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Compact Brillouin-erbium fiber laser

Harun SW, Shahi S, Ahmad H

Opt Lett, 2009 Jan 01;34(1):46-8.
PMID: 19109635

A single-wavelength Brillouin fiber laser (BFL) is demonstrated at the extended L-band region using bismuth-based erbium-doped fiber (Bi-EDF) for the first time to the best of our knowledge. A 2.15-m-long Bi-EDF is used to provide both nonlinear and linear gains to generate a stimulated Brillouin scattering (SBS) and to amplify the generated SBS, respectively. The BFL operates at 1613.93 nm, which is upshifted by 0.09 nm from the Brillouin pump with a peak power of 2 dBm and a side-mode suppression ratio of more than 22 dB. The generated BFL has a narrow linewidth and many potential applications, such as in optical communication and sensors.

Matched MeSH terms: Antacids
Tumor-responsive dynamic nanoassemblies for targeted imaging, therapy and microenvironment manipulation

Low LE, Wu J, Lee J, Tey BT, Goh BH, Gao J, et al.

J Control Release, 2020 Aug 10;324:69-103.
PMID: 32423874 DOI: 10.1016/j.jconrel.2020.05.014

The recent designs of dynamic nanoassemblies exploiting the tumor-targeting properties have received increasing attention for tumor imaging and therapy due to their tumor-specific delivery and enhanced antitumor efficacy. However, these designs are mainly focused on the macroscopic tumor therapeutic effect, while the nano-bio interactions in the tumor microenvironment (TME) remain poorly understood. This review aims to provide an overview of the development of tumor-responsive nanoassemblies towards the imaging, therapy and TME modulation in the tumor site. The tumor biology leading to TME formation and the potential TME properties for the practicable design of tumor-targeting nanoassemblies has been outlined. Furthermore, the various approaches for TME modification and the realization via dynamic nanoassemblies for enhanced tumor therapy were reviewed. Lastly, the prospects of these methods were briefly discussed. These strategies may inspire the development of new combinational cancer therapeutics.

Matched MeSH terms: Antacids
Fulltext Single dose antacid therapy before caesarian section

Tan KH

Med J Malaysia, 1984 Sep;39(3):246-9.
PMID: 6100563

The severity of pulmonary aspiration depends mainly on the acidity of the aspirate. Mist magnesium trisilicate (MMT) has been used for many years at the maternity unit in General Hospital, Kuala Lumpur, to neutralise the acidic gastric contents in all obstetric patients requiring caesarian section. This preliminary study shows that a single dose of 15 mls of MMT before general anaesthesia raises the intragastric pH to above the critical level of 2.5 in 80% of the patients. Recently there have been doubts over the protective role of MMT. Sodium citrate which is the other antacid available may be a better alternative.

Matched MeSH terms: Antacids/administration & dosage; Antacids/therapeutic use*
Development and applications of remote stereocontrol using allylic organobismuth reagents

Basar N, Donnelly S, Sirat HM, Thomas EJ

Org Biomol Chem, 2013 Dec 28;11(48):8476-505.
PMID: 24212203 DOI: 10.1039/c3ob41931b

Reactions of 5-benzyloxy-4-methylpent-2-enyl(tributyl)stannane with aldehydes promoted by bismuth(III) iodide were usefully stereoselective in favour of the (E)-1,5-anti-6-benzyloxy-5-methylalk-3-en-1-ols. Similar stereoselectivity was observed for reactions of analogous 5-benzyloxy-4-methylpent-2-enyl bromides with aldehydes when promoted by a low valency bismuth species prepared by reduction of bismuth(III) triiodide with powdered zinc so providing a "tin-free" procedure. The analogous reactions of 4-benzyloxypent-2-enyl(tributyl)stannane with aldehydes promoted by bismuth(III) iodide were also stereoselective but gave lower yields. Attempted 1,6-stereocontrol using these reactions resulted in only modest stereoselectivities. Aspects of the chemistry of the products were studied in particular their stereoselective conversion into aliphatic compounds with methyl bearing stereogenic centres at 1,5,9,13- and 1,3,5-positions along the aliphatic chain. Mechanistically, allylic organobismuth species may be involved in both sets of reactions but this was not confirmed although the similar stereoselectivities observed for both the bismuth(III) iodide mediated reactions of the pent-2-enylstannanes and the low-valency bismuth promoted reactions of the pent-2-enyl bromides are consistent with participation of similar intermediates.

Matched MeSH terms: Antacids
Fulltext Physico-chemical and electrical properties of bismuth chromate solid solutions

Tan, Y.P., Wong, Y.C.

Pertanika Journal of Science & Technology, 2013;21(1):97-110.
MyJurnal

Bismuth chromium solid solutions, with a general formula Bi6-xCr2Oδ, where -1 ≤ x ≤ 2, were successfully synthesized via the conventional solid state method. The phases of the synthesized samples were determined by X-ray diffraction (XRD) analysis. The properties of single-phase compounds were characterized by using differential thermal analysis (DTA), thermal gravimetric analysis (TGA), AC impedance spectroscopy, and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The occurrence of phase transitions was confirmed by DTA and TGA, where a thermal event was observed by DTA at around 800oC. In addition, TGA studies also showed that there was a weight loss at around 800oC. Elemental analysis of Bi6Cr2O15 and its solid solutions by ICP-AES showed a good agreement between the expected value and the experimental value on the compositions, with no evidence of any systematic deviation from stoichiometric. Electrical properties of Bi6Cr2O15 and its solid solutions were investigated by using AC impedance spectroscopy from 300oC to 650oC. Ionic conductivity increased with the increasing temperature and bismuth content, and the best ionic conductivity was observed for Bi7Cr2O16.5. The activation energy (Ea) of Bi6Cr2O15 and its solid solutions were in the range of 1.22-1.32 eV.

Matched MeSH terms: Antacids
Fulltext Ranitidine and sodium citrate as prophylaxis against acid aspiration syndrome in obstetric patients undergoing caesarean section

Lim SK, Elegbe EO

Singapore Med J, 1992 Dec;33(6):608-10.
PMID: 1488672

The efficacy of a single oral dose of 0.3M of sodium citrate alone as a prophylaxis against acid aspiration syndrome in obstetric patients undergoing LSCS (elective and emergency) was compared with that of intravenous ranitidine. One group of patients was given 30 ml of 0.3M sodium citrate orally just before the induction of anaesthesia while the other group was given 50mg of ranitidine intravenously together with the 30ml of 0.3M sodium citrate. This was done for both the elective and the emergency groups of patients. There was no significant difference in the mean pH of the gastric aspirate obtained from those given sodium citrate alone and those given sodium citrate and ranitidine in either the elective or the emergency group. However, in the emergency group, those who were given sodium citrate alone tend to have a larger volume of gastric aspiration when compared with those given ranitidine together with the sodium citrate. There were significantly more patients with gastric aspirates of more than 25ml in the emergency group to which sodium citrate alone was given. It would appear that supplementing an intravenous dose of ranitidine with the oral dose of sodium citrate is useful in emergency LSCS as a prophylaxis against acid aspiration syndrome.

Matched MeSH terms: Antacids/administration & dosage*
Fulltext Editorial: simultaneous, prolonged monitoring of the acid pocket and oesophageal reflux. Authors' reply

Ma ZF, Deraman MA, Coyle C, Lee YY

Aliment Pharmacol Ther, 2020 07;52(2):398-399.
PMID: 32592257 DOI: 10.1111/apt.15835
Matched MeSH terms: Antacids
Fulltext In vitro ultrastructural changes of MCF-7 for metastasise bone cancer and induction of apoptosis via mitochondrial cytochrome C released by CaCO3/Dox nanocrystals

Kamba AS, Ismail M, Ibrahim TA, Zakaria ZA, Gusau LH

Biomed Res Int, 2014;2014:391869.
PMID: 25028650 DOI: 10.1155/2014/391869

Bones are the most frequent site for breast cancer cells to settle and spread (metastasise); bone metastasis is considered to have a substantial impact on the quality of patients with common cancers. However, majority of breast cancers develop insensitivity to conventional chemotherapy which provides only palliation and can induce systemic side effects. In this study we evaluated the effect of free Dox and CaCO3/Dox nanocrystal on MCF-7 breast cancer using MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide), neural red, and lactate dehydrogenase colorimetric assays while DNA fragmentation and BrdU genotoxicity were also examined. Apoptogenic protein Bax, cytochrome C, and caspase-3 protein were analysed. Morphological changes of MCF-7 were determined using contrast light microscope and scanning and transmission electron microscope (SEM and TEM). The findings of the analysis revealed higher toxicity of CaCO3/Dox nanocrystal and effective cells killing compared to free Dox, morphological changes such as formation of apoptotic bodies, membrane blebbing, and absent of microvilli as indicated by the SEM analysis while TEM revealed the presence of chromatin condensation, chromosomal DNA fragmentation, cell shrinkage, and nuclear fragmentation. Results of TUNEL assay verified that most of the cells undergoes apoptosis by internucleosomal fragmentation of genomic DNA whereas the extent of apoptotic cells was calculated using the apoptotic index (AI). Therefore, the biobased calcium carbonate nanocrystals such as Dox carriers may serve as an alternative to conventional delivery system.

Matched MeSH terms: Antacids/pharmacology*
Helicobacter pylori infection and non-ulcer dyspepsia: the effect of treatment with colloidal bismuth subcitrate

Goh KL, Parasakthi N, Peh SC, Wong NW, Lo YL, Puthucheary SD

Scand. J. Gastroenterol., 1991 Nov;26(11):1123-31.
PMID: 1754846

A study was undertaken to determine the role of Helicobacter pylori in non-ulcer dyspepsia (NUD) and to determine the efficacy of colloidal bismuth subcitrate (CBS) in the treatment of NUD. Seventy-one patients were randomly allocated (double blind) to CBS or placebo, two tablets twice daily for 4 weeks. The severity of dyspepsia was scored and endoscopies performed before and after treatment, and antral biopsy specimens were taken for bacteriologic and histologic examination. Forty patients had H. pylori infection, and all had changes of chronic active gastritis. H. pylori was cleared from 17 to 21 patients (81%) treated with CBS, whereas none of the 19 patients treated with placebo cleared the bacteria. Improvement in histology was noted in 15 of 21 patients (71.4%) treated with CBS, whereas no improvement was noted in any of the placebo controls. Thirty-one patients were negative for H. pylori. All had either normal gastric histology or minor degrees of inflammation. Seventeen of these patients received CBS, and 14 received placebo. All groups reported improvement in the symptom score; however, the H. pylori-positive, CBS-treated group recorded a significantly higher improvement than the other groups (p less than 0.001). Relapse of H. pylori infection after initial clearance of the bacteria was high. Twelve of 16 patients evaluated relapsed 1 month after withdrawal of CBS.

Matched MeSH terms: Antacids/therapeutic use*
Fulltext Evaluation of therapies in the treatment of Helicobacter pylori associated non-ulcer dyspepsia

Nafeeza MI, Shahimi MM, Kudva MV, Ahmad H, Isa MR, Sood IM, et al.

Singapore Med J, 1992 Dec;33(6):570-4.
PMID: 1488663

This randomised double blind placebo controlled study evaluated the effectiveness of colloidal bismuth subcitrate (CBS), ampicillin and their combination in the treatment of Helicobacter Pylori in non-ulcer dyspepsia (NUD) and assessed if elimination of this organism is associated with improvement of gastritis and the symptoms. Forty-eight NUD patients with H. pylori and histologic gastritis were randomly allocated to one of the three regimens for 28 days. Symptoms were assessed before and after treatment. Forty-three patients completed the trial. Repeat endoscopy within 48 hours of completing treatment showed suppression of H. pylori in 6 of 7 patients (85.7%) on combined therapy and one of 8 patients (12.5%) on CBS therapy (p = 0.0205). There was no suppression of the bacteria in patients treated with ampicillin. Repeat endoscopy performed 2 weeks after completing treatment showed suppression of H. pylori in 3 of 7 patients (42.9%) on combined therapy and none in the other two groups. Patients on combined therapy who had suppression of H. pylori, 48 hours or 2 weeks after completing treatment were noted to have historical improvement of their gastritis (p = 0.0001 and p = 0.05 respectively). This was also associated with improvement of symptoms in these patients.

Matched MeSH terms: Antacids/therapeutic use
Fulltext Gastro-oesophageal reflux disease in 'difficult-to-control' asthma: prevalence and response to treatment with acid suppressive therapy

Wong CH, Chua CJ, Liam CK, Goh KL

Aliment Pharmacol Ther, 2006 May 1;23(9):1321-7.
PMID: 16629937 DOI: 10.1111/j.1365-2036.2006.02888.x

BACKGROUND: The causal association between gastro-oesophageal reflux disease (GERD) and difficult-to-control asthma is unclear.
AIM: To determine the prevalence of GERD and response to proton pump inhibitor therapy in patients with difficult-to-control asthma.
METHODS: Consecutive patients with difficult-to-control asthma as defined by persistent and recurrent symptoms despite on optimal asthmatic medications were recruited for the study. GERD was diagnosed by symptoms, gastroscopy and 24-h oesophageal pH monitoring. All patients were prescribed a course of lansoprazole 30 mg daily for 8 weeks. Improvement to treatment was assessed by a change in pulmonary symptom score and also by patient's subjective assessment of improvement.
RESULTS: Seventeen of 30 (56.7%) patients with difficult-to-control asthma were diagnosed with GERD. Pulmonary symptom score improved significantly only in patients with GERD (35.0 to 21.0; P = 0.002). Twelve of 16 (75%) patients with GERD reported an improvement in asthma symptoms; 1 of 11 (9.1%) without GERD reported mild symptom improvement. There was no significant change in peak expiratory flow rate and forced expiratory volume.
CONCLUSIONS: More than half of patients with difficult-to-control asthma were diagnosed with GERD. In these patients the severity of asthma improved significantly with potent acid suppression therapy. This underlines the critical role of acid reflux in this subset of patients with difficult-to-control asthma.
Study site: Respiratory clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia

Matched MeSH terms: Antacids/therapeutic use*
Fulltext Randomised clinical trial: the effectiveness of Gaviscon Advance vs non-alginate antacid in suppression of acid pocket and post-prandial reflux in obese individuals after late-night supper

Deraman MA, Abdul Hafidz MI, Lawenko RM, Ma ZF, Wong MS, Coyle C, et al.

Aliment Pharmacol Ther, 2020 06;51(11):1014-1021.
PMID: 32343001 DOI: 10.1111/apt.15746

BACKGROUND: Late-night supper increases the risk of postprandial reflux from the acid pocket especially in obesity. An alginate-based, raft-forming medication may be useful for obese patients with GERD.
AIMS: To compare the efficacy of Gaviscon Advance (Reckitt Benckiser, UK) and a non-alginate antacid in post-supper suppression of the acid pocket and post-prandial reflux among obese participants.
METHODS: Participants underwent 48 h wireless and probe-based pH-metry recording of the acid pocket and lower oesophagus, respectively, and were randomised to single post-supper (10 pm) dose of either Gaviscon Advance or a non-alginate antacid on the second night. Primary outcomes were suppression of median pH of acid pocket and lower oesophagus, measured every 10-minutes post-supper for 1 h. Secondary outcomes were suppression of % time pH

Matched MeSH terms: Antacids/therapeutic use*