Fabrication of Ag-Decorated CaTiO3 Nanoparticles and Their Enhanced Photocatalytic Activity for Dye Degradation.

CaTiO3nanoparticles of 30-40 nm in size were synthesized via a polyacrylamide gel route. Ag nanoparticles with size of 8-16 nm were deposited onto CaTiO3particles by a photochemical reduction method to yield CaTiO3@Ag composites. The photocatalytic activity of prepared samples was evaluated by degrading methyl orange under ultraviolet irradiation. It is demonstrated that Ag-decorated CaTiO3 particles exhibit an enhanced photocatalytic activity compared to bare CaTiO3 particles. After 60 min of photocatalysis, the degradation percentage of MO increases from 54% for bare CaTiO3particles to 72% for CaTiO3@Ag composites. This can be explained by the fact that photogenerated electrons are captured by Ag nanoparticles and photogenerated holes are therefore increasingly available to react with OH⁻/H2O to generate hydroxyl (·OH) radicals. ·OH radicals were detected by fluorimetry using terephthalic acid as a probe molecule, revealing an enhanced yield on the irradiated CaTiO3@Ag composites. In addition, it is found that the addition of ethanol, which acts as an ·OH scavenger, leads to a quenching of ·OH radicals and simultaneous decrease in the photocatalytic efficiency. This suggests that ·OH radicals are the dominant active species responsible for the dye degradation.

Pheochromocytoma in pregnancy: a case report.

BACKGROUND: Pheochromocytoma (PHEO) in pregnancy is a rare disease, and the management of this situation is not well established. The misdiagnosis of the disease often leads to adverse outcomes for both mothers and infants. CASE REPORT: Here, we describe a case of a pregnant woman at 25 weeks' gestation presenting with headache, chest tightness, and shortness of breath, which was found to have a left adrenal mass and hypertensive urgency and diagnosed pregnancy with PHEO in our hospital. The timely diagnosis and proper treatment came with an optimal maternal and fetal outcome. CONCLUSIONS: The case of pheochromocytoma in pregnancy we report demonstrated that early diagnosis and a multidisciplinary approach ensured a favorable prognosis for both maternal and fetal, and we also addressed the importance of individual basis evaluation during the whole journey.

Association of MTHFR gene C677T polymorphism with pregnancy outcome.

OBJECTIVE: The two objectives of the present study were to analyze the correlation between pregnancy outcomes and methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism, and to provide evidence for clinical improvement of adverse pregnancy outcomes. PATIENTS AND METHODS: 1,995 cases of pregnant women were selected as objects of the study, and underwent MTHFR gene C677T polymorphism detection in the Second Affiliated Hospital of Guangxi Medical University from October 2020 to September 2021, in which 919 cases whose pregnancy outcomes could be tracked. According to the result of MTHFR gene C677T polymorphism detection, 1,995 cases of pregnant women were classified into a wild-type (CC) group, heterozygous (CT) group, or homozygous (TT) group, and the distributions of MTHFR gene C677T polymorphism in pregnant women were analyzed. In addition, according to complications, 919 cases of pregnant women whose pregnancy outcomes could be tracked were divided into the normal pregnancy group (676 cases), GDM group (146 cases), HDP group (47 cases), abnormal fetus group (13 cases), and spontaneous abortion group (37 cases), and the genotype distributions of MTHFR gene C677T in each group were analyzed. Besides, according to genotype, 919 cases of pregnant women whose pregnancy outcome could be tracked were divided into CC group (515 cases), CT group (289 cases), and TT group (115 cases), and the correlation between genotype and pregnancy outcomes, such as fetal distress, postpartum hemorrhage, premature birth, and full-term delivery, was then analyzed. RESULTS: For the C677T locus of MTHFR gene in the 1,995 cases of pregnant women, there are 1,162 (58.25%) cases of CC genotype, 649 (32.53%) cases of CT genotype, 184 (9.22%) cases of TT genotype. The proportion of TT genotype in GDM, HDP, abnormal fetus, and spontaneous abortion groups were respectively 19.86% (29/148), 25.53% (12/47), 46.15% (6/13), 40.54% (15/37), which were significantly higher than that in normal pregnancy group (7.84%, 53/676), and there were statistically significant differences (p < 0.05). The full-term birth rate in TT group (75.65%, 87/115) was lower than those of CC group (91.26%, 470/515) and CT group (89.27%, 258/289), and there were statistically significant differences (p < 0.05). CONCLUSIONS: The TT type gene mutation at the C677T site ofMTHFR gene is closely related to conditions that contribute to a decrease in the number of full-term births and increase the risk of adverse pregnancy outcomes, including GDM, HDP, spontaneous abortion, and fetal abnormalities.

Analysis of the anemia characteristics in early pregnancy and outcomes of pregnant women with hemoglobin H disease.

OBJECTIVE: This study aimed to analyze the anemia characteristics in early pregnancy of pregnant women with hemoglobin H (Hb H) disease and their pregnancy outcomes, and to provide reference to the pregnancy management and treatment of these women. PATIENTS AND METHODS: Twenty-eight cases of pregnant women who had been diagnosed with Hb H disease in the Second Affiliated Hospital of Guangxi Medical University from August 2018 to March 2022 were retrospectively analyzed. Moreover, 28 cases of normal pregnant women in the same period were randomly enrolled as a control group for comparison. The means and percentages of the anemia characteristics in early pregnancy and the pregnancy outcomes were calculated and the analysis of variance, Chi-square test, and Fisher's exact test were applied for comparison. RESULTS: A total of 13 cases of missing type (46.43%) and 15 cases of non-missing type (53.57%) were observed in the 28 cases of pregnant women with Hb H disease. The genotypes were as follows: 8 cases of -α3.7/--SEA (28.57%), 4 cases of -α4.2/--SEA (14.29%), 1 case of -α4.2/--THAI (3.57%), 9 cases of αCSα/--SEA (32.14%), 5 cases of αWSα/--SEA (17.86%), and 1 case of αQSα/--SEA (3.57%). Twenty-seven patients with Hb H disease (96.43%) were anemic, including 5 cases of mild anemia (17.86%), 18 cases of moderate anemia (64.28%), 4 cases of severe anemia (14.29%), and 1 case of non-anemia (3.57%). Compared with the control group, the Hb H group had significantly higher red blood cell count and significantly lower Hb, mean corpuscular volume, and mean corpuscular hemoglobin, and the differences were statistically significant (p < 0.05). The Hb H group had higher incidence rates of blood transfusion during pregnancy (BTDP), oligohydramnios fetal growth restrictions (FGR), and fetal distress than the control group. The weights of neonates were lower in the Hb H group than in the control group. Statistically significant differences were found between these two groups (p < 0.05). CONCLUSIONS: The genotype missing type of pregnant women with Hb H disease was mainly -α3.7/--SEA and the non-missing type was mainly αCSα/--SEA. Hb H disease can easily cause various degrees of anemia (mainly moderate anemia in this study). Moreover, it can increase the incidence rate of pregnancy complications such as BTDP, oligohydramnios, FGR, and fetal distress, which will reduce the weight of neonates and seriously affect maternal and infant safety. Therefore, maternal anemia and fetal growth and development should be monitored during pregnancy and delivery, and transfusion therapy should be used to improve adverse pregnancy outcomes caused by anemia when necessary.

Analysis of the results of non-invasive prenatal testing (NIPT) in 545 pregnant women in advanced maternal age.

OBJECTIVE: This research aimed to explore the value of non-invasive prenatal testing (NIPT) as a prenatal screening method for common aneuploidy in pregnant women in advanced maternal age. PATIENTS AND METHODS: A retrospective analysis was conducted on a cohort of 545 mothers with singleton pregnancy who were of advanced age and underwent NIPT testing voluntarily at the Second Affiliated Hospital of Guangxi Medical University between November 2020 and February 2023. In cases where NIPT testing suggested chromosomal abnormalities, amniocentesis was conducted, karyotype analysis or gene copy number variation (CNV) testing was performed, and the pregnancy outcome was tracked. RESULTS: Among 545 pregnant women in advanced maternal age, 11 cases had high risk of NIPT, and the detection rate was 2.02%. Among 11 pregnant women deemed to be at high risk for NIPT, 10 cases underwent amniotic fluid puncture, and one case refused amniocentesis despite a suggestive chromosomal abnormality in NIPT. The overall rate of amniocentesis was 1.83%. Among 11 pregnant women deemed to be at high risk for NIPT, the results suggested that 5 of them had trisomy 21, 1 had trisomy 18, 2 had sex chromosome abnormalities (specifically, 47, XYY), and 3 had other autosomal abnormalities. The positive predictive values of NIPT were 100.00% for the cases of trisomy 21 and trisomy 18, while the values were 0.00% for the cases of sex chromosome abnormalities and other autosomal abnormalities, respectively. After the follow-up, each of the 6 cases that were diagnosed with definite chromosomal abnormalities during prenatal screening opted to induce labor and terminate the pregnancy, including 5 cases that exhibited a high risk of trisomy 21 (47, XN,+21) and 1 case that showed a high risk of trisomy 18 (47, XN,+18). One instance of NIPT indicated a potential abnormality in the sex chromosomes, the individual declined to undergo amniocentesis. Another instance of NIPT suggested a sex chromosome abnormality, amniocentesis revealed a deletion of 0.72 Mb in the 4q22.1 region. They all had normal pregnancies and normal newborns. The remaining three cases had normal prenatal diagnoses (46, XN) and experienced normal pregnancies with healthy neonatal outcomes. CONCLUSIONS: NIPT has demonstrated its efficacy as a screening tool in the face of increasing maternal age. As a result, it can substantially decrease the requirement for invasive prenatal diagnosis. Nonetheless, there are instances of erroneous positive outcomes in NIPT testing, and therefore, interventional prenatal diagnosis remains necessary for individuals with high-risk screening outcomes to prevent false positives or unwarranted labor induction.

Pregnancy outcome analysis of 94 patients with pulmonary arterial hypertension during pregnancy.

OBJECTIVE: The aim of the study was to analyze the pregnancy outcomes of patients with pulmonary arterial hypertension to provide a reference for clinical diagnosis and treatment. PATIENTS AND METHODS: Clinical data of 94 patients with a pregnancy complicated by pulmonary hypertension were retrospectively analyzed. The means and percentages of the pregnancy outcomes were calculated, and the analysis of variance, Chi-square test, and Fisher's exact test were applied for comparison. RESULTS: The pregnancy outcomes were less favorable in the severe pulmonary arterial hypertension group compared to the mild and moderate groups. The more severe the pulmonary arterial hypertension, the worse the heart function. A poorer heart function was associated with a poorer prognosis across different pregnancy outcomes. CONCLUSIONS: A pregnancy with more severe pulmonary arterial hypertension and worse cardiac function has a poorer maternal and infant prognosis and pregnancy outcome. Cesarean section is the preferred delivery method for patients with severe pulmonary arterial hypertension, whereas vaginal delivery is preferred for patients with mild or moderate pulmonary arterial hypertension and good cardiac function.

Analysis results of 579 cases of genomic copy number variation sequencing of pregnant women in prenatal diagnosis.

OBJECTIVE: This study explored the usefulness of genomic copy number variation sequencing (CNV-Seq) in the prenatal diagnosis of pregnant women. PATIENTS AND METHODS: Based on prenatal diagnostic indications, CNV-Seq analysis was done in the samples from the 579 pregnant women of the 7 subgroups that included advanced maternal age (group A), high risk noninvasive prenatal test (NIPT) (group B), high risk Down's (Group C), abnormal ultrasound findings (Group D), adverse pregnancy history (Group E), chromosome abnormalities in couples (Group F), and the mixed group (Group G). RESULTS: A total of 57 (9.84%) cases have abnormal CNV-Seq results. Among them, 21 cases were aneuploid chromosomal number abnormalities (3.63%, 21/579), and 36 cases were CNV abnormalities (6.22%, 36/579), including 7 cases of pathogenic copy number alteration (pCNA) (1.21%, 7/579) and 29 cases variants of uncertain significance (VUS) (5.01%, 29/579). The total detection rates of abnormal CNV-Seq in Group G and Group B were 20.27% (15/74) and 15.91% (14/88), which were significantly higher than those in other groups (p < 0.05). Among 36 cases of abnormal CNV-Seq, 7 cases were chromosome fragment deletion or duplication, which were pathogenic CNV, and some rare chromosomal diseases were detected. CONCLUSIONS: Patients with a high risk of NIPT or multiple indications of prenatal diagnosis are highly suspected of chromosomal diseases. CNV-Seq is a useful tool for detecting chromosome abnormalities for prenatal diagnosis of pregnant women more accurately and provides more comprehensive information for prenatal diagnosis to reduce birth defects.

Analysis results of 169 cases of chorionic villus samples of missed abortion using high throughput sequencing.

OBJECTIVE: This study aimed to evaluate the use of high-throughput sequencing (HTS) technology to detect chromosomes in chorionic villus samples of missed abortion embryos and investigate its utility in the genetic diagnosis of missed abortion. PATIENTS AND METHODS: HTS was used to assess chorionic villus samples obtained from 169 patients with missed abortions from August 2020 to March 2022, at the Second Affiliated Hospital of Guangxi Medical University. The test results were statistically analyzed. To investigate the impact of advanced age on the incidence of chromosomal abnormalities, the patients were divided into two groups: elderly (≥35 years) and nonelderly pregnant women (<35 years). RESULTS: (1) Among the samples of 169 patients, 100 (59.17%) cases of chromosomal abnormalities were detected. Among these 100, 90 (90%) had chromosomal numerical abnormalities and 10 (10%) had chromosomal structural abnormalities. (2) Chromosomal numerical abnormality was abnormalities mainly included aneuploidy (92.22%, 83/90), with trisomy (62.22%, 56/90) and monosomy (22.22%, 20/90) accounting for the majority. The top three numerical abnormalities included 18 cases of Turner syndrome (monosomy X; 20%, 18/90), 10 cases of trisomy 16 (11.11%, 10/90), and 10 cases of trisomy 22 (11.11%, 10/90). (3) Villous chromosomal abnormalities were found in 48 (70.59%) elderly pregnant women, and 52 (51.48%) nonelderly pregnant women, with statistically significant differences (p < 0.05). CONCLUSIONS: (1) Chromosomal abnormality is an important cause of missed abortion, it majorly includes chromosomal numerical abnormality, of which most cases are of aneuploidy. (2) Advanced age may increase the risk of embryonic chromosomal abnormalities. (3) Villus chromosome detection using HTS has a positive value and can be used for analyzing and determining the causes of missed abortion.

[Advance in the research of graphene and its derivatives in wound dressings].

Graphene, as a new two-dimensional nanomaterial, is isolated and prepared for various industries application, which has become a hot research topic at present. It is also used in biomedicine for drug carriers, biological detection, cancer treatment, and tissue engineering. Graphene and its derivatives have great potential in the application of wound dressings attributed to the unique and good properties, including self-antibacterial property and antibacterial property in combination with different substances, excellent mechanical property, biocompatibility, etc. This article reviews the research of graphene and its derivatives in wound dressings.

[Study of iron overload assessment by T2* magnetic resonance imaging in patients with myelodysplastic syndromes].

Objectives: To analyze the cardiac T2* value, liver iron concentration (LIC) , and related laboratory parameters in myelodysplastic syndrome (MDS) with iron overload and evaluate the changes of organ functions after iron chelation therapy. To explore the value of magnetic resonance imaging (MRI) T2* in making early diagnosis and assessing organs iron overload. Methods: Retrospective investigation was used to observe the cardiac T2* value, LIC, iron metabolism parameters and related laboratory parameters of 85 MDS patients from Nov 2014 to Jan 2018. Among them, 7 MDS patients with Low/Int-1 have received iron chelation therapy for 6 months during two MRI examinations. The above parameters were collected before and after iron chelation therapy for comparison. Results: Correlations were found between heart T2* value and age (rs=-0.290, P=0.007) and left ventricular ejection fraction (LVEF) (rs=0.265, P=0.009) . There was a significant negative correlation between heart T2* value and blood transfusion units (rs=-0.701, P<0.001) . There was a significant positive correlation between LIC and serum ferritin (SF) (rs=0.577, P<0.001) . There was also a correlation between LIC and ALT (rs=0.268, P=0.014) and blood transfusion units (rs=0.244, P=0.034) . There was no correlation between heart T2* and pro-BNP, SF (all P>0.05) , and no correlation between LIC and age (P>0.05) . The increase of heart T2* between the normal and abnormal groups was statistically significant (P=0.005) , but the iron overload ratio of the heart T2*<20 ms was not significant between the two groups. There was statistical significance in the proportion of severe liver iron overload (LIC>15 mg/g DW) (P=0.045) . After iron chelation therapy, the values of SF, transferrin saturation, ALT, AST, pro-BNP and LIC of 7 patients were decreased compared with values before iron chelation therapy, and the peripheral blood cell level was increased. However, the changes of LVEF and T2* values after iron chelation were not obvious. Conclusion: MRI T2* may be a predictor of iron overload in patients with MDS in early stage, and may be more valuable compare with LVEF, SF and other laboratory indicators. The safety and repeatability of MRI cardiac T2* examination are recognized, and it can be used as an ideal detection for patients with iron overload.

Spatiotemporal characteristics of neural activity in tibial nerves with carbon nanotube yarn electrodes.

BACKGROUND: Reliable interfacing with peripheral nervous system is essential to extract neural signals. Current implantable peripheral nerve electrodes cannot provide long-term reliable interfaces due to their mechanical mismatch with host nerves. Carbon nanotube (CNT) yarns possess excellent mechanical flexibility and electrical conductivity. It is of great necessity to investigate the selectivity of implantable CNT yarn electrodes. NEW METHOD: Neural interfaces were fabricated with CNT yarn electrodes insulated with Parylene-C. Acute recordings were carried out on tibial nerves of rats, and compound nerve action potentials (CNAPs) were electrically evoked by biphasic current stimulation of four toes. Spatiotemporal characteristics of neural activity and spatial selectivity of the electrodes, denoted by selectivity index (SI), were analyzed in detail. RESULTS: Conduction velocities of sensory afferent fibers recorded by CNT yarn electrodes varied between 4.25 m/s and 37.56 m/s. The SI maxima for specific toes were between 0.55 and 0.99 across seven electrodes. SIs for different CNT yarn electrodes are significantly different among varied toes. COMPARISON WITH EXISTING METHODS: Most single CNT yarn electrode with a ∼ 500 µm exposed length can be sensitive to one or two specific toes in rodent animals. While, it is only possible to discriminate two non-adjacent toes by multisite TIME electrodes. CONCLUSION: Single CNT yarn electrode exposed ∼ 500 µm showed SI values for different toes comparable to a multisite TIME electrode, and had high spatial selectivity for one or two specific toes. The electrodes with cross section exposed could intend to be more sensitive to one specific toe.

Dietary supplementation with arginine and glutamic acid enhances key lipogenic gene expression in growing pigs.

Our previous study showed dietary supplementation with Arg and Glu increased intramuscular fat deposition and decreased back fat thickness in pigs, suggesting that the genes involved in lipid metabolism might be regulated differently in muscle and s.c. adipose (SA) tissues. Sixty Duroc × Large White × Landrace pigs with an average initial BW of 77.1 ± 1.3 kg were randomly assigned to 1 of 5 treatment groups (castrated male to female ratio = 1:1). Pigs in the control group were fed a basic diet, and those in experimental groups were fed the basic diet supplemented with 2.05% alanine (isonitrogenous group), 1.00% arginine (Arg group), 1.00% glutamic acid + 1.44% alanine (Glu group), or 1.00% arginine + 1.00% glutamic acid (Arg+Glu group). Fatty acid percentages and mRNA expression levels of the genes involved in lipid metabolism in muscle and SA tissues were examined. The percentages of C14:0 and C16:0 in the SA tissue of Glu group pigs and C14:0 in the longissimus dorsi (LD) muscle of Glu and Arg+Glu groups decreased ( < 0.05) compared to the basic diet group. The Arg+Glu group showed the highest ( < 0.05) hormone-sensitive lipase expression level in SA tissue and higher ( < 0.05) mRNA levels of in the LD muscle than the basic diet and isonitrogenous groups. Additionally, the mRNA level of fatty acid synthase in the Arg+Glu group was more upregulated ( < 0.05) than that of the Arg group. An increase in the mRNA level of in the biceps femoris muscle was also observed in the Arg+Glu group ( < 0.05) compared with the basic diet and isonitrogenous groups. Collectively, these findings suggest that dietary supplementation with Arg and Glu upregulates the expression of genes involved in adipogenesis in muscle tissues and lipolysis in SA tissues.

[Study of abnormal iron metabolism parameters and iron overload in patients with myelodysplastic syndromes].

Objective: To investigate the abnormalities of iron metabolism parameters, the prevalence and risk factors of iron overload and clinical characteristics of patients with myelodysplastic syndromes(MDS). Methods: Retrospective investigation was used to observe abnormal iron metabolism parameters and clinical characteristics of newly diagnosed 94 MDS patients in our center from June 2015 to March 2016. Results: Of 94 patients, 71(75.53%)had a hemoglobin level of less than 100 g/L at diagnosis. Iron overload was observed in 52(55.32%)of 94 MDS patients, in which a higher prevalence of iron overload was observed in low risk groups(IPSS low/Int-1 risk groups)than higher risk groups(Int-2/high risk groups). Higher levels of serum iron(SI)[36.5(8.5-64.7)mmol/L vs 25.2(3.7-45.3)mmol/L, P<0.01], transferrin saturation(TSAT)[43.5(12.2-77.2)% vs 53.4(14.8-97.5)%, P <0.01]and serum ferritin(SF)were observed in iron overload group. No differences of labile cellular iron(LCI)and reactive oxygen species(ROS)were observed between two groups(P=0.88, P=0.06). As the results of clinical complication of iron overload, alanine aminotransferase(ALT)[25(3-158)U/L vs 16(5-80)U/L, P=0.03]and type B natriuretic peptide precursor(proBNP)[190(6-4281)ng/L vs 84(12-2 275)ng/L, P= 0.05]levels were increased in iron overload group. There was no significant difference in iron metabolism parameters between patients with refractory anemia(RARS)and non RARS patients(P>0.05). Both frequency and volume of RBC transfusion had a significant effect on all iron metabolism parameters(SI, TSAT and SF)(P <0.01)except LCI and ROS. Excluded the patients with history of blood transfusion and SF levels over 1 000 µg/L, higher levels of LCI were mainly observed in dysplastic erythropoiesis and increased bone marrow erythroblasts ratio groups(P<0.01, P<0.05). Conclusion: The main cause of iron overload in MDS is chronic transfusion therapy. Both frequency and intensity of transfusion regimen have a main effect on iron metabolism parameters. LCI levels are mainly increased in newly diagnosed patients with the abnormalities of iron metabolism and have a stronger association with dysplastic erythropoiesis and increased bone marrow erythroblasts ratio. As the toxic fraction of iron and its negative impact on MDS, iron overload monitoring and chelation treatment decision can also be supported by LCI.

[miR-202 contributes to sensitizing MM cells to drug significantly via activing JNK/SAPK signaling pathway].

Objective: To explore the role of miR-202 in multiple myeloma (MM) cells, and study the regulation of miR-202 on drug sensitivity of MM cells. Methods: miR-202 and BAFF mRNA levels were detected by real-time PCR. U266 cells were transfected with miR-202-mimics, miR-202-inhibitor, siBAFF and their negative controls. After above treatments, protein levels of Bcl-2 family and MAPK signaling pathway were detected by Western blot analysis, and the proliferation and apoptosis ability of MM cells were examined by WST-1, Annexin V-FLUOS assay, respectively. Results: The results showed that the expression of miR-202 in CD138+ MM cells (0.304±0.354) and U266 cells (0.052± 0.009) were lower than in normal controls (3.550 ± 1.126) (P<0.001, P=0.009), whereas BAFF mRNA levels (5.700 ± 0.734, 9.576 ± 2.887) were higher than in normal controls (1.819 ± 0.853) (P<0.001, P= 0.006). The proliferation ability of U266 cells transfected with miR-202 mimics was significantly inhibited than in control group [(56.04±0.021)% vs (18.89±0.32)%, P=0.002]. The result of Western blot showed that the expression of Bcl-2 decreased by about 24%, and the expression of Bax increased by about 124% in cells transfected with miR-202 mimics. The apoptosis rate in cells transfected with miR-202 mimics was significantly more than in control group [(49.60±4.89)% vs (26.20±1.28)%, P=0.029]. The apoptosis rate in miR-202 mimics combined with Bort group (51.23±5.41)% was higher as compared with Bort treatment alone (31.70±4.40)% or miR-202 mimics control combined with Bort group (27.94±4.04)%, (P=0.047, P= 0.028), whereas the apoptosis rate in miR-202 mimics combined with Thal or Dex had no significant difference compared with miR-202 mimics control [(11.66±1.91)% vs (10.63±1.74)%, P=0.700; (16.35± 1.32)% vs (17.43 ± 1.95)%, P=0.400]. The inhibitory rate of cell growth in miR-202 mimics combined with Bort group was higher as compared with Bort treatment alone [(36.93±5.98)% vs (18.18±4.10)%, P= 0.029]. The expressions of p-JNK protein decreased in U266 cells transfected with miR-202 mimics and treated with Bort. Conclusion: miR-202 mimics combined with Bort could inhibit proliferation and induce apoptosis of U266 cells through negative regulating target gene BAFF, which further inhibited the JNK/SAPK signaling pathway.

Genetic and molecular analysis of the SOE1 gene: a tRNA(3Glu) missense suppressor of yeast cdc8 mutations.

The CDC8 gene of Saccharomyces cerevisiae encodes deoxythymidylate (dTMP) kinase and is required for nuclear and mitochondrial DNA replication in both the mitotic and meiotic cell cycles. All cdc8 temperature-sensitive mutants are partially defective in meiotic and mitochondrial functions at the permissive temperature. In a study of revertants of temperature-sensitive cdc8 mutants, the SOE201 and SOE1 mutants were isolated. The SOE201 mutant is a disome of chromosome X to which the cdc8 gene maps. Using the chromosome X aneuploids to vary cdc8 gene dosage, we demonstrate that different levels of dTMP kinase activity are required for mitotic, meiotic or mitochondrial DNA replication. The SOE1 mutant contains a dominant suppressor that suppresses five different cdc8 alleles but does not suppress a complete cdc8 deletion. The SOE1 gene is located less than 1.5 cM from the CYH2 gene on chromosome VII and is adjacent to the TSM437-CYH2 region, with the gene order being SOE1-TSM437-CYH2. SOE1 is an inefficient suppressor that can neither suppress the cdc8 hypomorphic phenotype nor restore dTMP kinase activity in vitro. SOE1 is a single C to T mutation in the anticodon of a tRNA(3Glu) gene and thereby, produces a missense suppressor tRNA capable of recognizing AAA lysine codons. We propose that the resultant lysine to glutamate change stabilizes thermo-labile dTMP kinase molecules in the cell.

Influence of hyperthyroidism on glycerol-extracted cardiac muscle from rabbits.

The mechanism responsible for the enhancement of myocardial contractility in hyperthyroidism is unclear. The possibility that this mechanism may involve a direct effect on the contractile proteins was investigated using the glycerol-extracted muscle strip from right ventricular papillary muscles of euthyroid rabbits and rabbits made hyperthyroid by the intraperitoneal injection of 0.25 mg/kg 1-thyroxine for 10 d. Intact papillary muscles from the hyperthyroid rabbits had an enhanced rate of tension development, a decreased time to peak tension, and a slight though insignificant increase in active tension compared to control animals. Maximal isometric contractions were induced in glycerol-extracted cardiac muscle strips from the two animal groups by the addition of 5 mmol/litre ATP and 5 mmol/litre MgCl in a buffer solution containing 0.15 mol/litre Tris-HCl (pH 7.1) at 26 degrees C. Peak isometric tension was increased in glycerinated muscle strips from hyperthyroid rabbits (1.52+/-0.10 vs 1.26 +/-0.13g/mm2), but the differences did not reach statistical significance. However, there was a marked increase in the rate of tension development in the hyperthyroid group (62.5+/-5.4 vs 41.8+/-4.7 mg/mm-2/s, P less than 0.01). This increase in the rate of isometric tension development in both intact and glycerinated muscles from hyperthyroid rabbits may be related to changes in the intrinsic turnover of actomyosin cross-bridge links in this condition. Thus, these findings suggest that thyroid hormone may influence cardiac muscle function by a direct effect on the contractile proteins.

Identification of a Xenopus cDNA that prevents mitotic catastrophe in the fission yeast Schizosaccharomyces pombe.

A Xenopus total ovary cDNA library was constructed in a fission yeast expression vector. Using a genetic functional complementation method, we have identified a Xenopus cDNA clone that can rescue several different yeast mitotic catastrophe mutants defective in Wee1 kinase function at the restrictive temperature. The 3.0-kb cDNA clone contains an open reading frame (ORF) of 2226 nucleotides, encoding a predicted 82-kDa protein. The deduced amino acid (aa) sequence shows seven almost identical 30-aa tandem repeats, each of which contains a phosphorylation site meeting the consensus for both Cdc2 kinase and MAP kinase.

Salutary effects of nitrendipine, a new calcium entry blocker, in hemorrhagic shock.

Intracellular accumulation of calcium is thought to play an integral role in the progression of ischemic injury and cell death. We infused the calcium entry blocker, nitrendipine (1.5 micrograms/kg per min), into cats in order to investigate the importance of extracellular Ca2+ influx during hemorrhagic shock. Nitrendipine proved to be a potent hypotensive agent in sham shock cats when infused over a 4 h period (156 +/- 9 to 90 +/- 5 mm Hg) (P less than 0.01). However, in hemorrhaged animals, nitrendipine treatment maintained the post-reinfusion MABP at a significantly higher (P less than 0.01) value than untreated controls (79 +/- 5 vs. 51 +/- 4 mm Hg, respectively). Superior mesenteric artery flow (SMAF) for hemorrhaged animals treated with nitrendipine was significantly higher (9.8 +/- 1.4 ml/min per kg) (P less than 0.01) than that for untreated cats (4.2 +/- 0.4 ml/min per kg), at 2 h post reinfusion. There was no significant increase in SMAF during oligemia in the nitrendipine-treated animals. Nitrendipine was also found to significantly retard the appearance of cathepsin D in the plasma of hemorrhaged cats as well as reduce plasma proteolysis to values not significantly different from sham shock animals. Furthermore, myocardial depressant factor (MDF) activity in the plasma of nitrendipine-treated shock cats was not significantly different from sham shock animals, while the plasma MDF activity for shock cats receiving vehicle increased 3-fold (P less than 0.001). The beneficial effects for nitrendipine in hemorrhagic shock are likely due to both its vasodilator function and its ability to reduce intracellular Ca2+ accumulation during ischemia, thereby reducing disruption of cell membrane systems.

Reduction of H2O2-evoked, intracellular calcium increases in the rat N18-RE-105 neuronal cell line by pretreatment with an electrophilic antioxidant inducer.

Pretreatment of the neuronal cell line N18-RE-105 with the antioxidant enzyme inducer dimethyl fumarate (DMF) reduced cell death elicited by H2O2 (50 mM for 1 h) as measured 24 h after H2O2 washout. Oxidants like H2O2 may contribute to cell death by increasing intracellular ionized calcium ([Ca2+]i), suggesting that DMF may in part confer protection by altering H2O2-induced [Ca2+]i signals. To examine this possibility, we measured [Ca2+]i of fura-2-loaded cultures of DMF- and vehicle-pretreated cells during H2O2 superfusion. H2O2 exposure induced a delayed [Ca2+]i increase that was significantly lower in DMF-pretreated cells than controls. Elevation of extracellular cystine also reduced the H2O2 induced [Ca2+]i elevation. Thus, antioxidant upregulation may contribute to protection during oxidative stress by stabilizing [Ca2+]i. However, since oxidative stress may induce cytotoxicity by multiple pathways, [Ca2+]i stabilization may not be the only mechanism responsible for the protective effect of DMF.

Intracellular mechanisms of verapamil and diltiazem action on striated muscle of the rabbit.

Skinned fibers from striated muscle were used to study the intracellular mechanisms (contractile proteins and sarcoplasmic reticulum [SR]) of action of diltiazem (DT) and verapamil (VP) on muscle contraction. Rabbit papillary muscle (PM), and the skeletal muscles adductor magnus (AM, fast-twitch) and soleus (SL, slow-twitch) were used. The muscles were skinned by homogenization and fibre bundles for PM and single fibres for AM and SL were dissected from the homogenate and mounted on photodiode force transducers. VP (0.1-3.0 mmol/l) (and to a lesser degree DT) increased Ca2+-activated tension development of the contractile protains in PM and SL and decreased it in AM (+[4-20]%, +4%, -[14-28]%, respectively). Both drugs increased the submaximal Ca2+-activated tension development at the order of PM = SL greater than AM in a dose-dependent manner. The changes of half-maximal pCa50 at 1 mmol/l VP were 0.25, 0.25, and 0.15, respectively. For Ca2+ uptake and release from the SR, VP as well as DT (0.1-3.0 mmol/l) in the uptake phase decreased caffeine-induced tension transients in a dose-dependent fashion. At 0.01-3.0 mmol/l, the drugs directly induced Ca2+ release from the SR or enhanced caffeine-induced tension transients with the exception that in PM, DT attenuated caffeine-induced tension transients. Thus, VP and DT have similar intracellular mechanisms of action in striated muscle. Both drugs induced calcium release from the SR and increase Ca2+ sensitivity of the contractile proteins, and thus could be the underlying mechanisms for potentiating twitch tension, and inducing contracture in skeletal muscle.