A High Efficiency, Low Resistance Antibacterial Filter Formed by Dopamine-Mediated In Situ Deposition of Silver onto Glass Fibers

The coating of filter media with silver is typically achieved by chemical deposition and aerosol processes. Whilst useful, such approaches struggle to provide uniform coating and are prone to blockage. To address these issues, an in situ method for coating glass fibers is presented via the dopamine-mediated electroless metallization method, yielding filters with low air resistance and excellent antibacterial performance. It is found that the filtration efficiency of the filters is between 94 and 97% and much higher than that of silver-coated filters produced using conventional dipping methods (85%). Additionally, measured pressure drops ranged between 100 and 150 Pa, which are lower than those associated with dipped filters (171.1 Pa). Survival rates of Escherichia coli and Bacillus subtilis bacteria exposed to the filters decreased to 0 and 15.7%±1.49, respectively after 2 h, with no bacteria surviving after 6 h. In contrast, survival rates of E. coli and B. subtilis bacteria on the uncoated filters are 92.5% and 89.5% after 6 h. Taken together, these results confirm that the in situ deposition of silver onto fiber surfaces effectively reduces pore clogging, yielding low air resistance filters that can be applied for microbial filtration and inhibition in a range of environments.

Bioinspired Structures Made of Silicone Nanofilaments for Upcycling Waste Masks to Reusable N95 Respirators

The increasing demand for personal protective equipment such as single-use masks has led to large amounts of nondegradable plastic waste, aggravating economic and environmental burdens. This study reports a simple and scalable approach for upcycling waste masks via a chemical vapor deposition technique, realizing a trichome-like biomimetic (TLB) N95 respirator with superhydrophobicity (water contact angle ≥150°), N95-level protection, and reusability. The TLB N95 respirator comprising templated silicone nanofilaments with an average diameter of ∼150 nm offers N95-level protection and breathability comparable to those of commercial N95 respirators. The TLB N95 respirator can still maintain its N95-level protection against particulate matter and viruses after 10 disinfection treatment cycles (i.e., ultraviolet irradiation, microwave irradiation, dry heating, and autoclaving), demonstrating durable reusability. The proposed strategy provides new insight into upcycle waste masks, breaking the existing design and preparation concept of reusable masks.

Trichome-Like Biomimetic Air Filters via Templated Silicone Nanofilaments

Air pollution threats to human health have increased awareness of the role of filter units in air cleaning applications. As an ideal energy-saving strategy for air filters, the slip effect on nanofiber surfaces can potentially overcome the trade-off between filtration efficiency and pressure drop. However, the potential of the slip effect in nanofibrous structures is significantly limited by the tight nanofiber stacks. In this study, trichome-like biomimetic (TLB) air filters with 3D-templated silicone nanofilaments (average diameter: ≈74 nm) are prepared based on an in situ chemical vapor deposition (CVD) method inspired by plant purification. Theoretical modeling and experimental results indicate that TLB air filters make significant use of the slip effect to overcome the efficiency-resistance tradeoff. The selectable filter class (up to U15, ≈99.9995%) allows TLB air filters to meet various requirements, and their integral filtration performance surpasses that of most commodity air filters, including melt-blown cloth, ePTFE membranes, electrospun mats, and glass fiber paper. The proposed strategy directly transforms commercial filter media and filters into TLB air filters using a bottom-up, one-step approach. As a proof-of-concept, reusable N95 respirators and air purifiers equipped with TLB air filters are fabricated, overcoming the limitations of existing filter designs and fabrication methods.

[Effect of continuous blood purification for acute renal injury after acute Stanford type A aortic dissection]

Objective: To investigate the effect of continuous renal replacement therapy (CRRT) on acute kidney injury (AKI) after acute Stanford type A aortic dissection (ATTAD). Methods: In this study, 120 patients with AKI after ATTAD surgery treat in Gansu Provincial People's Hospital were selected as research objects. Among them, there were 86 males (71.7%) and 34 females (28.3%) with a mean age of (55±5) years. These patients were randomly divided into experimental group (n=60) and control group (n=60) with stratified random sampling. CRRT and intermittent hemodialysis (IHD) were performed in the experimental group and the control group respectively. The therapeutic effect of CRRT on ATTAD patients with AKI was evaluated by blood purification index, renal function index, Sequential Organ Failure Assessment (SOFA) score, inflammatory level, hemodynamic index and fluid infusion volume. Results: The two treatment schemes both had considerable therapeutic effects on the condition of patients, but the therapeutic effect of CRRT was more superior. In the patients treated with CRRT, the levels of serium creatinine (SCr), blood urea nitrogen (BUN) and blood lactic acid (Lac) were all lower than those in the control group (all P<0.05). The time of staying in intensive care units (ICU), the period of oliguria, the times of renal replacement therapy, the time from the first dialysis to the last dialysis and the total hospital stay in the experimental group were all shorter than those in the control group (all P<0.05). The volume of fluid infusion was less and the hemodynamic index was better than that in the control group, but there was no significant difference in hospital mortality between the two groups (P>0.05). The levels of interleukin (IL)-6, IL-8 and C-reactive protein (CRP) in the experimental group were (21.9±1.8) ng/L, (18.6±1.4) ng/L and (22.7±2.2) mg/L, respectively, which were all significantly lower than those in control group ((27.9±3.2) ng/L, (28.3±1.4) ng/L, (60.1±2.5)mg/L, respectively; t=14.527, 13.255, 11.247, all P<0.05). The scores of SOFA at all time points in the experimental group were all lower than those in the control group (all P<0.05). Conclusion: Compared with IHD, CRRT brings no significant reduction in hospital mortality in patients with AKI after ATTAD, but shows better prognosis.

MiR-21 regulates pulmonary hypertension in rats via TGF-β1/Smad2 signaling pathway

OBJECTIVE

To investigate the effects of micro ribonucleic acid (miR)-21 on pulmonary hypertension (PH) in rats via regulating tumor growth factor-β1 (TGF-β1)/mothers against decapentaplegic homolog 2 (Smad2) signaling pathway and the possible underlying mechanism.

MATERIALS AND METHODS

MiR-21 inhibition vector (pLKO-anti-miR-21) was first constructed. The rat model of PH was established by hypoxia feeding induction. A total of three groups were established, including: blank control group, model group and miR-21 low-expression group were set up, with 12 rats in each group. The expression level of miR-21 in lung tissues of rats in each group was detected via quantitative polymerase chain reaction (qPCR). The right ventricle systolic pressure (RVSP) and right ventricular hypertrophy index (RVHI) of rats in each group were measured. The pathological changes in lung tissues of rats were detected using hematoxylin and eosin (H&E) staining. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was used to detect the level of apoptosis in lung tissues of rats in each group. Furthermore, Western blotting was adopted to detect the expression levels of TGF-β1/Smad2 signal pathway-related proteins and apoptosis-related proteins in lung tissues of rats in each group.

RESULTS

Compared with blank control group, the expression level of miR-21 in lung tissues of rats in model group was significantly increased (p<0.01). Meanwhile, miR-21 expression in lung tissues of rats in miR-21 low-expression group was significantly decreased by transfection of miR-21 inhibition vector (p<0.01). The RVSP and RVHI of rats in model group were significantly higher than those of blank control group and miR-21 low-expression group (p<0.01). H&E staining results indicated that the degree of lung tissue injury in model group was remarkably higher than blank control group and miR-21 low-expression group (p<0.01). According to TUNEL staining results, the number of apoptotic cells in lung tissues of rats in model group was markedly smaller than that of miR-21 low-expression group (p<0.01). Moreover, the expression level of Caspase 3 in lung tissues of rats in model group was significantly lower than that of miR-21 low-expression group, while the expression level of B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X protein (BAX) was markedly higher. The expression levels of TGF-β1 and phosphorylated (p)-Smad2 in lung tissues of rats in model group were evidently higher than those of blank control group (p<0.01). In addition, lowly expressed miR-21 could effectively reduce the expressions of TGF-β1 and p-Smad2 (p<0.01).

CONCLUSIONS

MiR-21 regulates the symptoms of PH in rats by activating TGF-β1/Smad2 signaling pathway.

MiR-21 regulates pulmonary hypertension in rats via TGF-β1/Smad2 signaling pathway

The article "MiR-21 regulates pulmonary hypertension in rats via TGF-β1/Smad2 signaling pathway, by F. Ding, T. You, X.-D. Hou, K. Yi, X.-G. Liu, P. Zhang, X.-K. Wang, published in Eur Rev Med Pharmacol Sci 2019; 23 (9): 3984-3992-DOI: 10.26355/eurrev_201905_17828-PMID: 31115027" has been withdrawn from the authors. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/17828.

Clinical and molecular insights into Glanzmann's thrombasthenia in China

Glanzmann's thrombasthenia (GT) is a rare bleeding disorder characterized by spontaneous mucocutaneous bleeding. The disorder is caused by quantitative or qualitative defects in integrin αIIbβ3 (encoded by ITGA2B and ITGB3) on the platelet and is more common in consanguineous populations. However, the prevalence rate and clinical characteristics of GT in non-consanguineous populations have been unclear. We analyzed 97 patients from 93 families with GT in the Han population in China. This analysis showed lower consanguinity (18.3%) in Han patients than other ethnic populations in GT-prone countries. Compared with other ethnic populations, there was no significant difference in the distribution of GT types. Han females suffered more severe bleeding and had a poorer prognosis. We identified a total of 43 different ITGA2B and ITGB3 variants, including 25 previously unidentified, in 45 patients. These variants included 14 missense, 4 nonsense, 4 frameshift, and 3 splicing site variants. Patients with the same genotype generally manifested the same GT type but presented with different bleeding severities. This suggests that GT clinical phenotype does not solely depend on genotype. Our study provides an initial, yet important, clinical and molecular characterization of GT heterogeneity in China.

Respiratory signal prediction based on adaptive boosting and multi-layer perceptron neural network

To improve the prediction accuracy of respiratory signals using adaptive boosting and multi-layer perceptron neural network (ADMLP-NN) for gated treatment of moving target in radiation therapy. The respiratory signals acquired using a real-time position management (RPM) device from 138 previous 4DCT scans were retrospectively used in this study. The ADMLP-NN was composed of several artificial neural networks (ANNs) which were used as weaker predictors to compose a stronger predictor. The respiratory signal was initially smoothed using a Savitzky-Golay finite impulse response smoothing filter (S-G filter). Then, several similar multi-layer perceptron neural networks (MLP-NNs) were configured to estimate future respiratory signal position from its previous positions. Finally, an adaptive boosting (Adaboost) decision algorithm was used to set weights for each MLP-NN based on the sample prediction error of each MLP-NN. Two prediction methods, MLP-NN and ADMLP-NN (MLP-NN plus adaptive boosting), were evaluated by calculating correlation coefficient and root-mean-square-error between true and predicted signals. For predicting 500 ms ahead of prediction, average correlation coefficients were improved from 0.83 (MLP-NN method) to 0.89 (ADMLP-NN method). The average of root-mean-square-error (relative unit) for 500 ms ahead of prediction using ADMLP-NN were reduced by 27.9%, compared to those using MLP-NN. The preliminary results demonstrate that the ADMLP-NN respiratory prediction method is more accurate than the MLP-NN method and can improve the respiration prediction accuracy.

Concomitant mitral valve replacement and tricuspid valvuloplasty for severe mitral stenosis

OBJECTIVE

The purpose of this work is to analyze the clinical results of treating severe mitral stenosis (MS) with mild to moderate functional tricuspid regurgitation (FTR) with mitral valve replacement (MVR) alone or together with two different methods of tricuspid valvuloplasty (TVP).

PATIENTS AND METHODS

We split 132 patients into three groups: simple MVR with 47 cases (control group), MVR+ TVP (De Vega loop reduction) with 45 cases (observation group 1) and MVR+ TVP (Edwards MC3 tricuspid forming ring implantation) with 40 cases (observation group 2).

RESULTS

As expected, surgery for both observation groups was longer than for the control group, but we found no differences in aortic clamping time, cardiopulmonary bypass time, perioperative complications, and postoperative hospital stay. We found significantly fewer complications in both observation groups compared to the control group. After surgery, the diameter of the tricuspid valve ring and the maximum reflux bundle were significantly lower in the observation groups compared to the control group.

CONCLUSIONS

Overall, the long-term clinical effect of combined MVR and TVP to treat severe MS with mild to moderate FTR is better than using the simple MVR procedure. Our results also suggest that the Edwards MC3 tricuspid forming ring implantation is superior to the De Vega loop reduction.

[Correlation between morphogical factor of lateral plateau fracture and meniscus injury]

OBJECTIVE

To analyze morphological character of lateral tibial plateau fracture fragment, and its correlation to the presence of a meniscus injury in tibial plateau fractures.

METHODS

A total of 79 consecutive patients of the simple lateral tibial plateau fractures from July 2011 to July 2015 were included in this study, with 65 males and 14 females with an average age of (34.3±7.2) years and 22-61 years. According to Schatzker classification, 21 cases were of Type I, 41 cases Type II, and 17 cases Type III. The characteristics of lateral tibial plateau fractures were evaluated by plain X-ray and magnetic resonance imaging (MRI). The type and severity of meniscus injury were diagnosed by MRI scan. Three-dimensional measurements of the lateral fragment width (LFW), the lateral plateau depression (LPD), the coronal angulation of lateral fragment (CALF), and tibial plateau widening (TPW) were measured with Picture Archiving and Communication Systems(PACS) software. The patients with and without meniscus injuries were divided into different groups and analyzed respectively. Comparison of the above measurements between the two groups was analyzed by independent t test.

RESULTS

In all the 79 lateral tibial plateau fracture patients, 26 cases (32.9%) of meniscus injuries were detected by MRI. Among all the meniscus injury cases, 3 were of Schatzker I, 16 Schatzker II, and 7 Schatzker III. In meniscus intact group, the average LFW was (22.0±2.8) mm while in meniscus injury group it was (21.3± 3.3) mm (t=-1.008, P=0.317).The average LPD of non meniscus injury group was (5.4±2.8) mm, while in meniscus injury group was (8.7±2.8) mm (t=4.98, P=0.001). The average CALF of the two groups were 9.1°±6.1°and 10.6°± 7.1°, and there was no significant difference between the two groups (t=0.38, P=0.831). The average TPW was (3.0± 1.1) mm, and (4.8±1.7) mm of the two groups. There were significant differences between the two groups (t=5.216, P=0.001).

CONCLUSION

There was no obvious correlation between the LFD and meniscus injury. The CALF of lateral tibial plateau fracture had no significant correlation with meniscus injury either. The degree of LPD and TPW may indicate injury of the meniscus in tibial plateau fractures.

MiR-125b inhibits cell biological progression of Ewing's sarcoma by suppressing the PI3K/Akt signalling pathway

OBJECTIVES

Increasing evidence has suggested the close relationship between microRNAs (miRNAs) dysregulation and the carcinogenesis of Ewing's sarcoma (ES), among of which miR-125b has been reported to be decreased in ES tissues recently. Strikingly, ectopic expression of miR-125b could suppress cell proliferation of ES cell line A673, suggesting the tumor suppressor role of miR-125b in ES. However, the other accurate mechanistic functions and relative molecule mechanisms are largely unknown.

MATERIALS AND METHODS

Herein, we completed a series of experiments to investigate the role of miR-125b in Ewing's sarcoma. We restored the expression of miR-125b in ES cell line A673 through transfection with miR-125b mimics. To further understand the role of miR-125b in ES, we detected the effects of miR-125b on the cell proliferation, migration and invasion, cell cycle as well as cell apoptosis.

RESULTS

We found that restored expression of miR-125b in ES cell line A673 inhibited cell proliferation, migration and invasion, arrested cell cycle progression, and induced cell apoptosis. Moreover, bioinformatic prediction suggested the oncogene, phosphoinositide-3-kinase catalytic subunit delta (PIK3CD), was a target gene of miR-125b in ES cells. Further quantitative RT-PCR and western blot assays identified over-expression of miR-125b suppressed the expression of PIK3CD mRNA and protein. PIK3CD participates in regulating the PI3K signaling pathway, which has been reported to play an important role in the development of ES. Suppression of PIK3CD down-regulated the expression of phospho-AKT and phospho-mTOR proteins and inhibited the biologic progression of A673 cells.

CONCLUSIONS

Collectively, these data suggest that miR-125b functions as a tumor suppressor by targeting the PI3K/Akt/mTOR signaling pathway, and may provide potential therapy strategy for ES patients by targeting miRNA expression.

Abstract P4-04-09: Extensive novel hybrid isoforms revealed by RNA sequencing of 120 primary breast cancer samples

Introduction

Recent studies of next generation sequencing (NGS) have highlighted the extensive transcriptional heterogeneity of cancer cells. Alternative splicing is one of the evolutionary process by which cells and tissues achieve their specificity within central dogma. Also it is highly assumed to contribute to oncogenesis and thought to be a critical mechanism how cancer cells gain resistance to therapeutic agents and adapt to various circumstances. Relevance of differential splicing in breast cancer biology is mostly unknown. We performed whole transcriptome sequencing (RNA-Seq) to reveal novel splicing alterations among 120 primary breast cancer samples.

Materials and Method

Total RNA was prepared using the Illumina TrueSeq™ RNA sample Preparation Kit and TrueSeq mRNA library was constructed. Clustering and sequencing was done using Illumina HiSeq 2000. RNA-Seq reads were aligned to human reference genome(hg19) using TopHat software and expression was measured using cufflinks software. We used tissues extracted from previously collected 120 fresh-frozen primary breast cancer samples obtained after surgical resection whose clinicopathological data are available. Patients undergone neoadjuvant systemic therapies or stage lV disease at diagnosis were excluded. Thirty-six(30%) cases occurred distant metastasis during follow up. Hormone receptor(HR) was positive in 61(50.8%) samples, 20(16.7%) had HER2 oncogene overexpression and 36(30%) were triple negative breast cancer.

Results and discussion

Total 11345 novel isoforms were detected among 120 tumors. Isoforms of pseudo-genes and exon skipping of the ‘non-coding exon’ were excluded. Splice variants detected in normal reference were sorted out as well. 4045 were in-frame exon skipping and 4960 were off-frame exon skipping which may lead to protein truncation. 5036 were private exon skipping and 3969 isoforms were detected recurrently in more than 2 samples. To minimize false positivity we confined ‘exon skipping’ analysis to those with the expression level (Fragments per kilo-base of exon per million fragments mapped, FPKM) of the skipped exon below 0.1 compared to the adjacent exons. Mean number of exon skipping events per sample was 196.8 (range 75-299, SD 35.9). There were no differences in numbers of exon skipping event among breast cancer subtypes nor distant metastasis. We have identified novel exon skipping in ESR1, CHEK2, EIF3E, FGFR, MAP2K, PIK3R2, TERT, VAV3 genes which is strongly suspected to be novel driver isoforms and is under validation process.

Conclusion We performed whole-transcriptome sequencing with a large set of primary breast cancer samples and revealed extensive transcriptional heterogeneity by isoform profiling. As distinguishing the natural transcriptomic dynamics from oncogenic ‘driver’ isoform is a major challenge, validation and functional studies are ongoing.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-04-09.

Detection of hydrazine, methylhydrazine, and isoniazid by capillary electrophoresis with a palladium-modified microdisk array electrode

A palladium particle-modified carbon fiber microdisk array electrode was designed and employed in capillary electrophoresis for the simultaneous detection of hydrazine, methylhydrazine, and isoniazid. The Pd-modified microdisk electrode had high catalytic ability for hydrazines and exhibited good reproducibility and stability. The response for hydrazine was linear over 3 orders of magnitude with a correlation coefficient of 0.993. The detection limits for hydrazine, methylhydrazine, and isoniazid were 1.2, 2.1, and 6.2 pg, respectively.

Effects of disulfide bridges in domain I of Bacillus thuringiensis Cry1Aa delta-endotoxin on ion-channel formation in biological membranes

The delta-endotoxin family of toxic proteins represents the major component of the insecticidal capability of the bacterium Bacillus thuringiensis. Domain I of the toxins, which is largely alpha-helical, has been proposed to unfold at protein entry into the membrane of a target insect, following models known as the penknife and umbrella models. We extended the analysis of a previous work in which four disulfide bridges were constructed in domain I of the Cry1Aa delta-endotoxin that putatively prevented unfolding during membrane partitioning. Using bioassays and voltage clamping of whole insect midgut instead of artificial lipid bilayers, it was found that, while toxicity and inhibition of the short-circuit current were reduced, only one of the disulfide bridges eliminated the activity of the toxins in the insect midgut membrane, and in that case, the loss of toxicity was due to the single amino acid substitution, R99C. It is proposed that at least alpha helices 4, 5, 6, and 7 and domain II partition in the midgut membranes of target insects, in support of an insertion model in which the whole protein translocates into the midgut membrane.

Addition of aerobic exercise to dietary weight loss preferentially reduces abdominal adipocyte size

OBJECTIVE

To determine if hypocaloric diet, diet plus low-intensity exercise, and diet plus high-intensity exercise differentially influence subcutaneous abdominal and gluteal adipocyte size in obese individuals.

DESIGN

Longitudinal intervention study of hypocaloric diet, diet plus low-intensity exercise, and diet plus high-intensity exercise (calorie deficit = 2800 kcal/week, 20 weeks).

SUBJECTS

Forty-five obese, middle-aged women (BMI = 33.0+/-0.6 kg/m2, age = 58+/-1 years).

MEASUREMENTS

Body composition testing and adipose tissue biopsies were conducted before and after the interventions. Subcutaneous abdominal and gluteal adipocyte size was determined.

RESULTS

All three interventions reduced body weight, fat mass, percent fat, and waist and hip girths to a similar degree. Diet only did not change subcutaneous abdominal adipocyte size, whereas both diet plus exercise groups significantly reduced abdominal adipocyte size. Changes in abdominal adipocyte size in the diet plus exercise groups were significantly different from that of the diet group. Gluteal adipocyte size decreased similarly in all three groups.

CONCLUSION

Addition of exercise training to dietary weight loss preferentially reduces subcutaneous abdominal adipocyte size in obese women. This may be of importance for the treatment of health complications associated with subcutaneous abdominal adiposity.

Illuminated lens fixator for bimanual pars plana lensectomy

Pars plana vitrectomy and lensectomy are effective methods for removing posteriorly dislocated lens material. We describe an illuminated nucleus fixator that assists in the removal of posteriorly dislocated lens fragments. We tested the efficacy of the illuminated nucleus fixator compared to a standard endoilluminator in removing lens nuclei from the vitreous cavity of a cadaveric eye model. Use of the illuminated nucleus fixator as compared to a standard endoilluminator significantly reduced the time needed to remove lens nuclei from the vitreous cavity. This instrument could penetrate and fixate lens nuclei and could safely stabilize small and intermediate-sized lens fragments against the activated fragmatome. Bimanual lensectomy using the illuminated nucleus fixator significantly shortens the surgical time needed to remove posteriorly dislocated lens fragments. Shortening the surgical time for lensectomy may minimize such complications as retinal tears, trauma, and phototoxicity.

Characterisation of patients with primary biliary cirrhosis responding to long term ursodeoxycholic acid treatment

BACKGROUND

In some patients with primary biliary cirrhosis, ursodeoxycholic acid causes full biochemical normalisation of laboratory data; in others, indexes improve but do not become normal.

AIMS

To characterise complete and incomplete responders.

METHODS

Seventy patients with primary biliary cirrhosis were treated with ursodeoxycholic acid 10-15 mg/kg/day and followed up for 6-13 years.

RESULTS

In 23 patients (33%) with mainly stage I or II disease, cholestasis indexes and aminotransferases normalised within 1-5 years, except for antimitochondrial antibodies. Histological findings improved. Indexes were not normalised in 47 patients (67%) although the improvement of their biochemical functions parallelled the trend in the first group. In these incomplete responders histological findings improved to a lesser extent. The only difference between the two groups before treatment was higher levels of alkaline phosphatase and gamma glutamyl transpeptidase in the incomplete responders. At onset of treatment the discriminant value separating responders from incomplete responders was 660 U/l for alkaline phosphatase and 131 U/l for gamma glutamyl transpeptidase. One year later it was 239 and 27 U/l (overall predictive value for responders 92%, for incomplete responders 81%). There were no differences between the two groups concerning immune status, antimitochondrial antibody subtypes, liver histology, or any other data. HLA-B39, DRB1*08, DQB1*04 dominated in both groups.

CONCLUSIONS

In patients with mainly early stages of primary biliary cirrhosis, higher values of alkaline phosphatase and gamma glutamyl transpeptidase are the only biochemical indexes which allow discrimination between patients who will completely or incompletely respond to ursodeoxycholic acid treatment.

Detection of hydrazine, methylhydrazine and isoniazid by capillary electrophoresis with a 4-pyridyl hydroquinone self-assembled microdisk platinum electrode

Capillary electrophoresis (CE)/electrochemical detection (EC) for the simultaneous detection of hydrazine, methylhydrazine, and isoniazid has been developed with a 4-pyridyl hydroquinone self-assembled microdisk platinum electrode. Such an electrode has very high catalytic ability for hydrazines and they could be detected even at 0.0 V. The responses for hydrazine, methylhydrazine, and isoniazid are linear over 3 orders of detected concentration and of magnitude of 0.2-400 microM, 0.2-400 microM, 0.5 microM-2 mM, with correlation coefficients of 0.9998, 0.9991, and 0.9982, respectively. And they could be detected to levels of 0.1, 0.1 and 0.2 microM, respectively. This modified electrode was found to be very stable and reproducible when continuously used as detector for capillary electrophoresis for period of at least 4 weeks with no apparent loss of response.

Determination of sulfadiazine and sulfamethoxazole by capillary electrophoresis with end-column electrochemical detection

Capillary electrophoresis (CE) with end-column electrochemical detection (EC) of sulfadiazine (SDZ) and sulfamethoxazole (SMZ) is described. Under the optimum conditions, SDZ and SMZ were separated satisfactorily, and a highly sensitive and stable response was obtained at a potential of 1.1 V versus Ag/AgCl. Optimized end-column detection provides detection limits as low as 0.1 microM for both compounds, which corresponds to 0.024 and 0.021 fmol with peak efficiencies of 394,000 and 335,000 theoretical plates for SDZ and SMZ, respectively. The calibration graph was linear over three order of magnitude. The relative standard deviations (n = 12) of peak currents and migration times were 2.3 and 2.7%, and 0.8 and 1.3%, respectively, for the two compounds. The proposed method was applied to the analysis of tablets and human urine samples with satisfactory results.

Ursodeoxycholic acid and prednisolone versus ursodeoxycholic acid and placebo in the treatment of early stages of primary biliary cirrhosis

BACKGROUND

Ursodeoxycholic acid probably is not able to cure primary biliary cirrhosis. Therefore in this study ursodeoxycholic acid was administered together with prednisolone, since monotherapy with glucocorticoids has been shown to have some positive effects.

METHODS

Thirty patients with primary biliary cirrhosis (stages I-III) were entered into the study. Fifteen were treated with ursodeoxycholic acid 10 mg.kg-1.day-1 and placebo (group A), 15 with ursodeoxycholic acid and 10 mg prednisolone (group B) for 9 months. Apart from the usual laboratory examinations, liver biopsies were taken from 29 patients before and after therapy.

RESULTS

Liver enzymes decreased significantly compared to the initial values in both groups (p < 0.001), but in group B cholestasis-indicating enzymes and the immunoglobulins G and A improved more rapidly. Between both groups the differences for AP, GGT, IgG, IgA and gamma-globulins were significant (p < 0.05), but only for short terms. In group B, liver histology improved significantly (p < 0.003), which correlated with the decrease of IgG. Ursodeoxycholic acid became the predominant bile acid in the serum. Toxic bile acids did not increase. Bone densitometry revealed a slight deterioration of preexisting osteoporosis in one patient.

CONCLUSIONS

Although combination therapy with ursodeoxycholic acid and prednisolone was not superior to monotherapy with ursodeoxycholic acid with regard to liver function tests, it had a highly beneficial influence on liver histology. In our previous trials with monotherapy histology remained unchanged. An early decrease in IgG during combination therapy seems to be an indicator of an amelioration of liver histology.

TUDCA and UDCA are incorporated into hepatocyte membranes: different sites, but similar effects

The aim of this paper is to point out that: 1) CDCA and DCA increase the polarity of cell membranes and cause the release of cholesterol and phospholipid from the membranes; 2) the extent of this damage is inversely correlated with the cholesterol content of the membrane investigated; 3) UDCA, TUDCA and GUDCA decrease membrane polarity; 4) they prevent membrane damage when added prior to CDCA or DCA; 5) UDCA appears to be incorporated into the apolar domain of the membrane, TUDCA, GUDCA into the interface; 6) UDCA decreases HLA class I expression on hepatocyte membranes; 7) CDCA induces GLDH-release from liver mitochondria and increases mitochondrial membrane polarity and mobility; and 8) UDCA reduces the release of GLDH from mitochondria caused by CDCA.

Neurons derived from a human teratocarcinoma cell line establish molecular and structural polarity following transplantation into the rodent brain

Studies of neurons grafted into the brains of experimental animals have been limited by the lack of suitably homogeneous populations of neurons for transplantation. Here we describe the transplantation and survival of pure, postmitotic human neurons (NT2N cells) into the rat brain. NT2N cells were derived from a human teratocarcinoma line (NTera2/clone D1 or NT2 cells) in vitro by retinoic acid treatment. Approximately 5-10 x 10(4) NT2N cells (including previously frozen aliquots of NT2N cells) were injected into the neocortex, subjacent white matter, or hippocampus of adult (N = 51) or neonatal (N = 17) Sprague-Dawley rats. Cyclosporine (7-10 mg/kg) was administered daily to 13 adult rats for up to 12 weeks post-transplant prior to sacrifice. Untreated rats survived for up to 21 weeks post-transplant. Injection sites were serially sectioned and NT2N grafts were analyzed immunohistochemically using antibodies to diverse neuronal and glial proteins to assess the lineage of the grafted cells and their ability to establish molecular and structural polarity. NT2N cells transplanted into untreated adult and neonatal rat brains were committed exclusively to the neuronal phenotype and survived for as long as 8 weeks, although most were rejected after 4 weeks. However, cyclosporine prolonged survival of the NT2N grafts for up to 12 weeks. Further, grafted NT2N cells exhibited an asymmetric geometry (with long axons and simplified dendrites), as well as molecular polarity (with highly phosphorylated neurofilament proteins segregated in axons and microtubule associated protein 2 confined to perikarya and dendrites) by 4 weeks post-transplant. However, the grafted neurons did not become fully mature as evidenced by their failure to express the most highly phosphorylated heavy neurofilament proteins. Finally, previously frozen NT2N cells survived in the rat brain, and none of the grafts formed neoplasms. We conclude from these studies that transplanted NT2N cells represent a highly advantageous model system for studies of the developmental biology of neurons.

Molecular aspects of membrane stabilization by ursodeoxycholate [see comment]

BACKGROUND

Ursodeoxycholate, used for therapy in biliary liver diseases, prevents bile salt damage in animal experiments. Using isolated red blood cell and both canalicular and basolateral hepatocyte membranes, the present study examined this protective effect.

METHODS

Membranes were incubated with chenodeoxycholate, with chenodeoxycholate and ursodeoxycholate simultaneously, and first with ursodeoxycholate followed by chenodeoxycholate. Changes in membrane structure were investigated by electron paramagnetic resonance spectroscopy, using different spin labels. Data were confirmed by analysis of membrane lipids and studies with 14C-labeled bile acids.

RESULTS

The increase of polarity in the apolar domain of the membrane caused by chenodeoxycholate corresponded to the amount of solubilized lipids. After preincubation with ursodeoxycholate or its conjugates, membrane damage by subsequent chenodeoxycholate incubation was prevented. This effect was caused by binding of ursodeoxycholate in the apolar domain, of its conjugates in the interface of the membrane.

CONCLUSIONS

Chenodeoxycholate solubilizes membrane lipids and permits water to permeate into plasma membranes. The steroid nucleus of ursodeoxycholate is bound to the apolar domain and that of the conjugates to the interface of the membrane, thus stabilizing membrane structure.

High performance liquid chromatographic determination of free and conjugated bile acids in serum, liver biopsies, bile, gastric juice and feces by fluorescence labeling

Separation and measurement of commonly occurring free and conjugated bile acids in serum, liver biopsies, bile, gastric juice and feces have been successfully accomplished using high performance liquid chromatography with fluorescence labeling. Free and conjugated bile acids were extracted from pretreated samples using Sep-Pak C18 cartridges and then fractionated on a piperidinohydroxypropyl Sephadex LH-20 column. Free and glycine conjugated bile acids were labelled with 4-bromomethyl-7-methoxycoumarin. Taurine conjugated bile acids were hydrolysed with cholylglycine hydrolase prior to derivatization with 4-bromomethyl-7-methoxycoumarin. Labelled bile acids were eluted using an acetonitrile/methanol/water gradient on an ultrasphere ODS column. The eluate was monitored by a fluorophotometer at 360 nm (excitation) and 410 nm (emission). Linearity was obtained between 50 and 400 nmol. Recoveries from serum, gastric juice and feces were greater than 87%. This is therefore a sensitive method for the precise quantification of bile acids in serum, liver biopsies, bile, gastric juice and feces.