A nationwide, cross-sectional survey on unusual sleep postures and sleep-disordered breathing-related symptoms in people with Down syndrome

BACKGROUND

People with Down syndrome (DS) often have sleep-disordered breathing (SDB). Unusual sleep postures, such as leaning forward and sitting, are observed in people with DS. This study aimed to clarify the prevalence of unusual sleep postures and their relationships with SDB-related symptoms (SDB-RSs), such as snoring, witnessed apnoea, nocturnal awakening and excessive daytime sleepiness.

METHODS

A questionnaire, including demographic characteristics and the presence of unusual sleep postures, as well as SDB-RSs, was completed by 1149 parents of people with DS from Japan.

RESULTS

Unusual sleep postures were recorded in 483 (42.0%) people with DS. These participants were significantly younger and had a history of low muscle tone more frequently than people without unusual sleep postures. In all ages, the leaning forward posture was more frequent than sitting. People with DS with unusual sleep postures suffered from SDB-RSs. Those who slept in the sitting posture had more frequent SDB-RSs than did those who slept with the leaning forward posture. Snoring, witnessed apnoea and nocturnal awakening were observed in 73.6, 27.2 and 58.2% of participants, respectively. Snoring increased with aging. Witnessed apnoea was more common in males and in those with hypothyroidism than in females and in those without hypothyroidism.

CONCLUSIONS

Our study shows that there is a close relationship between unusual sleep postures and SDB-RSs. We recommend that all people with DS with unusual sleep postures should be checked for the presence of SDB.

Myocardial torsional deformations in cats with hypertrophic cardiomyopathy using two-dimensional speckle-tracking echocardiography

OBJECTIVES

The objective of our study was to quantitatively measure systolic torsional deformations in cats with hypertrophic cardiomyopathy (HCM) and in controls.

ANIMALS

Twenty-six client-owned cats with HCM and 14 healthy cats. HCM cats were categorized based on their symptoms (asymptomatic and symptomatic) and with or without left ventricular outflow tract obstruction (obstructive and non-obstructive).

METHODS

The cats were examined for myocardial deformations using two-dimensional speckle-tracking echocardiography and were evaluated for peak systolic rotation and the rotation rate at each basal and apical view. Cats were also evaluated for the peak systolic torsion and torsion rate.

RESULTS

The peak systolic apical rotation and torsion were higher in asymptomatic and symptomatic cats with HCM than in control cats. Also, the peak systolic apical rotation, apical rotation rate, torsion, and torsion rate were higher in cats with obstructive HCM than in control cats.

CONCLUSIONS

Myocardial torsional deformations assessed by two-dimensional speckle-tracking echocardiography may be useful for evaluating compensatory myocardial function of HCM.

Living cells of probiotic Bifidobacterium bifidum YIT 10347 detected on gastric mucosa in humans

The probiotic strain Bifidobacterium bifidum YIT 10347 has been demonstrated to inhibit Helicobacter pylori activity, prevent injury to the gastric mucosa, and improve general gastric malaise symptoms in H. pylori positive patients. This study aimed to investigate the adhering activity and localisation of B. bifidum YIT 10347 to gastric cells and tissue in vitro, and in human in vivo to clarify the mechanism of its beneficial effects on the stomach. The in vitro study found the adhesion rate of B. bifidum YIT 10347 to human gastric epithelial cells was about 10 times higher than that of lactic acid bacteria and other bifidobacteria. In the human study, 5 H. pylori negative and 12 H. pylori positive subjects ingested milk fermented with B. bifidum YIT 10347. B. bifidum YIT 10347 cells were measured by RT-qPCR for in gastric biopsy samples. Living B. bifidum YIT 10347 cells were detected in the biopsy samples in H. pylori negative subjects (105 cells/g and 104 cells/g at 1 h and 2 h after ingestion, respectively) and H. pylori positive subjects (104 cells/g at 1 h after the ingestion). Moreover, immunostaining analysis of tissue sections found that B. bifidum YIT 10347 cells were located at the interstitial mucin layer of the stomach. These results suggest that cells of probiotic B. bifidum YIT 10347 adhered to the human gastric mucosa in a live state, and that the higher adhering activity of B. bifidum YIT 10347 to the gastric mucosa may be involved in its beneficial effects on the human stomach.

Adjunct antibiotic combination therapy for steroid-refractory or -dependent ulcerative colitis: an open-label multicentre study

BACKGROUND

We previously demonstrated that antibiotic combination therapy is effective for induction and maintenance of ulcerative colitis (UC) remission.

AIM

To assess whether antibiotic combination therapy is effective for active UC refractory to or dependent on steroids in a multicentre, open-label trial.

METHODS

We enrolled 30 patients with steroid-refractory and 64 with steroid-dependent active UC. These patients received three-times-daily by mouth amoxicillin 500 mg, tetracycline 500 mg and metronidazole 250 mg, for two weeks, as well as conventional treatment. Symptom assessment and colonoscopic evaluation were performed before enrolment and at 3 and 12 months after treatment completion. Clinical response was defined as a Lichtiger symptom score decrease in ≥3 points and clinical remission as a score ≤4.

RESULTS

Nineteen of the 30 steroid-refractory (63.3%) and 47 of the 64 steroid-dependent (73.4%) patients showed a clinical response within 2 weeks. At 3 and 12 months, 60% and 66.6% of steroid-refractory patients, and 56.3% and 51.6% of steroid-dependent patients, respectively, achieved clinical remission. In the steroid-dependent group, 39 of the 64 patients (60.9%) were able to stop steroid therapy and remained in remission for 3 months. Three (10%) steroid-refractory and four (6.3%) steroid-dependent patients underwent colectomy.

CONCLUSIONS

This multicentre, long-term follow-up study suggests 2 week antibiotic combination therapy to be effective and safe in patients with active UC refractory to or dependent on steroids.

Effect of CYP2C19 polymorphism on the safety and efficacy of omeprazole in Japanese patients with recurrent reflux oesophagitis

BACKGROUND

The polymorphic enzyme cytochrome P450 2C19 affects omeprazole metabolism. This influence on metabolism might affect serum gastrin levels, and safety, during long-term treatment of reflux oesophagitis.

AIM

To examine the relationship between cytochrome P450 2C19 genotype and the safety profile of long-term omeprazole treatment.

METHODS

A total of 119 Japanese patients with recurrent reflux oesophagitis underwent cytochrome P450 2C19 genotyping prior to receiving daily omeprazole 10 mg or 20 mg for 6-12 months, during which adverse event frequency, serum gastrin levels and endoscopic findings were monitored.

RESULTS

The incidences of adverse events, serious adverse events and adverse events leading to withdrawal did not differ between homozygous extensive metabolizer (n = 46), heterozygous extensive metabolizer (n = 53) or poor metabolizer (n = 20) groups. In all genotype groups, serum gastrin increased during the first 3 months of dosing but stabilized thereafter. No significant differences were seen either in the rate of reflux oesophagitis healing or symptom improvement among genotype groups.

CONCLUSIONS

Long-term treatment with omeprazole was well-tolerated in Japanese patients, irrespective of their cytochrome P450 2C19 metabolic genotype, indicating that dose adjustment depending on metabolic genotype is not required during treatment with omeprazole.

Mucosa-associated bacteria in ulcerative colitis before and after antibiotic combination therapy

BACKGROUND

We proposed that Fusobacterium varium is one of the causative agents in ulcerative colitis.

AIM

To examine the efficacy of antibiotic combination therapy against F. varium and to investigate the mucosa-associated bacteria before and after the therapy using a new molecular approach.

METHODS

Twenty patients with ulcerative colitis were randomly assigned into the antibiotic treatment group (amoxicillin, tetracycline and metronidazole for 2 weeks) and no-antibiotics group. Clinical assessment, colonoscopic and histological evaluations were performed at 0 and 3-5 months after the treatment. DNA from mucosal bacteria was isolated from biopsy specimens. We investigated the mucosa-associated bacterial components by terminal restriction fragment length polymorphism with the restriction enzyme HhaI and MspI, and quantified the change in the number of bacteria by real-time polymerase chain reaction. Immunohistochemical detection of F. varium in biopsy specimens was also performed.

RESULTS

After the treatment, the clinical assessment, colonoscopic and histological scores improved in the antibiotic group compared with the control group. Three peaks of terminal restriction fragment length polymorphism decreased after treatment only in the antibiotic group. Eubacterium rectale, Dorea formicigenerans, Clostridium clostridioforme and F. varium were included in these peaks. Based on the real-time polymerase chain reaction study, only F. varium was significantly reduced after treatment. In the immunostaining, post-treatment scores in treatment group were significantly lower than that in control group.

CONCLUSIONS

Antibiotics combination therapy was effective for ulcerative colitis. The number of mucosa-associated F. varium significantly decreased after the treatment.

Down-regulation of sarcolipin mRNA expression in chronic atrial fibrillation

BACKGROUND

Abnormal intracellular Ca2+ homeostasis is an important modulator of chronic atrial fibrillation. Sarcolipin, a homologue of phospholamban, is specifically expressed in the atria, and may play an important role in modulating intracellular Ca2+ homeostasis in the atria. The aim of this study was to investigate the expression of sarcolipin mRNA in the atrial myocardium of patients with chronic atrial fibrillation.

METHODS

We analyzed the expression of sarcolipin, phospholamban, cardiac calsequestrin and sodium calcium exchanger mRNAs in the right atrial myocardium from nine patients with mitral valvular disease with atrial fibrillation (MVD/AF), nine patients with MVD who had normal sinus rhythm (MVD/NSR), and 10 control patients with normal sinus rhythm who received open heart surgery (controls). The expression of mRNA was measured using the ABI PRISM 7700 Sequence Detection System (Applied Biosystems, Foster City, CA).

RESULTS

Relative expression levels of sarcolipin mRNA were significantly lower in MVD/AF (0.60 +/- 0.11) than in either MVD/NSR (1.28 +/- 0.17, P < 0.01) or controls (1.10 +/- 0.10, P < 0.05). The expression levels of sarcolipin mRNA were significantly lower in the group with high values for right atrial pressure. The expression levels of phospholamban, cardiac calsequestrin and sodium calcium exchanger mRNAs were comparable among all three groups.

CONCLUSIONS

Chronic electrical and mechanical overload decreased the expression of sarcolipin mRNA in the right atrial myocardium in patients with chronic atrial fibrillation. Down-regulation of sarcolipin mRNA may be part of atrial fibrillation-induced atrial remodelling.

Oesophageal hypersensitivity in Japanese patients with non-erosive gastro-oesophageal reflux diseases

BACKGROUND

Visceral hypersensitivity plays a major role in the pathogenesis of non-erosive oesophageal reflux disease (NERD). Prevalence of NERD differs according to the population and geographical region. Oesophageal hypersensitivity in NERD has not been well studied, especially in Japanese patients.

AIM

To investigate oesophageal hypersensitivity in Japanese NERD patients.

PATIENTS AND METHODS

We performed upper GI endoscopy and the modified acid perfusion test on 14 control subjects and 68 GERD patients, including 26 with NERD, 34 with erosive GERD, and six with Barrett's oesophagus. The stimulus-response function to acid was quantified by three parameters (lag time, intensity rating and the acid perfusion sensory score) and compared among four groups.

RESULTS

The mean value of the lag time, intensity rating, and acid perfusion scores in NERD patients (4.6 +/- 3.4, 4.4 +/- 3.4, 27.8 +/- 26.7, respectively) were higher than in erosive GERD (3.2 +/- 3.3, 3.0 +/- 3.2, 18.2 +/- 24.8) and Barrett patients (2.5 +/- 4.0, 1.8 +/- 3.3, 15.0 +/- 28.8), and significantly higher than in the control group (1.7 +/- 2.7, 1.1 +/- 2.0, 5.4 +/- 11.8). The ratio of patients with higher sensory scores was also greater in the NERD group (57.7%) than in erosive GERD (32.3%) and Barrett group (16.7%), and significantly greater than in control group (6.7%).

CONCLUSION

Our findings suggest that oesophageal sensitivity is likely to be enhanced especially in NERD patients also in Japanese population in comparison with erosive GERD, Barrett's oesophagus and controls.

Improvement in serum pepsinogens and gastrin in long-term monitoring after eradication of Helicobacter pylori: comparison with H. pylori-negative patients

BACKGROUND

A decrease in pepsinogen and gastrin levels 1-3 months after Helicobacter pylori eradication is well known. However, few data are available on the long-term progression of these decreases beyond 1 year after eradication, and there has been no investigation into whether pepsinogen and gastrin levels return to normal levels as defined by data from H. pylori-negative patients with dyspepsia.

AIM

We studied the effect of H. pylori eradication on pepsinogen and gastrin levels for more than 1 year, and compared levels to those in H. pylori-negative patients with dyspepsia. We also investigated the effect of H. pylori eradication on the course of atrophic corpus gastritis as reflected by histology, and on PGI levels and PG I/II ratio.

METHODS

We enrolled 172 H. pylori-positive patients with dyspepsia who had undergone successful eradication therapy of more than 1 year's duration and 101 non-treated H. pylori-negative patients with dyspepsia. H. pylori status was assessed at entry and at each endoscopy after eradication by culture, histological results, the rapid urease test and the urea breath test. In both groups, patients were evaluated for fasting serum pepsinogen I and II and gastrin using a radioimmunoassay technique, and underwent detailed histological assessment according to the updated Sydney System.

RESULTS

In the H. pylori-negative patients, mean serum pepsinogen I and II, I/II ratio and gastrin levels were 52.6 +/- 20.8 ng/mL, 9.2 +/- 4.2 ng/mL, 6.0 +/- 1.7 and 53.5 +/- 29.2 pg/mL, respectively. In H. pylori-positive patients with long-term eradication, pepsinogen I and II, I/II ratio and gastrin levels were 81.3 +/- 46.6 ng/mL, 25.9 +/- 17.1 ng/mL, 3.4 +/- 1.3 and 131.9 +/- 130.8 pg/mL, respectively, before treatment. At 1-3 months after eradication, serum pepsinogen I and II levels in the H. pylori-positive patients decreased to levels similar to those in the negative patients, whereas pepsinogen I/II ratio and gastrin levels remained lower and higher, respectively, than in the negative patients. Serum pepsinogen I/II ratio and gastrin levels then became similar between the groups at 12-15 months after eradication. In histological findings, inflammation and neutrophil activity decreased by 1-3 months, and atrophy in the corpus and metaplasia in the antrum decreased by 12-15 months.

CONCLUSION

The results suggest that atrophic corpus gastritis and superficial gastritis are reversible, as indicated by both histological and serological findings in a long-term follow-up study.

Diagnostic performance of light-induced fluorescence endoscopy for gastric neoplasms

BACKGROUND AND STUDY AIM

Malignant tumors generate autofluorescent patterns that differ from those of normal tissue. However, whether autofluorescent diagnosis could be genuinely useful in screening for gastric neoplasms has not been well investigated in clinical practice. Accordingly, we retrospectively studied our experience with this diagnostic technique for various gastric lesions and assessed its diagnostic utility.

PATIENTS AND METHODS

Autofluorescence diagnosis of 109 gastric lesions in 79 patients was done, without knowledge of the diagnosis by conventional white light endoscopy, retrospectively and independently by three endoscopists with 6 years', two years' and no experience of the technique. After examination of the interobserver bias in the assessment of autofluorescent pseudocolor in light-induced fluorescence endoscopy (LIFE), the relationship between pseudocolor and characteristics of gastric lesions (including histology, macroscopic type, and depth of invasion) were investigated.

RESULTS

The kappa statistic for agreement in pseudocolor diagnosis between the three endoscopists was 0.71. The assessment of pseudocolor by all of the observers was in agreement in 67 of the total of 109 lesions (61.5 %). Experience with the LIFE technique did not improve the accuracy of pseudocolor determination. All of the cancers, 87.5 % of the adenomas, and 50.9 % of the benign lesions were recognized as having an abnormal autofluorescent image. None of the gastric cancers and 49.1 % of the benign lesions were evaluated as having a normal autofluorescence image. The histopathological and macroscopic types of tumors and their depths of invasion were not reflected in the autofluorescence diagnosis.

CONCLUSIONS

LIFE provided a sensitivity of 96.4 % and specificity of 49.1 %, suggesting that this technique has limited clinical utility, regardless of the merits of acceptable interobserver bias and lack of necessity for experience with this technique.

Is antimicrobial susceptibility testing necessary before second-line treatment for Helicobacter pylori infection?

BACKGROUND

An antimicrobial susceptibility test for Helicobacter pylori before second-line treatment is often performed, although whether the test is truly necessary remains unknown.

PATIENTS AND METHODS

Eighty-two patients with H. pylori infection for whom first-line treatment with a 1-week proton pump inhibitor/amoxicillin-clarithromycin (AC) regimen had failed were randomly assigned to two groups: those having or not having the susceptibility test before re-treatment. The cure rates for these two groups were compared.

RESULTS

Five of the 82 patients were excluded from the analysis. For 38 patients in the susceptibility-test group, we used what we considered the best regimen based on susceptibility testing: 10 patients [no resistance to clarithromycin (CAM)] received the lansoprazole-amoxicillin-clarithromycin regimen, 22 patients [19 CAM resistant, metronidazole (MNZ) susceptible; three failure of culture] were given the lansoprazole-amoxicillin-metronidazole (LAM) regimen, and six patients (both MNZ and CAM resistant) received dual therapy with omeprazole (OPZ) and amoxicillin (AMOX) in which the OPZ dose was determined by the CYP2C19 gene polymorphism. For 39 patients in the group with no susceptibility testing, LAM regimens were prescribed. The intention-to-treat (ITT)-based cure rates in the groups with and without susceptibility testing were 81.6% (95% confidence interval; 66-92%) and 92.4% (79-98%), respectively, and there was no significant difference between these two groups.

CONCLUSION

Susceptibility testing is not necessarily required before second-line therapy if the first-line treatment has been performed using proton pump inhibitor/AC regimens.

Helicobacter pylori infection induces duodenitis and superficial duodenal ulcer in Mongolian gerbils

BACKGROUND

There is no direct evidence for an animal model of Helicobacter pylori induced duodenal ulcer.

AIM

In this study we evaluated the roles of bacterial strain and age of experimental animals in induction of duodenitis and duodenal ulcer in Mongolian gerbils after H pylori infection.

METHODS

Specific pathogen free Mongolian gerbils were inoculated orally with three bacterial strains (H pylori ATCC 43504, TN2GF4, and K-6, a clinical isolate from a patient with gastric cancer in our clinic). These strains have both the cagA gene and VacA. Five week old gerbils were used to emulate prematurity infection and 14 week old animals were used as mature test subjects. Animals were observed for 12 weeks after inoculation. Interleukin 8 (IL-8) production in gastric epithelial cells (MKN74) after coculture with the H pylori strains was measured by ELISA.

RESULTS

Gastritis and gastric ulcers were found in all gerbils infected with the three strains. However, duodenitis and gastric metaplasia were seen more frequently in gerbils infected with TN2GF4 and K-6 strains than in the ATCC 43504 infected or control groups (p<0.05). Superficial duodenal ulcers with severe duodenitis and gastric metaplasia were found in two gerbils inoculated at 14 weeks with the TN2GF4 strain but none at five weeks. The TN2GF4 strain stimulated significantly higher levels of IL-8 than ATCC 43504 and K6 strains (p=0.0039).

CONCLUSIONS

When injected into adult Mongolian gerbils, a specific strain (TN2GF4) of H pylori can induce duodenitis with gastric metaplasia and superficial duodenal ulcers. Induction of duodenal ulcer in an animal model fulfills the requirements of Koch's postulates for establishing a role for H pylori as a causative agent.

Induction of experimental ulcerative colitis by Fusobacterium varium isolated from colonic mucosa of patients with ulcerative colitis

BACKGROUND

Bacteria are implicated in certain forms of model chronic colitis but the identity and role of bacteria in human ulcerative colitis (UC) are uncertain.

AIMS

To isolate pathogenic bacteria from inflamed mucosa of patients with UC, to examine whether the bacteria have a toxin to Vero cells, and to determine whether the toxin induces UC-like lesions in animals.

METHODS

Bacteria were isolated from UC patients and supernatants from cultures were filtered and tested for cytotoxicity to Vero cells. Bacterial cells producing the cytotoxic supernatants were examined by polymerase chain reaction for verotoxin genes. Culture supernatants of cytotoxic strains were examined by high performance liquid chromatography for organic acid concentrations. Mice were given enemas containing organic acid at the mean concentration in the supernatants of cytotoxic strains to ascertain whether colonic lesions appear in UC.

RESULTS

Only supernatants from cultures of Fusobacterium varium killed Vero cells. Bacterial cells lacked verotoxin genes. Bacterial culture supernatants contained high concentrations of n-butyric acid and the mean concentration (32 mmol/l) was cytotoxic to Vero cells. Twenty four hours after mice were given enemas containing either butyric acid or F varium culture supernatants, colonic ulcers with crypt abscesses, inflammatory cell infiltration, and apoptotic changes were observed.

CONCLUSIONS

Butyric acid in culture supernatants from cultures of F varium caused UC-like lesions in mice. This study indicates that F varium may be one of the elusive pathogenic factors in UC.

Alteration of histological gastritis after cure of Helicobacter pylori infection

BACKGROUND

It is still disputed whether gastric atrophy or intestinal metaplasia improves after the cure of Helicobacter pylori infection.

AIM

To clarify the histological changes after the cure of H. pylori infection through a literature survey.

METHODS

Fifty-one selected reports from 1066 relevant articles were reviewed. The extracted data were pooled according to histological parameters of gastritis based on the (updated) Sydney system.

RESULTS

Activity improved more rapidly than inflammation. Eleven of 25 reports described significant improvement of atrophy. Atrophy was not improved in one of four studies with a large sample size (> 100 samples) and in two of five studies with a long follow-up period (> 12 months), suggesting that disagreement between the studies was not totally due to sample size or follow-up period. Methodological flaws, such as patient selection, and statistical analysis based on the assumption that atrophy improves continuously and generally in all patients might be responsible for the inconsistent results. Four of 28 studies described significant improvement of intestinal metaplasia [corrected].

CONCLUSIONS

Activity and inflammation were improved after the cure of H. pylori infection. Atrophy did not improve generally among all patients, but improved in certain patients. Improvement of intestinal metaplasia was difficult to analyse due to methodological problems including statistical power.

Gastric mucosal density of Helicobacter pylori estimated by real-time PCR compared with results of urea breath test and histological grading

The accuracy of the urea breath test (UBT) and histological grading for estimation of the density of Helicobacter pylori in gastric mucosa is not known. Real-time (TaqMan) PCR was used to estimate the total number of H. pylori genomes in biopsy samples. These values were compared with those obtained by the UBT and the histological grade obtained by the Sydney system. The UBT and endoscopy with antral and corporal biopsies were performed in 88 consecutive untreated patients with dyspepsia. Bacterial culture and the rapid urease test were done with fresh biopsy materials. TaqMan PCR and histological examination were done on serial paraffin sections of the biopsy samples. Of the five methods tested, TaqMan PCR had the highest sensitivity and specificity (both 100%) in the diagnosis of H. pylori infection. The mean density of H. pylori genomes for pairs of biopsy samples from individual patients was compared with the individual values obtained by the UBT; correlation between the results was significant. The density of H. pylori genomes was higher in histological grades 1, 2 and 3 than in grade 0, without significant differences between adjacent grades from 1 to 3. These results suggest that the severity of H. pylori infection of the stomach can be estimated by the UBT and that histopathologists might state whether the organism is present or absent, rather than making a quantitative statement as recommended in the Sydney system.

Helicobacter pylori DNA in drinking water in Japan

Helicobacter pylori has been detected in drinking water in Peru and Sweden, suggesting the possibility of water-borne transmission. To date there have been few reports of H. pylori being detected in water; one was of the ureA gene of H. pylori in wells and springs in rural Japan. We examined water sampled in or near urban areas of Japan for H. pylori DNA by three assays using the polymerase chain reaction (PCR). Near Tokyo, samples were obtained: 10 of tap water, 6 of well water, 10 of river water, and 10 of sea water. Samples were filtered with membranes with 0.05- or 0.22-microm pores, which bacterial cells are caught by. Bacterial nucleic acids were extracted and purified and the PCR was done to amplify adhesin specific for H. pylori and the ureA gene, if present. Real-time PCR that measured the yield in terms of fluorescence was done with primers for 16S rRNA. None of the samples of tap, river, or sea water contained adhesin, ureA or 16S rRNA. None of the 6 samples of well water contained adhesin or ureA, but 2 of the 6 samples contained 16S rRNA. Some of the users of the well had had H. pylori infection in the past. H. pylori DNA was detected in well water and the users had been infected, so water-borne transmission via well water may occur even in towns in Japan.

Calcium handling and sarcoplasmic-reticular protein functions during heart-failure transition in ventricular myocardium from rats with hypertension

The objective of this study was to determine the primary event that occurs in Ca2+-regulatory sarcoplasmic-reticular (SR) proteins during subacute transition from concentric/mechanically-compensated left ventricular (LV) hypertrophy to eccentric/decompensated hypertrophy. Using Dahl salt-sensitive rats with hypertension, changes of myocardial contraction, intracellular Ca2+ transients, SR Ca2+ uptake, protein levels of SR Ca2+ ATPase (SERCA2), phospholamban, and calsequestrin (CSQ), and mRNA levels of SERCA2 and CSQ were serially determined and compared between the established stage of LV hypertrophy (LVH) and the subsequent stage of overt LV dysfunction (CHF). In LVH, isolated LV papillary muscle preparations showed an equal peak-tension level and a mild prolongation of the isometric tension decay compared to those of age-matched controls. The Ca2+ transients as measured by aequorin were unchanged. The Ca2+ uptake of isolated SR vesicles and the protein/mRNA levels of SR proteins were also equivalent to those of the controls. In contrast, in CHF, the failing myocardium showed a further prolongation of the contraction time course and a 39% reduction of the peak-tension development. The Ca2+ transients showed changes consisting of a decrease in the peak level and a prolongation of the time course. In addition, the SR Ca2+ uptake was decreased by 41%. Despite these functional changes, the protein and mRNA levels of the SR components remained equivalent to those of the age-matched controls. Thus, in this hypertensive animal, 1) at the LVH stage, myocardial contractility and intracellular capability to regulate Ca2+ remained normal; 2) at the CHF stage, impaired SR Ca2+ handling and the subsequent reduction of myocardial contraction were in progress; and 3) impairments of SR function occurred at the post-translational protein level rather than at the transcriptional/translational levels. Our findings support the role of SR proteins as the primary determinant of the contractile dysfunction that occurs during the heart-failure transition; however, post-translational modulators of these SR elements may also be critical.

Syncope induced by tobacco smoking in the head-up position

A 26-year-old man had a loss consciousness for a few minutes while smoking in the standing position, and was referred to hospital. No abnormalities were found in a computed tomography examination of his head, in a 24-h electrocardiogram or in an exercise tolerance test. The head-up tilt test (HUT) while tobacco smoking elicited a positive response in the tilted position, but the HUT without tobacco smoking was negative. The most noteworthy effect of tobacco smoking during the HUT was the high level of plasma epinephrine compared to the levels seen during supine smoking or the HUT alone. Syncope induced by tobacco smoking in the standing position is rare and the mechanism may be the same as that underlying neurally mediated syncope.

Kirsten ras mutations in patients with colorectal cancer: the 'RASCAL II' study

Researchers worldwide with information about the Kirsten ras (Ki-ras) tumour genotype and outcome of patients with colorectal cancer were invited to provide that data in a schematized format for inclusion in a collaborative database called RASCAL (The Kirsten ras in-colorectal-cancer collaborative group). Our results from 2721 such patients have been presented previously and for the first time in any common cancer, showed conclusively that different gene mutations have different impacts on outcome, even when the mutations occur at the same site on the genome. To explore the effect of Ki-ras mutations at different stages of colorectal cancer, more patients were recruited to the database, which was reanalysed when information on 4268 patients from 42 centres in 21 countries had been entered. After predetermined exclusion criteria were applied, data on 3439 patients were entered into a multivariate analysis. This found that of the 12 possible mutations on codons 12 and 13 of Kirsten ras, only one mutation on codon 12, glycine to valine, found in 8.6% of all patients, had a statistically significant impact on failure-free survival (P = 0.004, HR 1.3) and overall survival (P = 0.008, HR 1.29). This mutation appeared to have a greater impact on outcome in Dukes' C cancers (failure-free survival, P = 0.008, HR 1.5; overall survival P = 0.02, HR 1.45) than in Dukes' B tumours (failure-free survival, P = 0.46, HR 1.12; overall survival P = 0.36, HR 1.15). Ki-ras mutations may occur early in the development of pre-cancerous adenomas in the colon and rectum. However, this collaborative study suggests that not only is the presence of a codon 12 glycine to valine mutation important for cancer progression but also that it may predispose to more aggressive biological behaviour in patients with advanced colorectal cancer.

High risk of Helicobacter pylori infection in young Japanese dentists

BACKGROUND AND AIM

The route of person-to-person transmission of Helicobacter pylori may be either fecal-oral or oral-oral, because the bacterium is found in both dental plaque and feces. We assessed the prevalence of H. pylori seropositivity, which reflects present or past infection, in Japanese dentists exposed occupationally to dental plaque.

METHODS

We examined the sera of 60 dentists (34 who were 20-29 years or older, and 26 who were over 30 years of age) and 60 age-matched controls by using quantitative ELISA for antibodies of the immunoglobulin G class to H. pylori.

RESULTS

The proportion of dentists seropositive for H. pylori (42 of 60, 70%) was higher than in controls (23 of 60, 38%). The odds ratio for H. pylori seropositivity (3.8; 95% CI, 1.76-8.02) was high in the dentists. When dentists were classified in terms of the length of their practice, the odds ratio for seropositivity (10.4; 95% CI, 3.26-32.85) was high in the dentists practising for fewer than 4 years. The proportion of dentists in their 20s who were seropositive was greater than that in the group of age-matched controls.

CONCLUSION

Japanese young dentists are at a high risk for H. pylori infection, with the oral-oral transmission route being possibly the most common.

Influence of climatic factors in the incidence of upper gastrointestinal bleeding

BACKGROUND AND AIM

Previous reports have indicated seasonal fluctuations in the incidence of peptic ulcer activity, but the reasons for the seasonal pattern are not clear. We assessed the seasonal incidence of hematemesis caused by peptic ulcers or gastroesophageal varices, and the correlations between those and climatic factors.

METHODS

We examined the number of cases of upper gastrointestinal (GI) bleeding caused by gastric ulcer (GU), duodenal ulcer (DU), or gastroesophageal varices (varix) diagnosed by urgent endoscopies between 1 January 1996 and 31 December 1999 in our hospital (Tokyo Metropolitan Bokutou Hospital). We evaluated the monthly and seasonal incidence of them and investigated correlations among the incidence and climatic factors.

RESULTS

Four hundred and forty-one patients participated in this study, including 275 patients with GU (62.4%), 51 (11.6%) with DU, and 115 (26.0%) with varix. The number of cases of hematemesis caused by GU showed significant monthly and seasonal fluctuations (P = 0.0002, P = 0.0018): it decreased in summer and increased in autumn-winter. Moreover, there were inverse relations between the monthly number of cases of hematemesis caused by GU and the mean temperature (P = 0.0016) and vapor pressure (P = 0.0013), and a parallel relation to the mean atmospheric pressure (P = 0.0057). In contrast, the number of cases of hematemesis caused by DU and varices did not show any monthly or seasonal fluctuations.

CONCLUSIONS

We found that the incidence of hematemesis because of GU had an inverse relationship to temperature and vapor pressure, and had a parallel relation to atmospheric pressure. Therefore, climatic factors may play an important role in hemorrhage from GU.

Effects of cardioplegic arrest and reperfusion on rabbit cardiac ryanodine receptors

Calcium overload is considered to be a primary contributor to ischemia-reperfusion injury. Cardiac sarcoplasmic reticulum (SR), the main regulator of intracellular Ca2+ concentration under normal conditions, is a target for ischemic myocardial injury. The ryanodine receptor (RyR) is the SR Ca2+ release channel. Previous reports have shown that a reduction in RyR activity during global myocardial ischemia correlates with concomitant myocardial dysfunction. Crystalloid cardioplegia, a technique for myocardial protection during heart operations, reduces Ca2+ accumulation during global ischemia. Hence, the effects of cardioplegia on RyR in isolated rabbit hearts was investigated. The study also compared [3H] ryanodine binding before ischemia (control group), after 30 min of ischemia (either global ischemia (GI group) or cardioplegic arrest (CA group)), and after 20 min of reperfusion. The GI group, but not the CA group, showed a significant reduction in the maximum number of binding sites (Bmax) for RyR compared with the control group (Control vs GI group: after ischemia, 1.33+/-0.27 vs 0.83+/-0.12 pmol/mg protein, p<0.05; after reperfusion, 1.33+/-0.27 vs 0.80+/-0.08 pmol/mg protein; p<0.05). CA group: after ischemia, 1.22+/-0.20 pmol/mg protein; after reperfusion, 1.15+/-0.28 pmol/mg protein). The affinity (Kd) values for [3H] ryanodine binding were not different among the 3 groups at any point. The preservation of RyR numbers during cardioplegia correlated with the concomitant preservation of cardiac functions. The results indicate that number of functional RyR was much better preserved during cardioplegia than during global ischemia. It is postulated that cardioplegia-induced protection of cardiac RyR may result in the protection of SR function during ischemia-reperfusion.

Influence of timing and magnitude of arterial wave reflection on left ventricular relaxation

The influence of timing and magnitude of arterial wave reflection (WR) on afterload-dependent relaxation was evaluated in patients with a variety of heart diseases (group 1, age < 30 yr; group 2, age > 40 yr) and in dogs. While both femoral arteries were compressed (FC), WR returned just after the dicrotic notch (early diastole) in group 1 but before the dicrotic notch (late systole) in group 2. The time constant of the left ventricular pressure decay (tau) was shortened during FC in group 1, whereas it was prolonged in group 2. In dogs, a constriction of the thoracic aorta induced a late systolic augmentation of WR with a prolongation of tau (cf. group 2), whereas constriction of the lower abdominal aorta induced an early diastolic augmentation of WR with a shortening of tau (cf. group 1). With aortic constriction, coronary flow increased, and there was a close correlation between the peak change in backward aortic pressure and that in coronary flow regardless of the timing of WR. Thus the time at which WR returns during the cardiac cycle may have an important effect on left ventricular relaxation and coronary flow.

Up-regulation of inositol 1,4,5 trisphosphate receptor expression in atrial tissue in patients with chronic atrial fibrillation

OBJECTIVES

We examined whether patients with atrial fibrillation (AF) have alterations in atrial inositol 1,4,5 trisphosphate receptors (IP3 receptors).

BACKGROUND

Abnormal intracellular Ca2+ homeostasis occurs in chronic AF. The intracellular Ca2+ concentration is regulated by ryanodine and IP3 receptors. We recently reported alterations in ryanodine receptors in atrial tissue from patients in chronic AF.

METHODS

We analyzed IP3 receptor expression in the right atrial myocardium from 13 patients with mitral valvular disease (MVD) with AF (MVD/AF), five patients with MVD who had normal sinus rhythm (MVD/NSR) and eight control patients with NSR (tissue obtained during coronary artery bypass surgery). Hemodynamic and echocardiographic data were obtained preoperatively, and an immunohistochemical study was performed on atrial tissue.

RESULTS

The relative expression level of IP3 receptor protein was significantly greater in MVD/AF (0.75 +/- 0.26) than it was in MVD/NSR (0.42 +/- 0.13, p < 0.01), and both were significantly above control (0.14 +/- 0.08). The relative expression level of IP3 receptor messenger RNA was significantly greater in the MVD/AF group (0.028 +/- 0.008) than it was in the control group (0.015 +/- 0.004, p < 0.01), but patients with MVD/AF did not differ from patients with MVD/NSR (0.020 +/- 0.006). The relative expression levels of IP3 receptor protein and messenger RNA were higher in patients with left atrial dimension > or = 40 mm, pulmonary capillary wedge pressure > or = 10 mm Hg and right atrial pressure > or = 5 mm Hg. Inositol 1,4,5 trisphosphate receptors were over-expressed in the cytosol and at the nuclear envelope of atrial myocytes in MVD.

CONCLUSIONS

Since chronic mechanical overload of the atrial myocardium increased IP3 receptor expression, especially in patients with chronic AF, up-regulation of IP3 receptors may be important in modulating intracellular Ca2+ homeostasis and initiating or perpetuating AF.

Improvement in atrophic gastritis and intestinal metaplasia in patients in whom Helicobacter pylori was eradicated

BACKGROUND

Glandular atrophy and intestinal metaplasia are precancerous lesions; whether Helicobacter pylori eradication affects these lesions is controversial.

OBJECTIVE

To determine whether H. pylori eradication is associated with improvement in glandular atrophy and intestinal metaplasia after at least 1 year.

DESIGN

Single-blind, uncontrolled prospective trial.

SETTING

Academic gastroenterology clinic in Japan.

PATIENTS

163 consecutive patients with dyspepsia and H. pylori infection.

INTERVENTION

One-week course of a proton-pump inhibitor and antibiotic therapy.

MEASUREMENTS

Endoscopic examination with antral and corporal biopsy was done before treatment and at 1 to 3 and 12 to 15 months after treatment. Gastritis, atrophy, and metaplasia were graded according to the updated Sydney System.

RESULTS

In the 115 patients in whom H. pylori was eradicated, inflammation and mean neutrophil activity had decreased by 1 to 3 months, and both glandular atrophy in the corpus and intestinal metaplasia in the antrum had decreased by 12 to 15 months. Glandular atrophy in the corpus improved in 34 (89%) of 38 patients with atrophy before treatment, and intestinal metaplasia in the antrum improved in 28 (61%) of 46 patients who had metaplasia at baseline. In the 48 patients in whom eradication was unsuccessful, no significant histologic changes were observed.

CONCLUSION

In the year after successful H. pylori eradication, precancerous lesions improved in most patients.

Enhancement of Rho/Rho-kinase system in regulation of vascular smooth muscle contraction in tachycardia-induced heart failure

OBJECTIVE

The Rho/Rho-kinase system regulates Ca(2+) sensitivity in vascular smooth muscle. A new drug, Y-27632, specifically inhibits Rho-kinase and hence decreases the phosphorylation of myosin light chain, thus reducing contraction. Here, we compare the effects of Y-27632 and nifedipine on the vasoconstrictor response of the femoral artery in heart failure.

METHODS

Heart failure (HF) was produced by chronic rapid RV pacing (250 bpm, 28 days, six dogs). Indo1-AM was loaded into endothelium-denuded femoral artery segments for measuring intracellular [Ca(2+)]. Tension and changes in intracellular [Ca(2+)] [the change in the ratio (418 nm/468 nm) of Indo1 fluorescence (F(ratio))] were simultaneously measured in Krebs-Ringer solution.

RESULTS

In HF: (i) norepinephrine (10 microM) produced greater tension (784+/-52 g/cm(2)) than in control (502+/-64 g/cm(2)) despite a similar increase in F(ratio), indicating increased Ca(2+) sensitivity in vascular smooth muscle; (ii) nifedipine attenuated this enhanced response by only a maximum of 27% at 1 micromol/l with a 56% reduction in F(ratio); (iii) Y-27632 attenuated it by a maximum of 80% at 100 micromol/l without a significant change in F(ratio); (iv) RhoA protein and mRNA expression levels in the femoral artery were up-regulated by +110% and +56%, respectively, while those of Rho-kinase were unchanged.

CONCLUSIONS

The Ca(2+)-sensitizing mechanism involving the Rho/Rho-kinase system may be deeply involved in the enhanced arterial vasoconstriction seen in HF. Since Y-27632 attenuated this response in small arteries, it shows potential as a novel, potent vasodilator for the treatment of HF.

[A strategy for second-line anti-Helicobacter pylori therapy in patients with previously failed treatment]

Highly effective H. pylori eradication therapies are currently used in Japan. However, eradication failures still appear in a considerable proportion of cases. In such refractory cases, several second-line eradication therapies and therapeutic efficacies have been only exceptionally studied. Our aims were to analyze the reasons and evaluate the second-line therapies when first-line eradication therapies fail. We make a strategy for second-line anti-H. pylori therapy in patients with previously failed treatment.

Infective endocarditis with extensive calcified granulation of the mitral annulus and valve--a case report

Mitral annular calcification, a degenerative process usually seen in the elderly or in chronic renal failure, is rarely seen in an extensive form. A 69-year-old man with no history of renal failure, rheumatic fever, or heart disease had mitral valve vegetation and regurgitation, together with extensive mitral annuls and valve calcification, which may or may not have been secondary to the infective endocarditis.

Roles of mucosal bacteria and succinic acid in colitis caused by dextran sulfate sodium in mice

Intestines of mice with colitis caused by dextran sulfate sodium (DSS) contain more Bacteroidaceae cells than untreated controls. We investigated the roles of intestinal bacteria and succinic acid, a by-product of Bacteroidaceae metabolism, in this model of colitis. CBA/J mice were given 3% DSS in water for 14 days. After mice were anesthetized and killed, concentrations of organic acids in stools from the cecum and colon were measured. The resected rectum and colon were washed with sterile saline; some specimens were incubated with imipenem in saline for 1 h to kill bacteria on the surfaces and others were not. Their homogenates were cultured anaerobically and aerobically. Separately, 1 mL of 20 mM succinic acid was infused into the rectum of mice, whose anal verge was glued. Animals were anesthetized and killed the next day. The rectum and colon were examined histologically. Concentrations of succinate were higher everywhere in the colon of mice with colitis than in controls. Mice with colitis had more Bacteroidaceae cells, especially B. caccae, than controls. Mice given succinate enemas had focal erosions of the mucosa and edema of the submucosa. Succinic acid, produced abundantly by members of the family Bacteroidaceae, especially B. caccae, may be the ulcerogenic agent in DSS colitis.

Altered interaction of FKBP12.6 with ryanodine receptor as a cause of abnormal Ca(2+) release in heart failure

OBJECTIVE

Little information is available as to the Ca(2+) release function of the sarcoplasmic reticulum (SR) in heart failure. We assessed whether the alteration in this function in heart failure is related to a change in the role of FK binding protein (FKBP), which is tightly coupled with the cardiac ryanodine receptor (RyR) and recently identified as a modulatory protein acting to stabilize the gating function of RyR.

METHODS

SR vesicles were isolated from dog LV muscles [normal (N), n=6; heart failure induced by 3-weeks pacing (HF), n=6]. The time course of the SR Ca(2+) release was continuously monitored using a stopped-flow apparatus, and [3H]ryanodine-binding and [3H]dihydro-FK506-binding assays were also performed.

RESULTS

FK506, which specifically binds to FKBP12.6 and dissociates it from RyR, decreased the polylysine-induced enhancement of [3H]ryanodine-binding by 38% in N (P<0.05) but it had no effect in HF. In HF, the rate constant for the polylysine-induced Ca(2+) release from the SR was 61% smaller than in N. FK506 decreased the rate constant for the polylysine-induced Ca(2+) release by 67% in N (P<0.05) but had no effect in HF. The [3H]dihydro-FK506-binding assay revealed that the number (B(max)) of FKBPs was decreased by 83% in HF (P<0.05), while the K(d) value was unchanged. FK506 did not significantly change SR Ca(2+.)-ATPase activity in either N or HF.

CONCLUSIONS

In HF, the number of FKBPs showed a tremendous decrease; this may underlie the RyR-channel instability and the impairment of the Ca(2+) release function of RyR seen in the failing heart.

Altered stoichiometry of FKBP12.6 versus ryanodine receptor as a cause of abnormal Ca(2+) leak through ryanodine receptor in heart failure

BACKGROUND

In the pathogenesis of cardiac dysfunction in heart failure, a decrease in the activity of the sarcoplasmic reticulum (SR) Ca(2+)-ATPase is believed to be a major determinant. Here, we report a novel mechanism of cardiac dysfunction revealed by assessing the functional interaction of FK506-binding protein (FKBP12.6) with the cardiac ryanodine receptor (RyR) in a canine model of pacing-induced heart failure.

METHODS AND RESULTS

SR vesicles were isolated from left ventricular muscles (normal and heart failure). The stoichiometry of FKBP12.6 per RyR was significantly decreased in failing SR, as assessed by the ratio of the B(max) values for [(3)H]dihydro-FK506 to those for [(3)H]ryanodine binding. In normal SR, the molar ratio was 3.6 ( approximately 1 FKBP12.6 for each RyR monomer), whereas it was 1.6 in failing SR. In normal SR, FK506 caused a dose-dependent Ca(2+) leak that showed a close parallelism with the conformational change in RyR. In failing SR, a prominent Ca(2+) leak was observed even in the absence of FK506, and FK506 produced little or no further increase in Ca(2+) leak and only a slight conformational change in RyR. The level of protein expression of FKBP12.6 was indeed found to be significantly decreased in failing SR.

CONCLUSIONS

An abnormal Ca(2+) leak through the RyR is present in heart failure, and this leak is presumably caused by a partial loss of RyR-bound FKBP12.6 and the resultant conformational change in RyR. This abnormal Ca(2+) leak might possibly cause Ca(2+) overload and consequent diastolic dysfunction, as well as systolic dysfunction.

Relationship between fecal bile acids and the occurrence of colorectal neoplasia in experimental murine ulcerative colitis

OBJECTIVE

The possible role of fecal bile acids in colorectal carcinogenesis in ulcerative colitis has been reported. In this study, we investigated the relationship between fecal bile acids and the occurrence of colorectal neoplasia in experimental murine colitis induced by dextran sulfate sodium.

METHODS

Colorectal neoplasia in experimental colitis was induced by dextran sulfate sodium subsequent to a single azoxymethane pretreatment. Fecal bile acids were analyzed by gas-liquid chromatography.

RESULTS

Multiple high-grade dysplasias (intramucosal adenocarcinoma) and inflammatory changes were seen in all mice administered dextran sulfate sodium and azoxymethane. Inflammatory changes were also observed in all mice given dextran sulfate sodium only, while neither tumor nor inflammatory changes were detected in any of the control mice. Significant increases in cholic acid were observed in the mice of the colorectal tumor and experimental colitis groups during the experimental period, while in the control mice, no significant changes in fecal bile acids were observed.

CONCLUSION

It is suggested that fecal cholic acid and colitis may be intimately related to the development of colorectal neoplasia in this experimental model of murine colitis as well as in ulcerative colitis.

Effect of milrinone on left ventricular relaxation and Ca(2+) uptake function of cardiac sarcoplasmic reticulum

Milrinone, a phosphodiesterase 3 (PDE3) inhibitor, is known to enhance left ventricular (LV) contractility by an inhibition of the breakdown of cAMP through the mechanism inhibiting PDE3. However, it is unclear whether milrinone also exerts positive lusitropy, like dobutamine. Here, we assessed the effects of milrinone on in vivo LV relaxation, as well as the Ca(2+)-ATPase activity and the Ca(2+) uptake function of the cardiac sarcoplasmic reticulum (SR), compared with the effect of dobutamine on those functions. After dobutamine (3 microg x kg(-1) x min(-1)) was administered, the peak value of the first derivative of LV pressure (+dP/dt) increased by 46%, whereas the time constant (tau) of LV pressure decay decreased by 6.9%, respectively. After milrinone (10 microg/kg) was administered, the peak +dP/dt increased to a similar extent as dobutamine (46%), whereas tau decreased much more than dobutamine (19.9%; P < 0.05). In LV crude homogenate, the thapsigargin-sensitive, Ca(2+)-ATPase activity-cAMP relationships was significantly less increased by milrinone compared with dobutamine (P < 0.05), indicating the higher sensitivity of the SR Ca(2+)-ATPase activity on cAMP by milrinone than by dobutamine. In the SR vesicles purified from LV muscles, the addition of cAMP increased the SR Ca(2+) uptake in a dose-dependent fashion, and the PDE3 inhibitors (milrinone and cGMP) significantly augmented this response (P < 0.05). Hence, milrinone substantially improved LV relaxation in association with an acceleration of the SR Ca(2+)-ATPase activity and the SR Ca(2+) uptake. This acceleration might be due to an inhibition of the membrane-bound PDE3 in the SR, leading to a local elevation of cAMP.

Endoscopic and histological comparison of nonulcer dyspepsia with and without Helicobacter pylori infection evaluated by the modified Sydney system

OBJECTIVE

Our aim was to identify endoscopic features associated with Helicobacter pylori (H. pylori) infection in patients with nonulcer dyspepsia.

METHODS

A total of 50 infected patients with nonulcer dyspepsia who underwent endoscopy with antral and corporal biopsies and 50 patients matched for age and sex but with nonulcer dyspepsia without H. pylori were reviewed retrospectively by three endoscopists blinded to the H. pylori status and the patient's history. The endoscopic findings of gastritis, classified by a modification of the Sydney system as present or absent, were evaluated, and the histological severity was graded by the updated Sydney system.

RESULTS

For endoscopic features, the odds ratio was 53.1 (95% confidence interval, 6.8-414.9) for edema, 18.8 (5.8-60.5) for erythema with reddish streaks excluded, 0.0275 (0.0002-0.477) for reddish streaks, 17.4 (0.97-313.7) for friability, 14.2 (5.1-40.0) for exudate, 17.2 (2.2-137.6) for flat erosions, 2.54 (0.81-7.94) for raised erosions, 40.1 (2.3-694.5) for rugal hypertrophy, 19.1 (2.4-151.6) for rugal atrophy, 96.2 (23.4-395.9) for a vascular pattern, 0.125 (0.010-1.06) for bleeding spots, and 21.0 (2.6-166.5) for nodularity. The histological severity of inflammation, neutrophil activity, and atrophy in the antrum and corpus and of metaplasia in the antrum was greater in the infected patients than in the noninfected patients.

CONCLUSIONS

Endoscopic features associated with H. pylori were a vascular pattern, edema, rugal hypertrophy, nodularity, rugal atrophy, erythema with reddish streaks excluded, flat erosions, and exudate. These endoscopic features were associated with the histological findings of inflammation, neutrophil activity, atrophy, and metaplasia.

Mechanism of preserved positive lusitropy by cAMP-dependent drugs in heart failure

In tachycardia-induced heart failure (HF), positive lusitropic effects of milrinone or dobutamine were assessed by evaluating the time constant of left ventricular (LV) pressure decay (tau) and Ca(2+)-ATPase activity of the sarcoplasmic reticulum (SR). The peak value of the positive first derivative of LV pressure (+dP/dt) was less increased, either by dobutamine (2-10 microg x kg(-1) x min(-1)) or by milrinone (4-20 microg/kg), in HF than in control (P < 0.05), whereas tau was shortened to an extent similar to that in control with dobutamine [P = not significant (NS)] and to an even greater extent with milrinone (P < 0.05). Ca(2+)-ATPase activity increased similarly in HF and control with dobutamine (1 microM; +11% in HF vs. +12% in control, P = NS), whereas it increased more with milrinone (1 microM; +19% in HF vs. +11% in control, P < 0.05). Ca(2+)-ATPase activity-cAMP relationships were shifted to the left by milrinone or dobutamine in HF compared with control. Thus, in HF, the sensitivity of Ca(2+)-ATPase activity to cAMP was increased on addition of cAMP-dependent inotropic agents, contributing to the preservation of positive lusitropy.

Development of gap junctional channels and intercellular communication in rat liver during ontogenesis

BACKGROUND/AIMS

We investigated the expression of connexin (Cx) 32 and 26 subunit proteins of the gap junction (GJ) in the rat liver during ontogenesis to clarify their roles in control of growth and differentiation, and observed their channels in association with development of gap junctional intercellular communication (GJIC).

METHODS

The expression of Cx32 and 26 in prenatal and postnatal livers was examined by Western blot and immunofluorescence. GJ channels were investigated not only by double immunofluorescence study but also by immunogold electron microscopy. The spread of lucifer yellow 5 min after its microinjection was examined in the cultured liver tissues.

RESULTS

1) Western blot showed the expression of both Cx from the late stage of gestation and their peak a week after birth. 2) Cx32- or 26-positive plaques were scattered on hepatocytes of the fetal liver and some of them were colocalized; both were increased just after birth. On day 7 after birth, Cx32-positive plaques were present on all hepatocytes within a lobule, and Cx26-positive plaques were distributed in the periportal area. 3) Double-immunogold electron microscopy just after birth showed that most GJ channels were homotypic type of Cx32 or 26, and that few were heterotypic. On day 7 after birth, most channels had the homotypic type of type of Cx32 in the middle and pericentral areas, and there was a heterotypic type of Cx32 and 26 in the periportal area. 4) The dye transfer of lucifer yellow showed a wider spread in the liver tissues on day 7 after birth than on day 1.

CONCLUSION

Increased GJ formation and compatibility or incompatibility of GJ channels are closely associated with development of GJIC, and GJIC may develop at cytodifferentiation during ontogenesis.

Abnormal Ca2+ release from cardiac sarcoplasmic reticulum in tachycardia-induced heart failure

OBJECTIVE

In heart failure, little information is available as to the Ca2+ release function of sarcoplasmic reticulum (SR), which plays a major role in cardiac contractile function. Here, we assessed the rapid kinetics of drug-induced Ca2+ release from cardiac SR in combination with a measurement of ryanodine binding in heart failure.

METHODS

The SR vesicles were isolated from dog left ventricular (LV) muscles (normal (N), n = 10; pacing induced heart failure (HF), n = 10). The time course of SR Ca2+ release was continuously monitored by a stopped-flow apparatus using arsenazoIII as a Ca2+ indicator, and Ca2+ uptake and [3H]ryanodine binding assays were done using a filtration method.

RESULTS

The amount of Ca2+ uptake was reduced in HF to 55% of N (P < 0.05). Even the more marked and earlier appeared decrease was seen in the rate constant and the initial rate of polylysine (PL; a specific release trigger)-induced Ca2+ release (P < 0.05). However, the PL concentration dependency of the initial rate shifted towards lower concentrations of PL in HF than in N ([PL] at half maximum stimulation = 0.13 vs. 0.35 microM). The [3H]ryanodine binding assay revealed a lower Bmax (pmol/mg) in HF than in N (0.91 +/- 0.19 vs. 2.64 +/- 0.59, P < 0.05), but no difference in Kd (nM) (0.95 +/- 0.29 vs. 0.90 +/- 0.11, P = n.s.). The [PL] dependency on the enhancement of [3H]ryanodine binding again showed a shift towards lower [PL] in HF than in N.

CONCLUSIONS

In pacing-induced heart failure, the Ca2+ releasing function of SR is disturbed, which may result in an intra-cellular Ca2+ transient that was slowed down.

Alterations in cardiac sarcoplasmic reticulum Ca2+ regulatory proteins in the atrial tissue of patients with chronic atrial fibrillation

OBJECTIVES

Our purpose was to determine whether atrial fibrillation (AF) patients have alterations in sarcoplasmic reticulum (SR) Ca2+ regulatory proteins in the atrial myocardium.

BACKGROUND

Clinically, AF is the most frequently encountered arrhythmia. Recent studies indicate that an inability to maintain intracellular Ca2+ homeostasis with a consequent increase in membrane-triggered activity could be the primary initiating factor in some circumstances, and that cytosolic Ca2+ abnormalities are an important mediator of sustained AF.

METHODS

We measured the maximum number of [3H]ryanodine binding sites (Bmax) and the expression levels of ryanodine receptor (RyR) mRNA and calcium-adenosine triphosphatase (Ca2+-ATPase) mRNA in atrial myocardial tissue from 13 patients with AF due to mitral valvular disease (MVD) and 9 patients with normal sinus rhythm (NSR).

RESULTS

In AF patients, 1) Bmax was significantly lower in each atrium (0.21+/-0.03 pmol/mg [right], 0.16+/-0.04 pmol/mg [left]) than in the right atrium (0.26+/-0.08 pmol/mg) of NSR patients; 2) Bmax was significantly lower in the left atrium than in the right atrium; 3) Bmax in the left atrium was significantly lower at higher levels of pulmonary capillary wedge pressure; 4) the expression level of RyR mRNA was significantly lower in both the left (1.24 x 10(-2)+/-1.28 x 10(-2)) and right (1.70 x 10(-2)+/-1.78 x 10(-2)) atrium than in the right atrium of NSR patients (6.11 x 10(-2)+/-2.79 x 10(-2)); and 5) the expression level of Ca2+-ATPase mRNA was significantly lower in both the left (5.67 x 10(-2)+/-4.01 x 10(-2)) and right (7.71 x 10(-2)+/-3.56 x 10(-2)) atrium than in the right atrium (12.60 x 10(-2)+/-3.92 x 10(-2)) of NSR patients.

CONCLUSIONS

These results provide the first direct evidence of abnormalities in the Ca2+ regulatory proteins of the atrial myocardium in chronic AF patients. Conceivably, such abnormalities may be involved in the initiation and/or perpetuation of AF.