Acid inhibits TRPV4-mediated Ca²⁺ influx in mouse esophageal epithelial cells

BACKGROUND

The transient receptor potential vanilloid 4 (TRPV4), a thermo-sensitive stretch-activated cation channel, is expressed in the skin stratified squamous epithelium, contributing to the acquisition of barrier function. Similarly, functional TRPV4 may be located in the stratified squamous epithelial lining of the esophagus, being involved in the pathogenesis of gastroesophageal reflux disease (GERD). Here we investigated the expression of TRPV4 in the mouse esophageal epithelium.

METHODS

TRPV4 expression at the mRNA and protein levels was examined by reverse transcription-polymerase chain reaction (RT-PCR), in situ hybridization, and immunohistochemistry. A calcium imaging technique and ATP assay were used to evaluate the functionality of TRPV4 in freshly isolated esophageal epithelial cells.

KEY RESULTS

Transcripts and proteins encoding TRPV4 were colocalized in the basal and intermediate layers of the esophageal epithelium. Both 4α-phorbol 12,13- didecanoate (4α-PDD), a selective agonist for TRPV4, and hypo-osmolar solution (160 mOsm) elevated the intracellular calcium concentration ([Ca(2+) ](i) ) in a subset of the isolated cells (70%). These [Ca(2+) ](i) increases were potently inhibited by ruthenium red (RuR), a TRPV4 channel antagonist, and were suppressed by extracellular protons (pH 5.0). Finally, application of 4α-PDD evoked ATP release in primary esophageal epithelial cells.

CONCLUSIONS & INFERENCES

Acid-sensitive TRPV4 channels were mainly expressed in the esophageal epithelial cells of the basal and intermediate layers. Direct exposure of TRPV4-expressing cells to gastric acid, as would occur in cases of GERD, could influence their cellular functions, possibly aggravating the disease state.

Podoplanin is a potential marker for the diagnosis of ependymoma: a comparative study with epithelial membrane antigen (EMA)

Podoplanin is a mucin-type transmembrane sialoglycoprotein that is characteristically expressed in lymphatic endothelia. It is also expressed in the ependyma of the central nervous system as well as in ependymomas. Particularly, membrane-bound structures along the luminal surface, ring-like structures, and dot-like structures in the cytoplasm, all of which were originally reported for epithelial membrane antigen (EMA) immunohistochemistry in ependymoma, were also reported for podoplanin immunohistochemistry in ependymoma. This study was undertaken to evaluate podoplanin as compared with EMA as a marker of ependymoma. A total of 16 ependymomas (WHO Grade (G) II, 9 cases; GIII, 4; myxopapillary, 2; GIII clear cell, (1) were immunohistochemically studied using antibodies against podoplanin (clones D2-40 and NZ-1) as well as an antibody against EMA (clone E29). In all cases, D2-40 and NZ-1 excellently labeled linear signals along the luminal surface of ependymal canals/rosettes, dot-like structures, and/or ringlike structures, as did E29. These structures were generally more abundant in GII ependymomas than in GIII ependymomas. A semiquantitative analysis between the immunopositive structures of D2-40 or NZ-1 and E29 was conducted with a focus on the dot-like structures and the ring-like structures in the cases of GII and GIII ependymoma. The result showed that there was no statistical difference between D2-40 or NZ-1 and E29. Our study suggests that podoplanin is a potential marker for the diagnosis of ependymoma that corresponds to EMA. Anti-podoplanin antibodies and anti-EMA antibodies could cooperate with each other for the diagnostic immunohistochemistry of ependymoma.

A clinical study of Henoch-Schönlein Purpura associated with malignancy

BACKGROUND

Malignancy has been reported as a causative factor of cutaneous vasculitis, although only two retrospective epidemiological studies have analysed the association between Henoch-Schönlein purpura (HSP) and malignancy to date.

OBJECTIVE

To analyse the association between adult HSP and malignancy.

METHODS

We retrospectively reviewed the medical records of patients and found 103 cases of HSP over the past 20 years. Fifty-three cases (aged > or = 41 years) were categorized to two groups including 'with malignancy' or 'without malignancy', so that we could analyse the differences of clinical features between them. We also compared our study to previous reports.

RESULTS

Twenty-three cases out of 53 patients exhibited underlying malignant tumours. We focused on nine patients in which malignant tumours were thought to be strongly associated. Seven of nine patients exhibited new metastatic lesions or died due to underlying cancer within 1-32 months.

CONCLUSIONS

An association between HSP and malignant disease might have important diagnostic and pathophysiologic implications.

Development of a measuring system of contact force during braille reading using an optical 6-axis force sensor

A system with an optical 6-axis force sensor was developed to measure contact force during braille reading. In using this system, we encountered two problems. One is a variability of output values depending on the contact point. This was solved by using two transformation techniques. The other is that subjects read braille in a different manner from the usual. We compared two manners of braille reading, one-handed vs two-handed, and found a small reduction in reading speed. Using this system, we collected data from four braille readers and quantitatively showed more minute contact force trajectories than those in earlier studies.

[The strategy to avoid malperfusion of vital organs during operation for acute aortic dissection; multi-monitoring and right brachial artery perfusion]

BACKGROUND

Malperfusion of vital organs is the most serious complication during cardiopulmonary bypass for acute aortic dissection.

METHOD

From 2001 to 2006, 40 patients underwent operation for acute type A aortic dissection. Right brachial artery perfusion was performed in 20 patients. From May 2005, transesophageal echocardiography and cerebral oxygenation measured by near infrared spectroscopy were continuously monitored during operation.

RESULTS

There were 3 in-hospital deaths and 3 brain infarction. Switching of blood flow during cardiopulmonary bypass occurred in 3 patients; 2 patients suffered from diffuse brain infarction while. in the other patient, switching of perfusion was detected at once by multi-monitoring and resolved by induction of right brachial artery perfusion.

CONCLUSION

Close monitoring of cerebral oxygenation by near infrared spectroscopy, transesophageal echocardiography and right brachial artery perfusion are effective in operation for acute aortic dissection.

CD4+CD25high Regulatory T Cells Are Markedly Decreased in Blood of Patients with Pemphigus Vulgaris

BACKGROUND

It remains to be determined whether pemphigus vulgaris (PV), an autoimmune blistering disease, has a reduction and/or dysfunction of CD4(+)CD25(high) regulatory T (Treg) cells.

OBJECTIVES

To evaluate the frequency and phenotypes of Treg cells in blood of patients with PV.

METHODS

Peripheral blood mononuclear cells were prepared from PV patients as well as normal and disease control volunteers, and the frequency and phenotypes of Treg cells were determined by flow cytometry. CD4(+)CD25(+) and CD4(+)CD25(-) T cells isolated from peripheral blood mononuclear cells of PV patients and normal controls were subjected to real-time semiquantitative RT-PCR for the expression of Foxp3 gene.

RESULTS

The proportion of Treg cells in all PV patients was severely reduced, approximately ten times less than controls. These observations were further confirmed by both diminished gene and protein expression of Foxp3 in the CD4(+)CD25(+) T cell population in PV patients.

CONCLUSIONS

Numerical impairment of Treg cells may be involved in the pathogenesis of PV.

Direct injection of calcitriol or its analog into hyperplastic parathyroid glands induces apoptosis of parathyroid cells

Hyperplasia of the parathyroid gland (PTG) is associated not only with excessive secretion of parathyroid hormone (PTH) but also with changes in the parathyroid cell (PTC) characteristics (i.e. hyperproliferative activity, and low contents of vitamin D and calcium-sensing receptors). Control of PTG hyperplasia is most important in the management of secondary hyperparathyroidism, but the advanced stage of hyperplasia is considered irreversible. In the present study, dialysis patients with PTG hyperplasia underwent direct injection of calcitriol or maxacalcitol (OCT) into the PTG. Ultrasonography showed that this treatment had significantly reduced PTG volume and tissue analysis using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) method and DNA electrophoresis indicated that cellular apoptosis had been induced. The mechanism of apoptosis was evaluated in detail in uremic rats fed a high-phosphate diet. OCT or its vehicle was directly injected into the rats' PTGs. In the PTGs treated by OCT, there was a significantly increased number of TUNEL-positive PTCs and DNA electrophoresis revealed the characteristic ladder pattern of DNA fragmentation, both findings indicative of apoptosis. There was also a significant upregulation of both vitamin D and Ca-sensing receptors in the PTCs and a clear shift of the Ca-PTH response curve to the left and downward. None of these findings was observed in the PTGs treated by vehicle. This novel treatment is successful in causing regression of PTG hyperplasia. Thus, it is expected to significantly reduce the PTH level and ameliorate the abnormal bone turnover and mineral metabolism.

Ah receptor, CYP1A1, CYP1A2 and CYP1B1 gene polymorphisms are not involved in the risk of recurrent pregnancy loss

The etiology of recurrent pregnancy loss (RPL) remains unclear, but it may be related to a possible genetic predisposition together with involvement of environmental factors. We examined the relation between RPL and polymorphisms in four genes, human aryl hydrocarbon (Ah) receptor, cytochrome P450 (CYP) 1A1, CYP1A2 and CYP1B1, which are involved in the metabolism of a wide range of environmental toxins and carcinogens. All cases and controls were women resident in Sapporo, Japan and the surrounding area. The Ah receptor, CYP1A1, CYP1A2 and CYP1B1 genotypes were assessed in 113 Japanese women with recurrent pregnancy loss (RPL) and 203 ethnically matched women experiencing at least one live birth and no spontaneous abortion (control). No significant differences in Ah receptor, CYP1A1, CYP1A2 and CYP1B1 genotype frequencies were found between the women with RPL and the controls [Ah receptor: Arg/Arg (reference); Arg/Lys and Lys/Lys, odds ratio (OR)=0.67; 95% confidence interval (CI)=0.40-1.11, CYP1A1: m1m1 (reference); m1m2 and m2m2, OR = 0.86; 95% CI = 0.53-1.40, CYP1A2: C/C and C/A (reference); A/A, OR = 1.16; 95% CI = 0.71-1.88, CYP1B1: Leu/Leu (reference); Leu/Val and Val/Val, OR = 1.18; 95% CI = 0.68-2.02]. The present study suggests that the Ah receptor, CYP1A1, CYP1A2 and CYP1B1 gene polymorphisms are not major genetic regulators in RPL.

Characterization of antigenically and genetically similar influenza C viruses isolated in Japan during the 1999-2000 season

Between October 1999 and May 2000, a total of 28 strains of influenza C virus were isolated in four Japanese prefectures: Yamagata, Miyagi, Saitama and Hiroshima. Antigenic analysis showed that the 28 isolates were divided into three distinct antigenic groups, and viruses belonging to different antigenic groups were co-circulating in each of the four prefectures. Phylogenetic analysis of the seven protein genes demonstrated that the viruses having a similar genome composition spread in various areas of Japan during the same period. Furthermore, phylogenetic analysis showed that most of the influenza C viruses isolated in various areas of the world between the 1970s and 1980s were closely related to the contemporary Japanese viruses in all gene segments. These observations suggest that the influenza C viruses cause epidemics in some communities during the same season and that antigenically and genetically similar influenza C viruses spread throughout Japan and may be circulating worldwide.

Preoperative administration of rebamipide significantly lowers body temperature and circulating interleukin-6 in gastric cancer patients after gastrectomy

BACKGROUND/AIMS

It has recently been reported that rebamipide (OPC-12759) inhibits inflammatory cytokines and activation of neutrophils. The aim of the present study was to investigate the effects of preoperative administration of rebamipide on parameters of systemic inflammatory response syndrome (SIRS) and serum levels of inflammatory cytokines in gastric cancer patients after gastrectomy.

PATIENTS AND METHODS

We measured the parameters of SIRS, circulating cytokines and acute phase reactants in patients after (i). distal gastrectomy with D2 lymph node dissection (group 1, n = 10); (ii). distal gastrectomy with D2 lymph node dissection following administration of rebamipide (group 2, n = 10), and (iii). laparoscopy-assisted distal gastrectomy (LADG) with D1 lymph node dissection (group 3, n = 10). Group 2 was administered 100 mg of rebamipide 3 times/day after meals for 7 days before surgery.

RESULTS

Among the parameters of SIRS, a difference was observed in body temperature on day 3. The mean body temperature of group 2 was significantly lower than group 1 (p = 0.006), and was similar to group 3. In proinflammatory cytokines, a significant difference was observed in the serum levels of interleukin (IL)-6. On day 1 the IL-6 levels of group 2 were significantly lower than those of group 1 (p < 0.001). The changes in the IL-6 level of group 2 were similar to group 3, except in the very early postoperative phase. However, other proinflammatory cytokines, such as IL-8 and IL-10, were not detected, and there was no difference in C-reactive protein between the 3 groups.

CONCLUSION

Preoperative administration of rebamipide significantly decreased postoperative body temperatures and circulating IL-6 in gastric cancer patients after gastrectomy to levels similar to those of patients with LADG.

High-dose rabeprazole-amoxicillin versus rabeprazole-amoxicillin-metronidazole as second-line treatment after failure of the Japanese standard regimen for Helicobacter pylori infection

BACKGROUND

There is currently no optimal second-line treatment after failure of Helicobacter pylori triple therapy.

AIM

To determine effective salvage therapy after failure of lansoprazole-amoxicillin-clarithromycin.

METHODS

After failure of lansoprazole-amoxicillin-clarithromycin 123 out-patients were randomized to receive either 2-week rabeprazole (20 mg b.d.) + amoxicillin (1000 mg b.d.) (RA group) or 1-week rabeprazole (10 mg b.d.) + amoxicillin (750 mg twice b.d.) + metronidazole (250 mg b.d.) (RAM group). Eradication was assessed by the 13C-urea breath test. We also evaluated cytochrome p450 (CYP) 2C19 genotype status, determined by polymerase chain reaction - restriction fragment length polymorphism, and susceptibility to clarithromycin and metronidazole.

RESULTS

On an intention-to-treat basis, H. pylori infection cure was achieved in 37 of 63 (59%) patients in the RA group and in 49 of 60 (82%) patients in the RAM group. Per protocol-based eradication rates in the RA and RAM groups were 66% (37/56) and 88% (49/56), respectively. In both analytic sets there were significant differences between the treatment groups (P < 0.01 in each). Mild adverse events were observed in eight and five patients from the RA and RAM groups, respectively. Genetic predisposition of CYP2C19 and antibiotic resistance did not influence the treatment outcome either regimen.

CONCLUSIONS

The rabeprazole + amoxicillin + metronidazole therapy yielded satisfactory results. In contrast, the cure rate in high-dose rabeprazole + amoxicillin was below an acceptable level.

Metabolic fate of pitavastatin, a new inhibitor of HMG-CoA reductase: similarities and difference in the metabolism of pitavastatin in monkeys and humans

1. To elucidate any potential species differences, the in vitro metabolism of pitavastatin and its lactone was studied with hepatic and renal microsomes from rats, dogs, rabbits, monkeys and humans. 2. With the addition of UDP-glucuronic acid to hepatic microsomes, pitavastatin lactone was identified as the main metabolite in several animals, including humans. 3. Metabolic clearances of pitavastatin and its lactone in monkey hepatic microsome were much greater than in humans. 4. M4, a metabolite of pitavastatin with a 3-dehydroxy structure, was converted to its lactone form in monkey hepatic microsomes in the presence of UDP-glucuronic acid as well as to pitavastatin. These results implied that lactonization is a common pathway for drugs such as 5-hydroxy pentanoic acid derivatives. 5. The acid forms were metabolized to their lactone forms because of their structural characteristics. 6. UDP-glucuronosyltransferase is the key enzyme responsible for the lactonization of pitavastatin, and overall metabolism is different compared with humans owing to the extensive oxidative metabolism of pitavastatin and its lactone in monkey.

High-dose rabeprazole-amoxicillin versus rabeprazole-amoxicillin-metronidazole as second-line treatment after failure of the Japanese standard regimen for Helicobacter pylori infection

BACKGROUND

There is currently no optimal second-line treatment after failure of Helicobacter pylori triple therapy.

AIM

To determine effective salvage therapy after failure of lansoprazole-amoxicillin-clarithromycin.

METHODS

After failure of lansoprazole-amoxicillin-clarithromycin 123 out-patients were randomized to receive either 2-week rabeprazole (20 mg b.d.) + amoxicillin (1000 mg b.d.) (RA group) or 1-week rabeprazole (10 mg b.d.) + amoxicillin (750 mg twice b.d.) + metronidazole (250 mg b.d.) (RAM group). Eradication was assessed by the 13C-urea breath test. We also evaluated cytochrome p450 (CYP) 2C19 genotype status, determined by polymerase chain reaction - restriction fragment length polymorphism, and susceptibility to clarithromycin and metronidazole.

RESULTS

On an intention-to-treat basis, H. pylori infection cure was achieved in 37 of 63 (59%) patients in the RA group and in 49 of 60 (82%) patients in the RAM group. Per protocol-based eradication rates in the RA and RAM groups were 66% (37/56) and 88% (49/56), respectively. In both analytic sets there were significant differences between the treatment groups (P < 0.01 in each). Mild adverse events were observed in eight and five patients from the RA and RAM groups, respectively. Genetic predisposition of CYP2C19 and antibiotic resistance did not influence the treatment outcome either regimen.

CONCLUSIONS

The rabeprazole + amoxicillin + metronidazole therapy yielded satisfactory results. In contrast, the cure rate in high-dose rabeprazole + amoxicillin was below an acceptable level.