Marine biological injuries and their medical management: A narrative review

The marine environment can be extremely dangerous, and the harm caused by marine organisms when they contact the human body can be especially harmful, even deadly. Contact includes stings, bites, wounds, and consumption as food. In this article, the characteristics of the common marine biological injuries are summarized, the major marine organisms causing damage in China’s marine waters are described, and injury prevention and treatment methods are discussed.

COVID-19 and liver dysfunction: What nutritionists need to know

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus-2 has brought serious challenges for the medical field. Patients with COVID-19 usually have respiratory symptoms. However, liver dysfunction is not an uncommon presentation. Additionally, the degree of liver dysfunction is associated with the severity and prognosis of COVID-19. Prevention, diagnosis, and treatment of malnutrition should be routinely recommended in the management of patients with COVID-19, especially in those with liver dysfunction. Recently, a large number of studies have reported that nutrition therapy measures, including natural dietary supplements, vitamins, minerals and trace elements, and probiotics, might have potential hepatoprotective effects against COVID-19-related liver dysfunction via their antioxidant, antiviral, anti-inflammatory, and positive immunomodulatory effects. This review mainly focuses on the possible relationship between COVID-19 and liver dysfunction, nutritional and metabolic characteristics, nutritional status assessment, and nutrition therapy to provide a reference for the nutritionists while making evidence-based nutritional decisions during the COVID-19 pandemic.

Potential role of vitamin D in patients with diabetes, dyslipidaemia, and COVID-19

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 has become a worldwide public health crisis. Studies have demonstrated that diabetes and dyslipidaemia are common comorbidities and could be high-risk factors for severe COVID-19. Vitamin D, a group of fat-soluble compounds responsible for intestinal absorption of calcium, magnesium, and phosphate, has been widely used as a dietary supplement for the prevention and treatment of numerous diseases, including infectious and non-infectious diseases, due to its high cost-effectiveness; safety; tolerability; and anti-thrombotic, anti-inflammatory, antiviral, and immunomodulatory properties. In this letter to the editor, we mainly discuss the potential role of vitamin D in patients with diabetes, dyslipidaemia, and COVID-19.

COVID-19 and the digestive system: A comprehensive review

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is spreading at an alarming rate, and it has created an unprecedented health emergency threatening tens of millions of people worldwide. Previous studies have indicated that SARS-CoV-2 ribonucleic acid could be detected in the feces of patients even after smear-negative respiratory samples. However, demonstration of confirmed fecal-oral transmission has been difficult. Clinical studies have shown an incidence rate of gastrointestinal (GI) symptoms ranging from 2% to 79.1% in patients with COVID-19. They may precede or accompany respiratory symptoms. The most common GI symptoms included nausea, diarrhea, and abdominal pain. In addition, some patients also had liver injury, pancreatic damage, and even acute mesenteric ischemia/thrombosis. Although the incidence rates reported in different centers were quite different, the digestive system was the clinical component of the COVID-19 section. Studies have shown that angiotensin-converting enzyme 2, the receptor of SARS-CoV-2, was not only expressed in the lungs, but also in the upper esophagus, small intestine, liver, and colon. The possible mechanism of GI symptoms in COVID-19 patients may include direct viral invasion into target cells, dysregulation of angiotensin-converting enzyme 2, immune-mediated tissue injury, and gut dysbiosis caused by microbiota. Additionally, numerous experiences, guidelines, recommendations, and position statements were published or released by different organizations and societies worldwide to optimize the management practice of outpatients, inpatients, and endoscopy in the era of COVID-19. In this review, based on our previous work and relevant literature, we mainly discuss potential fecal-oral transmission, GI manifestations, abdominal imaging findings, relevant pathophysiological mechanisms, and infection control and prevention measures in the time of COVID-19.

Kinetics and equilibrium adsorption study of selenium oxyanions onto Al/Si and Fe/Si coprecipitates

Inappropriate treatments for the effluents from semiconductor plants might cause the releases and wide distributions of selenium (Se) into the ecosystems. In this study, Al/Si and Fe/Si coprecipitates were selected as model adsorbents as they often formed during the wastewater coagulation process, and the removal efficiency of selenite (SeO₃) and selenate (SeO₄) onto the coprecipitates were systematically examined. The removal efficiency of SeO₃ and SeO₄ was highly related to surface properties of Al/Si and Fe/Si coprecipitates. The surface-attached Al shell of Al/Si coprecipitates shielded a portion of negative charges from the core SiO₂, resulting in a higher point of zero charge than that of Fe/Si coprecipitates. Thus, adsorption of SeO₃/SeO₄ was favorable on the Al/Si coprecipitates. Adsorptions of both SeO₃ and SeO₄ on Al/Si coprecipitates were exothermic reactions. On Fe/Si coprecipitates, while SeO₃ adsorption also showed the exothermic behavior, SeO₄ adsorption occurred as an endothermic reaction. The kinetic adsorption data of SeO₃/SeO₄ on Al/Si and Fe/Si coprecipitates were described well by the pseudo-second-order kinetic model. SeO₄ and SeO₃ adsorption on Fe/Si or Al/Si were greatly inhibited by the strong PO₄ ligand, whereas the weak ligand such as SO₄ only significantly affected SeO₄ adsorption. The weakest complex between SeO₄ and Al was implied by the essentially SeO₄ desorption as SeO₄/PO₄ molar ratios decreased from 0.5 to 0.2. These results were further confirmed by the less SeO₄ desorption (41%) from Fe/Si coprecipitates than that from Al/Si coprecipitates (78%) while PO₄ was added sequentially.

The Use of Solitaire AB Stents in Coil Embolization of Wide-Necked Cerebral Aneurysms

BACKGROUND

The Solitaire AB stent is one of many assistant stents used for treating wide-necked cerebral aneurysm, and has been used since 2003. However, large sample studies on its safety and effectiveness are lacking. The objective of this study was to evaluate the effectiveness and safety of the Solitaire AB stent in the coil embolization of wide-necked cerebral aneurysms.

METHODS

Retrospective review of the clinical and image data of 116 patients with wide-necked cerebral aneurysms who had been enrolled at six interventional neuroradiology centers from February 2010 to February 2014 and had been treated by coil embolization; in total, 120 Solitaire AB stents were used. The degree of aneurysm occlusion was examined using digital subtraction angiography (DSA) immediately after the procedure and during follow-up, and was graded using the modified Raymond classification. We also observed complications to evaluate the safety and effectiveness of this therapy.

RESULTS

The 120 Solitaire AB stents (4 mm × 15 mm, four stents; 4 mm × 20 mm, 16 stents; 6 mm × 20 mm, 36 stents; 6 mm × 30 mm, 64 stents) were inserted to treat 120 wide-necked cerebral aneurysms. All stents were inserted successfully. DSA immediately post-surgery revealed 55 cases of complete occlusion, 59 cases of neck remnant, and six cases of aneurysm remnant. Perioperatively, there were four cases of hemorrhage and four cases of stent thrombosis. The follow-up spanned 3-37 months; of 92 patients examined by DSA at the 6-month follow up, 12 had disease recurrence.

CONCLUSIONS

The Solitaire AB stent is effective with a good technical success rate and short-term effect for assisting coil embolization of wide-necked cerebral aneurysms.

Effects of open drainage ditch design on bacterial and fungal communities of cold waterlogged paddy soils

A field experiment established in 1980 was conducted to evaluate the effects of open drainage ditch applied for water removal on bacterial and fungal communities of cold waterlogged paddy soils in 2011. In this experiment, traditional plate counting and temperature gradient gel electrophoresis were employed to characterize the abundance and diversity of soil bacterial and fungal communities. Four different distances from the open drainage ditch, 5, 15, 25 and 75 m with different degrees of drainage were designed for this study. Maximum populations of culturable aerobic bacteria and fungi were at 15-m distance while minimum populations were at 75-m distance. Significant differences (p < 0.05) in fungal populations were observed at all distances from open drainage ditch. The highest diversity of the bacterial community was found at a distance of 25 m, while that of the fungal community was observed at a distance of 5 m. Sequencing of excised TGGE bands indicated that the dominant bacteria at 75-m distance belonged to anaerobic or microaerobic bacteria. Relationships between microbial characteristics and soil physicochemical properties indicated that soil pH and available nitrogen contents were key factors controlling the abundance of culturable aerobic bacteria and fungi, while soil water capacity also affected the diversity of fungal community. These findings can provide the references for better design and advanced management of the drainage ditches in cold waterlogged paddy soils.

Oxidative removal of arsenite by Fe(II)- and polyoxometalate (POM)-amended zero-valent aluminum (ZVAl) under oxic conditions

Abiotic transformation of As(III) to As(V) is possible which would decrease As toxicity. This study investigated the potential applications of zero-valent Al (ZVAl) or Al wastes, such as Al beverage cans, for converting As(III) to As(V) in an acidic solution under aerobic conditions. Results showed that As(III) could not be oxidized by ZVAl within 150 min reaction at pH 1 because of the presence of an oxide layer on ZVAl. However, 85 μM As(III) could be completely oxidized with the addition of Fe(II) or POM due to the generation of a Fenton reaction or the enhancement of H2O2 production, respectively, on the ZVAl surfaces. Because Fe(II) or polyoxometalate (POM) exhibited more stable at low pH and scavenged rapidly the H2O2 produced on the aerated ZVAl surfaces, OH radical productions were more efficient and As(III) was rapidly oxidized in the ZVAl/O2 system with theses two catalysts. The catalytic oxidation kinetics of As(III) in the presence of Fe(II) or POM were best described by zero-order reaction, and the rate constants increased with a decrease of pH from 2 to 1. Following the oxidative conversion of As(III) to As(V) in the ZVAl/Fe/O2 system, As(V) was removed by the newly formed hydrous Al/Fe precipitates by increasing the solution pH to 6. Nonetheless, the As(V) removal was incomplete in the ZVAl/POM/O2 system because the hydrolyzed products of POM, e.g., PO4(3-), inhibited As(V) removal due to the competitive adsorption of the oxyanion on Al precipitates. Discarded Al-based beverage cans exhibit a higher efficiency for As(III) oxidation and final As removal compared with that of ZVAl, and thus, the potential application of Al beverage cans to scavenge As in solutions is feasible.

Different roles of TGF-β in the multi-lineage differentiation of stem cells

Stem cells are a population of cells that has infinite or long-term self-renewal ability and can produce various kinds of descendent cells. Transforming growth factor β (TGF-β) family is a superfamily of growth factors, including TGF-β1, TGF-β2 and TGF-β3, bone morphogenetic proteins, activin/inhibin, and some other cytokines such as nodal, which plays very important roles in regulating a wide variety of biological processes, such as cell growth, differentiation, cell death. TGF-β, a pleiotropic cytokine, has been proved to be differentially involved in the regulation of multi-lineage differentiation of stem cells, through the Smad pathway, non-Smad pathways including mitogen-activated protein kinase pathways, phosphatidylinositol-3-kinase/AKT pathways and Rho-like GTPase signaling pathways, and their cross-talks. For instance, it is generally known that TGF-β promotes the differentiation of stem cells into smooth muscle cells, immature cardiomyocytes, chondrocytes, neurocytes, hepatic stellate cells, Th17 cells, and dendritic cells. However, TGF-β inhibits the differentiation of stem cells into myotubes, adipocytes, endothelial cells, and natural killer cells. Additionally, TGF-β can provide competence for early stages of osteoblastic differentiation, but at late stages TGF-β acts as an inhibitor. The three mammalian isoforms (TGF-β1, 2 and 3) have distinct but overlapping effects on hematopoiesis. Understanding the mechanisms underlying the regulatory effect of TGF-β in the stem cell multi-lineage differentiation is of importance in stem cell biology, and will facilitate both basic research and clinical applications of stem cells. In this article, we discuss the current status and progress in our understanding of different mechanisms by which TGF-β controls multi-lineage differentiation of stem cells.

Chromate reduction on humic acid derived from a peat soil--exploration of the activated sites on HAs for chromate removal

Humic substances are a major component of soil organic matter that influence the behavior and fate of heavy metals such as Cr(VI), a toxic and carcinogenic element. In the study, a repetitive extraction technique was used to fractionate humic acids (HAs) from a peat soil into three fractions (denoted as F1, F2, and F3), and the relative importance of O-containing aromatic and aliphatic domains in humic substances for scavenging Cr(VI) was addressed at pH 1. Spectroscopic analyses indicated that the concentrations of aromatic C and O-containing functional groups decreased with a progressive extraction as follows: F1>F2>F3. Cr(VI) removal by HA proceeded slowly, but it was enhanced when light was applied due to the production of efficient reductants, such as superoxide radical and H(2)O(2), for Cr(VI). Higher aromatic- and O-containing F1 fraction exhibited a greater efficiency for Cr(VI) reduction (with a removal rate of ca. 2.89 mmol g(-1) HA under illumination for 3 h). (13)C NMR and FTIR spectra further demonstrated that the carboxyl groups were primarily responsible for Cr(VI) reduction. This study implied the mobility and fate of Cr(VI) would be greatly inhibited in the environments containing such organic groups.

Chromate removal as influenced by the structural changes of soil components upon carbonization at different temperatures

Surface fire could induce heat transferring into the soil, creating a carbonized environment, which may alter the chemical compositions of soil organic matters (SOM). In the study, a surface soil was carbonized at up to 600 °C with limited air to simulate soils experiencing a surface fire, and Cr(VI) removal on the carbonized soils was investigated. NMR and FTIR analyses demonstrated a remarkable change of SOM structures at 300-400 °C. TGA-MS spectra indicated that (e.g. C(2)H(4), CH(3)OH and C(3)H(8)) were the major components in the evolved gases from the pyrolyzed soil. A maximum amount of Cr(VI) removal (ca. 4 mg g(-1) soil) occurred for the 200 °C-carbonized soils, attributed mainly to a significant increase of Cr(VI) reduction by 0.1 M KCl extractable organic carbon (EOC) with abundant carboxylic groups. Nonetheless, the formation of aromatic C upon carbonization of the soil at >400 °C may be responsible for Cr(VI) reduction.

Influence of chemical compositions and molecular weights of humic acids on Cr(VI) photo-reduction

Humic acids (HA) strongly affect the fate of trace metals in soils and aquatic environments. One of the remarkable properties of HA is its ability to reduce Cr(VI), an extremely toxic anion. However, it is unclear which HA components are involved in Cr(VI) reduction and possess the photo-induced properties. In this study, an ultrafiltration technique was used to fractionate HAs into four fractions of different nominal molecular weights (M(w)): >100, 50-100, 10-50 and <10 kDa. Each HA fraction was characterized by spectroscopic analyses followed by examining Cr(VI) removal on each fraction of HA at pH 1-5. Spectroscopic results indicated that low-M(w) HA was enriched with polar and aromatic domains. These polar, including polar C in aliphatic region, and aromatic groups were the major sites for Cr(VI) reduction because they disappeared rapidly upon interaction with Cr(VI). As a result, low M(w) of HA exhibited greater efficiency of Cr(VI) reduction. Light induced the rapid transfer of electrons between chromate-phenol/carboxyl ester, or the formation of peroxide radicals or H(2)O(2) through the ready decay of peroxy radicals associated with polar substituents, explained the rapid scavenging of Cr(VI) on polar and aromatic groups of HAs under illumination.

Cr(VI) removal on fungal biomass of Neurospora crassa: the importance of dissolved organic carbons derived from the biomass to Cr(VI) reduction

Interactions of toxic Cr(VI) with renewable biomaterials are considered an important pathway for Cr(VI) removal in ecosystems. Biomaterials are susceptible to dissolution, and their dissolved derivatives may provide an alternative to surface-involved pathway for scavenging of Cr(VI). In this study, dissolved organic carbon (DOC) derived from Neurospora crassa biomass was investigated. The proportion of Cr(VI) reduction by DOC to that on biomass was determined to evaluate the importance of DOC to Cr(VI) reduction. A rapid increase in DOC concentration from 145.6 to 193.7 mg L(-1) was observed when N. crassa-biomass was immersed in 0.01 M KCl solution at pH of 1-5, and polysaccharides, peptides, and glycoproteins with carboxyl, amide, and -NH functional groups, are the major compositions of DOC. On reaction of 96.2 microM Cr(VI) with N. crassa-biomass or DOC, it was estimated that DOC contributed approximately 53.8-59.5% of the total Cr(VI) reduction on biomass in the dark. Illumination enhanced Cr(VI) reduction via photo-oxidation of biomass/DOC under aeration conditions, which formed superoxide for Cr(VI) reduction. At pH 1, photoinduced Cr(VI) reduction by DOC proceeded more rapidly than reduction on the biomass surface. However, at pH >3, with a decrease in Cr(VI) reduction by DOC, photon-excited biomass may become an important electron source for Cr(VI) photoreduction.

Biodegradation of phthalate esters in compost-amended soil

In this study, we investigated the biodegradation of the phthalate acid esters (PAEs) di-n-butyl phthalate (DBP) and di-(2-ethyl hexyl) phthalate (DEHP) in compost and compost-amended soil. DBP (50 mg kg(-1)) and DEHP (50 mg kg(-1)) were added to the two types of compost (straw and animal manure) and subsequently added to the soil; they were tested as a single compound and in combination. Optimal PAE degradation in soil was at pH 7 and 30 degrees C. The degradation of PAE was enhanced when DBP and DEHP were simultaneously present in the soil. The addition of either of the two types of compost individually also improved the rate of PAE degradation. Compost samples were separated into fractions with various particle size ranges, which spanned from 0.1-0.45 to 500-2000 microm. We observed that the compost fractions with smaller particle sizes demonstrated higher PAE degradation rates. When the different compost fractions were added to soil, however, compost particle size had no significant effect on the rate of PAE degradation.

Synthesis, characterization and photocatalytic activity of porous manganese oxide doped titania for toluene decomposition

The present study describes the photocatalytic degradation of toluene in gas phase on different porous manganese oxide doped titanium dioxide. As synthesized birnessite and cryptomelane type porous manganese oxide were doped with titania and tested for photocatalytic decomposition of toluene in gas phase. The effects of the inlet concentration of toluene, flow rate (retention time) were examined and the relative humidity was maintained constantly. Thermal and textural characterization of manganese oxide doped titania materials were characterized by X-ray diffraction (XRD), thermogravemetry (TG), BET and TEM-EDAX studies. The aim of the present study is to synthesize the porous manganese oxide doped titania and to study its photocatalytic activity for toluene degradation in gas phase. Cryptomelane doped titania catalyst prepared in water medium [K-OMS-2 (W)] is shown the good toluene degradation with lower catalysts loading compared to commercial bulk titania in annular type photo reactor. The higher photocatalytic activity due to various factors such as catalyst preparation method, experimental conditions, catalyst loading, surface area, etc. In the present study manganese oxide OMS doped titania materials prepared by both aqueous and non-aqueous medium, aqueous medium prepared catalyst shows the good efficiency due to the presence of OH bonded groups on the surface of catalyst. The linear forms of different kinetic equations were applied to the adsorption data and their goodness of fit was evaluated based on the R2 and standard error. The goodness to the linear fit was observed for Elovich model with high R2 (>or=0.9477) value.

Light-catalyzed chromium(VI) reduction by organic compounds and soil minerals

Detoxification of Cr(VI) through reduction has been considered an effective method for reclaiming Cr-contaminated soil, sediment, and waste water. Organic matter is widely distributed in soil and aquatic systems; however, low Cr(VI) reduction rates inhibit the adoption of Cr reduction technologies by industry. Scientists have been aware of Cr(VI) reduction catalyzed by soil minerals; however, most of the studies focused on using semiconductors as catalysts with UV irradiation to accelerate the redox reactions. The objective of this study was to evaluate the rates of Cr(VI) reduction by fluorescence light in the presence of organic materials with or without specific soil minerals. Experimental results showed that dissolved organic compounds reduced Cr(VI) slowly under laboratory light; however, Cr(VI) reduction was greatly enhanced when growth chamber light was applied. Low photon flux (i.e., laboratory light) only enhanced Cr(VI) reduction by organics when Fe(III) was also present, because the Fe(II)-Fe(III) redox couple accelerated electron transfer and decreased electrostatic repulsion between reactants. Laboratory light was required to initiate Cr(VI) reduction catalyzed by TiO2; nonetheless, light-catalyzed Cr(VI) reduction by smectite and ferrihydrite could occur only when greater light energy was provided with a growth chamber light. Our results suggest a potential pathway for Cr(VI) reduction using naturally occurring organic compounds and colloids in acidic water systems or in surface soils when light is available.

Effect of N-hydroxyethyl-ethylenediamine-triacetic acid (HEDTA) on Cr(VI) reduction by Fe(II)

The complexation of Fe(II) with organic ligand results in the decrease of redox potential, and enhances the reduction ability of Fe(II). An important example is the use of Fe(II)-organic complexes to accelerate Cr(VI) reduction. Dissolved O(2) and light can potentially affect Cr(VI) reduction; however, these two factors have not been adequately evaluated. A batch technique was used to investigate the Cr(VI) reduction as influenced by the light and dissolved O(2) using N-hydroxyethyl-ethylenediamine-triacetic acid (HEDTA) and Fe(II) solutions. The oxidation of Fe(II) by dissolved O(2) was rapid in the presence of HEDTA at low pH; nonetheless, the oxidation proceeded slowly when HEDTA was absent. Although Cr(VI) could be reduced by free Fe(II) at low pH, the reaction was considerably slower than that of systems involving HEDTA. The enhancement of Cr(VI) reduction by Fe(II) in the presence of high concentrations of HEDTA was achieved as a result of two processes. First, HEDTA acted as a ligand for expediting electron transfer between Fe(II) and Cr(VI). Secondly, HEDTA served as a reductant for Cr(VI) under illumination.

Sorption of phosphate and Cr(VI) by Fe(III) and Cr(III) hydroxides

Understanding the chemical behavior and interactions of Cr(VI) ( e.g., HCrO(4)(-)) and other anions, such as orthophosphate (P) with insoluble metal hydroxides ( i.e., Cr[III] and Fe[III]) in disposal landfills or in chromite ore processing residue (CORP)-enriched soil is very important in predicting the movement and the fate of Cr(VI). This study evaluates the sorption behavior of P and Cr(VI) by Fe(III) ( i.e., ferrihydrite), Cr(III) ( i.e., Cr[OH](3)), and coprecipitated Fe(III)/Cr(III) hydroxides. These metal hydroxide sorbents were synthesized, and sorption of P and Cr(VI) were conducted at different pH using a batch technology. Our results show that P and Cr(VI) sorption by metal hydroxides decreased with increasing suspension pH. Greater decrease in P sorption was observed when Cr(III) was present in the structures of hydroxides. Following the sorption of low concentration of P ( i.e., 0.5 mM), the sorption of subsequently added Cr(VI) by hydroxides was less influenced. However, Cr(VI) sorption was greatly inhibited when high concentration of P ( i.e., 10 mM) prereacted with hydroxides, particularly in Fe(III) hydroxide system. Results also indicated that high concentration of Cr(VI) (10 mM) could dissolve Cr(III) hydroxide at pH 3 and reprecipitate as an amorphous form of Cr(VI) and Cr(III) compound at pH about 6.5. Although coprecipitation of Cr(VI) with Cr(III) can inhibit Cr(VI) movement through soil profiles, the inhibition seems to be low due to the gradual release of Cr(VI) with increasing pH.

Assessment of sorbent/water ratio effect on adsorption using dimensional analysis and batch experiments

Many factors affect adsorption phenomena in solid-liquid systems. One of the most important factors is the sorbent/water (S/W) ratio in the system. However, the effect of varying S/W ratios on the adsorption is still unclear. In this study, batch experiments were examined to observe the adsorption of four contaminants (copper, cadmium, Butachlor, and Deltamethrin) in six soils with texture ranging from silty clay to loamy sand and with different S/W ratios. Dimensional analysis was used to assess the relationship between adsorption phenomena and S/W ratio. We have assumed that the total amount of sorbate sorbed in soil is a function of the equilibrium concentration, the volume of sorbate solution, and the sorbent amount in the system. A power function (Freundlich-like) model was obtained from the dimensional analysis. It can describe precisely the adsorption phenomena of different sorbents and sorbates in the moisture regime of paddy soils. Therefore, proper adsorption parameters can be obtained by this power function model regardless of the solids effect, which can then be utilized to describe the fate of solute in soil using solute transport models.

Refrigeration of donor cells in preparation for bovine somatic nuclear transfer

In mammals, preparation of donor cells for somatic nuclear transfer is very important because the character of the donor cell directly affects the efficiency and outcome of transfer. The protocols used most commonly for donor preparation are (i) disaggregating cells from fresh tissue 1-2 h before micromanipulation or (ii) trypsinizing cultured cells temporarily, after special treatments for 3-8 days (for example, serum starvation). In this study, a new simple protocol was designed, whereby the donor cells (cumulus cells) used in bovine somatic nuclear transfer were refrigerated. In brief, cultured cells at 80-100% confluency were detached using trypsin, washed by centrifugation, aliquoted into different vials and refrigerated at 4 degrees C. The density of viable cells was decreased after day 1 of refrigeration; however, the rate of decrease tended to slow down with increasing duration of refrigeration. Cells refrigerated for 15 days were seeded at a density of 5 x 10(4) ml(-1) and reached 70% confluency after day 2 of culture. Most cells had the normal number of chromosomes (2n = 60). Cells chilled at 4 degrees C for different durations were removed from refrigeration and immediately subjected to micromanipulation. The in vitro development of reconstructed embryos (fusion rates, cleavage rates, morula and blastocyst rates) indicated that there were no significant differences among treatment groups regardless of the duration of refrigeration (0-2 weeks) of the donor cells. Reconstructed embryos were transferred into the uteri of recipient cows. No significant differences were observed in established early pregnancies between embryos derived from the non-refrigerated donor cells and those derived from refrigerated donor cells. This study indicates that refrigeration of donor cells for 1-2 weeks is a feasible protocol for preparing donor cells for bovine somatic nuclear transfer, and does not compromise development in vitro and early development in vivo.

Refrigeration of donor cells in preparation for bovine somatic nuclear transfer

In mammals, preparation of donor cells for somatic nuclear transfer is very important because the character of the donor cell directly affects the efficiency and outcome of transfer. The protocols used most commonly for donor preparation are (i) disaggregating cells from fresh tissue 1-2 h before micromanipulation or (ii) trypsinizing cultured cells temporarily, after special treatments for 3-8 days (for example, serum starvation). In this study, a new simple protocol was designed, whereby the donor cells (cumulus cells) used in bovine somatic nuclear transfer were refrigerated. In brief, cultured cells at 80-100% confluency were detached using trypsin, washed by centrifugation, aliquoted into different vials and refrigerated at 4 degrees C. The density of viable cells was decreased after day 1 of refrigeration; however, the rate of decrease tended to slow down with increasing duration of refrigeration. Cells refrigerated for 15 days were seeded at a density of 5 x 10(4) ml(-1) and reached 70% confluency after day 2 of culture. Most cells had the normal number of chromosomes (2n = 60). Cells chilled at 4 degrees C for different durations were removed from refrigeration and immediately subjected to micromanipulation. The in vitro development of reconstructed embryos (fusion rates, cleavage rates, morula and blastocyst rates) indicated that there were no significant differences among treatment groups regardless of the duration of refrigeration (0-2 weeks) of the donor cells. Reconstructed embryos were transferred into the uteri of recipient cows. No significant differences were observed in established early pregnancies between embryos derived from the non-refrigerated donor cells and those derived from refrigerated donor cells. This study indicates that refrigeration of donor cells for 1-2 weeks is a feasible protocol for preparing donor cells for bovine somatic nuclear transfer, and does not compromise development in vitro and early development in vivo.

[Chemical constituents of Loxocalyx urticifolius Hemsl]

OBJECTIVE

To investigate the chemical constituents from the whole plant of Loxocalyx urticifolius.

METHOD

The chemical constituents were isolated by chromatography and identified by MS, 1H NMR, 13C NMR and 2D-NMR methods.

RESULT

The structures were established as poliothrysoside, beta-sitosterol and stigmasterol, palmitic acid and tyrosine.

CONCLUSION

This is the first time for the chemical constituents of L. urticifolius to be reported.

Maturation of the reconstructed oocytes by germinal vesicle transfer in rabbits and mice

The present study was designed to evaluate the feasibility of germinal vesicle (GV) transfer in rabbits and mice. The GV oocytes were collected from ovaries and cultured in 20 microg/mL 3-isobutyl-1-methylxanthin (IBMX) in TCM199 medium, which caused oocytes to shrink, enlarging the perivitelline space to facilitate the GV removal and transfer. Pairs of GV-cytoplast complexes were fused with electric pulses, and the fused, reconstructed oocytes were cultured in TCM199 for 24 h. Results are as follows: 1) The exposure time of rabbit GV oocytes to IBMX medium affected the success of GV removal. For oocytes cultured for 2 and 3 h in IBMX medium, removed rates were 56% and 44, respectively, significantly higher (P < 0.05) than removal rates of GV oocytes cultured for 1 and 4 h (27% and 27%, respectively); 2) There was no significant difference (P > 0.1) in fusion and maturation rates of rabbit reconstructed oocytes collected at 72 and 84 h after initiation of FSH injection to donors; 3) eCG in the maturation media improved development of rabbit-to-rabbit GV transferred oocytes but had no positive effect on mouse-to-rabbit GV transferred oocytes; 4) When mouse GV-karyoplasts were injected into enucleated rabbit oocytes, fusion rates of GV-karyoplasts measuring 40- to 50-microm and 80- to 90-microm in diameters obtained were 84% and 93%, respectively. The rates were significantly higher (P < 0.05) than fusion rates after transferring GV-karyoplasts measuring 30- to 35-microm in diameter (63%). The maturation rate (89%) of reconstructed oocytes composed of 80- to 90-microm mouse GV-karyoplasts and rabbit GV-enucleated cytoplasts was higher than that seen for oocytes composed of 40- to 50-microm (77%, P<0.05) or 30- to 35-microm (59%, P<0.01) mouse karyoplasts. Thirty-five of the 63 (56%) mature mouse-to-rabbit reconstructed oocytes had the normal complement of 20 chromosomes.

[Chemical constituents from the fruit of Rosa bella Rehd. et Wils]

OBJECTIVE

To investigate the chemical constituents from the fruit of Rosa bella and its bioactivity.

METHOD

The compounds were isolated from the methanol extract by column chromatography, then identified by 1H, 13C NMR and by comparison with authentic samples. The unorganized hoptoad heart was used for testing the contracting force of cardiac muscle and enzymology for measuring the bloody lipid of serum in rats.

RESULT

Seven compounds were isolated and identified as pomolic acid, tiliroside, euscaphic acid, daucosterol, quercetin, oleanolic acid and beta-sitosterol, respectively. In the concentration of 0.4-1.0 mg.ml-1, the methanol extract had obvious cardiotonic effect. While at 400 mg.kg-1, there are no obvious effect to the TC, HDL-ac and TG of serum in rats.

CONCLUSION

The isolated compounds may be the active components of this plant.

Transport modeling of copper and cadmium with linear and nonlinear retardation factors

The predictive accuracy of using the one-dimensional advection-dispersion equation to evaluate the fate and transport of solute in a soil column is usually dependent on the proper determination of chemical retardation factors. Typically, the distribution coefficient (Kd) obtained by fitting the linear sorption isotherm has been extensively used to consider general geochemical reactions on solute transport in a low-concentration range. However, the linear distribution coefficient cannot be adequately utilized to describe the solute fate at a higher concentration level. This study employed the nonlinear equilibrium-controlled sorption parameters to determine the retardation factor used in column leaching experiments. Copper and cadmium transportation in a lateritic silty-clay soil column was examined. Through the explicit finite-difference calculations with a third-order total-variation-diminishing (TVD) numerical solution scheme, all results of the theoretical copper and cadmium breakthrough curves (BTCs) simulated by using the Freundlich nonlinear retardation factors revealed good agreement with the experimental observations.

Mouse-rabbit germinal vesicle transfer reveals that factors regulating oocyte meiotic progression are not species-specific in mammals

A series of experiments were designed to evaluate the meiotic competence of mouse oocyte germinal vesicle (GV) in rabbit ooplasm. In experiment 1, an isolated mouse GV was transferred into rabbit GV-stage cytoplast by electrofusion. It was shown that 71.8% and 63.3% of the reconstructed oocytes completed the first meiosis as indicated by the first polar body (PB1) emission when cultured in M199 and M199 + PMSG, respectively. Chromosomal analysis showed that 75% of matured oocytes contained the normal 20 mouse chromosomes. When mouse spermatozoa were microinjected into the cytoplasm of oocytes matured in M199 + PMSG and M199, as many as 59.4% and 48% finished the second meiosis as revealed by the second polar body (PB2) emission and a few fertilized eggs developed to the eight-cell stage. In experiment 2, a mouse GV was transferred into rabbit MII-stage cytoplast. Only 13.0-14.3% of the reconstructed oocytes underwent germinal vesicle breakdown (GVBD) and none proceeded past the MI stage. When two mouse GVs were transferred into an enucleated rabbit oocyte, only 8.7% went through GVBD. In experiment 3, a whole zona-free mouse GV oocyte was fused with a rabbit MII cytoplast. The GVBD rates were increased to 51.2% and 49.4% when cultured in M199 + PMSG and M199, respectively, but none reached the MII stage. In experiment 4, a mouse GV was transferred into a partial cytoplasm-removed rabbit MII oocyte in which the second meiotic apparatus was still present. GVBD occurred in nearly all the reconstructed oocytes when one or two GVs were transferred and two or three metaphase plates were observed in ooplasm after culturing in M199 + PMSG for 8 hr. These data suggest that cytoplasmic factors regulating the progression of the first and the second meioses are not species-specific in mammalian oocytes and that these factors are located in the meiotic apparatus and/or its surrounding cytoplasm at MII stage.

Sucrose pretreatment for enucleation: an efficient and non-damage method for removing the spindle of the mouse MII oocyte

Oocytes enucleated at metaphase II stage can support reprogramming of transferred nucleus and further developing to term. However, the first polar body in mice sometimes migrates away from the original place of expulsion, so the chromosomes of the oocyte will displace from the first polar body. Thus, it is not always possible to successfully enucleate according to the position of the first polar body. Here we use sucrose treatment to visualize metaphase spindle fibers and chromosomes with standard light microscopy. In the manipulation medium containing 3% sucrose, oocytes of poor quality become shrunken, deformed or fragmented, while oocytes of good quality in the same medium would show a swelling around the metaphase chromosomes and a transparent spindle area, shaped like "infinity" and "0". So it is easy to remove the well-distinguished spindle and chromosomes in oocytes of good quality. Re-examined by Hoechst 33342 stain under the UV light, the enucleation rate was 100%. There was no significant difference in IVF and cleavage rates between the sucrose treatment and the control group. In conclusion, this study demonstrated that 3% sucrose pretreatment can give a method for evaluating embryo quality and more importantly, it can, under a common microscope, allow the visualization of the spindle and chromosomes in oocytes of good quality and hence efficiently improve enucleation rate without any harm.

In vitro fertilisation of mouse oocytes reconstructed by transfer of metaphase II chromosomes results in live births

The interaction between nucleus and cytoplasm can be explored through nuclear transfer. We describe here another tool to investigate this interaction: MII meiotic apparatus transfer (MAT) between mouse oocytes. In this study, the MII oocyte meiotic apparatus or spindle from C57BL/6 mice, a black strain, was transferred into an enucleated metaphase oocyte from Kunming mouse, a white strain. The results showed that the enucleation rate by treating oocytes with 3% sucrose was 100%, but the electrofusion efficiency was very low, with only 17.6% of reconstructed karyoplast-recipient cytoplasm pairs fused. When the fused oocytes were exposed to spermatozoa from C57BL/6 mice, 9 of 11 (82%) were fertilised. Eight reconstructed embryos at 1- to 4-cell stages were transferred into the oviducts of two synchronously pregnant Kunming strain fosters and one delivered two normal C57BL/6 offspring. This study indicates that MII meiotic apparatus or spindle sustains normal structure and function after micromanipulation and electrofusion. MAT provides a model for further research on the application of this technique to assisted human reproduction.

Viable rabbits derived from reconstructed oocytes by germinal vesicle transfer after intracytoplasmic sperm injection (ICSI)

Abnormal oocyte spindle due to the improper function of ooplasm is associated with female infertility of advanced maternal age. A possible way to overcome this problem is to transfer an oocyte germinal vesicle (GV) which contains genetic materials of a patient with a history of poor embryo development to the cytoplast from a donor oocyte. Here we demonstrate that GV transfer is feasible using a rabbit model. When the GVs were transferred to auto- or hetero-cytoplasts of GV stage oocytes, around 80% of the reconstructed oocytes could mature in vitro and 7.1-9.4% of the oocytes developed to blastocyst stage after intracytoplasmic sperm injection (ICSI). Transfer of 93 fertilized eggs reconstructed via GV transfer into six recipients resulted in two live offspring. Results of this experiment indicate that GV transfer can potentially become a new approach in treatment of infertility because of advanced maternal age.

[Chemical constituents from the root of Rubus chroosepalus]

AIM

To investigate the chemical constituents of Rubus chroosepalus Focke.

METHODS

The methanol extracts were suspended in H2O and then extracted with EtOAc. Column chromatography was used for separation and purification, while spectral analysis was used for identification.

RESULTS

Seven compounds were isolated and identified as 2 alpha, 3 beta-dihydroxy-urs-12, 19-dien-23, 28-oic acid (I), 2 alpha, 3 beta, 23-trihydroxy-urs-12,18-dien-28-oic acid (IIa), 2 alpha, 3 beta, 23-trihydroxy-urs-12,19-dien-28-oic acid (IIb), 2 alpha, 3 alpha-dihydroxy-urs-12,18-dien-28-oic acid (IIIa), 2 alpha, 3 alpha-dihydroxy-urs-12,19-dien-28-oic acid (IIIb), and the acetonide of IIIa and IIIb (IVa and IVb).

CONCLUSION

I was found to be a new pentacyclic triterpenoid acid.

A geometric approach to determine adsorption and desorption kinetic constants

A geometric method based on Langmuir kinetics has been derived to determine adsorption and desorption kinetic constants. In the conventional procedure, either the adsorption kinetic constant (k(a)c) or desorption kinetic constant (k(d)c) is found from kinetic experiments and the other is calculated by their correlation with the equilibrium constant, i.e, k(d)c = Kcon/k(a)c, where Kcon has been known from equilibrium studies. The determined constants (Kcon, k(a)c, k(d)c), if based only on the conventional procedure, may not be accurate due to their mathematical dependence. Therefore, the objectives of this study are applying a geometric approach to directly determine Langmuir kinetic constants and describe adsorption behavior. In this approach, both adsorption kinetic constant (k(a)g) and desorption kinetic constant (k(d)g) are obtained only from data of kinetic experiments, and a geometric equilibrium constant (Kgeo) is calculated by Kgeo = k(a)g/k(d)g. The deviation between Kgeo and Kcon can prove the accuracy of k(a)g and k(d)g which were determined by this method. This approach was applicable to selenate, selenite and Mg2+ adsorption onto SiO2 regardless of whether the adsorbate formed inner- or outer-sphere complexes. However, this method showed some deviation between Kcon and Kgeo for Mn2+ adsorption because of the formation of surface Mn(II)-hydroxide clusters, which was inconsistent with the basic assumption of this method of monolayer adsorption.

Effect of telophase enucleation on bovine somatic nuclear transfer

Telophase enucleation has been proven to be an efficient method for preparing recipient cytoplasts in bovine embryonic nuclear transfer (2, 11). This research was designed to study in vitro development of bovine oocytes containing transferred somatic cell nuclei, reconstructed by using enucleated in vitro-matured oocytes 32 h of age at telophase II stage as recipient cytoplasts, compared with those 24 h of age at metaphase II stage. Two protocols for donor cell injection were adopted, i.e., subzonal injection (SUZI) and intracytoplasmic injection (ICI). Bovine oviduct epithelial cells (BOECs) and bovine cumulus cells (BCCs) from an adult cow were used as nuclear donors for these experiments. In SUZI groups, the fusion rate of donor cells, both BOECs and BCCs, with MII enucleated oocytes were higher than those with TII enucleated oocytes (54% vs. 41% and 53% vs. 39%, respectively; P<0.05), but the development rates to morula plus blastocyst stage in MII groups were lower than those in TII groups (22% vs. 39% and 21% vs. 41%, respectively; P<0.05). In ICI groups, about 26% of enucleated MII oocytes injected with BOECs or BCCs cleaved and only small parts of them developed to blastocyst stage (4% and 3%, respectively; P>0.05). When BOECs or BCCs were intracytoplasmically injected into oocytes enucleated at TII stage, no blastocyst was formed in either donor cell group and no cleavage occurred in BOEC group. Our data demonstrated that telophase enucleation is beneficial to early embryo development when bovine somatic nuclei are transferred by subzonal injection. However, it is harmful when donor cells are directly injected into the cytoplast of the enucleated oocytes.

Triterpenoid saponins from Berneuxia thebetica

Four triterpenoid saponins were isolated from Berneuxia thibetica. On the basis of chemical and spectroscopic evidence, three new saponins, berneuxia saponins A, B and C, were elucidated as 21-tigloylbarringtogenol C-3 beta-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-galactopyranosyl(1-->3)[bet a- D-glucopyranosyl(1-->2)-beta-D-glucuronopyranoside], 28-tigloylbarringtogenol C-3 beta-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-galactopyranosyl(1-->3)[bet a- D-glucopyranosyl(1-->2)-beta-D-glucuronopyranoside] and 16 alpha-28-dihydroxyolean-12-en-21-one-3-O-alpha-L-rhamnopyranosyl(1 -->2) -beta-D-galactopyranosyl(1-->3)[beta-D-glucopyranosyl(1-->2)-beta-D- glucuronopyranoside]. The known saponin was desacyl jegosaponin.

Triterpenoid saponins from Anemone hupehensis

Two new triterpenoid saponins, named hupehensis saponin F and G, were isolated from the water soluble part of Anemone hupehensis Lemoine. By chemical and spectroscopic evidence, their structures were elucidated as 3-O-beta-D-ribopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1--> 2)-alpha-L-arabinopyranosyl hederagennin-28-O-alpha-rhamnopyranosyl(1--> 4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranosyl(1--> 3)-alpha-L-rhamnopyranosyl(1-->4)-beta-glucopyranosyl(1--> 6)-beta-D-glucopyranoside and 3-O-beta-D-ribopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1--> 2)-alpha-L-arabinopyranosyl hederagenin-28-O-beta-glucopyranosyl(1-->3)-alpha-rhamnopyranosyl( 1--> 4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranosyl(1--> 3)-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1--> 6)-beta-D-glucopyranoside, respectively.

Triterpenoid saponins from Anemone hupehensis

Four triterpenoid saponins were isolated from Anemone hupehensis. On the basis of chemical and spectroscopic evidence, two new saponins, hupehensis saponins D and E, were elucidated as 3-O-beta-D-glucopyranosyl (1-->3)-beta-D-ribopyranosyl (1-->3)-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranosyl oleanolic acid-28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranoside and 3-O-beta-D-glucopyransoyl (1-->3-beta-D-ribopyranosyl (1-->3)-alpha-L-rhamnopyranosyl (1-->2)-alpha-L-arabinopyranosyl hederagenin-28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranoside. The two known saponins were identified as huzhangosides B and D.

Skin protection, Viton, and solubility parameters

Permeation is a function of diffusion and solubility of the solvent/polymer system. A physical-chemical constant that has been used previously to predict solubility is the three-dimensional solubility parameter (3-DSP). This paper reports a method for calculating the 3-DSP for the polymer Viton, new permeation data for Viton and 14 solvents, and the application of the 3-DSP to a model for predicting permeation parameters. The 3-DSP values for Viton (J/cc)1/2 were dispersion = 17.0, polar = 10.6, and hydrogen bonding = 6.1. A correlation coefficient of 0.65 was obtained when the natural log of breakthrough time for 19 solvents was regressed against the differences of the 3-DSP's for these 19 solvents and Viton. A value of 0.69 was obtained for the natural log of the permeation rate vs 16 solvent-Viton 3-DSP differences. While the variance unaccounted for in these regression tests does not allow quantitative prediction of permeation parameters, qualitative prediction of polymer suitability is possible.

Effect of polybasic acids on structure of aluminum hydroxycarbonate gel

The effect of oxalic acid, citric acid, and their sodium salts on the structure of aluminum hydroxycarbonate gel was studied to illustrate the various mechanisms by which polybasic acids interact with aluminum hydroxycarbonate gel. Analysis of changes in the pH-stat titrigram, the carbonate to aluminum ratio, the aluminum content of the supernate following centrifugation, and the adsorption of the organic solute indicates that polybasic acids may: (a) partially neutralize the aluminum hydroxycarbonate gel by a general acid effect, (b) modify the aluminum hydroxycarbonate surface by adsorption of the anionic form of the polybasic acid, (c) extract aluminum by the formation of a soluble complex, and (d) lead to the precipitation of a new crystalline phase.

Letter: Other systemic effects of eye drops

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Cataract aspiration-irrigation through separate needles with push-pull syringes

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