Prevalence of Staphylococcus argenteus among food handlers, kitchen utensils, and food samples in Japan

Staphylococcus argenteus has received increased attention from an aspect of food safety since several food poisoning outbreaks caused by the bacterium were reported in Japan. However, S. argenteus prevalence among food handlers and utensils has not yet been investigated. In this study, we investigated S. argenteus prevalence among a collection of coagulase-positive staphylococci (CPS) that were isolated during food sanitary inspections in Japan. Out of a total of 191 CPS isolates, 14 were identified as S. argenteus. One was isolated from shelled shrimp, nine were isolated from food handlers' hand swabs, and four were isolated from kitchen utensils. Whole-genome sequencing revealed that transmission of S. argenteus from human hands to utensils was possible. Though all 14 isolates were negative for the pvl and tst-1 genes, 6 harbored the seb gene. Only 21.4% of S. argenteus isolates were resistant to antibiotics, while 62.1% of the S. aureus isolates from the same sources were confirmed to be resistant. To the best of our knowledge, this is the first report to demonstrate possible transmission of S. argenteus from food handlers to utensils in food-processing environments.

Isolation and characterization of Staphylococcus argenteus strains from retail foods and slaughterhouses in Japan

Staphylococcus argenteus has been recently established as a novel species of Staphylococcus aureus complex. It is known to cause various human diseases, such as skin and soft-tissue infections, sepsis, and staphylococcal food poisoning, although the source of infection has not been clearly described. In food poisoning cases, the source of bacterial contamination in food is unknown. This study examined the prevalence of S. argenteus among retail fresh food and poultry slaughterhouses in Japan. Among 642 food samples examined, successful isolation of S. argenteus was achieved in 21 of 151 (13.9%) chicken samples. No isolations from pork, beef, fish, or vegetables in retail markets were confirmed. Multiple-locus sequence typing revealed that the 21 isolates were classified into four sequence types (ST) that were divided into 14 subtypes using spa-typing. All food isolates were susceptible to methicillin and did not show positivity for the Panton-Valentine leukocidin gene. When bacteria were isolated from two poultry slaughterhouses in the same region, 14 S. argenteus strains were successfully isolated from only one slaughterhouse. Thirteen of 14 strains were isolated from a poultry carcass and slaughterhouse environments during a certain sampling period and were all classified as ST5961 with identical spa-type. Also, the number of single nucleotide variants (SNVs) detected on the core genomes of the same 13 strains were between 0 and 17, suggesting a long-term inhabitation of an S. argenteus strain inside the facility. Furthermore, one isolate from chicken meat was also genetically linked with the same lineage of slaughterhouse isolates, with ≤15 SNVs being detected. Additionally, one slaughterhouse isolate from chiller water and three chicken isolates were classified into the same cluster by phylogenetic analysis, although the number of pairwise SNVs ranged from 62 to 128. To the best of the authors' knowledge, this is the first study that demonstrated S. argenteus in a food processing facility and the possible bacterial contamination on food during food processing.

Whole-genome analyses of extended-spectrum or AmpC β-lactamase-producing Escherichia coli isolates from companion dogs in Japan

The emergence and global spread of extended-spectrum or AmpC β-lactamase (ESBL/AmpC)-producing Enterobacteriaceae in companion animals have led to the hypothesis that companion animals might be reservoirs for cross-species transmission because of their close contact with humans. However, current knowledge in this field is limited; therefore, the role of companion animals in cross-species transmission remains to be elucidated. Herein, we studied ESBL/AmpC-producing Enterobacteriaceae, Escherichia coli in particular, isolated from extraintestinal sites and feces of companion dogs. Whole-genome sequencing analysis revealed that (i) extraintestinal E. coli isolates were most closely related to those isolated from feces from the same dog, (ii) chromosomal sequences in the ST131/C1-M27 clade isolated from companion dogs were highly similar to those in the ST131/C1-M27 clade of human origin, (iii) certain plasmids, such as IncFII/pMLST F1:A2:B20/bla_CTX-M-27, IncI1/pMLST16/bla_CTX-M-15, or IncI1/bla_CMY-2 from dog-derived E. coli isolates, shared high homology with those from several human-derived Enterobacteriaceae, (iv) chromosomal bla_CTX-M-14 was identified in the ST38 isolate from a companion dog, and (v) eight out of 14 tested ESBL/AmpC-producing E. coli isolates (i.e., ST131, ST68, ST405, and ST998) belonged to the human extraintestinal pathogenic E. coli (ExPEC) group. All of the bla-coding plasmids that were sequenced genome-wide were capable of horizontal transfer. These results suggest that companion dogs can spread ESBL/AmpC-producing ExPEC via their feces. Furthermore, at least some ESBL/AmpC-producing ExPECs and bla-coding plasmids can be transmitted between humans and companion dogs. Thus, companion dogs can act as an important reservoir for ESBL/AmpC-producing E. coli in the community.

A comparative effectiveness pilot study of teriparatide for medication-related osteonecrosis of the jaw: daily versus weekly administration

We studied the effectiveness of teriparatide (TPTD) for treating medication-related osteonecrosis of the jaw (MRONJ) in patients with osteoporosis and examined differences in the clinical outcomes following daily versus weekly TPTD. The outcomes were significantly improved in the entire patient series and the daily group.

PURPOSE

Teriparatide (TPTD) treatment for Stage II-III medication-related osteonecrosis of the jaw (MRONJ) in osteoporotic patients has yielded promising results in uncontrolled studies. The daily administration and the weekly administration of TPTD have been reported to improve outcomes in MRONJ. Herein, we sought to identify differences in the clinical outcomes of MRONJ patients treated with daily TPTD versus weekly TPTD.

METHODS

We enrolled 13 patients and randomly assigned them to receive either of two treatments: 1×/week 56.5-μg TPTD injection for 6 months (weekly group; n = 6 patients after 1 dropout), or 20-μg TPTD injection daily for 6 months (daily group; n = 6 patients). Patients in both groups received conventional therapy plus intensive antibiotic therapy as necessary. We compared the changes in the patients' clinical stage of MRONJ, bone metabolism, percentage of bone formation, and bone turnover markers between the weekly and daily groups.

RESULTS

TPTD treatment with MRONJ led to partial remission or complete remission in 5 daily-group patients and 3 weekly-group patients. The MRONJ stage was significantly improved from baseline to 6 months of treatment in the entire series of 12 patients (p = 0.008); the weekly group did not show significant improvement, but the daily group did (p = 0.01).

CONCLUSIONS

This study provides the first comparison of clinical outcomes between MRONJ patients who received daily or weekly TPTD injections. Six months of treatment with TPTD realized a significant improvement of MRONJ stage in both the entire patient series and the daily group.

P1444 Occurrence and predictors of right ventricular dysfunction after pericardiocentesis

Background—The changes in cardiac function that occur after pericardiocentesis are unclear.Purpose—This study was performed to assess right ventricular (RV) and left ventricular (LV) function with echocardiography before and after pericardiocentesis.

Method and Results—In total, 19 consecutive patients who underwent pericardiocentesis for more than moderate pericardial effusion were prospectively enrolled from August 2015 to October 2017. Comprehensive transthoracic echocardiography was performed before, immediately after (within 3 hours), and 1 day after pericardiocentesis to investigate the changes in RV and LV function. RV dysfunction is defined as meeting three of the four criteria: a TAPSE of <17 mm, an S’ of <9.5 cm, an FAC of <35%, and an RV free wall longitudinal strain >−20%. The mean age of all patients was 72.6 ± 12.2 years. The changes of echocardiographic parameters related to RV function are shown in Table. After pericardiocentesis, RV inflow and outflow diameters increased and the parameters of RV function significantly decreased. These abnormal values or RV dysfunction remained at 1 day after pericardiocentesis. Conversely, no parameters of LV function parameters changed after pericardiocentesis. Of 19 patients, 13 patients showed RV dysfunction immediately after pericardiocentesis and 6 patients did not. RV free wall longitudinal strain before pericardiocentesis was higher in patients with post-procedural RV dysfunction (−18.9 ± 3.6%) than in those without (−28.4 ± 6.3%). ROC analysis revealed that a RV free wall longitudinal strain cut-off value of −23.0% had a sensitivity of 100% and a specificity of 83.3% for predicting the occurrence of RV dysfunction after pericardiocentesis (AUC = 0.910).

Conclusions—The occurrence of RV dysfunction after pericardiocentesis should be given more attention. Pre-existing RV dysfunction maybe related to the occurrence of RV dysfunction after pericardiocentesis.

Changes in RV function before and after Before Immediately after One day after P−value Basal right ventricular linear dimension (mm) 32.8 ± 5.0 37.1 ± 4.4† 33.6 ± 5.4 0.028 Mid-cavity right ventricular linear dimension (mm) 34.5 ± 4.6 38.8 ± 5.3† 37.0 ± 5.6 0.0504 Proximal right ventricular outflow diameter (mm) 30.2 ± 4.0 33.9 ± 3.5† 31.4 ± 3.9 0.014 TAPSE (mm) 20.0 ± 4.2 13.6 ± 4.3* 14.7 ± 3.9 <0.001 S" (cm/s) 12.6 ± 3.3 8.7 ± 2.4* 9.1 ± 2.4 <0.001 Fractional area change (%) 48.3 ± 5.9 37.8 ± 8.0* 40.0 ± 9.0 <0.001 Right ventricular free wall strain (%) −21.3 ± 6.3 −15.8 ± 6.7* −16.9 ± 5.2 0.036 Tricuspid regurgitation velocity peak (m/s) 2.41 ± 0.29 2.43 ± 0.25 2.34 ± 0.32 0.37

Adherence of Clostridium perfringens spores to human intestinal epithelial Caco-2 cells

Clostridium perfringens is a gram-positive, spore-forming bacillus, and is a causative agent of foodborne infection, antibiotic-associated diarrhoea and sporadic diarrhoea in humans. In cases of antibiotic-associated and sporadic diarrhoea, C. perfringens colonises the intestine, proliferates and causes disease. However, bacterial colonisation of the intestine is not considered necessary in the pathogenesis of foodborne illness, because such pathogenesis can be explained by anchorage-independent production of diarrhoeic toxin by the bacterium in the intestine. In this study, we used an in vitro adherence assay to examine the adherence of C. perfringens spores to human intestinal Caco-2 cells. Adherence of spores from isolates of foodborne illness and nosocomial infection was observed within 15 min, and plateaued 60 min after inoculation. Electron microscopy revealed a tight association of spores with the surface of Caco-2 cells. The adherence of vegetative cells could not be confirmed by the same method, however. These results suggest that C. perfringens spores may adhere to intestinal epithelial cells in vivo, although its biological significance remains to be determined.

Phosphorothioation of foreign DNA influences the transformation efficiency in Clostridium perfringens NCTC8239

Major advances in Clostridium perfringens genetics have been achieved through the development of electroporation-induced transformation; however, highly transformable strains are still limited. SM101 is the only useful strain for genetic manipulation via transformation in C. perfringens causing foodborne illness (FBI). We focused on the FBI strain NCTC8239, which is transformed at a low frequency, because it has a gene cassette that is predicted to encode enzymes involved in DNA phosphorothioation (PT). The oxidant-dependent degradation of NCTC8239 genomic DNA suggested that the genome is PT-modified. When foreign DNA was PT-modified using a plasmid expressing Salmonella enterica PT modification enzymes, the transformation efficiency of NCTC8239 was significantly higher than that using an unmodified plasmid. We then attempted to establish a highly transformable derivative of NCTC8239, and focused on DptFGH, which are predicted to be PT restriction enzymes. A dptG-null mutant exhibited significantly higher transformation efficiency with unmodified foreign DNA than did the wild-type strain. Furthermore, the mutant was transformed with the unmodified plasmid as efficiently as with a PT-modified plasmid, implying that DptG is involved in PT-dependent restriction. Thus, the present results revealed that PT modifications of foreign DNA influence the transformation frequency of NCTC8239 and suggest that PT is a factor contributing to transformation efficiency in NCTC8239.

An enhanced green fluorescence protein (EGFP)-based reporter assay for quantitative detection of sporulation in Clostridium perfringens SM101

Clostridium perfringens type F is a spore-forming anaerobe that causes bacterial food-borne illness in humans. The disease develops when ingested vegetative cells reach the intestinal tract and begin to form spores that produce the diarrheagenic C. perfringens enterotoxin (CPE). Given that CPE production is regulated by the master regulator of sporulation (transcription factor Spo0A), the identification of sporulation-inducing factors in the intestine is relevant to better understanding of the disease. To examine these factors, we established assays to quantify C. perfringens sporulation stage under microscopy by using two fluorescent reporters, namely, Evoglow-Bs2 and CpEGFP. When the reporter genes were placed under control of the cpe promoter, both protein products were expressed specifically during sporulation. However, the intensity of the anaerobic reporter Evoglow-Bs2 was weak and rapidly photobleached during microscopic observation. Alternatively, CpEGFP, a canonical green fluorescence protein with optimized codon usage for Clostridium species, was readily detectable in the mother-cell compartment of most bacteria at early stages of sporulation. Additionally, CpEGFP expression predicted final spore yield and was quantifiable in 96-well plates using fluorescence plate reader. These results indicate that CpEGFP can be used to analyze the sporulation of C. perfringens and has a potential application in the large-scale screening of sporulation-regulating biomolecules.

Effect of sublethal heat treatment on the later stage of germination-to-outgrowth of Clostridium perfringens spores

Sublethal heating of spores has long been known to stimulate or activate germination; however, the underlying mechanisms are not yet fully understood. In this study, the entire germination-to-outgrowth process of spores from Clostridium perfringens, an anaerobic sporeformer, was visualized at single-cell resolution. Quantitative analysis revealed that sublethal heating significantly reduces the time from completion of germination to the beginning of the first cell division, indicating that sublethal heating of C. perfringens spores not only sensitizes the responsiveness of germinant receptors but also directly or indirectly facilitates multiple steps during the bacterial regrowth process.

Nitrate salts suppress sporulation and production of enterotoxin in Clostridium perfringens strain NCTC8239

Clostridium perfringens type A is a common source of food-borne illness in humans. Ingested vegetative cells sporulate in the small intestinal tract and in the process produce C. perfringens enterotoxin (CPE). Although sporulation plays a critical role in the pathogenesis of food-borne illness, the molecules triggering/inhibiting sporulation are still largely unknown. It has previously been reported by our group that sporulation is induced in C. perfringens strain NCTC8239 co-cultured with Caco-2 cells in Dulbecco's Modified Eagle Medium (DMEM). In contrast, an equivalent amount of spores was not observed when bacteria were co-cultured in Roswell Park Memorial Institute-1640 medium (RPMI). In the present study it was found that, when these two media are mixed, RPMI inhibits sporulation and CPE production induced in DMEM. When a component of RPMI was added to DMEM, it was found that calcium nitrate (Ca[NO₃ ]₂ ) significantly inhibits sporulation and CPE production. The number of spores increased when Ca(NO₃ )₂ -deficient RPMI was used. The other nitrate salts significantly suppressed sporulation, whereas the calcium salts used did not. qPCR revealed that nitrate salts increased expression of bacterial nitrate/nitrite reductase. Furthermore, it was found that nitrite and nitric oxide suppress sporulation. In the sporulation stages, Ca(NO₃ )₂ down-regulated the genes controlled by Spo0A, a master regulator of sporulation, but not spo0A itself. Collectively, these results indicate that nitrate salts suppress sporulation and CPE production by down-regulating Spo0A-regulated genes in C. perfringens strain NCTC8239. Nitrate reduction may be associated with inhibition of sporulation.

Angiogenin promotes tumoral growth and angiogenesis by regulating matrix metallopeptidase-2 expression via the ERK1/2 pathway

Tumor angiogenesis is essential for tumor growth and metastasis and is dependent on key angiogenic factors. Angiogenin (ANG), a 14.2-kDa polypeptide member of the RNase A superfamily, is an angiogenic protein that has been reported to be upregulated and associated with poor prognosis in some human cancers. The mechanisms through which aberrant ANG levels promote specific steps in tumor progression are unknown. Here, we show that ANG expression in human tissues is strongly correlated with an invasive cancer phenotype. We also show that ANG induces cellular survival, proliferation, endothelial tube formation and xenograft angiogenesis and growth. Novel mechanistic investigations revealed that ANG expression stimulated matrix metallopeptidase-2 (MMP2) expression through the phosphorylation of ERK1/2. Targeting ANG in vivo with N65828, a small-molecule inhibitor of the ribonucleolytic activity of human ANG, resulted in the diminution of xenograft tumoral growth through the inhibition of angiogenesis. Our findings support an unrecognized interplay between ANG, ERK1/2 and MMP2 that can impact tumor growth and progression. The targeting of ANG and associated factors could provide a novel strategy to inhibit tumor establishment and growth.

Myostatin alters glucose transporter-4 (GLUT4) expression in bovine skeletal muscles and myoblasts isolated from double-muscled (DM) and normal-muscled (NM) Japanese shorthorn cattle

The purpose of this study was to determine whether myostatin alters glucose transporter-4 (GLUT4) expression in bovine skeletal muscles and myoblasts isolated from double-muscled (DM) and normal-muscled (NM) Japanese Shorthorn cattle. Plasma concentrations of glucose were lower in DM cattle than in NM cattle (P < 0.01). The expression of GLUT4 messenger RNA (mRNA) in the skeletal muscle ex vivo and in myoblasts at 72 h after differentiation in vitro was higher in DM cattle than in NM cattle (P < 0.01). In contrast, the NM and DM cattle did not differ with respect to skeletal muscle expression of GLUT1 and myocyte enhancer factor-2c (MEF2c), a transcription factor of GLUT4. In differentiated myoblasts, the expression of GLUT1, GLUT4, and MEF2c mRNAs was greater in DM cattle than in NM cattle (P < 0.01). In the presence and absence of insulin, glucose uptake in myoblasts was increased in DM cattle relative to that of NM cattle (P < 0.01). The addition of myostatin decreased the expression of GLUT4 and MEF2c mRNAs in DM myoblasts (P < 0.05). Results of the present study suggest that myostatin inhibits the expression of GLUT4 mRNA possibly via MEF2c and that the greater ability of the DM cattle to produce muscle relative to the NM cattle may be due to their greater sensitivity to insulin and greater use of glucose.

An in vitro chemosensitivity test for solid human tumors using collagen gel droplet embedded cultures

In vitro chemosensitivity testing using a collagen gel droplet embedded culture drug sensitivity test (CD-DST), was conducted with several types of solid cancer. The overall evaluable rate was 80% (443/554), including 76% for lung (n=243), 78% for breast (n=110), 87% for gastric (n=62), 83% for colorectal (n=107) cancers and 88% for 32 metastatic brain tumors. The in vitro sensitivity of breast, gastric and colorectal cancers to mitomycin C (MMC), cisplatin (CDDP), 5-fluorouracil (5-FU) and doxorubicin (DXR) was similar to the efficacy rates reported for each drug. This was also observed with lung cancer, the sensitivity of which to MMC, CDDP, vindesine (VDS) and etoposide (VP-16) was similar to the clinical efficacy. The clinical response to chemotherapy was compared with the results of in vitro chemosensitivity testing in Il patients: the clinical correlation was 91%, with a 80% true positive and 100% true negative rate. These results suggest that the CD-DST may be clinically useful by allowing the prediction of clinical response in various solid cancers.

A circulating heat-resistant mucin-like antigen in patients with lung-cancer detected by a new murine monoclonal-antibody

We discovered a circulating mucin-like antigen designated as CAM-14 detected by a new murine monoclonal antibody KL-14 (IgM). We found different heat resistant properties between serum CAM- 14 from normal individuals and from lung cancer patients. Heat treatment had less effect on the levels of CAM-14 in sera from lung cancer patients, whereas CAM-14 levels in sera from normal individuals were markedly decreased after heat treatment at tempratures > 65-degrees-C. As a serum tumor marker, CAM- 14 had only very low levels of false-positive values with a high specificity and effectively increased the positive rate for lung cancer patients when used together with carcinoembryonic antigen.

MRP-1/CD9 and KAI1/CD82 expression in normal and various cancer tissues

As part of our evaluation of MRP-1/CD9 and KAI1/CD82 as prognostic predictors among patients with cancer, we have extended our studies to solid tumors of a variety of anatomical sites. Normal tissues were included for comparison. Immunohistochemical techniques were used throughout. Our results indicate that MRP-1/CD9 was strongly expressed by many normal tissues, including the epithelium of the gastrointestinal tract, alveolar epithelium of the lung, urothelium and smooth muscle. Expression was weak in the pituitary gland, spleen and hepatocytes, and absent in testes and spinal cord. KAI1/CD82 was also expressed by many normal tissues, but was absent in some MRP-1/CD9-positive tissues (e.g., smooth muscle, adrenal cortex, urothelium, myelin of peripheral nerves, epithelium of amnion). On the other hand, KAI1/CD82 was strongly expressed in spinal cord gray matter, which was MRP-1/CD9-negative. Expression of these glycoproteins was detected in almost all types of tumors examined. In certain cancers, MRP-1/CD9 and KAI1/CD82 positivity was inversely related to lymph node involvement. Whereas lymph node metastases were present in 22.2% of lung cancer patients whose tumors were MRP-1/CD9 and KAI1/CD82-positive, 65.5% of patients with MRP-1/CD9 and KAI1/CD82-reduced/negative tumors had lymph node metastases. A similar inverse relationship was seen in colon cancer and breast cancer patients with respect to MRP-1/CD9 expression. The present data, together with our previous results suggest that evaluating the MRP1/CD9 and KAI1/CD82 status of cancers of the lung, breast and colon may provide useful information on the metastatic potential of the tumors.

IFN-γ elicits macrophage autophagy via the p38 MAPK signaling pathway

Autophagy is a major innate immune defense pathway in both plants and animals. In mammals, this cascade can be elicited by cytokines (IFN-γ) or pattern recognition receptors (TLRs and nucleotide-binding oligomerization domain-like receptors). Many signaling components in TLR- and nucleotide-binding oligomerization domain-like receptor-induced autophagy are now known; however, those involved in activating autophagy via IFN-γ remain to be elucidated. In this study, we engineered macrophages encoding a tandem fluorescently tagged LC3b (tfLC3) autophagosome reporter along with stably integrated short hairpin RNAs to demonstrate IFN-γ-induced autophagy required JAK 1/2, PI3K, and p38 MAPK but not STAT1. Moreover, the autophagy-related guanosine triphosphatase Irgm1 proved dispensable in both stable tfLC3-expressing RAW 264.7 and tfLC3-transduced Irgm1(-/-) primary macrophages, revealing a novel p38 MAPK-dependent, STAT1-independent autophagy pathway that bypasses Irgm1. These unexpected findings have implications for understanding how IFN-γ-induced autophagy is mobilized within macrophages for inflammation and host defense.

[Lung cancer accompanied by active pulmonary tuberculosis]

We report 2 patients with lung cancer accompanied by active pulmonary tuberculosis. Case1 was a 82-year-old woman with stage I A bronchioloalveolar carcinoma and tuberculosis in right upper lobe. Right upper lobectomy was performed after the histological diagnosis of lung cancer by intraoperative frozen section. Case2 was a 69-year-old man with papillary adenocarcinoma in right lower lobe and tuberculosis in bilateral upper lobe. Partial resection in right lower lobe was performed for diagnosis of lung cancer. Smear-positive tuberculosis was diagnosed by sputum examination after the operation. Post-operative anti-tuberculosis chemotherapy was added in both patients.

Heterogeneity of colorectal cancers and extraction of discriminator gene signatures for personalized prediction of prognosis

Dissected specimens of colorectal cancer (CRC) have been intensively studied using molecular sketches (gene signatures) to obtain a set of discriminator gene signatures for accurate prognosis prediction in individual patients. The discriminators obtained so far are not universally applicable, as the gene sets reflect the method and site of the study. In this study, we show that dissected stage II and III CRC samples are significantly heterogeneous in molecular sketches, and are not appropriate sources for discriminator extraction unless handled individually. To search for an accurate discriminator gene set for prediction of metastases, we need to start with less heterogeneous stage II CRC. We examined 198 (92 stage II and 106 stage III) CRC dissected samples for the predictability of discriminator gene signatures by analyzing stage II CRC alone, stage III alone, or in combination. The best predictive power of discriminator genes was obtained only when these genes were extracted and validated with stage II CRC samples. An accurate discriminator gene set for the prediction of CRC metastases can be obtained by focusing on stage II CRC samples.

New analysis of the hypertension mechanism in bevacizumab-treated patients using 3-tesla dynamic contrast-enhanced magnetic resonance imaging

450

Background: Vascular endothelial growth factor (VEGF) signaling inhibitors, such as bevacizumab (BV), leads to endothelial dysfunction and microvascular rarefaction in noncancer tissue. Angiotensin II has been reported to induce VEGF production by inhibiting VEGF, but the reasons for activation of angiotensin II are unclear. We conducted a study to examine the relationship between renin-angiotensin axis and renal blood perfusion using dynamic contrast magnetic resonance imaging (DCE-MRI) in colorectal cancer patients.

Methods: Sixteen patients with colorectal cancer were enrolled. They received BV+FOLFIRI regimen as second line. DCE-MRI was performed before the treatment and after 12th courses. Renin, angiotensin I, angiotensin II and aldosterone were examined before treatment and at 3, 5, 8, 12th courses. DCE-MRI parameters, Area under the time-intensity curve over the first 90 seconds after injection of contrast material (AUC90) and volume transfer constant of contrast material (Ktrans, Kep) were calculated in the normal kidney and examine the correlation with renin-angiotensin axis.

Results: All DCE-MRI parameters decreased significantly after 12th courses compared with before treatment (Variables median: Ktrans -1.51, Kep -2.30, AUC90 -26.0, P < 0.001, all). A decrease in Kep correlated with higher renin, angiotensin I and angiotensin II (renin: P =0.001, angiotensin I: P =0.003, angiotensin II: P =0.002, respectively). A decrease in AUC90 correlated with higher aldosterone (P =0.005). Blood pressure did not correlate with each DCE-MRI parameters.

Conclusions: VEGF inhibition decreases vessel permeability and raises interstitial pressure in normal kidney. Our data suggest that renin-angiotensin axis is also one mechanism of hypertension caused by BV.

No significant financial relationships to disclose.

Association of Bordetella dermonecrotic toxin with the extracellular matrix

Background

Bordetella dermonecrotic toxin (DNT) causes the turbinate atrophy in swine atrophic rhinitis, caused by a Bordetella bronchiseptica infection of pigs, by inhibiting osteoblastic differentiation. The toxin is not actively secreted from the bacteria, and is presumed to be present in only small amounts in infected areas. How such small amounts can affect target tissues is unknown.

Results

Fluorescence microscopy revealed that DNT associated with a fibrillar structure developed on cultured cells. A cellular component cross-linked with DNT conjugated with a cross-linker was identified as fibronectin by mass spectrometry. Colocalization of the fibronectin network on the cells with DNT was also observed by fluorescence microscope. Several lines of evidence suggested that DNT interacts with fibronectin not directly, but through another cellular component that remains to be identified. The colocalization was observed in not only DNT-sensitive cells but also insensitive cells, indicating that the fibronectin network neither serves as a receptor for the toxin nor is involved in the intoxicating procedures. The fibronectin network-associated toxin was easily liberated when the concentration of toxin in the local environment decreased, and was still active.

Conclusions

Components in the extracellular matrix are known to regulate activities of various growth factors by binding and liberating them in response to alterations in the extracellular environment. Similarly, the fibronectin-based extracellular matrix may function as a temporary storage system for DNT, enabling small amounts of the toxin to efficiently affect target tissues or cells.

Morphological study of cationic polymer-anionic surfactant complex precipitated in solution during the dilution process

We investigated the phase diagrams and the morphology of the complexes that were formed by cationic polymers, cationic cellulose (CC) and cationic dextran (CD), and by anionic surfactant-based sodium poly(oxyethylene) lauryl ether sulfate (LES). The anionic charge of the LES-based surfactants was changed by adding an amphoteric surfactant, lauryl amidopropyl betaine acetate (LPB), or a nonionic surfactant, polyoxyethylene stearyl ether (C18EO25). We discuss the relationship between the complex aggregation process and the morphology of the precipitated complexes. The morphologies of CC complex aggregates, which precipitated during the dilution process in a model shampoo solution, changed from membranous forms to mesh-like forms by decreasing the charges of both the CC and the surfactant. Their touch on hair in the rinsing process changed from sticky to smooth and velvety, corresponding to their rheological properties. In contrast, CD complex aggregates had a membranous form and a smooth touch independently of the charges on the polymer and surfactant. These results suggested that the control of the charges of both the polymer and surfactant and the choice of polymer structure are important for excellent conditioning effects upon rinsing with shampoo.

Characterization of the membrane-targeting C1 domain in Pasteurella multocida toxin

Pasteurella multocida toxin (PMT) is a virulence factor responsible for the pathogenesis of some forms of pasteurellosis. The toxin activates G(q)- and G(12/13)-dependent pathways through the deamidation of a glutamine residue in the alpha-subunit of heterotrimeric GTPases. We recently reported the crystal structure of the C terminus (residues 575-1285) of PMT (C-PMT), which is composed of three domains (C1, C2, and C3), and that the C1 domain is involved in the localization of C-PMT to the plasma membrane, and the C3 domain possesses a cysteine protease-like catalytic triad. In this study, we analyzed the membrane-targeting function of the C1 domain in detail. The C1 domain consists of seven helices of which the first four (residues 590-670), showing structural similarity to the N terminus of Clostridium difficile toxin B, were found to be involved in the recruitment of C-PMT to the plasma membrane. C-PMT lacking these helices (C-PMT DeltaC1(4H)) neither localized to the plasma membrane nor stimulated the G(q/12/13)-dependent signaling pathways. When the membrane-targeting property was complemented by a peptide tag with an N-myristoylation motif, C-PMT DeltaC1(4H) recovered the PMT activity. Direct binding between the C1 domain and liposomes containing phospholipids was evidenced by surface plasmon resonance analyses. These results indicate that the C1 domain of C-PMT functions as a targeting signal for the plasma membrane.

Application of positron emission tomography in physical medicine

Positron emission tomography (PET) is widely used in the fields of clinical and basic medicine. The PET device utilizes coincidence logic to detect annihilation photons emitted from positrons and estimates physiological functions of human organs in vivo. Radiopharmaceutical 18F- fluorodeoxyglucose (FDG), an analogue of glucose, is trapped metabolically in cells after being administered into the body, and can be substantially used for evaluating physiological and biochemical functions in vivo. Here, we attempted to describe the basics of PET as well as to apply the technique together with 18F-FDG as a tracer for evaluating organ glucose metabolism induced by exercise. Three-dimensional (3D) FDG-PET was applied to normal volunteers who performed exercise to evaluate whole-body glucose metabolism. Regions of interest analysis were drawn on visually defined regions (i.e., lower limbs, thigh, liver, intestine, brain, heart, etc.) to determine radioactivity distribution. FDG-PET clearly showed the recruitment of energy resources from abdominal organs to lower limb skeletal muscles to balance energy expenditures. The results suggested that 3D FDG-PET can be applied as an imaging tool to physical medicine.

Early morphological events of in vitro fertilized bovine oocytes with frozen-thawed spermatozoa

Bovine follicular oocytes were matured and inseminated in vitro with spermatozoa capacitated in vitro. The first evidence of sperm penetration was observed at 3 h after insemination. The penetration rate increased until 5 h, and reached a maximum rate (92%) at 5 h. Decondensation of the sperm head and pronuclear formation were observed 4 h and 7 h after insemination, respectively. Female chromatins of all penetrated oocytes were activated at 3 h, and female pronuclei were formed at 7 h after insemination. Percentages of oocytes with male and female pronuclei at 9 h were 88 and 94%. Polyspermy (4, 7, 19 and 29% at 4, 5, 7 and 9 h after insemination, respectively) and abnormal development of male pronuclei (6 and 7% at 7 and 9 h after insemination, respectively) were also seen.

Clostridium perfringens enterotoxin interacts with claudins via electrostatic attraction

Clostridium perfringens enterotoxin (CPE), a causative agent of food poisoning, is a pore-forming toxin disrupting the selective permeability of the plasma membrane of target cells, resulting in cell death. We previously identified claudin as the cell surface receptor for CPE. Claudin, a component of tight junctions, is a tetratransmembrane protein and constitutes a large family of more than 20 members, not all of which serve as the receptor for CPE. The mechanism by which the toxin distinguishes the sensitive claudins is unknown. In this study, we localized the region of claudin responsible for interaction with CPE to the C-terminal part of the second extracellular loop and found that the isoelectric point of this region in sensitive claudins was higher than insensitive claudins. Amino acid substitutions to lower the pI resulted in reduced sensitivity to CPE among sensitive claudins, whereas substitutions to raise the pI endowed CPE-insensitive claudins with sensitivity. The steric structure of the claudin-binding domain of CPE reveals an acidic cleft surrounded by Tyr(306), Tyr(310), Tyr(312), and Leu(315), which were reported to be essential for interaction with the sensitive claudins. These results imply that an electrostatic attraction between the basic claudin region and the acidic CPE cleft is involved in their interaction.