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1.
Rev. esp. patol ; 57(2): 84-90, Abr-Jun, 2024. ilus, tab
Article in English | IBECS | ID: ibc-232411

ABSTRACT

The clinical presentation of enteric duplication cysts is dependent on the location of the cyst with symptoms varying from nausea and vomiting to abdominal distension, pain and perforation. Four patients were identified who were diagnosed with enteric duplication cysts within the period from 2019 to 2023. Three of the patients presented with signs of intestinal obstruction-abdominal distension and pain, while one had an antenatally detected abdominal mass. There were three boys and one girl with ages ranging from 4 months to 14 years. Three cases of ileal and one case of caecal duplication cyst were reported. Most of the cases showed ileal/caecal mucosa while one case demonstrated ectopic gastric mucosa. The treatment of these cysts includes surgical excision. Although radiological investigations help in arriving at a provisional diagnosis, the final diagnosis can be confirmed only after histopathological examination. Early treatment prevents complications and results in a good prognosis for the patient. (AU)


La presentación clínica de los quistes de duplicación entérica depende de la ubicación del quiste, y los síntomas varían desde náuseas y vómitos hasta distensión abdominal, dolor y perforación. Se identificaron cuatro pacientes que fueron diagnosticados con quistes de duplicación entérica en el período de 2019 a 2023. Tres de los pacientes presentaron signos de obstrucción intestinal (distensión abdominal y dolor), mientras que uno tenía una masa abdominal detectada prenatalmente. Eran tres niños y una niña con edades comprendidas entre 4 meses y 14 años. Se notificaron tres casos de quiste de duplicación ileal y un caso de quiste de duplicación cecal. La mayoría de los casos mostraron mucosa ileal/cecal, mientras que un caso mostró mucosa gástrica ectópica. El tratamiento de estos quistes incluye la escisión quirúrgica. Aunque las investigaciones radiológicas ayudan a llegar a un diagnóstico provisional, el diagnóstico final solo puede confirmarse después del examen histopatológico. El tratamiento precoz previene complicaciones y redunda en un buen pronóstico para el paciente. (AU)


Subject(s)
Humans , Cysts , Metabolism, Inborn Errors , Urinary Diversion , Gastric Acid , Nausea , Vomiting
2.
Bull Math Biol ; 86(7): 77, 2024 May 22.
Article in English | MEDLINE | ID: mdl-38775877

ABSTRACT

Several recent theoretical studies have indicated that a relatively simple secretion control mechanism in the epithelial cells lining the stomach may be responsible for maintaining a neutral (healthy) pH adjacent to the stomach wall, even in the face of enormous electrodiffusive acid transport from the interior of the stomach. Subsequent work used Sobol' Indices (SIs) to quantify the degree to which this secretion mechanism is "self-regulating" i.e. the degree to which the wall pH is held neutral as mathematical parameters vary. However, questions remain regarding the nature of the control that specific parameters exert over the maintenance of a healthy stomach wall pH. Studying the sensitivity of higher moments of the statistical distribution of a model output can provide useful information, for example, how one parameter may skew the distribution towards or away from a physiologically advantageous regime. In this work, we prove a relationship between SIs and the higher moments and show how it can potentially reduce the cost of computing sensitivity of said moments. We define γ -indices to quantify sensitivity of variance, skewness, and kurtosis to the choice of value of a parameter, and we propose an efficient strategy that uses both SIs and γ -indices for a more comprehensive sensitivity analysis. Our analysis uncovers a control parameter which governs the "tightness of control" that the secretion mechanism exerts on wall pH. Finally, we discuss how uncertainty in this parameter can be reduced using expert information about higher moments, and speculate about the physiological advantage conferred by this control mechanism.


Subject(s)
Gastric Mucosa , Mathematical Concepts , Models, Biological , Hydrogen-Ion Concentration , Gastric Mucosa/metabolism , Humans , Gastric Acid/metabolism , Computer Simulation
3.
Drug Metab Pharmacokinet ; 55: 100995, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38447327

ABSTRACT

Pazopanib exhibits pH-dependent solubility and its absorption depends primarily on the stomach pH. Significant decrease of pazopanib absorption by coadministration with proton pump inhibitors in clinical situation need to be overcome. Thus, the purpose of this study is firstly to investigate the effect of acidic beverages and sodium citrate buffer on the solubility of pazopanib and secondly to examine the effect of sodium citrate buffer on pazopanib absorption in a rat model with esomeprazole-mediated gastric acid suppression. Pazopanib solubility decreased with increasing pH of sodium citrate buffer in vitro. Interestingly, its solubility in some acidic beverages was significantly lower than that in sodium citrate buffer of the same pH. The AUC0-24h of pazopanib administered in tap water to rats treated with esomeprazole (ESP rats) was 66 % lower than that in the control rats treated with saline. However, AUC0-24h was 4.8 times higher in ESP rats that received pazopanib with sodium citrate buffer (pH 2.3) compared to ESP rats that received pazopanib with tap water. Our results indicate that the drug-drug interactions between pazopanib and proton pump inhibitors can be overcome, at least in part, by suspending pazopanib in sodium citrate buffer.


Subject(s)
Esomeprazole , Indazoles , Proton Pump Inhibitors , Pyrimidines , Sulfonamides , Rats , Animals , Proton Pump Inhibitors/pharmacology , Esomeprazole/pharmacology , Sodium Citrate , Solubility , Gastric Acid , Sodium , Water , Hydrogen-Ion Concentration
4.
Postgrad Med ; 136(2): 131-140, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38385191

ABSTRACT

Gastroesophageal reflux disease (GERD) and Helicobacter pylori (H. pylori) infection are different disease states that are united by the core role of acid suppression in their management. In GERD, proton pump inhibitors (PPIs) have long been standard therapy based on abundant positive clinical trial data supporting their efficacy and safety. In H. pylori, PPIs are also a critical element of therapy in combination with 1 or more antibiotics to achieve and maintain a pH that maximizes the efficacy of therapy. Despite the considerable clinical success and widespread use of PPIs, room remains for agents with differentiated pharmacokinetic and pharmacodynamic profiles. The potassium-competitive acid blockers (PCABs) are mechanistically distinct from PPIs but are acid-stable and do not require activation of the proton pump by coadministration of food. In pharmacodynamic studies, these agents have shown greater durations of acid suppression above the critical threshold of pH 4 (for GERD) and pH 6 (for H. pylori), which have been shown to optimize therapeutic efficacy in these settings. These results have translated in clinical studies to similar and, in some cases, improved outcomes relative to PPIs in these disease states. This review summarizes current knowledge on the physiology of acid secretion, pathophysiology and management of GERD and H. pylori, and key characteristics and clinical trial data for PPIs and PCABs.


Subject(s)
Gastroesophageal Reflux , Helicobacter Infections , Helicobacter pylori , Proton Pump Inhibitors , Gastroesophageal Reflux/drug therapy , Humans , Helicobacter pylori/drug effects , Proton Pump Inhibitors/therapeutic use , Proton Pump Inhibitors/pharmacology , Helicobacter Infections/drug therapy , Gastric Acid/metabolism , Hydrogen-Ion Concentration , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/pharmacology
5.
Expert Rev Clin Immunol ; 20(6): 603-622, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38406978

ABSTRACT

INTRODUCTION: Systemic sclerosis (SSc) is a connective tissue disease with heterogeneous presentation. Gastrointestinal (GI) complications of SSc are characterized by esophageal reflux, abnormal motility, and microbiome dysbiosis, which impact patient quality of life and mortality. Preventative therapeutics are lacking, with management primarily aimed at symptomatic control. AREAS COVERED: A broad literature review was conducted through electronic databases and references from key articles. We summarize the physiology of gastric acid production and GI motility to provide context for existing therapies, detail the current understanding of SSc-GI disease, and review GI medications studied in SSc. Finally, we explore new therapeutic options. We propose a management strategy that integrates data on drug efficacy with knowledge of disease pathophysiology, aiming to optimize future therapeutic targets. EXPERT OPINION: SSc-GI complications remain a challenge for patients, clinicians, and investigators alike. Management presently focuses on treating symptoms and minimizing mucosal damage. Little evidence exists to suggest immunosuppressive therapy halts progression of GI involvement or reverses damage, leaving many unanswered questions about the optimal clinical approach. Further research focused on identifying patients at risk for GI progression, and the underlying mechanism(s) that drive disease will provide opportunities to prevent long-term damage, and significantly improve patient quality of life.


Subject(s)
Gastrointestinal Diseases , Quality of Life , Scleroderma, Systemic , Humans , Scleroderma, Systemic/therapy , Scleroderma, Systemic/complications , Gastrointestinal Diseases/etiology , Gastrointestinal Diseases/therapy , Animals , Gastrointestinal Motility , Dysbiosis , Gastric Acid/metabolism , Gastroesophageal Reflux/therapy , Gastrointestinal Microbiome
6.
Yakugaku Zasshi ; 144(1): 99-117, 2024.
Article in Japanese | MEDLINE | ID: mdl-38171801

ABSTRACT

In 1985, I was accepted as postdoc by Professor Forte of UC Berkeley. He discovered H+,K+-ATPase and established the membrane recycling theory as the activation mechanism for acid secretion using whole animals. H+,K+-ATPase is an enzyme that exchanges H+ with K+. In resting state, it locates on the tubulovesicles and the pump does not work because the membrane lacks K+ permeability. Upon stimulation, the tubulovesicles fuse to the apical membrane and acquire K+ permeability, turning the pump on. The main route was known to be protein kinase A (PKA), but its specific targets remained unknown. Right after I joined Forte's lab, I was fortunate enough to reproduce the above mechanism in vitro, and I discovered proteins of molecular weight 120 kDa and 80 kDa that were specifically phosphorylated in stimulated parietal cells. After I returned to Japan, the former was cloned and named as parchorin, which is one of the chloride intracellular channels. Although no progress was made on ezrin, I found out the importance of PIP2 and Arf6 using permeabilized gland models. After I left parietal cell research, the link between ezrin and Arf6 was revealed. PKA phosphorylates S66 of ezrin and also MST4. The former changes the N-terminal structure of ezrin to bind syntaxin3, and the latter phosphorylates ACAP4, an Arf6-GAP, to accelerate binding to ezrin. Subsequently, H+,K+-ATPase, SNAREs, ezrin, and Arf6-GAP are aligned on the apical membrane. However, there are still many unsolved questions and the intracellular mechanism of parietal cells remains an attractive research area.


Subject(s)
Gastric Acid , Parietal Cells, Gastric , Animals , Gastric Acid/metabolism , Phosphorylation , Parietal Cells, Gastric/metabolism , Biological Transport , H(+)-K(+)-Exchanging ATPase/metabolism , Cyclic AMP-Dependent Protein Kinases/metabolism
9.
Int J Biol Macromol ; 258(Pt 1): 128815, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38114010

ABSTRACT

First-line drugs for peptic ulcer (PU) treatment are typically limited by poor targeting and adverse effects associated with long-term use. Despite recent advancements in novel therapeutic approaches for PU, the development of sustained-release delivery systems tailored to specific pathological characteristics remains challenging. Persistent inflammation, particularly gastric inflammatory microenvironment imbalance, characterizes the PU. In this study, we prepared an in situ gel composed of sodium alginate, deacetylated gellan gum, calcium citrate, and Bletilla striata polysaccharide (BSP) to achieve sustained release of BSP. The BSP in situ gel demonstrated favorable fluidity in vitro and completed self-assembly in vivo in response to the acidic milieu at a pH of 1.5. Furthermore, the shear, extrusion, and deformation properties increased by 26.4 %, 103.7 %, and 46.3 %, respectively, with long-term gastric retention (4 h) and mucosal adaptation. Animal experiments confirmed that the BSP in situ gel could attenuate necrotic injury and inflammatory cell infiltration, maintain mucosal barrier integrity, regulate cytokine imbalance and inflammation-associated hyperapoptosis, thus effectively alleviate the inflammatory microenvironmental imbalance in PU without significant side effects. Overall, our findings demonstrated that the BSP in situ gel is a promising therapeutic strategy for PU and opens avenues for developing self-assembled formulations targeting the pathological features of PUs.


Subject(s)
Orchidaceae , Peptic Ulcer , Animals , Alginates/chemistry , Gastric Acid , Polysaccharides/chemistry , Ethanol , Inflammation , Orchidaceae/chemistry
10.
Niger J Clin Pract ; 26(10): 1505-1511, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37929527

ABSTRACT

Background: Gastric acid, which is among erosive substances, gradually rises to the mouth in individuals with reflux and bulimia nervosa disorders, and this causes various effects on dental restorations. Aim: The objective of this study is in vitro investigation of gastric acid's effect on flexural strength and hardness on aesthetic restorative computer-aided design and computer-aided manufacturing (CAD-CAM) materials. Materials and Methods: For this study, four materials have been used, namely Enamic (Vita), Superfect Zir (Aidite) Zirconia, IPS e.max CAD (Ivoclar Vivadent), and Mark II (Vita). From these four different materials, 24 samples with 14 × 4 × 1 dimensions in rectangular prism form are used, which makes a total of 96 samples. One group was separated as the control group, while the rest was allowed to wait at 37°C, 5 ml gastric acid for 96 hours. Hardness value and flexural strengths were measured as pre-exposure and post-exposure to gastric acid. Results: There is a statistically significant difference between the groups in terms of the amount of decrease in the mean hardness after exposure to gastric acid compared to pre-exposure values (p: 0,000; P < 0,05). There was no statistically significant difference between the groups in terms of the amount of decrease in the post-exposure average flexural strength compared to the pre-exposure value (p: 0.063; P > 0.05). There is a statistically significant difference between the groups in terms of the average flexural strength after exposure to the acid. Conclusions: According to the data obtained, it was concluded that exposure to gastric acid affects the hardness and flexural strength properties of dental restorative ceramic materials.


Subject(s)
Flexural Strength , Gastric Acid , Humans , Materials Testing , Hardness , Ceramics , Computer-Aided Design , Surface Properties , Dental Materials
12.
Clin Oral Investig ; 27(11): 6865-6877, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37821653

ABSTRACT

OBJECTIVES: To investigate the impact of simulated gastric acid on the surface properties of lithium disilicate-reinforced glass-ceramics and zirconia-reinforced lithium silicate glass-ceramic after certain polishing and glazing procedures. MATERIALS AND METHODS: Four different types of square-shaped specimens (10 × 10 × 2 mm3, n = 13) were manufactured: lithium disilicate-reinforced glass-ceramic milled and polished (LDS-P); milled, polished, and glazed (LDS-PG); milled, glazed, and no polishing (LDS-G); and milled and polished zirconia-reinforced lithium silicate glass-ceramic (ZR-LS). Specimens were immersed in hydrochloride acid (HCl 0.06 M, pH 1.2) to simulate gastric acid irritation and stored in the acid for 96 h in 37 °C. Specimen weight, surface gloss, Vickers surface microhardness and surface roughness (Ra, Rq, with optical profilometer), and surface roughness on nanometer level (Sq, Sal, Sq/Sal, Sdr, Sds with atomic force microscope) were measured before and after the acid immersion. RESULTS: ZR-LS specimens lost significantly more weight after acid immersion (p = 0.001), also surface microhardness of ZR-LS was significantly reduced (p = 0.001). LDS-G and LDS-PG showed significantly lower surface roughness (Sa, Sq) values compared to LDS-P before (p ≤ 0.99) and after (p ≤ 0.99) acid immersion and ZR-LS after acid immersion (p ≤ 0.99). CONCLUSIONS: Gastric acid challenge affects the surface properties of lithium disilicate-reinforced glass-ceramic and zirconia-reinforced lithium silicate glass-ceramic. Glazing layer provides lower surface roughness, and the glazed surface tends to smoothen after the gastric acid challenge. CLINICAL RELEVANCE: Surface finish of lithium disilicate-reinforced glass-ceramic and zirconia-reinforced lithium silicate glass-ceramic has a clear impact on material's surface properties. Gastric acidic challenge changes surface properties but glazing seems to function as a protective barrier. Nevertheless, also glazing tends to smoothen after heavy gastric acid challenge. Glazing can be highly recommended to all glass-ceramic restorations but especially in patients with gastroesophageal reflux disease (GERD) and eating disorders like bulimia nervosa.


Subject(s)
Gastric Acid , Lithium , Humans , Materials Testing , Computer-Aided Design , Dental Porcelain/chemistry , Ceramics/chemistry , Zirconium/chemistry , Silicates , Surface Properties
13.
J Clin Pediatr Dent ; 47(5): 145-151, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37732448

ABSTRACT

In this study, we aimed to demonstrate changes in the surface roughness and microhardness of three different restorative materials routinely used in pediatric dentistry (composite, compomer and resin-modified glass ionomer cement (RMCIS)) in response to continuous daily exposure to gastric acid. Twelve samples of each of type of restorative material were prepared. Eleven of the specimens were included in the gastric acid cycle. The microhardness and surface roughness of ten samples were measured before and after the cycle. Another sample included in the cycle was compared with the sample not included in the cycle by scanning electron microscopy (SEM). There was a significant difference between the groups in terms of roughness scores following gastric acid cycle (p = 0.039). RMCIS material possessed the highest roughness value. A significant difference was identified in terms of microhardness levels before and after the gastric acid cycle (p = 0.001). The most significant change was observed in the compomer material. SEM analysis, performed after the gastric acid cycle, revealed that most cracks were identified in RMCIS material; this was followed by compomer and composite materials, respectively. Our analysis indicates that the restorative materials used frequently in pediatric dental procedures, show increased surface roughness and reduced microhardness when exposed to gastric acid.


Subject(s)
Compomers , Gastric Acid , Humans , Child , Microscopy, Electron, Scanning , Dental Materials , Glass Ionomer Cements
14.
Indian J Gastroenterol ; 42(4): 525-533, 2023 08.
Article in English | MEDLINE | ID: mdl-37266896

ABSTRACT

BACKGROUND: Current gold standard for the diagnosis of gastroesophageal reflux disease (GERD) is 24-hour pH metry though it fails to detect non-acidic reflux. The sensitivity of 24-hour pH metry alone (both catheter-based and Bravo capsule) is questionable, especially if gastric acid secretion is low due to reduced parietal cell mass, Helicobacter pylori-induced gastric atrophy and antisecretory therapy. Accordingly, we analyzed the diagnostic ability of 24-hour pH metry as compared to impedance monitoring in relation to the gastric pH without antisecretory therapy. METHODS: A retrospective analysis of prospectively collected data from 150 patients with suspected GERD undergoing a 24-hour pH impedance study was done. RESULTS: Among 150 patients with symptoms suggestive of GERD, 106 (70.6%) had confirmed GERD diagnosed either by 24-hour pH metry alone (10 [9.4%]), impedance monitoring alone (49 [46.2%]) or both (47 [44.3%]). Abnormal reflux of acidic and non-acidic gastric contents was detected by 24-hour pH metry and 24-hour impedance monitoring in 57/106 (53.7%) and 96/106 (90.5%) of patients, respectively (p < .00001). Patients with GERD diagnosed by 24-hour impedance monitoring had a higher mean gastric pH (2.9 [median 1.3, IQR 5.3]) than those diagnosed by 24-hour pH metry (2.1 [median 1.4, IQR 2.6]) or both (1.6 [median 1.2, IQR 2.1]) (p = 0.001). CONCLUSION: Twenty-four-hour impedance monitoring detects GERD more often than 24-hour pH metry. Patients with higher mean gastric pH leading to non-acidic reflux were more often diagnosed by 24-hour impedance monitoring than 24-hour pH metry. Thus, 24-hour pH metry alone is inferior to additional impedance monitoring in the diagnosis of GERD, particularly in presence of reduced gastric acid secretion.


Subject(s)
Gastric Acid , Gastroesophageal Reflux , Humans , Retrospective Studies , Electric Impedance , Gastroesophageal Reflux/diagnosis , Hydrogen-Ion Concentration , Esophageal pH Monitoring
15.
J Neuroendocrinol ; 35(11): e13305, 2023 11.
Article in English | MEDLINE | ID: mdl-37317882

ABSTRACT

The physiology of gastric acid secretion is one of the earliest subjects in medical literature and has been continuously studied since 1833. Starting with the notion that neural stimulation alone drives acid secretion, progress in understanding the physiology and pathophysiology of this process has led to the development of therapeutic strategies for patients with acid-related diseases. For instance, understanding the physiology of parietal cells led to the developments of histamine 2 receptor blockers, proton pump inhibitors (PPIs), and recently, potassium-competitive acid blockers. Furthermore, understanding the physiology and pathophysiology of gastrin has led to the development of gastrin/CCK2 receptor (CCK2 R) antagonists. The need for refinement of existing drugs in patients have led to second and third generation drugs with better efficacy at blocking acid secretion. Further understanding of the mechanism of acid secretion by gene targeting in mice has enabled us to dissect the unique role for each regulator to leverage and justify the development of new targeted therapeutics for acid-related disorders. Further research on the mechanism of stimulation of gastric acid secretion and the physiological significances of gastric acidity in gut microbiome is needed in the future.


Subject(s)
Gastric Acid , Gastrins , Humans , Animals , Mice , Proton Pump Inhibitors/pharmacology , Parietal Cells, Gastric , Receptor, Cholecystokinin B
17.
Pharmacol Res Perspect ; 11(3): e01090, 2023 06.
Article in English | MEDLINE | ID: mdl-37147903

ABSTRACT

The global prevalence of GERD is substantially increasing each year, and GERD is a chronic disease that reduces the quality of life of patients. The efficacy of conventional drugs is diverse, and most require long-term or lifetime administration; thus, the development of more effective therapeutic agents is needed. Herein, a more effective treatment for GERD was tested. We investigated whether JP-1366 affected gastric H+/K+-ATPase activity and used the Na+/K+-ATPase assay to confirm the selectivity of H+/K+-ATPase inhibition. To clarify the mechanism of enzyme inhibition, JP-1366 and TAK-438 were analyzed by Lineweaver-Burk. Also, we investigated the effects of JP-1366 in various models involving reflux esophagitis. We found that JP-1366 mediates strong, selective, and dose-dependent inhibition of H+/K+-ATPase. We found that JP-1366 significantly suppressed gastric acid secretion in histamine-treated pylorus-ligated rats in a dose-dependent manner. Additionally, we confirmed that JP-1366 inhibited histamine-stimulated gastric acid secretion in the HPD model. JP-1366 exhibited a more than 2-fold higher inhibitory effect on esophageal injury than TAK-438 in GERD lesions and had a more potent inhibitory effect in indomethacin- or aspirin-induced gastric ulcer rat models than TAK-438. Additionally, JP-1366 inhibited gastric ulcers. These results support the possibility that JP-1366 is a good candidate drug for treating acid-related diseases.


Subject(s)
Gastroesophageal Reflux , Proton Pump Inhibitors , Rats , Animals , Proton Pump Inhibitors/pharmacology , Proton Pump Inhibitors/therapeutic use , Histamine , Potassium/therapeutic use , Quality of Life , Gastric Acid , Gastroesophageal Reflux/drug therapy , Adenosine Triphosphatases
18.
Bioorg Chem ; 137: 106588, 2023 08.
Article in English | MEDLINE | ID: mdl-37167705

ABSTRACT

H+, K+-ATPase, as the most critical enzyme in gastric acid secretion, has long been an attractive target for the treatment of acid-related diseases. In this study, a series of benzimidazole derivatives were designed and synthesized through conformational restriction and skeleton hopping strategies by using vonoprazan as the lead compound. Among them, compounds A12 (IC50 = 9.32 µM) and A18 (IC50 = 5.83 µM) showed better inhibition at the enzyme level. In addition, gastric acid secretion inhibition was assessed in vivo, and the results showed that A12 and A18 significantly inhibited basal gastric acid secretion, 2-deoxy-d-glucose (2DG) stimulated gastric acid secretion and histamine-stimulated gastric acid secretion. In further in vitro metabolic experiments, A12 and A18 demonstrated excellent stability and low toxicity. Pharmacokinetic studies showed that the p.o. and i.v. half-lives of A18 were 3.21 h and 8.67 ± 1.15 h, respectively. In summary, A18 might be a novel and effective potassium-competitive acid blocker, and this study provides strong support for it use in the treatment of acid-related diseases.


Subject(s)
Gastric Acid , Proton Pump Inhibitors , Proton Pump Inhibitors/pharmacology , Gastric Acid/metabolism , Potassium , Histamine/metabolism , Benzimidazoles/pharmacology , Benzimidazoles/metabolism , H(+)-K(+)-Exchanging ATPase/metabolism
19.
Adv Sci (Weinh) ; 10(20): e2206957, 2023 07.
Article in English | MEDLINE | ID: mdl-37127895

ABSTRACT

Helicobacter pylori (H. pylori) has infected more than half of the world's population, and is the major cause of gastric cancer. The efficacy of standard antibiotic-based triple therapy is declining due to drug resistance development. Herein, a pH-responsive reactive oxygen species (ROS) nanogenerator (Fe-HMME@DHA@MPN) composed of acid-responsive metal polyphenol network (MPN) shell and mesoporous metal-organic nanostructure core [Fe-HMME (hematoporphyrin monomethyl ether, sonosensitizer)] loaded with dihydroartemisinin (DHA) is reported. These nanoparticles generate more ROS singlet oxygen than sonosensitizer HMME under ultrasonication, and this sonodynamic process is fueled by oxygen generated through Fenton/Fenton-like reactions of the degraded product in gastric acid Fe (II) and hydrogen peroxide (H2 O2 ) in the infection microenvironment. The encapsulated DHA, as a hydroperoxide source, is found to enhance the peroxidase-like activity of the Fe-HMME@DHA@MPN to generate ROS hydroxyl radical, beneficial for the microenvironment without sufficient H2 O2 . In vitro experiments demonstrate that the ROS nanogenerators are capable of killing multidrug-resistant H. pylori and removing biofilm, and ROS nanogenerators show high therapeutic efficacy in a H. pylori infection mouse model. Unlike the triple therapy, the nanogenerators display negligible side effects toward the normal gut microbiota. Taken together, these self-enhanced ROS nanogenerators have a great potential for treatment of H. pylori infection.


Subject(s)
Gastrointestinal Microbiome , Helicobacter Infections , Helicobacter pylori , Animals , Mice , Helicobacter Infections/drug therapy , Reactive Oxygen Species/metabolism , Helicobacter pylori/metabolism , Gastric Acid/metabolism
20.
Food Res Int ; 169: 112828, 2023 07.
Article in English | MEDLINE | ID: mdl-37254404

ABSTRACT

Gastric acid diffusion and penetration constitute an essential process in the structural breakdown and enzymatic hydrolysis of solid food during digestion. This study aimed to quantify the real-time diffusion and spatial distribution of gastric acids in whey protein isolate (WPI) gels in the presence of 0-0.05 M NaCl during simulated digestion using a wide-field fluorescence microscope. For all the gels regardless of NaCl concentration, the outer surface rapidly developed a near-saturated layer, resulting in a higher normalized gastric acid concentration in the outer layer than in the inner layer. The pH decrease was more significant for the gels at a higher NaCl concentration (i.e., 0.05 M) due to the formation of a more discontinuous and looser network structure that would facilitate acid diffusion into the gel matrix and decrease the gel buffering capacity. Consistently, the effective diffusion coefficient (DA) estimated via the Fick diffusion model was 6.19 × 10-10 m2/s for 0.05 M WPI-RITC gels, significantly higher than 0.015 M (4.46 × 10-10 m2/s) and 0 M (3.54 × 10-10 m2/s) gels. The present study has provided a quantitative understanding of the diffusion process and spatial distribution of gastric acids within the WPI gel matrix in real-time during in vitro gastric digestion as influenced by NaCl concentration.


Subject(s)
Gastric Acid , Sodium Chloride , Whey Proteins/chemistry , Gastric Acid/metabolism , Gels/chemistry , Stomach
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