Variations in Helicobacter pylori lipopolysaccharide to evade the innate immune component surfactant protein D

Helicobacter pylori is a common and persistent human pathogen of the gastric mucosa. Surfactant protein D (SP-D), a component of innate immunity, is expressed in the human gastric mucosa and is capable of aggregating H. pylori. Wide variation in the SP-D binding affinity to H. pylori has been observed in clinical isolates and laboratory-adapted strains. The aim of this study was to reveal potential mechanisms responsible for evading SP-D binding and establishing persistent infection. An escape variant, J178V, was generated in vitro, and the lipopolysaccharide (LPS) structure of the variant was compared to that of the parental strain, J178. The genetic basis for structural variation was explored by sequencing LPS biosynthesis genes. SP-D binding to clinical isolates was demonstrated by fluorescence-activated cell sorter analyses. Here, we show that H. pylori evades SP-D binding through phase variation in lipopolysaccharide. This phenomenon is linked to changes in the fucosylation of the O chain, which was concomitant with slipped-strand mispairing in a poly(C) tract of the fucosyltransferase A (fucT1) gene. SP-D binding organisms are predominant in mucus in vivo (P = 0.02), suggesting that SP-D facilitates physical elimination. Phase variation to evade SP-D contributes to the persistence of this common gastric pathogen.     

Susceptibility pattern and molecular type of species-specific Candida in oropharyngeal lesions of Indian human immunodeficiency virus-positive patients

A study of oropharyngeal candidiasis (OPC) in Indian human immunodeficiency virus (HIV)/AIDS patients was conducted over a period of 15 months. This study revealed that 75% of the HIV/AIDS patients had OPC. MIC testing revealed that 5% of the Candida isolates were fluconazole resistant. A correlation between CD4(+)-T-cell counts and development of OPC in HIV/AIDS patients was also observed. Molecular typing of C. albicans isolates showed that all were genetically unrelated.     

Development and Face Validity of Explicit indicators of Appropriateness of Long Term Prescribing

Objectives: To develop a set of explicit and operationalisable indicators of appropriate prescribing and assess their face validity using clinical pharmacists practising in secondary and primary care. Method: Appropriateness indicators were derived from the literature, applied to data in the hospital clinical records of all newly prescribed long-term drugs for 50 randomly selected patients, further refined and then applied to another 25 randomly selected patients. A pre-piloted postal questionnaire was sent to 200 hospitals and primary care pharmacists, asking them to assess the indicators as to their importance for the assessment of appropriateness of long-term prescribing initiated in hospitals. Results: Fourteen indicators were developed and piloted. Of the 16 original indicators, 5 were discarded, as they were unable to be operationalised, and 2 were subdivided to reflect the routinely available data. Eighty-six pharmacists with individual patient-focussed clinical duties took part in the assessment of the face validity (response rate 43%). Eleven indicators achieved a median importance rating of 1 (very important), and three indicators a median importance rating of 2 on a 5-point scale. The three most important indicators overall were ‘indication included in discharge summary’, ‘questionable high-risk therapeutic combination’ and ‘hazardous drug-drug combination’. Conclusion: It was possible to develop and operationalise 14 indicators of the appropriateness of long-term prescribing commenced in hospital practice, all of which were considered to have face validity by an expert panel of clinical pharmacists. The development of these explicit indicators highlighted the incompleteness of the patient’s record. Further work is needed to assess their validity and reliability, before their use in research or audit can be recommended.     

Attenuation of Aluminum Chloride-Induced Neuroinflammation and Caspase Activation Through the AKT/GSK-3β Pathway by Hesperidin in Wistar Rats

Hesperidin, a flavanoglycone abundantly present in citrus fruits, is reported to have antioxidant, anti-inflammatory, and neuroprotective properties. Previous reports from our laboratory indicated the neuroprotective effect of hesperidin against aluminum chloride (AlCl₃)-induced memory loss, acetylcholine esterase hyperactivity, oxidative stress, and enhanced expression of amyloid β protein biosynthesis-related markers. However, their role on AlCl₃-induced inflammation, caspase activation, Tau pathology, altered Akt/GSK 3β signaling pathway, and Aβ clearance marker has not yet been fully elucidated. Intraperitonial injection of AlCl₃ (100 mg/kg body weight) for 60 days significantly elevated the expressions of insulin-degrading enzyme (IDE), cyclin-dependent kinase 5 (CDK 5), and phosphoTau (pTau); inflammatory markers such as glial fibrillary acidic protein (GFAP), ionized calcium-binding adapter molecule 1 (Iba-1), NF-kB, cyclooxygenase-2 (COX-2), interleukin (IL)-1β, IL-4, IL-6, tumor necrosis factor-alpha (TNF-α), inducible nitric oxide synthase (iNOS); and apoptotic markers including cytosolic cytochrome c (cyto c), caspase-3, caspase-8, and caspase-9, and lowered expressions of mitochondrial cyto c, phospho-Akt (pAkt) and phospho-glycogen synthase kinase-3β (pGSK-3β) in the hippocampus and cortex. Co-administration of hesperidin to AlCl₃ rats for 60 days significantly ameliorated the aluminum-induced pathological changes. The behavioral studies also supported the above findings. Our results imply that treatment with hesperidin might be a potent option for treating the symptoms of cognitive impairment in Alzheimer’s disease by targeting its most prominent hallmarks.     

Putty Index for Tripoding

Precise orientation and transfer of the selected path of insertion and removal is a critical step in cast removable partial denture prosthesis design. An easy technique for registering the same is described using addition silicon putty and a used diamond disk.     

Novel derivatives of 5-amino-1-cyclopropyl-7-[(3R,5S)3,5-dimethylpiperazine-1-yl]-6,8-difluoro-4-oxo-quinoline-3-carboxylic acid: their synthesis,antimicrobial, antifungal,and urease inhibitory studies

Sparfloxacin (SPFX) or 5-amino-1-cyclopropyl-7-[(3R,5S)3,5-dimethylpiperazine-1-yl]-6,8-difluoro-4-oxo-quinoline-3-carboxylic acid is an orally active synthetic, broad spectrum third generation quinolone, with excellent activity against Gram-positive bacteria with selectivity against anaerobes and atypical pathogens. Three derivatives of SPFX (2, 3, and 4) were synthesized by reacting different aromatic carboxylic acids with SPFX (1). Chemistry involved the formation of amide between reacting species through nucleophilic substitution reactions. The synthesized derivatives were then structurally characterized by IR, NMR, and mass spectroscopic techniques. The antimicrobial activities of these derivatives were evaluated against four Gram-positive, seven Gram-negative bacteria, and six fungi, using SPFX as a reference. Statistical analysis revealed these derivatives as active antimicrobial agents, and 2 was more potent antimicrobial agents than the parent drug as well other fluoroquinolones. Compounds 3 and 4 showed a significant activity against Fusarium solani. Moreover, these three derivatives were evaluated for inhibitory activities against enzyme urease, carbonic anhydrase II, and α-chymotrypsin. Results showed their selectivity against urease enzyme. Based on their nontoxic behavior, these derivatives may be potential agents for further studies.     

Endogenous adenosine differentially modulates 5-hydroxytryptamine release from a human enterochromaffin cell model

BACKGROUND & AIMS: The aim was to determine whether adenosine receptors modulate cAMP, intracellular free calcium ([Ca(2+)](i)), and 5-hydroxytryptamine (5-HT) release in human carcinoid BON cells. METHODS: Adenosine receptor (R) mRNA, proteins, and function were identified by Western blots, immunofluorescent labeling, Fluo-4/AM [Ca(2+)](i) imaging, and pharmacologic/physiologic techniques. RESULTS: A1, A2, and A3Rs were present in BON cells and carcinoid tumors. Baseline 5-HT levels increased with adenosine deaminase, activation of A2Rs, and inhibition of A3Rs, whereas A3R activation decreased 5-HT. A2R antagonists or blockade of adenosine reuptake that elevates extracellular adenosine reduced mechanically evoked 5-HT release. In single BON cells, touch elevated [Ca(2+)](i) responses were augmented by adenosine deaminase, A1, and A3R antagonists. CONCLUSIONS: Tonic or mechanically evoked release of endogenous adenosine is a critical determinant of differential activation of adenosine receptors and may have important implications for gut mechanosensory reflexes.     

Enhanced tissue responsiveness in colonic ion transport of cow's milk-sensitized guinea pigs

The effects of leukotriene D₄ (LTD₄) on ion transport were investigated in submucosa/mucosa colonic segments from guinea pigs sensitized to cow's milk and in age-matched, non-immune animals. Mediators released from mast cells in immune animals challenged with -lactoglobulin evoked an increase in short-circuit current that was reduced by SK&F 102922, a peptidoleukotriene antagonist. Serosal addition of LTD₄ (0.15–1 M) evoked a concentration-dependent, bumetanide-sensitive increase in short-circuit current which was greater in immune than non-immune controls. In the absence of ongoing neural activity, 1 M LTD₄ evoked an 8–20 A/cm² increase in short-circuit current which was increased 8–13-fold when ongoing neural activity was present. In tissues with ongoing activity, the response to 0.15 M LTD₄ was reduced by SK&F 102922, tetrodotoxin and atropine. LTD₄ enhanced the responsiveness of the tissue to carbachol by a factor of two, but did not affect responses of T₈₄ colonic epithelial cell monolayers to this agent. These results show enhanced secretory function for LTD₄ in animals with allergy to cow's milk. They suggest that the level of ongoing neural activity in the enteric neural microc ircuits is one of the major determinants of colonic secretory capacity.