidence demonstrating that unlike the homodimers of BMP-4 or BMP-7, the purified recombinant heterodimer of Xenopus BMP-4 and BMP-7 (BMP-4/7) has a potent mesoderm inducing activity at physiological concentrations. These results provide the first evidence for an embryonic function of BMP-4/7 heterodimers in the vertebrate embryo.

Induction of hepatic heme oxygenase and changes in cytochrome P-450s in response to oxidative stress produced by stilbenes and stilbene oxides in rats

Both trans- and cis-stilbene oxide (TSO and CSO) markedly induced heme oxygenase-1 (HO-1) at the transcriptional level in rat liver. HO-1 induction by TSO and CSO was preceded by glutathione (GSH) depletion in the liver. Pretreatment of rats with buthionine sulfoximine (BSO), an inhibitor of GSH biosynthesis, enhanced GSH depletion evoked by either TSO or CSO and augmented the increase in HO-1 mRNA. In contrast, pretreatment with perfluorodecanoic acid (PFDA), which reduced hepatic GSH S-transferase activity, prevented TSO- and CSO-mediated GSH depletion and abolished HO-1 induction. In addition, TSO and CSO enhanced c-jun but not c-fos mRNA, which is in parallel with the HO-1 mRNA change. These findings indicate that the oxidative stress evoked by GSH depletion after the treatment of rats with stilbene oxides could stimulate both HO-1 and c-jun gene expression. Pretreatment with either BSO or PFDA also affected the induction of CYP2B1/2 mRNA and apoprotein by TSO or CSO, suggesting that not only the change of heme pool size but also some other unknown factor or factors may be involved in the regulation of the CYP2B1/2 and HO-1 gene expression. cis-Stilbene (CS), a parent compound of CSO, also induced HO-1 mRNA, together with hepatic GSH depletion, but trans-stilbene (TS) failed to elevate HO-1 mRNA under the experimental conditions. In addition, CS increased CYP2B1/2 mRNA, whereas TS did not. These results suggest that CS could be rapidly oxidized by cytochrome P-450 (P-450) to CSO, leading to GSH depletion in the liver. Such differences in the hepatic metabolic pathways of CS and TS are attributable to the differential effects on HO and P-450 induction by these compounds. Like other phenobarbital-type P-450 inducers, TSO and CSO also induced CYP2C6 and 3A2 apoproteins in rat liver. Stilbene oxide reduced CYP2E1 mRNA and apoproteins for CYP2E1 and 2C11. All of these findings indicate that stilbene compounds have unique effects on hepatic HO-1 and P-450 regulation in rats.

Percentage changes in serum pepsinogens are useful as indices of eradication of Helicobacter pylori

OBJECTIVE

Eradication of Helicobacter pylori has been gaining significance for the treatment of gastroduodenal diseases. Establishment of a precise diagnostic method for H. pylori is of great value. The aim of this study was to establish a new method for precisely judging the eradication of this bacteria.

METHODS

We measured serum pepsinogen I (PG I) and pepsinogen II (PG II) levels in 105 cases of peptic ulcer with H. pylori infection before and after anti-H. pylori treatment, determined percentage changes in serum PG I:PG II ratios before and 1 month after the treatment, and established cut-off values for them to distinguish success from failure of H. pylori eradication. Cut-off values for percentage changes in serum PG I:PG II ratios were tentatively set as +40%, +25%, and +10% when the serum PG I:PG II ratios before treatment were less than 3.0, not less than 3.0 but less than 5.0, and not less than 5.0, respectively.

RESULTS

With these cut-off values, the sensitivity, specificity, and validity for determination of eradication of H. pylori-on the basis of culture, histology, the rapid urease test, and a polymerase chain reaction method-were 100.0%, 93.1%, and 96.2%, respectively. These cut-off values could be applied to both gastric ulcer and duodenal ulcer.

CONCLUSION

Our findings suggest that percentage changes in serum PG I:PG II ratios are useful as indices for distinguishing success from failure in eradication therapy for H. pylori.

Quantitative study of Helicobacter pylori in gastric mucus by competitive PCR using synthetic DNA fragments

Helicobacter pylori is closely related to upper gastrointestinal diseases, and the precise evaluation of H. pylori infection is necessary for the treatment of these diseases. The aim of the present study was to establish a method for the quantitative detection of H. pylori. We applied a competitive PCR method using various amounts of synthetic DNA fragments containing the same primer-binding and a subset of the same template sequences as the target competing for primer binding and amplification in order to quantify H. pylori in gastric mucus. The results obtained by this method were compared with the results of histological examination, the rapid urease test, bacterial culture, the [13C]urea breath test, and urea and ammonia measurements in gastric juice. As the quantity of H. pylori in gastric mucus increased, the rates of positivity of histological examination, the rapid urease test, and bacterial culture increased. The quantity of H. pylori in gastric mucus was also significantly correlated with the results of the [13C]urea breath test and was negatively correlated with the urea/ammonia ratio in gastric juice. The competitive PCR method provides an objective measure of the quantity of H. pylori and makes it possible to distinguish true negatives from false negatives due to incomplete PCR and true positives from false positives due to contamination. This method is very useful for the precise evaluation of gastric H. pylori infection.

A very large villous adenoma with an adjacent cancer of the rectum: an informative case for testing the proposed molecular basis of colorectal tumorigenesis

It is currently accepted that colorectal tumorigenesis results from accumulation of multiple mutations in certain genes. This concept prompted us to search for possible mutations in the APC, k-ras, and p53 genes in an advanced cancer coexisting with a large villous adenoma of the rectum in a 54-year-old patient with no family history of colorectal cancer. Genomic DNA extracted from multiple subregions of the tumor and surrounding normal mucosa was studied by polymerase chain reaction (PCR) followed by single-strand conformation polymorphism (SSCP) analysis and direct sequencing. Both the adenoma and carcinoma had abnormal PCR-SSCP for APC (exon 11) and k-ras, irrespective of the location within the tumors. However, p53 abnormality (exon 7) was detected only in samples taken from the carcinoma. Subsequent sequencing revealed a TTG to TAG mutation at codon 479 of APC, a GGT to GAT mutation at codon 12 of k-ras in both the adenoma and carcinoma, and a CGG to TGG mutation at codon 248 of p53 (exon 7) in the carcinoma. These findings were in accord with the current concept of colorectal tumor progression whereby genetic alteration of APC and k-ras occurs relatively early while that of p53 is rather late and is possibly a decisive event in relation to malignancy.

Effects of aging on the regulation of intracellular pH in the rat jejunum

Jejunal villus cells from young-adult (6 months) and senescent (24 months) male Wistar rats were studied to evaluate the effect of aging on intracellular pH (pHi) regulation. pHi was measured by quantitative fluorescence microscopy by using BCECF-AM [2',7'-bis(carboxyethyl)-5(6)-carboxy-fluorescein acetoxy methylester] under basal conditions and after inducing cytoplasmic acidification with pulsed NH4Cl. In the senescent rats, the recovery rate from the acidified levels was significantly lower than that in the young-adult rats (.208 +/- .005 vs .255 +/- .004 pH units/min). The relationship between pHi recovery and external Na+ concentration followed Michaelis-Menten type kinetics, the maximum velocity (Vmax) of alkalinization being significantly lower in the senescent rats than in the young-adult rats (.227 +/- .033 vs .297 +/- .024 pH units/min). These results indicate that the recovery of pHi from an acidic level was slower in the senescent rats, due to the reduced activity of Na+/H+ exchange as revealed by the decreased Vmax value.

Late onset diabetes mellitus in patients with hereditary aceruloplasminemia

Aceruloplasminemia is a systemic degenerative disorder characterized by mutations in the ceruloplasmin gene, the absence of serum ceruloplasmin, and iron accumulation in the brain, liver, and other tissues. Iron is an important catalyst of oxyradical-mediated cellular and tissue injury, and beta-cells in the pancreatic islets are susceptible to the cytotoxic effects of oxidative stress. We report three patients with aceruloplasminemia who have late-onset diabetes mellitus (DM) and impaired glucose tolerance (IGT) as well as neurologic symptoms. Their basal lipid peroxide levels, measured as thiobarbituric acid-reactive products, in plasma samples were three times the values for the controls. This increased susceptibility to lipid peroxidation in patients with aceruloplasminemia suggests that free-radical-mediated tissue injury plays a role in the occurrence of DM and IGT.