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Digestion 2024The prevalence of constipation in Japan is estimated to be 2-5%. Constipation is a disease found in older adults. In particular, Japan is an aging society, with 65% of... (Review)
Review
BACKGROUND
The prevalence of constipation in Japan is estimated to be 2-5%. Constipation is a disease found in older adults. In particular, Japan is an aging society, with 65% of men and 80.5% of women aged 65 years or older accounting for the majority of its population. Chronic constipation may be associated with survival, cardiovascular events, decreased quality of life, and death. This study summarizes the recent findings regarding constipation treatment practice in Japan.
SUMMARY
Until recently, the diagnosis of constipation was mainly based on medical interviews; however, with the recent development of handheld ultrasound devices, both physicians and nurses can easily and objectively diagnose fecal retention. Magnesium oxide and stimulant laxatives have been the mainstay treatments; however, since 2012, more than five new drugs for treating constipation have become available in Japan.
KEY MESSAGES
Magnesium oxide is less effective in patients who use acid-secretion inhibitors and patients who have undergone total gastrectomy and should be cared for hypermagnesemia. In addition, regular use of stimulant laxatives may lead to colonic inertia and decreased bowel movements; therefore, they should be used only occasionally. The following is an overview of the different uses of conventional and newer laxatives for treating constipation.
Topics: Male; Humans; Female; Aged; Laxatives; Magnesium Oxide; Japan; Quality of Life; Constipation
PubMed: 37696258
DOI: 10.1159/000533548 -
Materials (Basel, Switzerland) Jul 2021Many scholars are concerned about the effect of nano-MgO as an expansion agent on the performance of cement-based materials at an early age, but over a long period less...
Many scholars are concerned about the effect of nano-MgO as an expansion agent on the performance of cement-based materials at an early age, but over a long period less attention is paid to expansion stability and mechanical properties. This article examines the influence of nano-MgO on the long-term consistency, fluidity, expansion stability, hydration, and mechanical properties of 30% fly ash cement-based materials and improves research into nano-MgO as an expansion agent. Expansion performance, flexural and compressive strength, and stability after boiling and autoclave treatment were tested for specimens mixed with a 2, 4, 6, 8 and 10% cementitious material mass of nano-MgO. X-ray diffraction (XRD) and scanning electronic microscopy (SEM) were employed to study their hydration process and microstructure. The results showed that nano-MgO had an obvious effect on the consistency, fluidity and expansion performance of cement paste. After curing in water for 365 days and autoclaving thereafter, the hydration of nano-MgO was relatively complete. The volumetric expansion pressure of the magnesium hydroxide (Mg(OH)) crystals and the crystallization pressure generated after their continuous precipitation were the main reasons for the expansion of the slurry. Nano-MgO improved the microstructure of cement paste and significantly enhanced its long-term flexural strength and compressive strength. When the content of nano-MgO was less than 10%, the cement with 30% fly ash had good long-term stability with the potential to compensate for the shrinkage of large-volume concrete.
PubMed: 34279336
DOI: 10.3390/ma14133766 -
Nutrients Jul 2020Functional constipation (FC) is a chronic constipation for which no physiological, anatomical or iatrogenic origin can be evidenced. This condition has a high impact on... (Review)
Review
Functional constipation (FC) is a chronic constipation for which no physiological, anatomical or iatrogenic origin can be evidenced. This condition has a high impact on a patient's quality of life and healthcare costs. Since FC is frequently associated with low physical activity and a diet low in fiber and/or water, first-line recommendations focus on sufficient activity, and sufficient fiber and water intake. In case of inefficacy of these measures, numerous drug treatments are available, either over the counter or on prescription. Magnesium sulfate has a long history in the treatment of FC, and magnesium sulfate-rich mineral waters have been used for centuries for their laxative properties. The laxative effect of magnesium and sulfate has since been widely demonstrated. Nevertheless, it appears that no clinical studies aiming at demonstrating their efficacy in FC had been conducted before the 21st century. In this paper, we reviewed the clinical data reporting the efficacy of magnesium sulfate-rich natural mineral waters. In view of their reported efficacy and safety, magnesium sulfate-rich natural mineral waters may represent a natural treatment for FC.
Topics: Constipation; Defecation; Dietary Fiber; Female; Humans; Laxatives; Magnesium Oxide; Magnesium Sulfate; Male; Mineral Waters; Probiotics; Quality of Life
PubMed: 32664341
DOI: 10.3390/nu12072052 -
Materials (Basel, Switzerland) Aug 2022Materials with violent hydration reaction such as cement are used to solidify sandy soil slopes, which will cause destructive damage to the ecology of the slopes. In...
Materials with violent hydration reaction such as cement are used to solidify sandy soil slopes, which will cause destructive damage to the ecology of the slopes. In this paper, polyvinyl alcohol (PVA) and activated magnesium oxide (MgO) are used to improve sandy soil, and the effects of the dosage and curing age of modifiers on the mechanical properties of solidified sandy soil are studied. The dry-wet durability of the composite improved sandy soil is analyzed using a dry-wet cycle test, and the improvement mechanism of PVA and activated magnesium oxide is revealed using an electron microscope. The results show that the curing effect of polyvinyl alcohol and activated magnesium oxide on sand particles is better than that of polyvinyl alcohol alone. The compressive strength of improved soil samples increases with the increase of curing time, and magnesium oxide as an improved material needs appropriate reaction conditions to give full play to its role. The compressive strength of composite improved samples increases first and then decreases during the dry-wet cycle. Through the observation of microstructure, it can be seen that the cementing material wraps and connects the sand particles, and the cementing material of the sample after the dry-wet cycle develops more completely; if the magnesium oxide content is high, cracks may appear inside the sample.
PubMed: 36013746
DOI: 10.3390/ma15165609 -
Nature Communications Mar 2023Magnesium Oxide (MgO) and water (HO) are abundant in the interior of planets. Their properties, and in particular their interaction, significantly affect the planet...
Magnesium Oxide (MgO) and water (HO) are abundant in the interior of planets. Their properties, and in particular their interaction, significantly affect the planet interior structure and thermal evolution. Here, using crystal structure predictions and ab initio molecular dynamics simulations, we find that MgO and HO can react again at ultrahigh pressure, although Mg(OH) decomposes at low pressure. The reemergent MgO-HO compounds are: MgOH above 400 GPa, MgOH above 600 GPa, and MgOH in the pressure range of 270-600 GPa. Importantly, MgOH contains 57.3 wt % of water, which is a much higher water content than any reported hydrous mineral. Our results suggest that a substantial amount of water can be stored in MgO rock in the deep interiors of Earth to Neptune mass planets. Based on molecular dynamics simulations we show that these three compounds exhibit superionic behavior at the pressure-temperature conditions as in the interiors of Uranus and Neptune. Moreover, the water-rich compound MgOH could be stable inside the early Earth and therefore may serve as a possible early Earth water reservoir. Our findings, in the poorly explored megabar pressure regime, provide constraints for interior and evolution models of wet planets in our solar system and beyond.
PubMed: 36859401
DOI: 10.1038/s41467-023-36802-8 -
BMJ Supportive & Palliative Care Jan 2024The initiation of peripherally acting μ-opioid receptor antagonists (PAMORAs) should be considered 2 weeks after conventional laxatives have failed to achieve an...
OBJECTIVES
The initiation of peripherally acting μ-opioid receptor antagonists (PAMORAs) should be considered 2 weeks after conventional laxatives have failed to achieve an adequate response, and affected patients should be evaluated every 2 weeks thereafter. However, this guidance is difficult to implement in acute care hospitals. This study aimed to examine how naldemedine (PAMORA) should be introduced in combination with other laxatives in the acute care setting.
METHODS
This retrospective study evaluated 93 inpatients who received at least four doses of naldemedine. We investigated changes in the average daily defecation counts during the first 7 days after compared with before naldemedine administration and the incidence of diarrhoea.
RESULTS
Daily defecation counts during the first 7 days after compared with before naldemedine administration were greater in both the naldemedine, magnesium oxide (MgO) and another laxative group, and in the naldemedine and another laxative other than MgO group than in the naldemedine only group. The incidence rates of diarrhoea were significantly higher in the naldemedine, MgO, and another laxative group, and in the naldemedine and another laxative other than MgO group than in the naldemedine only group.
CONCLUSIONS
The introduction of naldemedine alone or in combination with MgO should be considered.
Topics: Humans; Laxatives; Retrospective Studies; Magnesium Oxide; Inpatients; Analgesics, Opioid; Constipation; Naltrexone; Narcotic Antagonists; Diarrhea
PubMed: 35750467
DOI: 10.1136/spcare-2022-003685 -
BioMed Research International 2022A simple process based on the dual roles of both magnesium oxide (MgO) and iron oxide (FeO) with boron (B) as precursors and catalysts has been developed for the...
A simple process based on the dual roles of both magnesium oxide (MgO) and iron oxide (FeO) with boron (B) as precursors and catalysts has been developed for the synthesis of borate composites of magnesium and iron (MgBO-FeBO) at 1200°C. The as-synthesized composites can be a single material with the improved and collective properties of both iron borates (FeBO) and magnesium borates (MgBO). At higher temperatures, the synthesized MgBO-FeBO composite is found thermally more stable than the single borates of both magnesium and iron. Similarly, the synthesized composites are found to prevent the growth of both gram-positive () and gram-negative () pathogenic bacteria on all the tested concentrations. Moreover, the inhibitory effect of the synthesized composite increases with an increase in concentration and is more pronounced against as compared to .
Topics: Magnesium; Iron; Borates; Staphylococcus aureus; Escherichia coli; Bacteria
PubMed: 36420094
DOI: 10.1155/2022/3605054 -
Redox Biology Aug 2023Diabetic retinopathy (DR) is a major cause of blindness in adult, and the accumulation of advanced glycation end products (AGEs) is a major pathologic event in DR....
Metformin inhibits methylglyoxal-induced retinal pigment epithelial cell death and retinopathy via AMPK-dependent mechanisms: Reversing mitochondrial dysfunction and upregulating glyoxalase 1.
Diabetic retinopathy (DR) is a major cause of blindness in adult, and the accumulation of advanced glycation end products (AGEs) is a major pathologic event in DR. Methylglyoxal (MGO), a highly reactive dicarbonyl compound, is a precursor of AGEs. Although the therapeutic potential of metformin for retinopathy disorders has recently been elucidated, possibly through AMPK activation, it remains unknown how metformin directly affects the MGO-induced stress response in retinal pigment epithelial cells. Therefore, in this study, we compared the effects of metformin and the AMPK activator A769662 on MGO-induced DR in mice, as well as evaluated cytotoxicity, mitochondrial dynamic changes and dysfunction in ARPE-19 cells. We found MGO can induce mitochondrial ROS production and mitochondrial membrane potential loss, but reduce cytosolic ROS level in ARPE-19 cells. Although these effects of MGO can be reversed by both metformin and A769662, we demonstrated that reduction of mitochondrial ROS production rather than restoration of cytosolic ROS level contributes to cell protective effects of metformin and A769662. Moreover, MGO inhibits AMPK activity, reduces LC3II accumulation, and suppresses protein and gene expressions of MFN1, PGC-1α and TFAM, leading to mitochondrial fission, inhibition of mitochondrial biogenesis and autophagy. In contrast, these events of MGO were reversed by metformin in an AMPK-dependent manner as evidenced by the effects of compound C and AMPK silencing. In addition, we observed an AMPK-dependent upregulation of glyoxalase 1, a ubiquitous cellular enzyme that participates in the detoxification of MGO. In intravitreal drug-treated mice, we found that AMPK activators can reverse the MGO-induced cotton wool spots, macular edema and retinal damage. Functional, histological and optical coherence tomography analysis support the protective actions of both agents against MGO-elicited retinal damage. Metformin and A769662 via AMPK activation exert a strong protection against MGO-induced retinal pigment epithelial cell death and retinopathy. Therefore, metformin and AMPK activator can be therapeutic agents for DR.
Topics: Mice; Animals; Metformin; AMP-Activated Protein Kinases; Pyruvaldehyde; Reactive Oxygen Species; Magnesium Oxide; Lactoylglutathione Lyase; Mitochondria; Retinal Diseases; Glycation End Products, Advanced; Epithelial Cells; Retinal Pigments
PubMed: 37348156
DOI: 10.1016/j.redox.2023.102786 -
Micromachines Nov 2022This research was conducted for the synthesis and application of ophthalmic lens materials with improved oxygen permeability and durability. Polyvinylpyrrolidone (PVP),...
This research was conducted for the synthesis and application of ophthalmic lens materials with improved oxygen permeability and durability. Polyvinylpyrrolidone (PVP), N-vinyl-2-pyrrolidone (NVP), 3-(trifluoromethyl)styrene (3-TFMSt), and magnesium oxide nanoparticles were used as additives for the basic combination of 2-hydroxyethyl methacrylate (HEMA). Additionally, the materials were copolymerized with ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent and azobisisobutyronitrile (AIBN) as the initiator. The addition of magnesium oxide nanoparticles was found to increase the tensile strength from 0.0631 to 0.0842 kgf/mm. Copolymerization with a small amount of 3-TFMSt of about 1% increased the tensile strength to 0.1506 kgf/mm and the oxygen permeability from 6.00 to 9.64 (cm/s)∙(mLO/mL·mmHg)∙10. The contact lens material produced using N-vinyl-2-pyrrolidone and magnesium oxide nanoparticles as additives satisfied the basic physical properties required for hydrogel contact lenses and is expected to be used usefully as a material for fabricating high-performance hydrogel lenses.
PubMed: 36363917
DOI: 10.3390/mi13111897 -
Materials (Basel, Switzerland) Nov 2022The influence of a magnesium oxide admixture on the activation process and catalytic activity of the iron catalyst with a wustite structure was investigated during the...
The influence of a magnesium oxide admixture on the activation process and catalytic activity of the iron catalyst with a wustite structure was investigated during the ammonia synthesis reaction. The incorporation of magnesium oxide into wustite grains is considered to be a structure-forming and activating promoter. It stabilizes the α-Fe structure and increases the activity of the catalysts in the ammonia synthesis reaction. Moreover, magnesium oxide forms a solid solution with the wustite, which slows down the reduction of a catalyst precursor. Similar to calcium and potassium compounds, magnesium oxide is present on the α-Fe surface of the active form of the catalyst. The optimum MgO concentration in the catalyst structure was determined to be 1.2% wt.
PubMed: 36499805
DOI: 10.3390/ma15238309