Total Synthesis of the Repeating Unit of Bacteroides fragilis Zwitterionic Polysaccharide A1.

Zwitterionic polysaccharides isolated from commensal bacteria are endowed with unique immunological properties and are emerging as immunotherapeutic agents as well as vaccine carriers. Reported herein is a total synthesis of the repeating unit of Bacteroides fragilis zwitterionic polysaccharide A1 (PS A1). The structurally complex tetrasaccharide unit contains a rare sugar 2-acetamido-4-amino-2,4,6-trideoxy-d-galactose (AAT) and two consecutive 1,2-cis glycosidic linkages. The repeating unit was efficiently assembled by rapid synthesis of d-galactosamine and AAT building blocks from cheap and abundant d-mannose via a one-pot SN2 displacement of 2,4-bistriflates and installation of all of the glycosidic bonds in a highly stereoselective manner. The total synthesis involves a longest linear sequence of 17 steps with 3.47% overall yield.

Threshold of Thioglycoside Reactivity Difference Is Critical for Efficient Synthesis of Type I Oligosaccharides by Chemoselective Glycosylation.

Synthesis of type I LacNAc (Galß1 → 3GlcNAc) oligosaccharides usually suffers from low yields. We herein report the efficient synthesis of type I LacNAc oligosaccharides by chemoselective glycosylation. With 16 relative reactivity values (RRVs) measured thiotoluenyl-linked disaccharide donors and acceptors, chemoselective glycosylations were investigated to obtain optimal conditions. In these reactions, the RRV difference between the donors and acceptors had to be more than 6311 to obtain type I LacNAc tetrasaccharides in 72-86% yields, with minimal occurrence of aglycon transfer. The threshold of RRV difference was further applied to plan the synthesis of longer glycans. Because it is challenging to measure the RRVs of tetrasaccharides, anomeric proton chemical shifts were utilized to predict the corresponding RRVs, which consequently explained the outcome of glycosylations for the synthesis of type I LacNAc hexasaccharides. The result supported the idea that elongation of glycan chains has to proceed from the reducing to the nonreducing end for a better yield.

Unusually Stable Picoloyl-Protected Trimethylsilyl Glycosides for Nonsymmetrical 1,1'-Glycosylation and Synthesis of 1,1'-Disaccharides with Diverse Configurations.

Nonsymmetrical 1,1'-disaccharides and related derivatives constitute structural components in various glycolipids and natural products. Some of these compounds have been shown to exhibit appealing biological properties. We report a direct yet stereoselective 1,1'-glycosylation strategy for the synthesis of nonsymmetrical 1,1'-disaccharides with diverse configurations and sugar components. The strategy is based on the joined forces of a new class of configurationally stable glycoside acceptors and stereodirecting thioglycoside donors. The new glycoside acceptors feature a picoloyl (Pico) protecting group at the remote C4/C3 position that confers unusual stability on TMS glycosides under acidic conditions.

Tubular lysosome induction couples animal starvation to healthy aging.

Dietary restriction promotes longevity in several species via autophagy activation. However, changes to lysosomes underlying this effect remain unclear. Here using the nematode Caenorhabditis elegans, we show that the induction of autophagic tubular lysosomes (TLs), which occurs upon dietary restriction or mechanistic target of rapamycin inhibition, is a critical event linking reduced food intake to lifespan extension. We find that starvation induces TLs not only in affected individuals but also in well-fed descendants, and the presence of gut TLs in well-fed progeny is predictive of enhanced lifespan. Furthermore, we demonstrate that expression of Drosophila small VCP-interacting protein, a TL activator in flies, artificially induces TLs in well-fed worms and improves C. elegans health in old age. These findings identify TLs as a new class of lysosomes that couples starvation to healthy aging.

A Fat-Promoting Botanical Extract From Artemisia scoparia Exerts Geroprotective Effects on Caenorhabditis elegans Life Span and Stress Resistance.

Like other biological processes, aging is not random but subject to molecular control. Natural products that modify core metabolic parameters, including fat content, may provide entry points to extend animal life span and promote healthy aging. Here, we show that a botanical extract from Artemisia scoparia (SCO), which promotes fat storage and metabolic resiliency in mice, extends the life span of the nematode Caenorhabditis elegans by up to 40%. Notably, this life-span extension depends significantly on SCO's effects on fat; SCO-treated worms exhibit heightened levels of unsaturated fat, and inhibition of Δ9 desaturases, which oversee biosynthesis of monounsaturated fatty acids, prevents SCO-dependent fat accumulation and life-span extension. At an upstream signaling level, SCO prompts changes to C. elegans fat regulation by stimulating nuclear translocation of transcription factor DAF-16/FOXO, an event that requires AMP-activated protein kinase under this condition. Importantly, animals treated with SCO are not only long-lived but also show improved stress resistance in late adulthood, suggesting that this fat-promoting intervention may enhance some aspects of physiological health in older age. These findings identify SCO as a natural product that can modify fat regulation for longevity benefit and add to growing evidence indicating that elevated fat can be prolongevity in some circumstances.

Total Synthesis of the Repeating Units of O-Specific Polysaccharide of Pseudomonas chlororaphis subsp. aureofaciens UCM B-306 via One-Pot Glycosylation.

Herein we report the first total syntheses of the trisaccharide-repeating units of Pseudomonas chlororaphis subsp. aureofaciens UCM B-306 via a one-pot assembly of the core trisaccharide structure. The rare-sugar-containing trisaccharide-repeating units are comprised of d-bacillosamine, 2-amino-2-deoxy-d-galacturonic acid or amide, and d-rhamnose units linked through three consecutive α-linkages. The total syntheses of two repeating units were completed starting from d-mannose via a longest-linear sequence of 27 steps in 5.8% and 4.4% overall yields, respectively.

Degradative tubular lysosomes link pexophagy to starvation and early aging in C. elegans.

Organelle-specific autophagy directs degradation of eukaryotic organelles under certain conditions. Like other organelles, peroxisomes are subject to autophagic turnover at lysosomes. However, peroxisome autophagy (pexophagy) has yet to be analyzed in a live-animal system, limiting knowledge on its regulation during an animal's life. Here, we generated a tandem-fluorophore reporter that enabled real-time tracking of pexophagy in live Caenorhabditis elegans. We observed that pexophagy occurred at a population of non-canonical, tubular lysosomes specifically during starvation and aging. Remarkably, in these contexts, tubular lysosomes were the predominant type of lysosome in the intestine, transforming from vesicles. Though we found that peroxisomes were largely eliminated in early adulthood, they appeared restored in new generations. We identified peroxisomal genes that regulated age-dependent peroxisome loss and demonstrated that modifying this process altered animal lifespan. These findings reveal new facets of peroxisome homeostasis relevant to aging and challenge the prevailing perception of lysosome homogeneity in autophagy.Abbreviations: GFP: green fluorescent protein; SKL: serine-lysine-leucine peroxisome signal sequence; spin: spinster; TLs: tubular lysosomes.

The Mass General Brigham Biobank Portal: an i2b2-based data repository linking disparate and high-dimensional patient data to support multimodal analytics.

OBJECTIVE: Integrating and harmonizing disparate patient data sources into one consolidated data portal enables researchers to conduct analysis efficiently and effectively. MATERIALS AND METHODS: We describe an implementation of Informatics for Integrating Biology and the Bedside (i2b2) to create the Mass General Brigham (MGB) Biobank Portal data repository. The repository integrates data from primary and curated data sources and is updated weekly. The data are made readily available to investigators in a data portal where they can easily construct and export customized datasets for analysis. RESULTS: As of July 2021, there are 125 645 consented patients enrolled in the MGB Biobank. 88 527 (70.5%) have a biospecimen, 55 121 (43.9%) have completed the health information survey, 43 552 (34.7%) have genomic data and 124 760 (99.3%) have EHR data. Twenty machine learning computed phenotypes are calculated on a weekly basis. There are currently 1220 active investigators who have run 58 793 patient queries and exported 10 257 analysis files. DISCUSSION: The Biobank Portal allows noninformatics researchers to conduct study feasibility by querying across many data sources and then extract data that are most useful to them for clinical studies. While institutions require substantial informatics resources to establish and maintain integrated data repositories, they yield significant research value to a wide range of investigators. CONCLUSION: The Biobank Portal and other patient data portals that integrate complex and simple datasets enable diverse research use cases. i2b2 tools to implement these registries and make the data interoperable are open source and freely available.

Comparison of lignocaine gel-soaked Falope rings vs rectal diclofenac suppository for pain relief in laparoscopic sterilization.

STUDY OBJECTIVE: To compare the analgesic efficacy of lignocaine gel-soaked Silastic bands compared with rectal diclofenac suppositories in patients undergoing interval laparoscopic sterilization under conscious sedation. DESIGN: Prospective, randomized, controlled, single-blinded, clinical trial. SETTING: Day-case center in a tertiary care hospital in India. PATIENTS: Ninety-six women undergoing interval laparoscopic sterilization using Silastic bands (Yoon rings) randomly allocated by computer-generated random numbers into 3 groups. INTERVENTIONS: All women received intravenous sedation with injection diazepam and pentazocine along with local infiltration lignocaine injected at the site of the incision meant for insertion of the single site laparocator. In group 1 (n = 32), the Silastic bands (Falope rings) were presoaked in 2% sterile lignocaine gel; in group 2 (n = 32), women received a 100-mg rectal diclofenac suppository while on the operating table; and women in group 3 received only conventional analgesic. Pain perception was assessed using an 11-point visual analog score just after the procedure while still on the table (zero minutes), at 30 minutes and 1 hour after the procedure, and at discharge. MEASUREMENTS AND MAIN RESULTS: The women in all 3 groups were comparable insofar as age and parity. At zero minutes (while on the operating table), the pain score in all 3 groups was similar. However, the pain scores at 30 and 60 minutes, and at discharge were significantly lower in groups 1 and group 2 compared with group 3. However, 2 women (6.25%) in group 2 and 6 (18.75%) in group 3 required supplemental analgesia within 1 hour, and were administered a 500-mg oral dose of mefenamic acid. The need for further analgesia was significantly lower in groups 1 and 2 compared with group 3 (p = .02). Comparison of groups 1 and 3 revealed that in group 1, the pain scores were significantly lower at 30 minutes (p = .02), 1 hour (p = .005), and at discharge (p = .004). No patients in group 1 requested analgesia, whereas 6 women in group 3 asked for further analgesia within an hour postoperatively (p = .01). Similarly in groups 2 and 3, women who received diclofenac suppositories had significantly lower pain scores at the specified intervals (p = 0.02, 0.002, and 0.02, respectively). CONCLUSION: Application of lignocaine gel to Falope rings and preoperative insertion of a rectal diclofenac suppository are simple and effective measures for pain control in the early postoperative period in patients undergoing day-case laparoscopic sterilization under conscious sedation. Either method could be incorporated into routine practice, depending on patient and physician choice.

Organelle-Specific Autophagy in Cellular Aging and Rejuvenation.

The health of a cell requires proper functioning, regulation, and quality control of its organelles, the membrane-enclosed compartments inside the cell that carry out its essential biochemical tasks. Aging commonly perturbs organelle homeostasis, causing problems to cellular health that can spur the initiation and progression of degenerative diseases and related pathologies. Here, we discuss emerging evidence indicating that age-related defects in organelle homeostasis stem in part from dysfunction of the autophagy-lysosome system, a pivotal player in cellular quality control and damage clearance. We also highlight natural examples from biology where enhanced activity of the autophagy-lysosome system might be harnessed to erase age-related organelle damage, raising potential implications for cellular rejuvenation.

Advances in Protecting Groups for Oligosaccharide Synthesis.

Carbohydrates contain numerous hydroxyl groups and sometimes amine functionalities which lead to a variety of complex structures. In order to discriminate each hydroxyl group for the synthesis of complex oligosaccharides, protecting group manipulations are essential. Although the primary role of a protecting group is to temporarily mask a particular hydroxyl/amino group, it plays a greater role in tuning the reactivity of coupling partners as well as regioselectivity and stereoselectivity of glycosylations. Several protecting groups offer anchimeric assistance in glycosylation. They also alter the solubility of substrates and thereby influence the reaction outcome. Since oligosaccharides comprise branched structures, the glycosyl donors and acceptors need to be protected with orthogonal protected groups that can be selectively removed one at a time without affecting other groups. This minireview is therefore intended to provide a discussion on new protecting groups for amino and hydroxyl groups, which have been introduced over last ten years in the field of carbohydrate synthesis. These protecting groups are also useful for synthesizing non-carbohydrate target molecules as well.

Vaginal misoprostol for cervical priming prior to diagnostic hysteroscopy--efficacy, safety and patient satisfaction: a randomized controlled trial.

OBJECTIVE: To evaluate the effectiveness and safety of vaginal misoprostol for cervical priming prior to diagnostic hysteroscopy and to assess impact on pain scores and patient satisfaction. METHODS: One hundred women undergoing hysteroscopy were randomly allocated into two groups. The study group (n = 50) received 400 microg of misoprostol vaginally (self administered) 4-6 h prior to hysteroscopy while the control group (n = 50) did not receive any cervical priming. Primary outcome measured was need for cervical dilatation, analgesia or sedation. Secondary outcomes were pain scores, patient satisfaction and side effects. RESULTS: There was no significant difference in the need for cervical dilatation, analgesia or sedation in the two groups (P = 0.25, 0.64 and 0.5, respectively). In addition, there was no difference in subjective patient satisfaction (P = 0.70). However, those in the control group recorded a higher pain score (median +/- SD = 5 +/- 1.8) when compared to those who received misoprostol (median +/- SD = 4.5 +/- 2, P = 0.03). Only two women (4%) had bleeding per vaginum and one (2%) had a slight fever attributable to misoprostol. CONCLUSION: Vaginal misoprostol prior to diagnostic hysteroscopy did not facilitate cervical dilatation. It did effect a reduction in pain scores, but there was no difference in patient satisfaction, need for analgesia or sedation. No significant side effects were reported.

Successful management of live ectopic pregnancy with high beta-hCG titres by ultrasound-guided potassium chloride injection and systemic methotrexate.

BACKGROUND: Methotrexate (Mtx) is accepted modality for conservative treatment of ectopic pregnancy. However, there is no consensus regarding its use in live ectopic pregnancy and high serum beta-human chorionic gonadotrophin (beta-hCG) titres. CASE REPORT: We report a successful management of live ectopic pregnancy in a 27-year-old nulliparous woman, with very high beta-hCG titres (89,200 mIU/mL), using ultrasound-guided intra-sac potassium chloride (KCl) injection and systemic Mtx. Successful resolution of the ectopic pregnancy, with negative serum beta-hCG (<1 mIU/mL) was achieved after three doses of Mtx, and a prolonged follow-up of 71 days. No treatment related complications were encountered. CONCLUSION: Concurrent use of intra-sac hypertonic KCl, to produce cardiac asystole, with systemic Mtx could potentially improve outcome in live ectopic gestations with very high serum beta-hCG titres. However, individualised treatment, with a stringent follow-up regime is mandatory in such cases.

Comparison of oral naproxen and intrauterine lignocaine instillation for pain relief during hysterosalpingography.

OBJECTIVES: To compare the efficacy of oral naproxen with intrauterine instillation of 1% lignocaine for pain relief in women undergoing hysterosalpingography (HSG) as an infertility investigation. METHODS: One hundred women undergoing HSG were randomly allocated into 2 groups. Group A (n = 50) underwent intrauterine instillation of 5 mL of 1% lignocaine 2 minutes prior to the procedure, while the women in group B (n = 50) were instructed to self-administer a single oral dose of 375 mg of naproxen 1 hour prior to HSG. Pain scores immediately after the procedure (0 minutes) and delayed pain scores (30 minutes) were recorded and compared. RESULTS: Women in both groups were comparable in age and parity. The mean +/- SD pain scores in group A and group B at 0 minutes and 30 minutes were not significantly different (P = 0.12 and P = 0.07). CONCLUSION: Intrauterine lignocaine was no more effective than oral naproxen for pain relief during HSG.

The Biobank Portal for Partners Personalized Medicine: A Query Tool for Working with Consented Biobank Samples, Genotypes, and Phenotypes Using i2b2.

We have designed a Biobank Portal that lets researchers request Biobank samples and genotypic data, query associated electronic health records, and design and download datasets containing de-identified attributes about consented Biobank subjects. This do-it-yourself functionality puts a wide variety and volume of data at the fingertips of investigators, allowing them to create custom datasets for their clinical and genomic research from complex phenotypic data and quickly obtain corresponding samples and genomic data. The Biobank Portal is built upon the i2b2 infrastructure [1] and uses an open-source web client that is available to faculty members and other investigators behind an institutional firewall. Built-in privacy measures [2] ensure that the data in the Portal are utilized only according to the processes to which the patients have given consent.

Synthesis of oligomeric mannosides and their structure-binding relationship with concanavalin†A.

Small glycodendrimers with α-mannosyl ligands were synthesized by using copper-catalyzed azide-alkyne coupling chemistry and some of these molecules were used as multivalent ligands to study the induction of concanavalin A (Con A) precipitation. The results showed that the monovalent mannose ligand could induce the precipitation of Con A. This unexpected finding initiated a series of studies to characterize the molecular basis of the ligand-lectin interaction. The atypical precipitation is found to be specific to the mannose, fluorescein moiety (FITC), and Con A. Apparently the mannose ligand binds to Con A through hydrogen-bonding interactions, whereas the binding of FITC is mediated by hydrophobic forces.

Photoluminescent gold nanoclusters as sensing probes for uropathogenic Escherichia coli.

Glycan-bound nanoprobes have been demonstrated as suitable sensing probes for bacteria containing glycan binding sites. In this study, we demonstrated a facile approach for generating glycan-bound gold nanoclusters (AuNCs). The generated AuNCs were used as sensing probes for corresponding target bacteria. Mannose-capped AuNCs (AuNCs@Mann) were generated and used as the model sensors for target bacteria. A one-step synthesis approach was employed to generate AuNCs@Mann. In this approach, an aqueous solution of tetrachloroauric acid and mannoside that functionized with a thiol group (Mann-SH) was stirred at room temperature for 48 h. The mannoside functions as reducing and capping agent. The size of the generated AuNCs@Mann is 1.95±0.27 nm, whereas the AuNCs with red photoluminescence have a maximum emission wavelength of ~630 nm (λexcitation = 375 nm). The synthesis of the AuNCs@Mann was accelerated by microwave heating, which enabled the synthesis of the AuNCs@Mann to complete within 1 h. The generated AuNCs@Mann are capable of selectively binding to the urinary tract infection isolate Escherichia coli J96 containing the mannose binding protein FimH expressed on the type 1 pili. On the basis of the naked eye observation, the limit of detection of the sensing approach is as low as ~2×10(6) cells/mL.

Total synthesis of a glycoglycerolipid from Meiothermus taiwanensis through a one-pot glycosylation reaction and exploration of its immunological properties.

The total synthesis of a glycoglycerolipid isolate of Meiothermus taiwanensis and its truncated structural analogues is reported. Our synthesis employed DMF-modulated and low-concentration glycosylation reactions for the construction of α- and ß-glycosidic bonds in the absence of participating protecting groups. Further simplification of the synthesis was achieved by employing a low-concentration one-pot glycosylation procedure. Preliminary immunological studies showed that one of the truncated structural analogues suppressed the cytokine production of THP-1 monocytes.

In situ formation of ß-glycosyl imidinium triflate from participating thioglycosyl donors: elaboration to disarmed-armed iterative glycosylation.

ß-Glycosyl imidinium triflate is generated from participating thioglycoside donors for disarmed-armed iterative glycosylations and one-pot oligosaccharide synthesis.

Ectopic pregnancy following levonorgestrel emergency contraception: a case report.

Use of levonorgestrel as emergency contraception is a safe and effective measure to prevent unwanted pregnancy. However, ectopic gestation in case of failure is a known risk. Access to levonorgestrel without a prescription in many countries has made it impossible to estimate the exact incidence of this potential adverse event. Thus, spontaneous reporting of cases serves to alert physicians to this possibility. We present a case of ectopic pregnancy following use of levonorgestrel emergency contraception. To our knowledge, this is the first case report from India following introduction of levonorgestrel emergency contraception in 2001.