A water channel closely related to rat brain aquaporin 4 is expressed in acid- and pepsinogen-secretory cells of human stomach

We isolated a cDNA clone encoding a water channel protein, aquaporin ( AQP), from human stomach. The encoded protein consisted of 323 amino acid residues, containing six putative transmembrane domains. The protein was designated human aquaporin 4 (hAQP4) because of its 94% sequence similarity to rat brain AQP4. Expression of hAQP4 cRNA in Xenopus oocytes resulted in a significant increase in osmotic water permeability, indicating that this protein functions as a water channel. Northern blot analysis demonstrated a strong signal of hAQP4 mRNA in brain, lung, and skeletal muscle as well as in stomach. Immunohistochemical experiments with human stomach tissues showed that hAQP4 as a protein is expressed mainly in cells located in the glandular portion of the fundic mucosa. These include chief cells which secrete pepsinogen and parietal cells which secrete hydrochloric acid. These results strongly indicate that hAQP4 is a principal factor involved in the osmotic regulation of pepsinogen and acid secretion in the stomach.

Immunohistochemically demonstrated variation in expression of cathepsin E between uracil-induced papillomatosis and N-butyl-N-(4-hydroxybutyl)nitrosamine-induced preneoplastic and neoplastic changes in rat urinary bladder

Expression of rat urinary bladder cathepsin E in benign papillomatosis induced by uracil and various stages of N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced carcinogenesis was investigated immunohistochemically. Seven-week-old, male F344/DuCrj rats were used. In the normal urothelium of control rats, cathepsin E stained in all layers of cells, although in umbrella cells and some basal cells the reaction was relatively weak. In rats given a diet containing 3% uracil for 5 weeks immunoreactivity of cathepsin E in uracil-induced papillomatosis was consistently homogeneous in all layers, but weaker than in normal urothelium. In rats given 0.05% BBN in drinking water for 12 weeks and subsequently maintained without treatment for 48 weeks cells with little cathepsin E, never observed in normal urothelium, appeared at 5 weeks above the basement membrane in the earliest stage of BBN-induced urinary bladder cancer (simple hyperplasia). Throughout the neoplastic process, groups of cells with a little cathepsin E were randomly distributed, with expression in the urothelium being markedly unstable. Almost all areas of squamous cell proliferation in TCC were negative for cathepsin E. Instability of cathepsin E expression in rat urothelium therefore appears characteristic for carcinogenesis and offers the possibility of using this feature as an early biomarker for urinary bladder carcinogenesis.

Crystallization and preliminary X-ray diffraction study of aldehyde reductase from a red yeast, Sporobolomyces salmonicolor

Crystals of aldehyde reductase from a red yeast, Sporobolomyces salmonicolor, have been grown from an ammonium sulfate solution, pH 7.0, by means of the vapor-diffusion procedure. The crystals belong to the hexagonal system, space group P6(1)22 or its enantiomorph, P6(5)22, with unit-cell dimensions of a = 72.2 and c = 320 A. The X-ray diffraction patterns extend to at least 2 A resolution with the use of synchrotron radiation. The crystals are stable on exposure to X-rays and suitable for high-resolution X-ray structure determination.

Complementary DNA cloning and sequencing of rat enteropeptidase and tissue distribution of its mRNA

A cDNA clone encoding enteropeptidase (EC 3.4.21.9), a key enzyme for the conversion of trypsinogen to trypsin, was isolated from a rat duodenal mucosa cDNA library. Sequences of the 3585 base pair clone predicted that enteropeptidase is synthesized as a single-chain precursor form, proenteropeptidase, consisting of 1058 amino acid residues with an internal signal sequence (51 residues) and is then processed into the mature enzyme consisting of three different peptide chains, i.e., mini, light and heavy chains, not the previously reported two-chain enzyme. The structure of enteropeptidase is relatively conserved among different species and the rat enteropeptidase is 24 and 39 amino acids longer than the porcine and human ones, respectively. Northern blot analysis of rNAs from normal rat tissues revealed that the enteropeptidase mRNA of around 4.4 kb in size was expressed only in the duodenal mucosa, and high proteolytic activity of the enzyme was detected in the proximal small intestine. Additional analysis of the RNAs by RT-PCR revealed that a low level of the mRNA was also expressed in the other parts of the small intestine, i.e., jejunum and ileum. These results indicate that the biosynthesis of enteropeptidase takes place mainly in the proximal small intestine, the duodenum, and the importance of the region in the physiology of intestinal protein digestion regulated by the enzyme is suggested. Furthermore a faint signal of the mRNA was also detected in the stomach, colon and brain in which the existence of trypsin-like serine proteases were reported. The significance of the low level expression of the gene is unclear, but the potential peptide-processing function of the enzyme in these tissues is also suggested.

Increased risk of Helicobacter pylori associated with birth in wartime and post-war Japan

BACKGROUND

Helicobacter pylori infection is now widely recognized as a cause of stomach cancer. We assessed trends in H. pylori infection in Japan, a population with high rates of gastric malignancy.

METHODS

Using an enzyme-linked immunosorbent assay (ELISA), we tested sera collected between 1980 and 1993 from Tokyo University Hospital patients for anti-H. pylori IgG. Patients ranged in age from 0 to 94 years. Helicobacter pylori prevalence was then assessed for age and/or birth cohort effects.

RESULTS

Of 1207 sera, 470 (38.9%) were positive for H. pylori IgG. By univariate analysis, both older age and birth in an earlier decade were associated with an increased risk of infection. Age-specific prevalence of H. pylori by birth cohort suggested increases in infection during the decades from 1900 to 1959, and age-specific decreases since 1960. In multivariate analysis, H. pylori infection increased with age and was most prevalent among those born in the 1940s and 1950s.

CONCLUSION

Relative to other birth cohorts, people born in the 1940s and 1950s have a higher prevalence of H. pylori. This increased prevalence of infection among those born in wartime Japan likely attests to the impact of compromised living conditions on acquisition of H. pylori, and may portend continued high rates of gastric cancer in forthcoming years.

Re-speciation of the original reference strains of serovars in the Citrobacter freundii (Bethesda-Ballerup group) antigenic scheme of West and edwards

The antigenic scheme for the Bethesda-Ballerup group of bacteria established by West and Edwards in 1954 has continued to be applied as a serotyping scheme for Citrobacter freundii. In 1993, however, the classification of the Citrobacter was drastically revised and the species C. freundii redefined by Brenner et al. Accordingly, to judge the propriety to continuously use a single antigenic scheme for the C. freundii complex, the 90 reference strains listed in the antigenic scheme for C. freundii by West and Edwards were characterized phenotypically and specified based on the revised classification. Of these 90 strains, two strains of Hafnia alvei and one of Escherichia coli were found. Among the remaining 87 reference strains, Citrobacter youngae was the predominant species (40 strains), followed by Citrobacter braakii (25 strains), Citrobacter werkmanii (13 strains), and the unnamed Citrobacter genospecies 10 of Brenner et al (six strains). Citrobacter freundii, as redefined, accounted for only three strains and ranked behind the other four species. No overlapping with most of the 42 O-groups and 82 H-antigens was recognized between species with few exceptions. O-groups 1-9 inclusive, which were estimated to represent more than 90% of the former C.freundii strains, occurred in strains of C. youngae and C. braakii; and all nine strains of O-group 29, formerly known as the Ballerup group, were identified as C. braakii. These findings suggest that further study of the serotyping system is needed for all H2S-producing Citrobacter species.

Adaptation of circadian corticosterone and catecholamine rhythms to light-dark cycle reversal in the rat

Circadian rhythms of urinary excretion of corticosterone and catecholamines were examined in the rat before and after phase reversal of a 12-hour light and 12-hour dark cycle. After the reversal, the acrophase of rhythm was delayed and became constant again on the 6th day for corticosterone and on the 7th or 8th day for adrenaline. The ratios of light-period output to 24-hour output of adrenaline and noradrenaline, however, adjusted to the new light-dark cycle on 10th day, whereas this ratio became constant on 6th day for corticosterone. Thus, circadian corticosterone rhythm seems to adapt to light-dark reversal more quickly than catecholamine rhythm.

Rapid and simultaneous quantification of rhamnose, mannitol, and lactulose in urine by HPLC for estimating intestinal permeability in pediatric practice

Determination of intestinal permeability by measuring nonmetabolized sugars has been used to assess the integrity of intestinal mucosa. We have developed and validated a modified HPLC method for determining the concentration of L-rhamnose, mannitol, and lactulose in urine, using an amine-modified silica column and refractive index detection. Probe sugars are simultaneously resolved within 18 min. The calibration curve for each sugar is linear to 20 mmol/L. The minimum detectable concentration of lactulose is 0.05 mmol/L. Recovery of probe sugars is between 99.3% and 105.1%. Overall precision (CV) of estimation of probe sugars ranges from 4.2% to 6.5%. In 14 urine samples from healthy children who ingested the test solution containing 1 g of L-rhamnose, 1 g of mannitol, and 5 g of lactulose, the 5-h urinary excretion ratios of lactulose/rhamnose and lactulose/mannitol were 0.047 +/- 0.018 and 0.021 +/- 0.010 (mean +/- SD), respectively. This method presents a rapid, convenient, and practical technique for determining intestinal permeability in clinical pediatric practice.

Measurements of oxidoreductase-like activity of intact bacterial cells by an amperometric method using a membrane-coated electrode

The oxidation of D-glucose and nicotinic acid by intact cells of Gluconobacter industrious and Pseudomonas fluorescens, respectively, is successfully measured by an amperometric method using such compounds as Fe(CN)6(3-), p-benzoquinone, and dichlorophenolindophenol as electron acceptors. Analysis of the experimental results reveals that the intact cells behave like oxidoreductases whose kinetics follows a Michaelis-Mententype equation. The catalytic behavior is explained by a model which treats the bacterial cells as bags of enzymes and assumes distribution equilibrium in the concentrations of both the substrate and the electron acceptor between the test solution and the medium within the cells. The catalytic activity can be characterized by three quantities: the maximum reaction rate (vB) and the ratios of the Michaelis constant to the distribution constant for the substrate (Ks,cell/Ks,p) and to that for the electron acceptor (KM,cell/KM,p). Advanced modification of the model to involve the membrane permeability reveals that the three quantities are effective for explaining the catalytic behavior even when the permeability effect is significant. Thus, the three quantities should be regarded as the parameters which can reflect the permeability effect.

Rapid and simultaneous quantification of rhamnose, mannitol, and lactulose in urine by HPLC for estimating intestinal permeability in pediatric practice

Determination of intestinal permeability by measuring nonmetabolized sugars has been used to assess the integrity of intestinal mucosa. We have developed and validated a modified HPLC method for determining the concentration of L-rhamnose, mannitol, and lactulose in urine, using an amine-modified silica column and refractive index detection. Probe sugars are simultaneously resolved within 18 min. The calibration curve for each sugar is linear to 20 mmol/L. The minimum detectable concentration of lactulose is 0.05 mmol/L. Recovery of probe sugars is between 99.3% and 105.1%. Overall precision (CV) of estimation of probe sugars ranges from 4.2% to 6.5%. In 14 urine samples from healthy children who ingested the test solution containing 1 g of L-rhamnose, 1 g of mannitol, and 5 g of lactulose, the 5-h urinary excretion ratios of lactulose/rhamnose and lactulose/mannitol were 0.047 +/- 0.018 and 0.021 +/- 0.010 (mean +/- SD), respectively. This method presents a rapid, convenient, and practical technique for determining intestinal permeability in clinical pediatric practice.

Antisense oligonucleotide to NOR-1, a novel orphan nuclear receptor, induces migration and neurite extension of cultured forebrain cells

We previously identified a novel orphan nuclear receptor referred to as NOR-1 from rat forebrain cells. This study examined the role of NOR-1 in primary cultured forebrain cells by selectively inhibiting NOR-1 expression by addition of antisense oligonucleotide to the culture media. Treating cells with the antisense oligomer resulted in the following dramatic morphological changes: (i) cell migration, (ii) extension of processes, and (iii) formation of cellular aggregates. Immunocytochemistry for microtubule-associated protein 2 revealed that the processes were filled with neurites growing from neuronal cells. These findings suggest that NOR-1 may be involved in the molecular mechanisms regulating neural differentiation.

Structure of flavoprotein FP390 from a luminescent bacterium Photobacterium phosphoreum refined at 2.7 Å resolution

The three-dimensional structure of a flavoprotein, FP(390), from a luminescent bacterium, Photobacterium phosphoreum, solved by the molecular-replacement method, was refined to an R factor of 24.0% for 17 433 independent reflections, from 6.0 to 2.7 A resolution, collected by synchrotron radiation. The asymmetric unit of the crystal (space group P4(3)22, a = b = 76.8 and c = 242 A) contains two monomer molecules related by a non-crystallographic twofold axis to form a dimer. There are two Q-flavin [flavin mononucleotide (FMN) with myristic acid] molecules in FP(390) monomer. One of them is located at the interface of dimer which is bound to both monomer and the another is at the molecular surface. The electron density of myristic acids of Q-flavins at the dimer interface in both monomer are weak and unclear, showing the possibility that the Q-flavins bound in this site are not a single species but a mixture of two components, 6-(3"-myristic acid)-FMN and 6-(4"- myristic acid)-FMN.

Esophageal body and lower esophageal sphincter function in healthy premature infants

BACKGROUND & AIMS

Gastroesophageal reflux is a common problem in premature infants. The aim of this study was to use a novel manometric technique to measure esophageal body and lower esophageal sphincter pressures in premature infants.

METHODS

Micromanometric feeding assemblies (OD, < or = 2 mm) incorporating 4-9 manometric channels were used in 49 studies of 27 premature neonates. Esophageal body motility was recorded at three sites for 20 minutes after feeding. Twenty attempts (one per minute) were made to stimulate swallowing via facial stimulation (Santmyer reflex). In 32 studies lower esophageal sphincter pressures were recorded (sleeve) for 15 minutes before and after feeding.

RESULTS

Peristaltic motor patterns were less common than non-peristaltic motor patterns (26.6% vs. 73.4%; P < 0.0001) that comprised 31.1% synchronous, 34.6% incomplete, and 6.3% retrograde pressure waves. Reflex swallowing was elicited more frequently in neonates older than 34 weeks postconceptional age than in younger infants (33.4% vs. 20.4%; P < 0.05). Mean lower esophageal sphincter pressure was 20.5 +/- 1.7 mm Hg before and 13.7 +/- 1.3 mm Hg after feeding (P < 0.0005).

CONCLUSIONS

Premature infants show nonperistaltic esophageal motility that may contribute to poor clearance of refluxed material. In contrast, the lower esophageal sphincter mechanisms seem well developed.

Purification and characterization of intracellular proteinases in Pleurotus ostreatus fruiting bodies

A serine proteinase (ProA, EC 3.4.22.9) and two metalloendopeptidases (ProB, EC 3.4.99.32 and ProC, 3.4.24.4), have been purified to homogeneity from the fruiting bodies of Pleurotus ostreatus. ProA is a serine proteinase with a mass of 30 kDa, which has amidolytic and esterolytic activities besides proteolysis and catalyzes preferential cleavage of the peptide bonds involving the carboxyl groups of hydrophobic amino acid residues in oxidized bovine insulin B chain. The N-terminal amino acid sequence was VTQTNAPWGLSRL. ProB is a zinc-enzyme with a mass of 18 kDa, which is devoid of lysine, and its N-terminal sequence was ATFVGCSATRQ. The enzyme is inactivated completely by EDTA and 1,10-phenanthroline, and Zn(2+)-depleted ProB can regain the activity with Zn2+, Co2+, or Mn2+. Specific cleavage of Pro29-Lys30 in oxidized bovine insulin B chain, preferential generation of lysylpeptides from proteins, and a high susceptibility of polylysine suggest that ProB splits specifically the peptide bonds involving the alpha-amino group of lysyl residues. ProC is a metalloendopeptidase of a mass of 42.5 kDa, and Zn2+ was the most effective divalent metal ion to activate the EDTA-inactivated enzyme.

Inhibitory effect of a single local probucol administration on neointimal formation in balloon-injured rat carotid artery

The aim of this study was to determine whether a single local probucol administration could suppress neointimal formation in balloon-injured rat carotid artery. Rats were divided into four groups; (i) rats receiving no probucol (control group); (ii) rats receiving topical application of 50 mg probucol at the time of ballooning (p-top group); (iii) rats fed chow containing 1% probucol (p-fed group; (iv) rats receiving both topical application of 50 mg probucol and chow containing 1% probucol (p-top/fed group). Although serum total cholesterol levels did not significantly differ between the control and the p-top groups at two weeks after balloon injury, the p-top group had a smaller intimal/medial ratio or intimal area than the control group (0.97 +/- 0.11 vs. 0.53 +/- 0.08 or 0.15 +/- 0.02 mm2 vs. 0.08 +/- 0.02 mm2 respectively, P < 0.01). Neointimal formation was suppressed to a similar extent in the p-fed group, in which serum total cholesterol level was approximately 40% lower than that in the control group. Thus, a single local delivery of probucol can suppress neointimal formation in balloon-injured rat carotid artery without altering serum lipid level.

Preliminary X-ray diffraction study of a new crystal form of C-1027-AG, the apoprotein of the macromolecular antitumor antibiotic C-1027 fromStreptomyces globisporus

A new crystal form of C-1027-AG, the apoprotein of the macromolecular antitumor antibiotic C-1027 isolated from Streptomyces globisporus was obtained by the vapor-diffusion procedure using lithium sulfate as a precipitant. In the present crystallization, it is noteworthy that large-sized single crystals successfully grew from very small droplets (less than 1.01 micro l). The present crystals belong to the trigonal system, space group P3(1)21 or P3(2)21 with cell dimensions of a = b = 62.6 and c = 54.2 A. Assuming that the asymmetric unit contains one molecule, the V(m) value is calculated as 2.9 A(3) Da(-1). A total of 3654 independent reflections from two native crystals was obtained up to 2.5 A resolution with synchrotron radiation, the merging R factor being 0.097.

Substance P induced by peripheral nerve injury in primary afferent sensory neurons and its effect on dorsal column nucleus neurons

Using in situ hybridization and the retrograde tracer, Fluorogold, we examined the expression of preprotachykinin (PPT) mRNA in the rat dorsal root ganglion neurons projecting to the gracile nucleus. Seven days after unilateral sciatic nerve transection, some medium- to large-sized neurons in the rat dorsal root ganglia projecting to the gracile nucleus express PPT mRNA, whereas very few gracile nucleus-projecting neurons on the contralateral side express PPT mRNA. Immunohistochemistry revealed an increase in substance P (SP) immunoreactivity in the gracile nucleus and large myelinated fibers in the dorsal root 2 weeks after unilateral sciatic nerve transection. The results suggest that medium to large DRG cells that project to the gracile nucleus express PPT mRNA de novo in response to peripheral nerve injury, and increased SP is transported to the gracile nucleus through large myelinated fibers. To determine whether the increased SP might affect the excitability of the gracile nucleus neurons postsynaptically, Fos expression after electrical stimulation of the injured sciatic nerve was examined. Multiple injections of the NK-1 receptor antagonist, CP-96,345, suppressed stimulus-induced Fos expression in gracile nucleus neurons including thalamic relay neurons. The inactive enantiomer, CP-96,344, had no effect on stimulus-induced Fos expression. These data indicate that the de novo synthesized SP in the lesioned primary afferent neurons may be involved in an augmentation of excitability in the dorsal column-medial lemniscus sensory pathway. This hyperexcitability may play a role in the pathogenesis of abnormal neuropathic sensations following peripheral nerve injury.

Refined crystal structure of ferrocytochrome c2 from Rhodopseudomonas viridis at 1.6 A resolution

The three-dimensional structure of ferrocytochrome c2 from the purple photosynthetic bacterium Rhodopseudomonas viridis has been refined to a final R-factor of 18.2% for 15,014 unique reflections collected by synchrotron radiation between 6.0 and 1.6 A resolution. The refined model includes 107 amino acid residues, one heme prosthetic group and 125 water molecules. The root-mean-square deviations from the ideal bond lengths and angles were 0.014 A and 3.0 degrees, respectively. The atomic coordinate error was estimated to be less than 0.3 A. A structure comparison of this cytochrome c2 with those of the other c-type cytochromes demonstrated that these cytochromes exhibit a high degree of structural similarity with the exception of the surface loop and the terminal region of the polypeptide chain. The deletion of an intrahelical amino residue distorted the conformation of the alpha-helix and it divided into two pieces. The C-terminal extension of the polypeptide chain caused significant conformational changes of the contact residues compared with the other c-type cytochromes. Of the water molecules conserved in various c-type cytochromes, two are located internally in the vicinity of the heme group. One of these water molecules found in this cytochrome c2 is evolutionarily conserved among eukaryotic cytochromes c. This water molecule is located in the heme proximate environment in a position similar to that of eukaryotic cytochromes c. The position of this water molecule is associated with the oxidation state of the heme iron in electron transfer.

Determinants of plasma pepsinogen levels in a population at high risk for stomach cancer in Venezuela

Determinants of plasma pepsinogens (PG) levels were studied in 1365 participants in a chemoprevention trial for gastric pre-cancerous lesions being conducted in Venezuela. Gastric biopsies, plasma samples and information on smoking and dietary habits were obtained at baseline examination. Both PG-I and PG-II levels increased progressively with the level of Helicobacter pylori infection in gastric biopsies, resulting in no clear trend in the I/II ratio. Instead, there was a progressive decrease in the I/II ratio with increasing degrees of infiltration of polynuclear cells and monocytes, atrophy, intestinal metaplasia and the stage of pre-cancerous lesions. The mean I/II ratios for atrophic gastritis or more advanced lesions were less than 4.0. When subjects with the I/II ratio 4 or higher were used as controls, severe reduction in the I/II ratio (< 2.0) was inversely associated with tobacco consumption. This may be due to a pharmacological effect of nicotine. The severe reduction of I/II ratio was also inversely associated with fresh fruit consumption. In addition, a decreased I/II ratio was positively associated with rice/pasta and arepas (tortilla made from corn) consumption and inversely associated with plantain consumption. Possible effects of vitamins and starchy food on the development of atrophic gastritis need to be studied further.

Crystallization and preliminary X-ray crystallographic analysis of chitosanase fromBacillus circulansMH-K1

Chitosanase, an enzyme which hydrolyzes chitosan, isolated from Bacillus circulans MH-K1, was crystallized by a vapor-diffusion procedure at 293 K using ammonium sulfate as a precipitant. Rod-shaped colorless crystals, which grew to 0.05 x 0.15 x 1.2 mm within a week, belong to the orthorhombic system and the space group P222(1) or P2(1)2(1)2 with unit-cell dimensions of a = 43.3, b = 57.7, and c = 128.0 A. The asymmetric unit is thought to contain one chitosanase molecule (29 024 Da). The crystals diffract X-rays to at least 2.3 A resolution and are suitable for high-resolution X-ray structure analysis.

Structure of a glutathionylated human lysozyme: a folding intermediate mimic in the formation of a disulfide bond

The three-dimensional structure of a mutant human lysozyme, C77A-a, in which the residue Cys77 is replaced by alanine, has been refined to an R value of 0.125 using 8230 reflections in the resolution range 10.0-1.8 A. It has been shown that C77A-a, in which the counterpart of Cys77 (Cys95) is modified with glutathione, has been shown to mimic an intermediate in the formation of the disulfide bond Cys77-Cys95 during the folding of human lysozyme [Hayano, Inaka, Otsu, Taniyama, Miki, Matsushima & Kikuchi (1993). FEBS Lett. 328, 203-208]. An earlier structure demonstrates that its overall structure is essentially identical to that of the wild-type protein and served as the starting model. The refined model includes atoms for all protein residues (1-130), 20 glutathione atoms and 113 water atoms. Further refinement shows more clearly the details of the protein, the bound glutathione molecule and solvent structure. However, the main-chain folding and the atomic thermal factors of the loop region from Thr70 to Leu79 were highly affected by the binding of the glutathione molecule, as compared with those of the wild-type protein. The bound glutathione shifted the main-chain atoms from Va174 to Ala77 by more than 6.0 A, and the temperature factors of the atoms in the loop region were quite high (more than 40 A(2)), indicating that the backbone conformation of this region is highly flexible and that the loop region is not folded in the specific conformation observed in the wild-type protein. These results strongly suggest that the loop structure in human lysozyme is folded later than the other regions of the protein in vivo, as observed in in vitro folding. Since the bound glutathione is efficiently and irreversibly dissociated by protein disulfide isomerase, the glutathione molecule may act as a protecting group to prevent the formation of an incorrect disulfide bond in the protein folding process in vivo.

Relationship between Helicobacter pylori infection, atrophic gastritis and gastric carcinoma in a Japanese population

AIM

To evaluate the possible relationship between Helicobacter pylori infection and gastric carcinoma, and its precursor lesion, intestinal metaplasia, in a Japanese population.

SUBJECTS AND METHODS

H. pylori infection was identified by the presence of anti-H. pylori immunoglobulin (Ig)G. The frequency of H. pylori infection was compared in 109 patients with gastric carcinoma, the same number of patients with atrophic gastritis and asymptomatic controls matched for age, sex and place of birth. To study the relation between H. pylori and intestinal metaplasia, sera and gastric antral and corpus mucosal biopsies were obtained from 58 asymptomatic controls, 92 patients with chronic gastritis and 80 patients with peptic ulcer.

RESULTS

The presence of IgG antibody to H. pylori was significantly more frequent in those with gastric carcinoma than in asymptomatic controls (87.2 versus 74.3%; odds ratio 2.4; 95% confidence interval 1.2-4.8). The positive rates of H. pylori IgG antibody were 80.7% in patients with atrophic gastritis. Mean serum gastrin and pepsinogen II levels in H. pylori-positive patients were higher than those in H. pylori-negative patients. Serum gastrin and pepsinogen I levels were significantly higher in controls than gastric carcinoma patients (P < 0.01 and P < 0.05, respectively). Serum pepsinogen I:II ratios were significantly lower in controls than in gastric carcinoma patients (P < 0.01). Intestinal metaplasia was strongly associated with H. pylori infection, and was only found in patients with IgG antibodies to H. pylori.

CONCLUSIONS

These results suggest that H. pylori infection is associated with the development of gastric cancer by providing a suitable environment for carcinogenesis of the gastric mucosa, such as gastric atrophy and intestinal metaplasia.

Utility of duplex Doppler ultrasound in evaluating portal hypertension in children

We measured the maximal velocity of the blood flow in the main portal trunk by duplex Doppler ultrasound in children suffering from a variety of liver diseases. The maximal velocity of the main portal vein in children with chronic active hepatitis and liver cirrhosis was decreased significantly as compared to those in control children (p < 0.01). The maximal velocity of the main portal trunk and K indocyanine green (ICG) had no significant correlation (r = 0.25, n = 27). The patient with the lowest portal velocity had esophageal and gastric varices with red color sign. We conclude that the measurement of the maximal velocity of the main portal trunk with duplex Doppler ultrasound is useful in evaluating portal hypertension in children.