The activity of the quorum sensing regulator HapR is modulated by the bacterial extracellular vesicle (BEV)-associated protein ObfA of Vibrio cholerae.

Vibrio cholerae, a facultative human pathogen and causative agent of the severe diarrheal disease cholera, transits between the human intestinal tract and aquatic reservoirs. Like other bacterial species, V. cholerae continuously releases bacterial extracellular vesicles (BEVs) from its surface, which have been recently characterised for their role during in vivo colonisation. However, between epidemic outbreaks, V. cholerae persists in the biofilm mode for extended periods in aquatic reservoirs, which enhances environmental fitness and host transition. In this study, we investigated the effect of V. cholerae BEVs on biofilm formation, a critical feature for ex vivo survival. In contrast to BEVs from planktonic cultures, our results show that physiological concentrations of BEVs from dynamic biofilm cultures facilitate V. cholerae biofilm formation, which could be linked to a proteinaceous factor. Comparative proteomic analyses of planktonic- and biofilm-derived BEVs identified a previously uncharacterised outer membrane protein as an abundant component of dynamic biofilm-derived BEVs, which was found to be responsible for the BEV-dependent enhancement of biofilm production. Consequently, this protein was named outer membrane-associated biofilm facilitating protein A (ObfA). Comprehensive molecular studies unravelled ObfA as a negative modulator of HapR activity. HapR is a key transcriptional regulator of the V. cholerae quorum sensing (QS) cascade acting as a potent repressor of biofilm formation and virulence. Consistently, obfA mutants not only exhibited reduced biofilm production but also reduced colonisation fitness. Surprisingly, our results demonstrate that ObfA does not affect HapR through the canonical QS system but via the Csr-cascade altering the expression of the small regulatory RNAs CsrC and CsrD. In summary, this study elucidates a novel intraspecies BEV-based communication in V. cholerae that influences biofilm formation and colonisation fitness via a new regulatory pathway involving HapR, Csr-cascade and the BEV-associated protein ObfA.

Formononetin Derivative for Osteoporosis by Simultaneous Regulating Osteoblast and Osteoclast.

Seven new formononetin derivatives (1-7) were designed and prepared from formononetin (phase II phytoestrogen). The derivatives 9-butyl-3-(4-methoxyphenyl)-9,10-dihydro-4H,8H-chromeno[8,7-e][1,3]oxazin-4-one (2) and 9-(furan-3-ylmethyl)-3-(4-methoxyphenyl)-9,10-dihydro-4H,8H-chromeno[8,7-e][1,3]oxazin-4-one (7) promoted significant osteoblast formation by modulating the BMP/Smad pathway. Compound 7 exhibited potent antiosteoclastogenesis activity in RANKL-induced RAW264.7 cells and ovariectomy (OVX)-induced osteoporosis in mice by regulation of the RANK/RANKL/OPG pathway. Compound 7 regulated osteoblast and osteoclast simultaneously and showed better effect than the well-known drug ipriflavone in vivo, suggesting 7 as a patented antiosteoporosis candidate.

Hypoglycemic effects of dracorhodin and dragon blood crude extract from Daemonorops draco.

BACKGROUND: Dragon blood is a red fruit resin from the palm tree Daemonorops draco and is a herbal ingredient used in the traditional Chinese medicine, "Jinchuang Ointment," which is used to treat non-healing diabetic wounds. According to the Taiwan Herbal Pharmacopeia, the dracorhodin content in dragon blood should exceed 1.0%. RESULTS: Our findings indicate that dracorhodin and dragon blood crude extracts can stimulate glucose uptake in mouse muscle cells (C2C12) and primary rat aortic smooth muscle cells (RSMC). Dracorhodin is not the only active compound in dragon blood crude extracts from D. draco. Next, we orally administered crude dragon blood extracts to male B6 mice. The experimental group displayed a decreasing trend in fasting blood glucose levels from the second to tenth week. In summary, crude extracts of dragon blood from D. draco demonstrated in vivo hypoglycemic effects in B6 male mice. CONCLUSIONS: We provide a scientific basis "Jinchuang ointment" in treating non-healing wounds in patients with diabetes.

Antimelanogenic Effect of Isoquinoline Alkaloids from Plumula Nelumbinis.

Plumula Nelumbinis, the green embryo of a lotus seed, is widely consumed in China as a well-known food with medicinal effects. In this study, 14 alkaloids, including 4 new and 10 known alkaloids, were isolated from it, which were elucidated by comprehensive spectroscopic analysis, and were investigated for their antimelanogenic effects in vitro and in vivo. As a result, melanogenesis in α-MSH-stimulated B16F10 cells was reduced significantly by a new compound 4 and known compound 12 at a concentration of 0.5 µg/mL, and the tyrosinase (TYR) activities were inhibited by 78.7 and 82.0% at 4 µg/mL, prior to α-arbutin (41.3%). Additionally, compounds 4 and 12 also exhibited superior antimelanogenic effects compared to α-arbutin on a zebrafish assay model at equivalent concentrations. Mechanistically, our preliminary findings suggested that compounds 4 and 12 exerted antimelanogenesis effect probably by inhibiting key proteins involved in melanin production such as microphthalmia-associated transcription factor, TYR, TRP-1, and TRP-2. The findings highlight the potential use of Plumula Nelumbinis containing compounds 4 and 12 as functional foods for treating hyperpigmentation.

Phytochemical Analysis and Anti-Ascaris suum Activity of Different Zanthoxylum Species In Vitro and In Vivo.

Zanthoxylum plants (ZPs), including multiple Chinese prickly ash species, are dual-purpose functional foods favored by the general population around the world in foods, cosmetics, and traditional medicines and have antipruritic, insecticidal, and fungicidal bioactivities. For the first time, the anti-roundworm bioactivity of ZPs and the active ingredients were compared and investigated. Through nontarget metabolomics following targeted quantitative analysis, qinbunamides, sanshools, sanshooel, asarinin, and sesamin were found to be the main different components of Zanthoxylum species. Coincidentally, the 12 chemical components were also the dominant anti-roundworm ingredients of ZP extracts. The extracts of three species of Chinese prickly ash (1 mg/mL) decreased the hatchability of roundworm eggs significantly, and the ChuanJiao seed killed roundworms (insecticidal rate 100%) and alleviated the symptoms of pneumonia in mice. Furthermore, retention time-accurate mass-tandem mass spectrometry-ion ratio (RT-AM-MS/MS-IR) were modeled by assaying 108 authentic compounds of ZP extracts, and 20 metabolites were confidently identified in biological samples from ZP extract-treated mice by analyzing the m/z values and the empirical substructures. This study provides a good reference for the proper application of ZPs.

The impact of social isolation from COVID-19-related public health measures on cognitive function and mental health among older adults: A systematic review and meta-analysis.

We aimed to estimate the impact of social isolation on cognitive function and mental health among older adults during the two-year-and-a-half COVID-19 period. Pubmed Central, Medline, CINAHL Plus and PsychINFO were searched between March 1, 2020, and September 30, 2022. We included all studies that assessed proportions of older adults with the mean or the median with a minimum age above 60 reporting worsening cognitive function and mental health. Thirty-two studies from 18 countries met the eligibility criteria for meta-analyses. We found that the proportions of older adults with dementia who experienced worsening cognitive impairment and exacerbation or new onset of behavioral and psychological symptoms of dementia (BPSD) were approximately twice larger than that of older adults with HC experiencing SCD and worsening mental health. Stage of dementia, care options, and severity of mobility restriction measures did not yield significant differences in the number of older adults with dementia reporting worsening cognitive impairment and BPSD, while the length of isolation did for BPSD but not cognitive impairment. Our study highlights the impact of social isolation on cognitive function and mental health among older adults. Public health strategies should prioritize efforts to promote healthy lifestyles and proactive assessments.

Prenatal diagnosis of Simpson-Golabi-Behmel syndrome type 1 with an 814 kb Xq26.2 deletion with the initial presentation of a thick nuchal fold.

OBJECTIVE: Simpson-Golabi-Behmel syndrome type 1 (SGBS1) is a rare X-linked recessive disorder characterized by overgrowth and multiple anomalies. Most clinical diagnoses of SGBS1 are made postnatally. We present the case of a pregnant woman in whom the fetus presented with a thick nuchal fold 5.6 mm at 15 weeks of gestation, leading to the prenatal diagnosis of SGBS1 with Xq26.2 (133408101-134221889) deletion. CASE REPORT: We report the case of a 34-year-old pregnant woman with the initial presentation of fetal thick nuchal fold 5.6 mm at 15 weeks of gestation. Amniocentesis of the fetal karyotype revealed a normal 46, XY, and single nucleotide polymorphism array showed Xq26.2 (133408101-134221889) deletion. Prenatal ultrasound at 21 weeks of gestation revealed a thick nuchal fold, hepatomegaly, nephromegaly, congenital diaphragmatic hernia, hypospadias, and polyhydramnios. Fetal magnetic resonance imaging revealed hepatomegaly, nephromegaly, congenital diaphragmatic hernia, and right lung hypoplasia. The woman had her pregnancy terminated at 24 weeks of gestation. The proband had a general appearance of low-set ears, hypertelorism, a large tongue, and hypospadias and some unique findings on autopsy, including hepatomegaly, right hiatal hernia, liver extensive extramedullary hematopoiesis, kidney marked congestion, and focal hemorrhage. DISCUSSION: The main prenatal ultrasound findings that alert clinical doctors about the possible diagnosis of SGBS1 included macrosomia, polyhydramnios, organomegaly, renal malformations, congenital diaphragmatic hernia, and cardiac anomalies. Our case underscores the importance of fetal karyotyping combined with single nucleotide polymorphism array when a thick nuchal fold is found. Genetic counseling is essential in SGBS1, and prenatal testing or preimplantation testing for subsequent pregnancies is necessary to identify possible pathogenic variants.

Antifungal compounds of Chinese prickly ash against drug-resistant Candida albicans.

The leaf of Chinese prickly ash, a unique spice having typical pungent sensation, is a popular food in Southwest China with antipruritic, insecticidal and fungicidal functions, but its bioactive constituents of fungistatic capacity remain unknown. In present investigation, twenty-nine compounds were isolated from leaf of Chinese prickly ash, and their antifungal bioactivity against drug-resistant Candida albicans were evaluated in vitro and in vivo. As a result, three compounds 3, 10, 29 showed antifungal bioactivity by damage of the fungal biofilm, and they might recover sensitive of drug resistant C. albicans to Fluconazole. Then Chinese prickly ash leaf was proved to be a functional food against fungus for the first time in experiment.

New steroidal alkaloids with anti-inflammatory and analgesic effects from Veratrum grandiflorum.

ETHNOPHARMACOLOGICAL RELEVANCE: "Li-Lu", the roots and rhizomes of Veratrum grandiflorum (Melianthiaceae), has been historically used as a traditional folk medicine for the treatment of wrist pain, fractures, sores, and inflammation in Yunnan Province, China. However, the anti-inflammatory and analgesic studies of this plant have seldom reported. AIM OF THE STUDY: To evaluate the anti-inflammatory and analgesic properties related to the traditional usage of V. grandiflorum both in vitro and in vivo, and further explore the accurate bioactive compounds from the medicinal plant. MATERIALS AND METHODS: Phytochemical investigation was carried out by chromatographic methods and their structures were established based on extensive spectra and comparison with corresponding data in the reported literatures. Anti-inflammatory activities were assessed by the suppression of lipopolysaccharide-activated inflammatory mediators in RAW 264.7 macrophage cells in vitro. Furthermore, anti-inflammatory and analgesic effects were evaluated based on carrageenan-induced paw edema and acetic acid-stimulated writhing in mice. RESULTS: The methanol extract (ME) of V. grandiflorum significantly alleviated the paw edema caused by carrageenan and the writhing numbers induced by acetic acid. Subsequent phytochemical investigation led to isolated of 21 steroidal alkaloids, including seven new compounds, veragranines C-I (1-7). Anti-inflammatory test indicated that steroidal alkaloids could decrease the expression of cyclooxygenase-2 (COX-2), interleukin-1ß (IL-1ß), and tumor necrosis factor α (TNF-α) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells at a concentration of 5.0 µg/ml in vitro, comparable to DXM. Moreover, five new steroidal alkaloids (2, 4, 5, 6, and 7) and two major steroidal alkaloids (9 and 13) significantly decreased the numbers of writhing in mice at the doses of 0.5 and/or 1.0 mg/kg (p < 0.01/0.05), roughly comparable to Dolantin™ at 10.0 mg/kg. CONCLUSIONS: The investigation supported the traditional use of V. grandiflorum and provided new steroidal alkaloids as potent analgesic agents.

Phytochemical and anti-MRSA constituents of Zanthoxylum nitidum.

Infectious diseases caused by multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus, pose a significant threat to humanity. Persistent and repeated invasive infection with MRSA led to higher morbidity and mortality, and required comprehensive measures in treatment and prevention. Zanthoxylum nitidum (Roxb.) DC. is used as detoxifying, analgesic, and hemostatic herbal medicine for thousands of years. Previously pharmacological studies showed that Z. nitidum had antibacterial bioactivity, but only the MIC of a few compounds, crude extracts, and fractions were reported. In our ongoing endeavor to explore bioactive compounds, two new coumarins, 6-(3-oxo-butyl)-limettin (1) and toddalin I (2), and 24 known compounds were isolated from the roots of Z. nitidum, in which two isoquinoline alkaloids, 6-acetonyl-dihydrofagaridine (16) and 6-acetonyl-dihydrochelerythrine (17) showed anti-MRSA bioactivity in vitro and in vivo. Both 16 and 17 showed synergistic action with ampicillin, which decreased the MIC significantly, and both compounds had a significant ability to destroy bacterial biofilm combined with ampicillin. The combined administration showed a strong scavenging effect on the planktonic bacteria in vitro and cleared skin infection effectively in the model of wound infection in vivo. Furthermore, compound 16 inhibited the efflux of the drug by combining with ampicillin or EtBr, resulting in the MIC decreased obviously. Our investigation supported the traditional use of Z. nitidum in treating infections caused by bacteria, and might provide new natural products to reduce the use of antibiotics and the treatment of drug-resistance bacteria.

Cardiovascular Benefits With Favorable Renal, Amputation and Hypoglycemic Outcomes of SGLT-2 Inhibitors in Type 2 Diabetes From the Asian Perspective: A Population-Based Cohort Study and Systematic Review.

Objective: We assessed the effects of sodium glucose cotransporter-2 inhibitors (SGLT2is) versus dipeptidyl peptidase-4 inhibitors (DPP4is) in a large real-world Asian cohort with type 2 diabetes (T2D) and performed a systematic review with integrating the present study findings to provide up-to-date evidence from the Asian perspective. Methods: New users of SGLT2is or DPP4is were identified from the Taiwan's National Health Insurance Research Database and followed until 2018. Primary outcomes were hospitalization for heart failure (HHF) and three-point major adverse cardiovascular event (3P-MACE; namely, myocardial infarction [MI], stroke, or cardiovascular death). Other outcomes included all-cause death, chronic kidney disease (CKD), amputation, and hospitalized hypoglycemia. Subdistribution hazard models were employed to assess treatment-associated clinical outcomes. Results: A total of 21,329 SGLT2i and DPP4i propensity-score-matched pairs were analyzed. SGLT2is versus DPP4is showed lower risks of HHF (hazard ratio [95% CI]: 0.52 [0.45-0.59]), 3P-MACE (0.62 [0.55-0.70]), MI (0.63 [0.50-0.79]), stroke (0.60 [0.51-0.70]), all-cause death (0.57 [0.49-0.67]), CKD (0.46 [0.43-0.50]), amputation (0.64 [0.42-0.98]), and hospitalized hypoglycemia (0.54 [0.45-0.64]). Our results were consistent with findings from a systematic review. Conclusion: Among Asian patients with T2D, SGLT2is versus DPP4is showed benefits for several clinical outcomes. More research is warranted to explore the heterogeneous treatment effects of SGLT2is and DPP4is by race/ethnicity.

The role of peptidoglycan hydrolases in the formation and toxicity of Pseudomonas aeruginosa membrane vesicles.

Bacterial membrane vesicles (MVs) have been reported to kill other bacteria. In the case of Pseudomonas aeruginosa the bactericidal activity has been attributed to an unidentified 26 kDa peptidoglycan (PG) hydrolase that is associated with MVs and gives rise to a lytic band on zymograms using murein sacculi as substrate. In this study, we employed a proteomics approach to show that this PG hydrolase is the AmphD3 amidase. The analysis of an amphD3 mutant as well as of an AmphD3 overexpression derivative revealed that this enzyme is not required for the bactericidal activity of P. aeruginosa MVs but is involved in cell wall recycling and thus protects the cell against PG damage. Another 23 kDa PG hydrolase, which we observed on zymograms of SOS-induced MVs, was identified as the endolysin Lys, which triggers explosive cell lysis but is shown to be dispensable for MV-mediated killing. We conclude that the lytic activities observed on zymograms do not correlate with the bactericidal potential of MVs. We demonstrate that P. aeruginosa MVs are enriched for several autolysins, suggesting that the predatory activity of MVs depends on the combined action of different murein hydrolases.

Cholesteryl α-D-glucoside 6-acyltransferase enhances the adhesion of Helicobacter pylori to gastric epithelium.

Helicobacter pylori, the most common etiologic agent of gastric diseases including gastric cancer, is auxotrophic for cholesterol and has to hijack it from gastric epithelia. Upon uptake, the bacteria convert cholesterol to cholesteryl 6'-O-acyl-α-D-glucopyranoside (CAG) to promote lipid raft clustering in the host cell membranes. However, how CAG appears in the host to exert the pathogenesis still remains ambiguous. Herein we identified hp0499 to be the gene of cholesteryl α-D-glucopyranoside acyltransferase (CGAT). Together with cholesteryl glucosyltransferase (catalyzing the prior step), CGAT is secreted via outer membrane vesicles to the host cells for direct synthesis of CAG. This significantly enhances lipid rafts clustering, gathers adhesion molecules (including Lewis antigens and integrins α5, ß1), and promotes more bacterial adhesion. Furthermore, the clinically used drug amiodarone was shown as a potent inhibitor of CGAT to effectively reduce the bacterial adhesion, indicating that CGAT is a potential target of therapeutic intervention.

Nonlinear climatic sensitivity to greenhouse gases over past 4 glacial/interglacial cycles.

The paleoclimatic sensitivity to atmospheric greenhouse gases (GHGs) has recently been suggested to be nonlinear, however a GHG threshold value associated with deglaciation remains uncertain. Here, we combine a new sea surface temperature record spanning the last 360,000 years from the southern Western Pacific Warm Pool with records from five previous studies in the equatorial Pacific to document the nonlinear relationship between climatic sensitivity and GHG levels over the past four glacial/interglacial cycles. The sensitivity of the responses to GHG concentrations rises dramatically by a factor of 2-4 at atmospheric CO2 levels of >220 ppm. Our results suggest that the equatorial Pacific acts as a nonlinear amplifier that allows global climate to transition from deglacial to full interglacial conditions once atmospheric CO2 levels reach threshold levels.

21st-century rise in anthropogenic nitrogen deposition on a remote coral reef.

With the rapid rise in pollution-associated nitrogen inputs to the western Pacific, it has been suggested that even the open ocean has been affected. In a coral core from Dongsha Atoll, a remote coral reef ecosystem, we observe a decline in the 15N/14N of coral skeleton-bound organic matter, which signals increased deposition of anthropogenic atmospheric N on the open ocean and its incorporation into plankton and, in turn, the atoll corals. The first clear change occurred just before 2000 CE, decades later than predicted by other work. The amplitude of change suggests that, by 2010, anthropogenic atmospheric N deposition represented 20 ± 5% of the annual N input to the surface ocean in this region, which appears to be at the lower end of other estimates.

Severe Decline of Estimated Glomerular Filtration Rate Associates with Progressive Cognitive Deterioration in the Elderly: A Community-Based Cohort Study.

Cognitive dysfunction is closely related to aging and chronic kidney disease (CKD). However, the association between renal function changes and the risk of developing cognitive impairment has not been elucidated. This longitudinal cohort study was to determine the influence of annual percentage change in estimated glomerular filtration rate (eGFR) on subsequent cognitive deterioration or death of the elderly within the community. A total of 33,654 elders with eGFR measurements were extracted from the Taipei City Elderly Health Examination Database. The Short Portable Mental Status Questionnaire was used to assess their cognitive progression at least twice during follow-up visits. Multivariable Cox regression models were used to estimate the hazard ratio (HR) for cognitive deterioration or all-cause mortality with the percentage change in eGFR. During a median follow-up of 5.4 years, the participants with severe decline in eGFR (>20% per year) had an increased risk of cognitive deterioration (HR, 1.33; 95% confidence interval [CI], 1.08-1.72) and the composite outcome (HR, 1.17; 95% CI, 1.03-1.35) when compared with those who had stable eGFR. Severe eGFR decline could be a possible predictor for cognitive deterioration or death among the elderly. Early detection of severe eGFR decline is a critical issue and needs clinical attentions.

miR-346 and miR-582-3p-regulated EG-VEGF expression and trophoblast invasion via matrix metalloproteinases 2 and 9.

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) is an important regulator for embryo implantation and placental development, and is clinically associated with several obstetric disorders related to insufficient or inappropriate trophoblast invasion, such as recurrent abortion, preeclampsia, and intrauterine fetal growth restriction. This study was performed to identify the microRNAs targeting EG-VEGF, and evaluate the regulatory effect on trophoblast biology. miR-346 and miR-582-3p were initially identified via bioinformatic tools, and their specific binding sites on the EG-VEGF 3'UTR were further confirmed using dual luciferase and a co-transfection assays. miR-346 and miR-582-3p were demonstrated not only to suppress EG-VEGF expression, but also inhibit trophoblast invasion and migration in the JAR and HTR-8/SVneo cell lines. We further evaluated the effect of microRNAs in HTR-8/SVneo cells coexpressing EG-VEGF and miR-346 or miR-582-3p on matrix metalloproteinase (MMP 2 and MMP 9) and the tissue inhibitors of metalloproteinase (TIMP 1 and TIMP 2) using RT-PCR, western blotting and gelatin zymography. TIMP 1 and TIMP 2 were not affected by the two microRNAs, whereas the expressions and activities of MMP 2 and MMP 9 were significantly downregulated, which in turn inhibited the invasion ability of trophoblasts. In conclusion, miR-346 and miR-582-3p regulate EG-VEGF-induced trophoblast invasion through repressing MMP 2 and MMP 9, and may become novel diagnostic biomarkers or therapeutic targets for EG-VEGF-related obstetric disorders. © 2016 BioFactors, 43(2):210-219, 2017.

A Common Variant of PROK1 (V67I) Acts as a Genetic Modifier in Early Human Pregnancy through Down-Regulation of Gene Expression.

PROK1-V67I has been shown to play a role as a modifier gene in the PROK1-PROKR system of human early pregnancy. To explore the related modifier mechanism of PROK1-V67I, we carried out a comparison study at the gene expression level and the cell function alternation of V67I, and its wild-type (WT), in transiently-transfected cells. We, respectively, performed quantitative RT-PCR and ELISA assays to evaluate the protein and/or transcript level of V67I and WT in HTR-8/SV neo, JAR, Ishikawa, and HEK293 cells. Transiently V67I- or WT-transfected HTR-8/SV neo and HEK293 cells were used to investigate cell function alternations. The transcript and protein expressions were down-regulated in all cell lines, ranging from 20% to 70%, compared with WT. There were no significant differences in the ligand activities of V67I and WT with regard to cell proliferation, cell invasion, calcium influx, and tubal formation. Both PROK1 alleles promoted cell invasion and intracellular calcium mobilization, whereas they had no significant effects on cell proliferation and tubal formation. In conclusion, the biological effects of PROK1-V67I on cell functions are similar to those of WT, and the common variant of V67I may act as a modifier in the PROK1-PROKR system through down-regulation of PROK1 expression. This study may provide a general mechanism that the common variant of V67I, modifying the disease severity of PROK1-related pathophysiologies.

Metabolic labelling of cholesteryl glucosides in Helicobacter pylori reveals how the uptake of human lipids enhances bacterial virulence.

Helicobacter pylori infects approximately half of the human population and is the main cause of various gastric diseases. This pathogen is auxotrophic for cholesterol, which it converts upon uptake to various cholesteryl α-glucoside derivatives, including cholesteryl 6'-acyl and 6'-phosphatidyl α-glucosides (CAGs and CPGs). Owing to a lack of sensitive analytical methods, it is not known if CAGs and CPGs play distinct physiological roles or how the acyl chain component affects function. Herein we established a metabolite-labelling method for characterising these derivatives qualitatively and quantitatively with a femtomolar detection limit. The development generated an MS/MS database of CGds, allowing for profiling of all the cholesterol-derived metabolites. The subsequent analysis led to the unprecedented information that these bacteria acquire phospholipids from the membrane of epithelial cells for CAG biosynthesis. The resulting increase in longer or/and unsaturated CAG acyl chains helps to promote lipid raft formation and thus delivery of the virulence factor CagA into the host cell, supporting the idea that the host/pathogen interplay enhances bacterial virulence. These findings demonstrate an important connection between the chain length of CAGs and the bacterial pathogenicity.

Obliquity pacing of the western Pacific Intertropical Convergence Zone over the past 282,000 years.

The Intertropical Convergence Zone (ITCZ) encompasses the heaviest rain belt on the Earth. Few direct long-term records, especially in the Pacific, limit our understanding of long-term natural variability for predicting future ITCZ migration. Here we present a tropical precipitation record from the Southern Hemisphere covering the past 282,000 years, inferred from a marine sedimentary sequence collected off the eastern coast of Papua New Guinea. Unlike the precession paradigm expressed in its East Asian counterpart, our record shows that the western Pacific ITCZ migration was influenced by combined precession and obliquity changes. The obliquity forcing could be primarily delivered by a cross-hemispherical thermal/pressure contrast, resulting from the asymmetric continental configuration between Asia and Australia in a coupled East Asian-Australian circulation system. Our finding suggests that the obliquity forcing may play a more important role in global hydroclimate cycles than previously thought.