A novel role of catalase in cholesterol uptake of Helicobacter pylori.

Helicobacter pylori infection is known to be a significant risk factor for the development of gastric cancers in humans. This pathogen exhibits unique biological characteristics in membrane lipid composition. Specifically, H. pylori incorporates exogenous cholesterol into biomembranes and uses cholesterol as the membrane lipid constituents. A previous study by our group demonstrated that phosphatidylethanolamine of H. pylori functions as the cholesterol-binding lipid. It is, however, unclear whether H. pylori is equipped with protein molecules involved in the cholesterol uptake. We, therefore, examined H. pylori proteins that tightly bind to cholesterol. As a consequence, H. pylori catalase (KatA) turned out to be a candidate of the cholesterol uptake-associated protein. In addition, an H. pylori mutant strain that expresses KatA protein lacking catalase activity was significantly lower in total cholesterol contents than the wild-type H. pylori strain. The putative amino acid sequence of KatA found out to contain a number of the cholesterol recognition/interaction amino acid consensus sequence domains (CRAC and CARC domains). These results suggest that H. pylori KatA with normal folding conformation acts as the cholesterol-binding or -storage protein.

A survey of Lasioderma serricorne (Fabricius) in Japanese Dental Clinics.

This study was to survey the capturing rate in Japanese dental clinics of the Lasioderma serricorne (cigarette beetles) , and to evaluate the beetle's potential as a carrier for transmission of nosocomial pathogens. L. serricorne imagoes were captured in pheromone traps in 14 Japanese dental clinics in August and September 2012 and 2013, and their numbers recorded. Polymerase chain reaction (PCR) for the bacterial antibiotic-resistant genes mecA, vanA, vanB, blaIMP, and blaVIM was performed on the captured L. serricorne imagoes. Bacterial species in the captured specimens were identified by 16S rRNA PCR and sequencing analysis. The L. serricorne imagoes were captured from 10 dental clinics (71.4%) . We failed to detect the presence of nosocomial antibiotic-resistant pathogens in L. serricorne imagoes. The bacterial species detected most commonly in the imagoes was Wolbachia sp., an intracellular proteobacterium infecting certain insect species. Monitoring of insects including L. serricorne should be incorporated into regiment of the infection control.

Lipopolysaccharides From Non-Helicobacter pylori Gastric Bacteria Potently Stimulate Interleukin-8 Production in Gastric Epithelial Cells.

BACKGROUND: Gastric acid secretion is compromised in chronic Helicobacter pylori (H. pylori) infection allowing overgrowth of non-H. pylori gastric bacteria (NHGB) in the stomach. METHODS: NHGB were isolated from gastric mucosa in selective media and further characterized with biochemical methods and 16S rRNA gene sequencing. Human gastric tissues were studied with indirect immunofluorescence with antibodies against H. pylori and Neisseria subflava (N. subflava). Gastric epithelial cell lines were cocultured with bacteria or incubated with lipopolysaccharides isolated from NHGB, and interleukin-8 released in the media was measured by enzyme-linked immunosorbent assay. Expression of Toll-like receptor (TLR)2, TLR4, it's coreceptor myeloid differentiation factor 2 (MD2), and CD14 in gastric cells was investigated by immunofluorescence microscopy and reverse transcriptase-polymerase chain reaction. RESULTS: Haemophilus species, Neisseria species, Fusobacterium species, and Veillonella species were predominant Gram-negative bacteria coinfected with H. pylori. Lipopolysaccharides from N. subflava potently stimulated interleukin-8 secretion in MKN45 cells which was cancelled by preincubation with polymyxin B. TLR2, TLR4, CD14, and myeloid differentiation factor 2 were expressed in MKN45 cells, though their levels of expression were low. N. subflava adhered to MKN45 cells in vitro and colocalized with H. pylori in the human gastric mucosa. CONCLUSIONS: Our data suggest that N. subflava colonized in the gastric mucosa contribute to gastric inflammation during chronic H. pylori gastritis. TRANSLATIONAL IMPACT: NHGB may perpetuate gastric inflammation and accelerate neoplastic progression in the hypochlorhydric stomach.

Identification and characterization of a vitamin D3 decomposition product bactericidal against Helicobacter pylori.

This study demonstrated that the vitamin D3 decomposition product VDP1 exerts an antibacterial action against Helicobacter pylori but not against other bacteria. Treatment with VDP1 induced a collapse of cell membrane structures of H. pylori and ultimately lysed the bacterial cells. A unique dimyristoyl phosphatidylethanolamine in the membrane lipid compositions contributed to the interaction of VDP1 with H. pylori cells. In separate experiments, VDP1 had no influence on the viability of the human cancer cell lines MKN45 and T47D and lacked any vitamin D3-like hormonal action against the latter. In both (1)H and (13)C NMR analyses, the spectra patterns of VDP1 corresponded with those of Grundmann's ketone. These results suggest that VDP1 (or Grundmann's ketone-type indene compound) may become a fundamental structure for the development of new antibacterial substances with selective bactericidal action against H. pylori.

Comparative analysis of gastrointestinal microbiota between normal and caudal-related homeobox 2 (cdx2) transgenic mice.

BACKGROUND/AIMS: Caudal-related homeobox 2 (Cdx2) is expressed in the human intestinal metaplastic mucosa and induces intestinal metaplastic mucosa in the Cdx2 transgenic mouse stomach. Atrophic gastritis and intestinal metaplasia commonly lead to gastric achlorhydria, which predisposes the stomach to bacterial overgrowth. In the present study, we determined the differences in gut microbiota between normal and Cdx2 transgenic mice, using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). METHODS: Twelve normal (control) and 12 Cdx2 transgenic mice were sacrificed, and the gastric, jejunal, ileac, cecal and colonic mucosa, and feces were collected. To quantitate bacterial microbiota, we used real-time qRTPCR with 16S rRNA gene-targeted, species-specific primers. RESULTS: The total numbers of bacteria in the gastric, jejunal, ileac, cecal, and colonic mucosa of the Cdx2 transgenic mice were significantly higher than those of the normal mice. The Bacteroides fragilis group and also Prevotella were not detected in the stomach of the normal mice, although they were detected in the Cdx2 transgenic mice. Moreover, the Clostridium coccoides group, Clostridium leptum subgroup, Bacteroides fragilis group, and Prevotella were not detected in the jejunum or ileum of the normal mice, although they were detected in the Cdx2 transgenic mice. The fecal microbiota of the normal mice was similar to that of the Cdx2 transgenic mice. CONCLUSIONS: Our results showed the differences in composition of gut microbiota between normal and Cdx2 transgenic mice, which may be caused by the development of gastric achlorhydria and intestinal metaplasia in Cdx2 transgenic mice.

Antibacterial activity of a novel synthetic progesterone species carrying a linoleic acid molecule against Helicobacter pylori and the hormonal effect of its steroid on a murine macrophage-like cell line.

Helicobacter pylori, a pathogen responsible for gastric and duodenal diseases, absorbs various steroid compounds into the cell membrane even though some are toxic to this bacterium. An earlier study by our group has demonstrated that progesterone is bactericidal to H. pylori. In this study, we newly synthesized a steroid compound, 17α-hydroxyprogesterone linoleic acid ester (17hPL), to examine antibacterial activity against H. pylori. As expected, 17hPL acted as a bactericidal agent to H. pylori and had no effect on the survival of other common bacterial species. This steroidal substance interacted with phosphatidylethanolamine (PE) on the outer membrane of H. pylori to induce the release of PE from the bacterial cell membrane and to ultimately lyse the bacterial cells. One of the hormonal effects of progesterone is the inhibition of nitric oxide (NO) production from mouse macrophages activated by lipopolysaccharide (LPS). We therefore examined the inhibition effect of 17hPL on the NO production of RAW 264.7 cells, a murine macrophage-like cell line, stimulated with LPS and demonstrated that 17hPL is relatively weaker in its capability to inhibit NO production in LPS-activated cells than progesterone. These results suggest the possibility that 17hPL could be an oral medicine for selectively treating patients infected with H. pylori.

Role of sphingomyelinase in infectious diseases caused by Bacillus cereus.

Bacillus cereus (B. cereus) is a pathogen in opportunistic infections. Here we show that Bacillus cereus sphingomyelinase (Bc-SMase) is a virulence factor for septicemia. Clinical isolates produced large amounts of Bc-SMase, grew in vivo, and caused death among mice, but ATCC strains isolated from soil did not. A transformant of the ATCC strain carrying a recombinant plasmid containing the Bc-SMase gene grew in vivo, but that with the gene for E53A, which has little enzymatic activity, did not. Administration of an anti-Bc-SMase antibody and immunization against Bc-SMase prevented death caused by the clinical isolates, showing that Bc-SMase plays an important role in the diseases caused by B. cereus. Treatment of mouse macrophages with Bc-SMase resulted in a reduction in the generation of H(2)O(2) and phagocytosis of macrophages induced by peptidoglycan (PGN), but no effect on the release of TNF-α and little release of LDH under our experimental conditions. Confocal laser microscopy showed that the treatment of mouse macrophages with Bc-SMase resulted in the formation of ceramide-rich domains. A photobleaching analysis suggested that the cells treated with Bc-SMase exhibited a reduction in membrane fluidity. The results suggest that Bc-SMase is essential for the hydrolysis of SM in membranes, leading to a reduction in phagocytosis.

Human intestinal spirochetosis in an immunocompromised host: evaluation of eradication therapy by endoscopy, histopathology and bacteriology.

Human intestinal spirochetosis (HIS) is a colorectal infectious disease caused by Brachyspira species. We describe HIS in an immunocompromised, 62-year-old Japanese man who presented at Jichi Medical University Hospital with symptoms of diarrhea and bloody stool. He had rheumatoid arthritis that had been treated with immunosuppressive drugs for 10 years. Colonoscopy revealed multiple erythematous spots in the cecum and colon. A histopathological examination identified intestinal colonization by spirochetes, and Brachyspira pilosicoli was isolated from biopsy specimens, indicating a diagnosis of HIS. Metronidazole eradicated the spirochetes, the intestinal mucosa recovered to normal, and the clinical symptoms disappeared. This case suggests that it is important to keep in mind HIS in the differential diagnosis of immunocompromised patients with chronic diarrhea and bloody stool.

[An example of metastasis to the iliopsoas muscle from sigmoid colon cancer].

Even though skeletal muscle, making up about 40% of body weight, is the largest organ in the human body, metastasis from malignant lesions is rare. Among reports of metastasis, those involving the iliopsoas muscle are numerous but few reports involve resection. Reported here is one example we experienced where metastasis developed in the iliopsoas muscle following colectomy, resection was then made possible by radiotherapy and chemotherapy. The case involved a 71-year- old male in which a Hartmann procedure was performed for sigmoid colon cancer. The pathology was Type 3 (8 × 7 cm, adenocarcinoma( mod), ss or more, ly1, v1, n0, ow(-), aw or ew(+), stage II). Upon additional sampling, thermal degredation of neoplastic cells was shown and outpatient oral UFT was performed. Five years following surgery, lymphoadenopathy was noted in the area of the left iliac artery upon US and CT. PET showed a probable metastasis to the left iliopsoas muscle. Early esophageal and stomach cancer were diagnosed by GFT. The esophageal cancer was located 30-32 cm from the incisors, unstained, Borrmann type 1, penetrating deeper than the muscularis propria. Biopsy revealed a diagnosis of tubular adenocarcinoma. ESD was performed for the esophageal cancer and one month later, a total gastrectomy D1+ß was performed. During surgery, the iliopsoas muscle tumor was determined to be large and impossible to resect. Radiotherapy of 10MV X-ray, 8 fields, 65-70 Gy/26 times for 6 . 5 weeks was performed for residual tumor but had no effect on tumor size. Fifteen courses of FOLFOX+bevacizumab were then performed. The tumor was markedly reduced in size, unidentifiable upon CT but showed slight uptake on PET and resection of the suspected residual tumor was performed. Histologically, atypical cells were shown in scarred muscle and connective tissue, however, degradation by chemotherapy was high. Residual tumor at resection margins was found, findings consistent with metastasis form sigmoid colon cancer. Taking into account the age and condition of the patient following surgery, chemotherapy was changed to S-1. Currently, 5 months after resection, there has been no recurrence.

[Preoperative S-1/CDDP combination chemotherapy was effective in a case of local advanced gastric cancer].

INTRODUCTION: The prognosis of type 4 advanced gastric cancer is extremely poor, even the use of multidisciplinary treatment cannot provide satisfactory results. Presented here is a case of highly advanced gastric cancer in which preoperative chemotherapy was effective and resection possible. CASE: A 64-year-old female complained of epigastric distress. Current medical history included: hypertension, hyperlipemia, diabetes, chronic heart disease and development of epigastric distress. Endoscopy was performed upon examination in the Gastroenterology Department. Visual inspection showed a lesion extending from the greater curvature of the fundus to the antrum. Type 4 advanced gastric cancer was strongly suspected. Biopsy samples taken from the antral lesser curvature and from the ulcer border on the upper anterior wall of the body were diagnosed as Group V, adenocarcinoma. Abdominal CT revealed no hepatic mass, but overall thickening of the gastric wall was noticeable and the lymph nodes in the area of the lesser curvature of the stomach and celiac artery were identified. Abdominal ultrasound showed an overall thickening of the gastric wall, and invasion into a portion of the left hepatic lobe and pancreas was suspected. Swelling of the lymph nodes surrounding the stomach was suspected. TREATMENT: Because of gastric cancer with suspected invasion of the left hepatic lobe and pancreas, it was decided to perform preoperative chemotherapy (S-1 + CDDP) and then perform a total gastrectomy. Four courses were performed. RESULTS: Endoscopy revealed no change in the lesion within the stomach. Only scarring in the body and antrum was found, the enlargement was greatly reduced and visual inspection revealed no esophageal infiltration. Biopsy samples were taken from 2 sites, the body center on the lesser curvature side and the greater curvature of the antrum. Scar-like fibrosis was significant and it was not possible to distinguish an increase in poorly differentiated adenocarcinoma. Abdominal CT showed a reduction in gastric wall thickening. These findings showed preoperative chemotherapy to be effective. Following the chemotherapy, a total gastrectomy in addition to splenectomy and cholecystectomy were performed. Histopathological findings showed MLU, type 5, approx. 8.5 × 13 cm, poorly differentiated adenocarcinoma (por 2), INF γ, sci, pT2 (SS), ly2, v0, pN2 (#1: 2/8, #6: 1/6, #11p: 2/5), pPM (-), pDM (-), Stage IIIA. Along with the formation of fibrous scar tissue, an invasive growth of por 2 poorly differentiated adenocarcinoma was found from the submucosal layer to just beneath the serosal layer. Therapeutic effect of the chemotherapy was Grade 2. Post operative S-1 + CDDP was begun but nausea developed and S-1 was reduced. Because of a decrease of neutrophils and nausea, the therapy was changed to UFT. It is currently 6 months after surgery and there are no signs of recurrence. CONCLUSION: Preoperative chemotherapy (S-1 + CDDP) is a therapy which shows promise in reducing tumor size even in highly advanced gastric cancer.

Effect of eradication of Helicobacter pylori on incidence of metachronous gastric carcinoma after endoscopic resection of early gastric cancer: an open-label, randomised controlled trial.

BACKGROUND: The relation between Helicobacter pylori infection and gastric cancer has been proven in epidemiological studies and animal experiments. Our aim was to investigate the prophylactic effect of H pylori eradication on the development of metachronous gastric carcinoma after endoscopic resection for early gastric cancer. METHODS: In this multi-centre, open-label, randomised controlled trial, 544 patients with early gastric cancer, either newly diagnosed and planning to have endoscopic treatment or in post-resection follow-up after endoscopic treatment, were randomly assigned to receive an H pylori eradication regimen (n=272) or control (n=272). Randomisation was done by a computer-generated randomisation list and was stratified by whether the patient was newly diagnosed or post-resection. Patients in the eradication group received lansoprazole 30 mg twice daily, amoxicillin 750 mg twice daily, and clarithromycin 200 mg twice daily for a week; those in the control group received standard care, but no treatment for H pylori. Patients were examined endoscopically at 6, 12, 24, and 36 months after allocation. The primary endpoint was diagnosis of new carcinoma at another site in the stomach. Analyses were by intention to treat. This trial is registered with the UMIN Clinical Trials Registry, number UMIN000001169. FINDINGS: At 3-year follow-up, metachronous gastric carcinoma had developed in nine patients in the eradication group and 24 in the control group. In the full intention-to-treat population, including all patients irrespective of length of follow-up (272 patients in each group), the odds ratio for metachronous gastric carcinoma was 0.353 (95% CI 0.161-0.775; p=0.009); in the modified intention-to-treat population, including patients with at least one post-randomisation assessment of tumour status and adjusting for loss to follow-up (255 patients in the eradication group, 250 in the control group), the hazard ratio for metachronous gastric carcinoma was 0.339 (95% CI 0.157-0.729; p=0.003). In the eradication group, 19 (7%) patients had diarrhoea and 32 (12%) had soft stools. INTERPRETATION: Prophylactic eradication of H pylori after endoscopic resection of early gastric cancer should be used to prevent the development of metachronous gastric carcinoma. FUNDING: Hiroshima Cancer Seminar Foundation.

Alterations in the glycoform of cisplatin-resistant human carcinoma cells are caused by defects in the endoplasmic reticulum-associated degradation system.

Cisplatin, cis-diamineplatinum-(II) dichloride (CDDP), is one of the most common and valuable chemotherapeutic reagents for various cancers. However, it is well known that tumor cells gain acquired or intrinsic resistance to treatment by this anti-cancer reagent. In spite of extensive efforts using genetic and proteomic approaches, the mechanism underlying CDDP resistance remains unclear. In the present study, we report drastic structural changes in the N-glycans of glycoproteins in CDDP-resistant tumor cells (the KCP-4 cell line obtained from KB-3-1 human carcinoma cells). It was suggested that the CDDP-resistant cells exhibited an increase in one of the high-mannose-type glycans, particularly M8.1. This N-glycan is well known as a tag for the transport of unfolded protein from the endoplasmic reticulum to the lysosome, a process known as endoplasmic reticulum-associated degradation (ERAD) system. The revertant cells (KCP-4R) obtained from the KCP-4 cell line showed almost the same glycoform profile as that of the parental cells, suggesting that N-glycan biosynthesis in tumor cells clearly corresponds to the alteration in the sensitivity against CDDP. Gene expression analysis using a cDNA microarray showed a decrease in the expression of major histocompatibility complex (MHC) proteins in the resistant cells. MHC proteins form a complex with lysosome-degradated proteins and are presented on the cell surface. These results suggest that CDDP tolerance in KCP-4 cells is caused by a defect in the ERAD system.

Antibacterial activity of hydrolyzable tannins derived from medicinal plants against Helicobacter pylori.

Helicobacter pylori is a major etiological agent in gastroduodenal disorders. In this study, we isolated 36 polyphenols and 4 terpenoids from medicinal plants, and investigated their antibacterial activity against H. pylori in vitro. All hydrolyzable tannins tested demonstrated promising antibacterial activity against H. pylori. Monomeric hydrolyzable tannins revealed especially strong activity. Other compounds demonstrated minimal antibacterial activity with a few exceptions. A monomeric hydrolyzable tannin, Tellimagrandin I demonstrated time- and dose-dependent bactericidal activity against H. pylori in vitro. On the other hand, hydrolyzable tannins did not affect the viability of MKN-28 cells derived from human gastric epithelium. Hydrolyzable tannins, therefore, have potential as new and safe therapeutic regimens against H. pylori infection. Furthermore, we investigated effects of hydrolyzable tannins on lipid bilayer membranes. All the hydrolyzable tannins tested demonstrated dose-dependent membrane-damaging activity. However, it remains to be elucidated whether their membrane-damaging activity directly contributes to their antibacterial action.

Characterization of elongated Helicobacter pylori isolated from a patient with gastric-mucosa-associated lymphoid-tissue lymphoma.

To date, two Helicobacter species, Helicobacter pylori and 'Helicobacter heilmannii' (formerly named 'Gastrospirillum hominis'), have been identified from the human stomach. In this study, we observed non-H. pylori-shaped bacteria in gastric tissue sections and successfully isolated them by cultivation. Elongated bacteria were isolated from a patient with gastric-mucosa-associated lymphoid-tissue lymphoma who had been diagnosed as H. pylori-negative by culture, rapid urease test and histopathology in another hospital. The bacteria were grown only on chocolate agar in a CO2 incubator, appeared more than 10 microm long in histological sections, formed small colonies and showed poor growth in a brain heart infusion broth; these characteristics apparently differed from common clinical isolates of H. pylori. However, the bacteria were identified as H. pylori by PCR of the urease gene, 16S rDNA sequencing, protein profile and antigenicity examined by anti-H. pylori polyclonal antibody. These observations suggest that the H. pylori strain identified in this study may contribute to the development of gastroduodenal diseases in cases judged as H. pylori-negative by ordinary methods.

Negative autoregulation of p73 and p53 by DeltaNp73 in regulating differentiation and survival of human neuroblastoma cells.

p73, mapped to 1p36.2-3, is a p53-related tumor suppressor but is also induced by the oncogene products such as E2F1, raising a question whether p73 is a tumor suppressor gene or oncogene. p73 has several splicing variants including DeltaNp73 which lacks the NH(2)-terminal transactivation domain. In developing neurons, DeltaNp73 is expressed abundantly and seems to inhibit the pro-apoptotic function of p53. However, the role of TAp73 and DeltaNp73 as well as their regulatory mechanism in cell growth and differentiation of neuroblastoma cells are poorly understood. We have found that TAp73 directly activates the transcription of endogenous DeltaNp73 by binding to the TAp73-specific target element located at position-76 to 57 within the DeltaNp73 promoter region. DeltaNp73 was physically associated with TAp73alpha, TAp73beta and p53, and inhibited their transactivation activities when used reporters of Mdm2, Bax or DeltaNp73 itself in SAOS-2 cells. Overexpression of DeltaNp73 in SH-SY5Y neuroblastoma cells promoted cell survival by competing with p53 and TAp73 itself. Thus, our results suggest that the negative feedback regulation of TAp73 by its target DeltaNp73 is a novel autoregulatory system for modulating cell survival and death, that is also functioning in neuroblastoma cells.

Identification of the p33(ING1)-regulated genes that include cyclin B1 and proto-oncogene DEK by using cDNA microarray in a mouse mammary epithelial cell line NMuMG.

The candidate tumor suppressor p33(ING1) plays an important role in inducinggrowth arrest at G(0)-G(1) phase of the cell cycle and/or promoting apoptosis in cancerous cells. p33(ING1) is reported to act as a transcriptional cofactor by associating with tumor suppressor p53, HAT, or histone deacetyltransferase, suggesting that p33(ING1) is involved in chromatin-mediated transcriptional regulation. However, the molecular mechanism of p33(ING1)-mediated transcriptional regulation is poorly understood. Here we analyzed expression profiles in mouse mammary epithelial cells (NMuMG) by using a cDNA microarray consisting of 2304 mouse cDNAs after inducing transformation with antisense inhibitor of growth 1 (ING1) in retrovirus vector. The subsequent confirmation of the altered expression levels of the selected genes by semiquantitative reverse transcription-PCR demonstrated that overexpression of the antisense ING1 stimulated expression of 14 genes, which included cyclin B1, 12-O-tetradecanoylphorbol-13-acetate-inducible sequence 11, proto-oncogene DEK, and osteopontin, whereas we have detected transcriptional repression of 5 genes, including TPT1. In addition, adenovirus-mediated overexpression of ING1 in NMuMG cells resulted in down-regulation of cyclin B1, 12-O-tetradecanoylphorbol-13-acetate-inducible sequence 11, DEK, and osteopontin, whereas the levels of TPT1 expression were increased. The further analysis using p53(-/-) SAOS2 cells showed that the p33(ING1)-induced cyclin B1 down-regulation was p53 dependent. Thus, our cDNA microarray analysis suggested that p33(ING1) targets the multiple genes, including proto-oncogene DEK and cyclin B1, at least some of which are regulated in a p53-dependent manner, in the cells undergoing cell growth or apoptosis.

Non-standard biological activities of lipopolysaccharide from Helicobacter pylori.

As assessed by the lipopolysaccharide (LPS)-specific chromogenic Limulus amoebocyte lysate (LAL) assay, Helicobacter pylori LPS extracted by the phenol-water procedure showed full potency to coagulate LAL, as did LPS from Salmonella minnesota and Escherichia coli. However, pretreatment of H. pylori LPS with polymyxin B, which easily destroys the endotoxic activity of enterobacterial LPS/lipid A, had little effect on the LAL coagulation activity, although the same treatment of E. coli LPS markedly diminished its activity. The H. pylori LPS induced very weak production of nitric oxide (NO) or tumour necrosis factor (TNF) by murine macrophages and TNF by human peripheral whole blood in vitro in comparison with S. minnesota LPS. These findings indicate that H. pylori LPS has the unique endotoxic characteristic of retaining full LAL coagulation activity with polymyxin B resistance, despite losing its endotoxic potencies such as the ability to induce NO and TNF production.