Between-hospital variation in outcomes of coronary artery bypass grafting in China, 2013–2019

Background

Coronary artery bypass grafting (CABG) is widely performed across China. Understanding current between-hospital variation is important for further quality improving initiatives.

Purpose

To assess the between-hospital variation comprehensively on outcomes of isolated CABG, and explore hospital-level characteristics and practice patterns explaining the variation.

Methods

We used the data of Chinese Cardiac Surgery Registry (2013–2019) to examine the between-hospital variation of outcomes, including in-hospital mortality (or treatment withdrawal) and major complications (mortality, postoperative myocardial infarction, stroke, renal failure, mediastinal infection, and reoperation for bleeding). Multilevel mixed-effect models and propensity score adjusting technique were used to quantify the variability and study hospital-level factors associated with the variation. Risk-standardized mortality rate (RSMR) was used to classify hospital performance.

Results

Among 60876 patients (62.6 years old, 75.4% male) undergoing isolated CABG in 70 hospitals, the mortality was 2.0% and 5.3% had major complications. After adjusting for patient case-mix, the median hospital RSMR was 2.1% (inter-quartile range [IQR], 1.3%-3.1%), with the median odds ratio (MOR) of 2.1; and 5.7% (IQR, 3.7%-7.5%) for risk-standardized major complications, with the MOR of 1.9. Compared with patients admitted in average-performance hospitals, patients undergoing CABG in worse-performance hospitals had a nearly twofold higher odds of in-hospital mortality (adjusted odds ratio [AOR]=1.92; 95% confidence interval (CI), 1.37–2.69), whereas patients in better-performance hospital had an approximately 60% lower odds (AOR=0.41; 95% CI, 0.30–0.57). Hospital location and average surgeon volume explained 20.2% of the between-hospital variation, where hospital-level perioperative blood transfusion rate and use of secondary prevention medication further contributed to the proportion change variance of 3.3% and 2.3%, respectively. Similar results were obtained for major complications.

Conclusion(s)

Consistent between-hospital variation of CABG performance exists in China. Improving the clinical practice management and reducing variability may better the overall outcomes.

Funding Acknowledgement

Type of funding sources: None.

[Correlation between systemic inflammation level and emphysema degree and bone mineral density in chronic obstructive pulmonary disease patients and its mechanism]

Objective: To study the correlation between systemic inflammation level and emphysema degree and bone mineral density in chronic obstructive pulmonary disease (COPD) patients and its possible mechanism. Methods: 90 patients with stable COPD who met the inclusion criteria and 50 controls in the physical examination center during the same period were recruited. All the enrolled objects have collected general clinical data, analyzed peripheral blood samples, measuring the Low-attenuation area of lung and CT value of lumbar 1 vertebra (L1-CT) by chest spiral CT. According to LAA%, COPD patients were divided into 36 cases of the non-emphysema group, 32cases of mild to moderate emphysema group, and 22 cases of severe emphysema group. The correlation between L1-CT value, LAA%, peripheral blood inflammatory factors, and pulmonary function indices in each group was analyzed and compared. Results: The HU value of L1-CT (107±32) in the COPD group was significantly lower than that in the control group (153±30), and the difference was statistically significant (P<0.05). The higher the LAA% in COPD patients was, the lower the value of L1-CT was, and the difference between groups was statistically significant. Compared with COPD patients in the non-emphysema group, peripheral blood neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and C-reactive protein (CRP) were all increased in the emphysema group, and the differences were statistically significant (P<0.05). L1-CT was negatively correlated with LAA, PLR, NLR, and CRP while uncorrelated with serum concentration of calcium and phosphorus. Conclusion: The decrease in bone density in COPD patients is closely related to the degree of emphysema. It is associated with increased levels of systemic inflammation caused by COPD itself. Early and timely broad-spectrum anti-inflammatory treatment may have certain clinical significance for the prevention and treatment of comorbidity with osteoporosis.

Fabrication of 1D Te/2D ReS2 Mixed-Dimensional van der Waals p-n Heterojunction for High-Performance Phototransistor

The superior optical and electronic properties of the two-dimensional (2D) rhenium disulfide (ReS₂) makes it suitable for nanoelectronic and optoelectronic applications. However, the internal defects coupled with with the low mobility and light-absorbing capability of ReS₂ impede its utilization in high-performance photodetectors. Fabrication of mixed-dimensional heterojunctions is an alternative method for designing high-performance hybrid photodetectors. This study proposes a mixed-dimensional van der Waals (vdW) heterojunction photodetector, containing high-performance one-dimensional (1D) p-type tellurium (Te) and 2D n-type ReS₂, developed by depositing Te nanowires on ReS₂ nanoflake using the dry transfer method. It can improve the injection and separation efficiency of photoexcited electron-hole pairs due to the type II p-n heterojunction formed at the ReS₂ and Te interface. The proposed heterojunction device is sensitive to visible-light sensitivity (632 nm) with an ultrafast photoresponse (5 ms), high responsivity (180 A/W), and specific detectivity (10⁹), which is superior to the pristine Te and ReS₂ photodetectors. As compared to the ReS₂ device, the responsivity and response speed is better by an order of magnitude. These results demonstrate the fabrication and application potential of Te/ReS₂ mixed-dimensional heterojunction for high-performance optoelectronic devices and sensors.

[Clinical characteristics and prognostic analysis of 458 children with high-risk neuroblastoma in a single center]

Objective: To summarize the clinical characteristics of high-risk neuroblastoma (HR-NB) in a single center, analyze the prognostic factors of HR-NB. Methods: The clinical data of children with HR-NB who were treated and followed up at the hematology-oncology center of Beijing Children's Hospital from February 1, 2007 to June 30, 2018 were analyzed retrospectively. The clinical features were summarized. Kaplan-Meier method was used for survival analysis and Cox regression was used to analyze the prognostic factors. The last follow-up time was June 30, 2019. Results: A total of 458 children with HR-NB were enrolled in this study, including 265 males (57.9%) and 193 females (42.1%), the age at diagnosis was 40.0 months (4.5-148.0 months), the follow-up time was 22.0 months (0.2-138.0 months) and the time of tumor progression or recurrence was 15 months (1-72 months). The 5-year event-free survival (EFS) rate was (31.2±2.6)% and the 5-year overall survival (OS) rate was (43.9±3.2)%. The 5-year EFS rate and 5-year OS rate in 142 hematopoietic stem cell transplantation (HSCT) patients with bone marrow metastases were better than that in 196 non-transplantation cases with bone marrow metastases ((26.5±4.5)% vs. (25.1±3.6)%, χ²=13.773, P=0.001; (38.1±5.5)% vs. (35.7±4.7)%, χ²=9.235, P=0.002); 128 transplantation patients with bone metastases had higher 5-year EFS rate and 5-year OS rate than 188 non-transplantation cases with bone metastases ((28.5±5.0)% vs. (26.7±3.8)%, χ²=10.222, P=0.001; (37.1±6.0)% vs. (36.2±4.8)%, χ²=7.843, P=0.005). The 5-year EFS rate was higher in 37 HSCT patients with MYCN amplification than in 49 non-transplantation cases with MYCN amplification ((26.8±8.0) % vs. (20.5±6.4) %, χ²=5.732, P=0.017). No significant difference was found in 5-years OS rate between transplantation group with MYCN amplification and non-transplantation group with MYCN amplification ((31.4±8.6) % vs. (26.2±7.4) %, χ²=3.230, P=0.072). Univariate survival analysis showed that lactate dehydrogenase (LDH)≥1 500 U/L was associated with poor prognosis of patients with MYCN amplification (χ²=6.960, P=0.008). Multivariate Cox analysis showed bone marrow metastasis and LDH≥1 500 U/L were independent risk factors for poor prognosis of patients with non-MYCN amplification (HR=2.427, 1.618;95%CI：1.427-4.126, 1.275-2.054, P<0.05) for both comparisons. Conclusions: LDH≥1 500 U/L was the poor prognostic factor for patients with MYCN amplification. The bone marrow metastasis and LDH≥1 500 U/L were the poor prognostic factors for HR-NB patients with non-MYCN amplification. HSCT can improve the prognosis of patients with bone or bone marrow metastasis. It can also retard the time of progression or recurrence for patients with MYCN amplification.

[Status on the use of anti-hypertensive drugs in the southwest areas of China]

Objective: To understand the current status of anti-hypertensive drug use in patients with hypertension in the Southwest areas of China. Methods: Based on the Program of Screening and Intervention Subjects with High Risk Cardiovascular Diseases, this study presented information on adults aged 35-75 in Southwest China by convenient sampling method, from January 2016 to November 2018. Basic information and cardiovascular related data were collected. Data on hypertensive patients were recorded, including names, doses and frequency of anti-hypertensive drugs they used. Information on the use of anti-hypertensive drugs among different hypertension subgroups, potential related characteristics, types and combination patterns of drugs, etc., were analyzed. Results: A total of 394 957 subjects were included in the study, with 159 014 identified as being hypertensive [mean age (58.8±9.5) years, 40.2% male]. 29.8% of them ever received antihypertensive drugs. A total of 30 445 of the patients reported detailed information of the drugs they ever used and 22.5% of them received therapy of combined drugs. Rates of using combination therapy were consistent among subgroups with different age, gender, blood pressure level and history of cardiovascular and cerebrovascular diseases. Results from the multivariate logistic regression analysis showed that patients with previous cardiovascular and cerebrovascular events, obesity or diabetes were more likely to have received combined therapy, while patients with less education or lower income were in the opposite. Calcium antagonists (58.6%) were the main drugs being used in single drug therapy, while traditional fixed-dose combination drugs (31.4%) were the most common ones in the drug-combination therapy, followed by angiotensin converting enzyme inhibitor/angiotensin receptor blocker combined with calcium antagonists (22.4%). Angiotensin converting enzyme inhibitor/angiotensin receptor blocker combined with beta blocker was the main drug used in patients with coronary heart disease. Conclusions: Treatment programs using the antihypertensive drugs for hypertensive patients in Southwest China needs to be improved, since the irrational use of antihypertensive drugs still exists. However, we would encourage the use of combination therapy for hypertensive patients.

Modification of 1D TiO2 nanowires with GaOxNy by atomic layer deposition for TiO2@GaOxNy core-shell nanowires with enhanced photoelectrochemical performance

As a well-known semiconductor that can catalyse the oxygen evolution reaction, TiO2 has been extensively investigated for its solar photoelectrochemical water properties. Unmodified TiO2 shows some issues, particularly with respect to its photoelectrochemical performance. In this paper, we present a strategy for the controlled deposition of controlled amounts of GaOxNy cocatalysts on TiO2 1D nanowires (TiO2@GaOxNy core-shell) using atomic layer deposition. We show that this modification significantly enhances the photoelectrochemical performance compared to pure TiO2 NW photoanodes. For our most active TiO2@GaOxNy core-shell nanowires with a GaOxNy thickness of 20 nm, a photocurrent density up to 1.10 mA cm-2 (at 1.23 V vs. RHE) under AM 1.5 G irradiation (100 mW cm-2) has been achieved, which is 14 times higher than that of unmodified TiO2 NWs. Furthermore, the band gap matching with TiO2 enhances the absorption of visible light over unmodified TiO2 and the facile oxygen vacancy formation after the deposition of GaOxNy also provides active sites for water activation. Density functional theory studies of model systems of GaOxNy-modified TiO2 confirm the band gap reduction, high reducibility and ability to activate water. The highly efficient and stable systems of TiO2@GaOxNy core-shell nanowires with ALD deposited GaOxNy demonstrate a good strategy for the fabrication of core-shell structures that enhance the photoelectrochemical performance of readily available photoanodes.

[Clinical and prognostic analysis of single-center multidisciplinary treatment for rhabdomyosarcoma in children]

Objective: To summarize the clinical characteristics, treatment response and prognostic factors of rhabdomyosarcoma (RMS) in children. Methods: The clinical characteristics such as age at diagnosis, primary tumor site, tumor size, pathological type, clinical stage, and risk grouping of 213 RMS patients (140 males and 73 females) treated in Hematology Oncology Center of Beijing Children's Hospital, Capital Medical University, from May 2006 to June 2018 were analyzed retrospectively. The clinical characteristics, overall survival (OS), event free survival (EFS) and prognostic factors of children treated with the Beijing Children's Hospital-Rhabdomyosarcoma (BCH-RMS) regimen were analyzed. Survival data were analyzed by Kaplan-Meier survival analysis, and single factor analysis was performed by Log-Rank test. Results: The diagnostic age of 213 cases was 48.0 months (ranged 3.0-187.5 months), of which 136 cases (63.8%) were younger than 10 years old. The head and neck region was the most common primary site of tumor (30%, 64 cases), followed by the genitourinary tract (26.8%, 57 cases). Among pathological subtypes, embryonal RMS accounted for 71.4% (152 cases), while alveolar RMS and anaplastic RMS accounted for only 26.8% (57 cases) and 1.9% (4 cases), respectively. According to the Intergroup Rhabdomyosarcoma Study Group (IRS), IRS-Ⅲ and Ⅳ accounted for 85.0% (181 cases) of all RMS patients. In all patients, 9.4% (20 cases) patients were divided in to low-risk group, 52.1% (111 cases) patients in to intermediate -risk group, 25.8% (55 cases) patients in to high-risk group, and 12.7% (27 cases) patients in to the central nervous system invasion group, respectively. All patients with RMS received chemotherapy. The cycles of chemotherapy were 13.5 (ranged 5.0-18.0) for patients without event occurrence, while 14.2 (ranged 3.0-30.0) for patients with event occurrence. Among the 213 patients, 200 patients had surgical operation, of whom 103 patients underwent surgery before chemotherapy and 97 patients at the end of chemotherapy, 21 patients had secondary surgical resection. Radiotherapy was performed in 114 patients. The follow-up time was 23.0 months (ranged 0.5-151.0 months) . There were 98 patients with relapsed or progressed disease and 67 patients with death. The median time to progression was 10 months, of which 67 (68.4%) relapse occurred within 1 year and no recurrence occurred after follow-up for more than 5 years. The 3-year EFS and 5-year EFS were (52±4) % and (48±4) %, while the 3-year OS and 5-year OS were (65±4) % and (64±4) % by survival analysis. The 5-year OS of the low-risk, intermediate-risk, the high-risk were 100%, (74±5) %, (48±8) %, and the 2-year OS of the central nervous system invasion group was (36±11) % (χ(2)=33.52, P<0.01). The 5-year EFS of the low-risk, intermediate-risk, the high-risk were (93±6) %, (51±5) %, (36±7) % and the 2-year EFS of the central nervous system invasion group was (31±10) % (χ(2)=24.73, P<0.01) . Survival factor analysis suggested that the OS of children was correlated with age(χ(2)=4.16, P=0.038), tumor TNM stage (χ(2)=22.02, P=0.001), IRS group (χ(2)=4.49, P<0.01) and the risk group (χ(2)=33.52, P<0.01). Conclusions: This study showed that the median age of newly diagnosed RMS patients was 4 years. The head and neck and the genitourinary tract were the most common primary origin of RMS. The OS was low in single-center RMS children. The median time to recurrence was 10 months, and recurrence was rare 3 years later.

[Research progress of maternal immunization]

Maternal immunization is an immune strategy that protects both mothers and early-life infants from disease by the vaccination of pregnant women. The effect of maternal immunization is influenced by the types of vaccines, the timing of vaccination, the subtypes of antibodies induced by vaccines, and the health status of mothers themselves. Inactivated influenza vaccination during pregnancy and DPT vaccination during the third trimester of pregnancy have been widely used in the world, while Hepatitis B vaccine, pneumococcal and meningococcal vaccines also show good efficacy and safety in pregnant women. This article reviews the research progress of Maternal Immunization in order to provide a reference for Maternal Immunization planning and policymaking in China.

Cross-coupling drift between magnetic field and temperature in depolarized interferometric fiber optic gyroscope

We propose a theory of cross-coupling drift in depolarized interferometric fiber optic gyroscopes (D-IFOGs) under the joint influence of magnetic field and temperature. The magnetic field and temperature cross-coupling drift (MTCD) originates from the interaction of the nonreciprocal circular birefringence produced by the magnetic field, the thermal stress birefringence from the varying temperature, and the inherent residual birefringence in the fiber coil. The MTCD is much greater than the sum of the individual drifts induced by magnetic field and temperature. We established a relevant theoretical model and carried out numerical simulations, and verified the results experimentally. For a typical D-IFOG, the experimental results showed a cross-coupling degree exceeding 170% when the temperature varied from -20 °C to 60 °C, as predicted in the simulations.

[Construction of latent membrane protein 2A chimeric antigen receptor-T cells and their lethal effects on nasopharyngeal carcinoma cells]

Objective: To produce latent membrane protein 2A (LMP2A) chimeric antigen receptor (CAR)-T cells and detect the lethal effect of LMP2A CAR-T cells on nasopharyngeal carcinoma (NPC) cells. Methods: The study was conducted from September 2016 to December 2017.Genetic engineering technology was used to construct anti-LMP2A CAR lentiviral expression vector and sequencing was identified. The expression of anti-LMP2A CAR in the 293T cells was confirmed by western blot. CCK8 assay was used to evaluate the cytotoxicity of LMP2A CAR-T cells to NPC cells. ELISA assay was performed to test IL-2 and IFN-γ releasing of activated LMP2A CAR-T cells. The inhibition effect of LMP2A CAR-T cells on NPC xenograft tumor was observed in vivo. Statistical analysis was performed by statistical software SPSS 21.0. Results: The results of PCR and sequencing showed that anti-LMP2A CAR lentiviral expression vector was constructed successfully. The result of western blot indicated the expression of anti-LMP2A CAR in the 293T cells effectively. The results of CCK-8 assay showed that the killing activities of LMP2A CAR-T cells to LV-LMP2A-CNE1 cells were (72.11±9.75)%, (54.65 ±5.42)% and (36.68±3.80)% at 20∶1, 10∶1 and 5∶1 ratio of effective cells to target cells, and had a statistical difference compared to CD19 CAR-T cells and T cells (P<0.05). There was no significant difference in the killing activities of LMP2A CAR-T cells to CNE1 cells compared with CD19 CAR-T cells and T cells. The results of ELISA showed that the content of IL-2 and IFN-γ in the co-culture supernatant of LMP2A CAR-T cells and LV-LMP2A-CNE1 cells was significantly higher than that of LMP2A CAR-T cells and CNE1 cells which had statistical difference (P<0.05); In vivo experiment, the volume of LMP2A CAR-T cell group was (80.3±10.0) mm(3) which was significantly lower than that of the control groups, and the difference was statistically significant (P<0.05). Conclusion: LMP2A CAR-T cells are successfully prepared and have an obvious targeting cytotoxicity on LMP2A-positive NPC cells.

[Research of the expression of subchondral bone of Indian hedgehog with early experimental osteoarthritis induced by mechanical stress]

Objective: To investigate the the expression of subchondral bone of Indian hedgehog(Ihh) with early experimental osteoarthritis induced by mechanical stress. Methods: The animals were equally divided into two groups: experimental group(E-group, n=15) and control group(S-group, n=15). The right knee joints of E-group underwent surgery, which involved in both medial collateral ligament (MCL) transaction and medial meniscectomy, while the control group was only carried out with a sham operation.The rats were killed at 1, 2 and 4 weeks postsurgery to obtain the right knee joints. Immunostaining and immunofluorescence double staining were performed to evaluate the expression of Ihh in subchondral bone, respectively. Results: The polynuclear giant cells in the subchondral bone of E-Group expressed Ihh in their cytoplasm 1 and 2 weeks post-surgery, except for 4 week, while those of S-Group appeared negative at all three time points postsurgery. There is statistically difference between the mean density of positive area of Ihh in sections of E-group and S-group both in 1 week (E-group: 0.351+ 0.086, S-group: 0.153±0.017, P<0.05) and 2 weeks (E-group: 0.303±0.026, S-group: 0.176±0.013, P<0.05), but without statistically difference in 4 weeks (E-group: 0.092±0.033, S-group: 0.136±0.014, P>0.05) post surgery. Trap positive giant cells in subchondral bone of E-group were also found Ihh positive, which indicated expression of Ihh in osteoclast . Conclusion: Ihh maybe play an important role in pathogenesis of early experimental osteoarthritis.

Note: Decoupling design for high frequency piezoelectric ultrasonic transducers with their clamping connections

This work presents the flexure-mechanism based decoupling design between high frequency piezoelectric ultrasonic transducers and their clamping connections to improve ultrasonic energy transmission efficiency. The ring, prismatic beam, and circular notched hinge based flanges were presented, and the crucial geometric dimensions of the transducers with the flexure decoupling flanges were determined. Finite element analysis (FEA) was carried out to investigate the dynamic characteristics of the transducers. Finally, experiments were conducted to examine and verify the effects of the proposed decoupling flanges. FEA and experimental results show that smaller frequency deviations and larger tip displacement amplitudes have been achieved by using the transducers with the flexure flanges compared with the transducer with a rigid ring-type flange, and thus the ultrasonic transmission efficiency can be improved through the flexure flanges.

Electrical level of defects in single-layer two-dimensional TiO2

The remarkable properties of graphene and transition metal dichalcogenides (TMDCs) have attracted increasing attention on two-dimensional materials, but the gate oxide, one of the key components of two-dimensional electronic devices, has rarely reported. We found the single-layer oxide can be used as the two dimensional gate oxide in 2D electronic structure, such as TiO2. However, the electrical performance is seriously influenced by the defects existing in the single-layer oxide. In this paper, a nondestructive and noncontact solution based on spectroscopic ellipsometry has been used to detect the defect states and energy level of single-layer TiO2 films. By fitting the Lorentz oscillator model, the results indicate the exact position of defect energy levels depends on the estimated band gap and the charge state of the point defects of TiO2.

REPAIR EFFECTS OF UMBILICAL CORD MESENCHYMAL STEM CELLS ON PODOCYTE DAMAGE OF IgA NEPHROPATHY

This study aimed to explore the influence of umbilical cord mesenchymal stem cells (UMSC) on stem cell homing and glomerular mesangial cell (GMC) after intravenous injection performed on mice tails with IgA nephropathy (IgAN) and its possible mechanism, which provide a new way and theoretical basis for the application of stem cell transplantation (SCT) in kidney disease treatment. Specific pathogen free (SPF) male Kunming mice were randomly divided into groups. A complex method applying bovine serum albumin (BSA) gavage, hypodermic injection of CCl4 and lipopolysaccharide (LPS) was used for building IgAN mice model. In addition, vascular endothelial growth factor (VEGF), connective tissue growth factor (CTGF) and cluster of differentiation (CD) 44 were observed by Masson staining and detected with immunohistochemistry (IHC) to confirm homing and location of mesenchymal stem cells (MSCs). Moreover, Western Blot was used for detecting VEGF and CTGF so as to explore the possible mechanism of applying UMSC in treating IgAN. Masson staining indicated that fibrosis degree of MSCs in treatment group was significantly lower than in negative control group after stem cell treatment. Routine urine test explained that proteinuria in treatment group were (7.15±0.31), (4.87±0.22), (2.95±0.16) g/24 h and (12.00±1.38) g/24 h in model group (P less than 0.05). MSCs were observed to be located in glomerulus and renal interstitium by IHC detection of CD44 and IHC qualitative observation of VEGF and CTGF had different positive expressions in three groups. Furthermore, different expressions of VEGF and CTGF were observed quantitatively by Western Blot. Fibrosis degree of renal tissue relieves, hematuresis and proteinuria eases and IgAN symptoms obviously improve after UMSC treatment, which hints that the treatment of HUMSC has protective effect on IgAN mice model.

Computational study of bindings of olive leaf extract (OLE) to HIV-1 fusion protein gp41

Recent experimental study found that OLE (olive leaf extract) has anti-HIV activity by blocking the HIV virus entry to host cells [Lee-Huang, S., Zhang, L., Huang, P.L., Chang, Y. and Huang, P.L. (2003) Anti-HIV activity of olive leaf extract (OLE) and modulation of host cell gene expression by HIV-1 infection and OLE treatment. Biochem. Biophys. Res. Commun. 307, 1029; Lee-Huang, S., Huang, P.L., Zhang, D., Lee, J.W., Bao, J., Sun, Y., Chang, Y.-Tae, Zhang, J.Z.H. and Huang, P.L. (2007) Discovery of small-molecule HIV-1 fusion and integrase inhibitors oleuropein and hydroxytyrosol. Biochem. Biophys. Res. Commun. 354, 872-878, 879-884]. As part of a joint experimental and theoretical effort, we report here computational study to help identify and characterize the binding complexes of several main compounds of OLE (olive leaf extract) to HIV-1 envelop protein gp41. A number of possible binding modes are found by docking oleuropein and its metabolites, aglycone, elenolic acid and hydroxytyrosol, onto the hydrophobic pocket on gp41. Detailed OLE-gp41 binding interactions and free energies of binding are obtained through molecular dynamics simulation and MM-PBSA calculation. Specific molecular interactions in our predicted OLE/gp41 complexes are identified and hydroxytyrosol is identified to be the main moiety for binding to gp41. This computational study complements the corresponding experimental investigation and helps establish a good starting point for further refinement of OLE-based gp41 inhibitors.

p53 negatively regulates the expression of FAT10, a gene upregulated in various cancers

FAT10 is a member of the ubiquitin-like modifier family of proteins and has been implicated to play important roles in antigen presentation, cytokine response, apoptosis and mitosis. We have recently demonstrated the upregulation of FAT10 gene expression in 90% of hepatocellular carcinoma patients. Here, we identified and characterized the promoter of the FAT10 gene to elucidate the mechanism of FAT10 gene expression. Notably, we found that the 5' untranslated region (5'UTR), from the transcription start site to 15 bases before the translational start site, displays significant promoter activity. Regions upstream of the 5'UTR (from +26 to -1997) do not confer any promoter activity. Curiously, FAT10 promoter activity and expression is significantly repressed in KB3-1 and HepG2 cells, which have wild-type p53, than in p53-negative Hep3B cells. The role of p53 in regulating FAT10 expression was evident by the significant downregulation (P<0.05) of FAT10 mRNA expression and promoter activity when wild-type p53 was transfected into p53-null Hep3B cells. Conversely, inhibiting p53 expression through siRNA against p53 significantly enhanced FAT10 expression and promoter activity. p53 was found to bind in vivo to the 5' half consensus sequence of p53-binding site located at the FAT10 promoter. Hence, we propose that FAT10 is a downstream target of p53 and dysregulation of FAT10 expression in p53-defective cells could contribute to carcinogenesis.

Molecular caps for full quantum mechanical computation of peptide-water interaction energy

We present a systematic study of numerical accuracy of various forms of molecular caps that are employed in a recently developed molecular fractionation scheme for full quantum mechanical computation of protein-molecule interaction energy. A previously studied pentapeptide (Gly-Ser-Ala-Asp-Val) or P5 interacting with a water molecule is used as a benchmark system for numerical testing. One-dimensional potential energy curves are generated for a number of peptide-water interaction pathways. Our study shows that various forms of caps all give consistently accurate energies compared to the corresponding full system calculation with only small deviations. We also tested the accuracy of cutting peptide backbone at different positions and comparisons of results are presented.

Fractionation of peptide with disulfide bond for quantum mechanical calculation of interaction energy with molecules

We present a computational study of a recently developed molecular fractionation with conjugated caps (MFCC) method for application to peptide/protein that has disulfide bonds. Specifically, we employ the MFCC approach to generate peptide fragments in which a disulfide bond is cut and a pair of conjugated caps are inserted. The method is tested on two peptides interacting with a water molecule. The first is a dipeptide consisting of two cysteines (Cys-Cys) connected by a disulfide bond and the second is a seven amino acid peptide consisting of Gly-Cys-Gly-Gly-Gly-Cys-Gly with a disulfide cross link. One-dimensional peptide-water potential curves are computed using the MFCC method at various ab initio levels for a number of interaction geometries. The calculated interaction energies are found to be in excellent agreement with the results obtained from the corresponding full system ab initio calculations for both peptide/water systems. The current study provides further numerical support for the accuracy of the MFCC method in full quantum mechanical calculation of protein/peptide that contains disulfide bonds.

Entangled double-helix phase

We present a novel phase with an entangled double-helix structure. Beams with this phase have the same transverse patterns as those of interference between two doughnut beams. This proposed method allows a complete set of the superpositions of the doughnut modes or the orbital angular momentum states with different topological orders to be obtained. Furthermore, it introduces a simple continuous and controlled rotation of the transverse patterns by use of a spatial light modulator. It can be used to form a three-dimensional structure by three-dimensional trapping in an optical tweezers setup or to study the quantum characteristics of an optical vortex.

Optical doughnut for optical tweezers

We describe novel optical doughnuts for optical tweezers. With new phase functions, the proposed doughnut beams have dark cores in specified shapes. The technique can offer a simple method for creating a variety of beam shapes to match the trapped objects. One can rotate the beams directly by revolving their phase structures about their axes on the initial plane. The technique for generating the traditional Laguerre-Gaussian beam can be used to create these novel beams.

Identification of a nonconserved amino acid residue in multidrug resistance protein 1 important for determining substrate specificity: evidence for functional interaction between transmembrane helices 14 and 17

Murine multidrug resistance protein 1 (mrp1), differs from its human ortholog (MRP1) in that it fails to confer anthracycline resistance and transports the MRP1 substrate, 17beta-estradiol 17-(beta-d-glucuronide) (E(2)17betaG), very poorly. By mutating variant residues in mrp1 to those present in MRP1, we identified Glu(1089) of MRP1 as being critical for anthracycline resistance. However, Glu(1089) mutations had no effect on E(2)17betaG transport. We have now identified a nonconserved amino acid within the highly conserved COOH-proximal transmembrane helix of MRP1/mrp1 that is important for transport of the conjugated estrogen. Converting Ala(1239) in mrp1 to Thr, as in the corresponding position (1242) in MRP1, increased E(2)17betaG transport 3-fold. Any mutation of mrp1 Ala(1239), including substitution with Thr, decreased resistance to vincristine and VP-16 without altering anthracycline resistance. However, introduction of a second murine to human mutation, Q1086E, which alone selectively increases anthracycline resistance, into mrp1A1239T restored resistance to both vincristine and VP-16. To confirm the importance of MRP1 Thr(1242) for E(2)17betaG transport and drug resistance, we mutated this residue to Ala, Cys, Ser, Leu, and Lys. These mutations decreased E(2)17betaG transport 2-fold. Conversion to Asp eliminated transport of the estrogen conjugate and also decreased leukotriene C(4) transport approximately 2-fold. The mutations also reduced the ability of MRP1 to confer resistance to all drugs tested. As with mrp1, introduction of a second mutation based on the murine sequence to create MRP1E1089Q/T1242A restored resistance to vincristine and VP-16, but not anthracyclines, without affecting transport of leukotriene C(4) and E(2)17betaG. These results demonstrate the important role of Thr(1242) for E(2)17betaG transport. They also reveal a highly specific functional relationship between nonconserved amino acids in TM helices 14 and 17 of both mrp1 and MRP1 that enables both proteins to confer similar levels of resistance to vincristine and VP-16.

Identification of an amino acid residue in multidrug resistance protein 1 critical for conferring resistance to anthracyclines

Murine multidrug resistance protein 1 (mrp1), unlike human MRP1, does not confer resistance to anthracyclines. Previously, we have shown that a human/murine hybrid protein containing amino acids 959-1187 of MRP1 can confer resistance to these drugs. We have now examined the functional characteristics of mutant proteins in which we have converted individual amino acids in the comparable region of mrp1 to those present at the respective locations in MRP1. These mutations had no effect on the drug resistance profile conferred by mrp1 with the exception of converting glutamine 1086 to glutamate, as it is in the corresponding position (1089) in MRP1. This mutation created a protein that conferred resistance to doxorubicin without affecting vincristine resistance, or the ability of mrp1 to transport leukotriene C(4) (LTC(4)) and 17beta-estradiol 17-(beta-d-glucuronide) (E(2)17betaG). Furthermore, mutation Q1086D conferred the same phenotype as mutation Q1086E while the mutation Q1086N did not detectably alter the drug resistance profile of mrp1, suggesting that an anionic side chain was required for anthracycline resistance. To confirm the importance of MRP1 E1089 for conferring resistance to anthracyclines, we mutated this residue to Gln, Asp, Ala, Leu, and Lys in the human protein. The mutation E1089D showed the same phenotype as MRP1, while the E1089Q substitution markedly decreased resistance to anthracyclines without affecting LTC(4) and E(2)17betaG transport. Conversion of Glu-1089 to Asn, Ala, or Leu had a similar effect on resistance to anthracyclines, while conversion to a positive amino acid, Lys, completely eliminated resistance to anthracyclines and vincristine without affecting transport of LTC(4), E(2)17betaG, and the GSH-dependent substrate, estrone-3-sulfate. These results demonstrate that an acidic amino acid residue at position 1089 in predicted TM14 of MRP1 is critical for the ability of the protein to confer drug resistance particularly to the anthracyclines, but is not essential for its ability to transport conjugated organic anions such as LTC(4) and E(2)17betaG.

[Studies on the distribution of actin during meiotic prophase I of Nicotiana rustica L]

The Pollen Mother Cells of Nicotiana Rustica L. were studied using the techniques of immunofluorescence microscopy and protein A-colloidal gold IEM. Immunofluorescence microscopy indicates the presence of actin in both nuclei and cytoplasm. IEM observation shows that gold particles are present in cytoplasm, chromatin and cytomictic channels. These results indicate that actin has some relation with chromatin condensing at synizesis. Moreover, actin may also play an important role in cytomixis.

A study of postoperative radiotherapy in patients with non-small-cell lung cancer: a randomized trial

PURPOSE

To study the value of postoperative radiotherapy for non-small-cell lung cancer (NSCLC) with positive regional lymph metastases (NI or N2) after radical surgery.

MATERIALS AND METHODS

From February 1982 to October 1995, 366 patients with NSCLC and N1 or N2 disease were randomized into postoperative radiotherapy (S + R) (183 patients) and no further treatment (S alone) (182 patients). Postoperative radiotherapy (RT) was administrated 3-4 weeks after radical operation. Irradiated fields covered the bronchial stump, ipsilateral hilum, and most of the mediastinum. The midplane dose was 6000 cGy/30 fractions/6 weeks, with the spinal cord limited to 4000 cGy/20 fractions/4 weeks or less. One hundred thirty-four patients in S + R group and 162 patients in S alone group were evaluated. Clinical data were comparable in both arms, except for the numbers of N2 patients.

RESULTS

The 3-year and 5-year overall survival rates were 51.9% and 42.9% in the S + R group and 50.2% and 40.5% in the S alone Group (p = 0.56). The 3-year and 5-year disease-free survival rates were 50.7% +/- 4.7% and 42.9% +/- 5.2% in the S + R group vs. 44.4% +/- 4.3% and 38.2% +/- 4.5% in the S alone group (p = 0.28), respectively. In the patients with NI or T3-4 tumors, there was a trend toward improved survival in the S + R group, especially in the patients with T3-4N1M0. These patients demonstrated 20% improvement in overall survival (p = 0.092) and greater than 20% better disease-free survival (p = 0.057). Postoperative RT reduced local recurrence but had no impact on distant metastases.

CONCLUSION

Postoperative RT significantly reduced local relapses, but did not improve overall survival, due to a high frequency of distant metastases in this patient group.

Alkaloid-fullerene systems through photocycloaddition reactions

The photocycloaddition of tertiary amines to ¿60fullerene (C(60)) is an interesting and useful reaction. We wished to extend the applications of this type of reaction through an investigation of the photoaddition of alkaloids to C(60) for the purpose of synthesizing novel and complex photoadducts that are difficult to obtain by usual methods. Irradiation of tazettine (2) or gramine (3) with C(60) in toluene leads to formation of one monoadduct (6 or 7), whereas scandine (1a) or 10-hydroxyscandine (1b) reacts with C(60) photochemically to give two products, the expected ¿6,6 monoadduct (5a, 5b) and a new type of monoadduct with a bis-¿6, 6 closed structure (4a, 4b). These new structures were characterized by UV-vis, FT-IR, (1)H NMR, (13)C NMR, (1)H-(1)H COSY, ROESY, HMQC (heteronuclear multiple-quantum coherence), and HMBC (heteronuclear multiple-bond connectivity) spectroscopy. The techniques of time-of-flight secondary ion MS (TOF-SIMS) and field desorption MS (FD-MS) were used for the mass determination. (3)He NMR analysis of the product mixture from photoaddition of 1a to C(60) containing a (3)He atom ((3)He@C(60)) led to two peaks at -9.091 and -11.090 ppm relative to gaseous (3)He, consistent with formation of a ¿6, 6-closed monoadduct and a bis-¿6,6 closed adduct. Presumably, the bis-¿6, 6 closed adducts are formed by an intramolecular ¿2 + 2 cycloaddition of the vinyl group to the adjacent 6,6-ring junction of C(60) after the initial photocycloaddition.

Randomized clinical trial on the combination of preoperative irradiation and surgery in the treatment of adenocarcinoma of gastric cardia (AGC)--report on 370 patients

PURPOSE

An attempt was made to define the role of radiotherapy before operation for AGC.

METHODS AND MATERIALS

From January 1978 to May 1989, a prospective randomized trial on preoperative radiotherapy (R+S) vs. surgery alone (S) for AGC was carried out in 370 patients. Patients were randomized into a combined group (R+S, 171 patients) or a surgery alone group (S, 199 patients) by the envelope method. 8-MV photon or telecobalt was used for the preoperative radiation therapy, using anterior-posterior opposing parallel fields to deliver 40 Gy to the cardia, lower segment of the esophagus, fundus, lesser curvature, and hepatogastric ligament. Surgery was performed after 2 to 4 weeks rest.

RESULTS

The 5- and 10-year survival rates of the R+S Group and the S Alone Group were 30.10% and 19.75%, 20.26% and 13.30%, respectively. The survival curves of these two groups diverged right from the beginning after the operation over the ninth year. Statistics by Kaplan-Meier log rank test proves that the difference is significant (chi2 = 6.74, p = 0.0094). The immediate results were: resection rate 89.5% and 79.4% (p < 0.01); pathologic stage after resection T2 12.9% and 4.5% (p < 0.01), T4 40.3% and 51.3% (p < 0.05), lymph node metastasis rates 64.3% and 84.9% (p < 0.001); operative mortality rates 0.6% and 2.5%; intrathoracic leak rates 1.8% and 4.0%, respectively. The causes of failure were: local uncontrol and recurrence 38.6% vs. 51.7% (p < 0.025), regional lymph node metastasis 38.6% vs. 54.6% (p < 0.005), distant metastasis 24.3% vs. 24.7%.

CONCLUSION

Preoperative radiation therapy is able to improve the results of surgery for adenocarcinoma of the gastric cardia.

Prospective multimodality treatment of SCLC--experience during the past 18 years

Lung cancer has been one of the leading malignancies in China. Since 1989 it has ranked first among common malignancies in the male population, and second in females. In 1975, a multimodality treatment study group for lung cancer was organized in our institute. The group has since expanded to 15 institutions in the Beijing and Tianjin area during the past four years. The present communication is based on our experiences and data, and tries to explain the treatment strategy of our study group.

Alternative splicing of ED-A and ED-B sequences of fibronectin pre-mRNA differs in chondrocytes from different cartilaginous tissues and can be modulated by biological factors

The alternative splicing of the ED-A and ED-B segments of fibronectin pre-mRNA was examined in epiphyseal, costal, and meniscal cartilage from 3-week-old beagles and in nasal, tracheal, articular, and meniscal cartilage from 1- and 2-year-old Labrador retrievers. In contrast to the 100% expression of ED-B(+) mRNA that has been reported for embryonic chick cartilage (Bennett, V.D., Pallante, K.M., and Adams, S.K. (1991) J. Biol. Chem. 266, 5918-5924), all cartilages studied expressed both the ED-B(+) and ED-B(-) forms of fibronectin mRNA with the exception of the trachea, in which expression was 100% ED-B(-). Of all cartilages studied, only the meniscus had detectable levels of ED-A(+) mRNA. Placing articular cartilage chondrocytes in primary monolayer culture dramatically up-regulated the expression of ED-A(+) mRNA to 25% of the total, and this expression was further increased by the addition of transforming growth factor beta 1 or fucoidan to the culture medium. The expression of ED-B(+) mRNA remained at about 18% in the cultured chondrocytes and was not further affected by either transforming growth factor beta 1 or fucoidan. In contrast, dibutyryl cyclic adenosine monophosphate decreased the relative expression of both the ED-A(+) and ED-B(+) forms of fibronectin pre-mRNA. We concluded that the expression of ED-B(+) fibronectin remains relatively high in chondrocytes from cartilaginous canine tissues (15-35%) with the exception of the trachea, in contrast to the less than 10% expression of ED-B(+) fibronectin reported for other non-fetal tissues.

Accumulation of fibronectin in articular cartilage explants cultured with TGF beta 1 and fucoidan

Fibronectin is a glycoprotein involved in cell matrix interactions. In osteoarthritis, fibronectin levels in the lesion cartilage are elevated up to 20-fold above control levels. In these experiments, explants of disease-free cartilage cultured in the presence of a combination of TGF beta 1 and the sulfated fucopolysaccharide, fucoidan, accumulated fibronectin at levels comparable to those found in osteoarthritic lesions. TGF beta 1 increased fibronectin synthesis, most of which was released to the medium. The addition of fucoidan favored retention of the newly synthesized fibronectin within the matrix. The fibronectin which accumulated as a result of these treatments was similar to the fibronectin in normal and osteoarthritic cartilage with respect to the ED-B+ alternative splice form. No change in the proteoglycan content of the cartilage explants with elevated fibronectin levels was detected.

Inefficient processing of human protein C in the mouse mammary gland

Vitamin K-dependent plasma protein, human Protein C (HPC) has been expressed in transgenic mice, using a 4.2 kb mouse whey acidic protein (WAP) promoter, 9.0 kb HPC gene and 0.4 kb 3' flanking sequences. Expression was mammary gland-specific and the recombinant human Protein C (rHPC) was detected in milk at concentrations of 0.1 to 0.7 mg ml-1. SDS-PAGE revealed that the single, heavy and light chains of rHPC migrated with increased electrophoretic mobility, as compared to HPC. Enzymatic deglycosylation showed that these molecular weight disparities are in part due to differential glycosylation. The substantial increase observed in the amount of single chain protein, as well as the presence of the propeptide attached to 20-30% of rHPC, suggest that mouse mammary epithelial cells are not capable of efficient proteolytic processing of rHPC. The Km of purified rHPC for the S-2366 synthetic substrate was similar to that of plasma-derived HPC, while the specific activity was about 42-77%. Amino acid sequence analyses and low anticoagulant activity of purified rHPC suggest that gamma-carboxylation of rHPC is insufficient. These results show that proteolytic processing and gamma-carboxylation can be limiting events in the overexpression of fully biologically active rHPC in the mouse mammary gland.

Regulation of human protein C gene expression by the mouse WAP promoter

A 4.1 kb mouse whey acidic protein (mWAP) promoter was cloned from a C57BL/6 cosmid library. The tissue-specific and developmental pattern of expression of a hybrid gene comprised of the mWAP promoter fragment and the human protein C (HPC) gene was analysed in transgenic mice. The corresponding RNA was detected mainly in the mammary gland, with 'leakage' of expression in the salivary gland and kidney. The developmental pattern of transgene expression differed from that of the endogenous WAP gene. In particular, recombinant HPC (rHPC) transcripts were detected earlier in pregnancy than WAP RNA, with no significant increase during lactation. This indicates that regulatory elements responsible for developmental regulation are located outside the 4.1 kb mWAP gene promoter fragment, or if present, may be subject to position effects. Precocious expression of the transgene did not compromise the health or nursing abilities of transgenic females. Expression of rHPC affected the appearance of the mammary alveoli and alveolar epithelial cells in lactating transgenic mice. The alveoli were less distended and alveolar epithelial cells appeared cuboidal with centrally positioned nuclei. We suggest that the inefficient intracellular processing of rHPC can alter the histological appearance of alveolar epithelial cells in the transgenic mammary gland.

Billings natural family planning in Shanghai, China

With cervical mucus, or Billings, method of family planning, a woman learns to recognize the characteristics of her cervical mucus that identify the fertile phase in her menstrual cycle. She and her partner abstain from sexual activity during a period from the first indication of mucus until four days after the mucus peak day, which includes ovulation. They also abstain during menses, because mucus can be confused with menstrual bleeding. This method of family planning is used widely, worldwide, by couples seeking a natural, reliable method of family planning. Between July 1988 and May 1990, 688 couples of child-bearing age, most of whom were parous, used the Billings method for contraception. Five hundred and fifty of these couples used the method for more than 12 months. Efficacy, continuation rates, and discontinuation rates were analyzed using life-table analysis for 10,175 woman-months of data collected. The net cumulative discontinuation rates per 100 women at 12 and 18 months were 19.85 and 34.58, respectively, resulting in continuation rates of 80.15 and 65.42. The discontinuation rates per 100 women for method-related reasons at 12 and 18 months were 1.61 and 2.84, respectively, while the discontinuation rates for unintended pregnancy were 1.02 and 1.18. During the study, 67 subjects volunteered to have vaginal smears taken from the upper part of the vaginal wall for cytologic examinations, and among them serum and urine LH levels were measured in 10 subjects and urinary estrogen and progesterone were assayed in 35 cases. These tests related other indications of the menstrual cycle to the ability of the women to judge ovulation by cervical mucus. Our research suggests that further investigation of the Billings method is warranted and that careful planning and organization are needed to disseminate the method more broadly.

Operable squamous esophageal cancer: current results from the East

From 1958 through 1992 a total of 3603 patients underwent surgery for esophageal squamous cell carcinoma in our department. Among these patients 3099 resections were performed, for an overall resectability of 86.0%. Of the resections, 2341 (75.5%) were classified as curative and 758 (24.5%) palliative. The overall morbidity and 30-day mortality rates were 23.4% and 3.8%, respectively. For resected cases the mortality was 4.0%. The more than 5-year follow-up rate of patients with resection was 97%. The actual 5-, 10-, and 15-year survival rates were 30.4%, 23.6%, and 17.9%, respectively. Recurrence or metastasis remained the cause of death in 60.9% and 25.5% of patients who lived longer than 5 years and 15 years, respectively, after operation. The TNM staging, lymph node metastasis, extra-esophageal invasion, tumor differentiation, tumor length, and category of operation were major determinants influencing long-term prognosis. The left thoracotomy approach was used exclusively in 2613 cases (84.3% of all resected cases) in which intrathoracic resections and anastomoses were performed. The stomach was used as a substitute for the esophagus in 98.8% of the resected cases compared with 1.2% colon transplants. The former procedure was far safer than the latter. Above-average results presented in this paper support the surgical policy we have pursued thus far: to resect the primary tumor by partial or subtotal esophagectomy and to remove all lymph nodes wherever they were found in all patients with disease earlier than stage III. Early detection and early treatment no doubt are the only ways to materially improve the long-term surgical results.

[Surgical results of neck reconstruction in esophageal cancer located at and above the high mid-thoracic segment--a report of 414 cases]

From July 1960 through 1990, a total of 414 patients with esophageal carcinoma, including cervical 29 cases, upper thoracic 239 cases and high mid-thoracic 146 cases, were operated on with reconstruction in neck. The overall resectability rate was 90.8%. The incidences of anastomotic leakage and recurrent laryngeal nerve injury were 20.5% and 12%, respectively. The resection mortality was 7.4% (within 30 days postoperatively). The 1-, 3-, 5-, 10- and 15-years survival rates were 72.3%, 39.5%, 33.1%, 26.6% and 20.5%, respectively. The authors consider that cervical esophagogastrostomy for reconstruction of esophagus after subtotal esophagectomy is an important method and a routine operative type for the surgical management of esophageal cancer at or above high mid-thoracic segment. The main factors influencing the postoperative long-term results were p-TNM stage, lymph node metastasis and the type of resection, either palliative or curative. The preoperative irradiation might remarkably increase resectability, but hardly improved long-term survival.

[Sleeve (bronchoplastic) lobectomy for the treatment of carcinoma of the lung: report of 135 cases]

135 cases of lung cancer were treated by sleeve (bronchoplastic) lobectomy within 24 years. 90 (66.7%) of them were of squamous cell carcinoma. Postoperative TNM classification showed 81 cases (60.0%) of stage I disease, 33 (24.4%) of stage II, 20 (14.8%) of stage III and 1 (0.7%) of stage IV. Upper lobe sleeve resection was used in 77.7% of the cases (right upper 57, left upper 48). Left upper sleeve lobectomy in 5 cases was accompanied by sleeve resection and reanastomosis of the left main pulmonary artery. One patient (0.7%) died of pulmonary thrombosis. The morbidity rate was 6.6%. Late complications included scar stricture of the anastomosis in 16 cases and recurrence at the site of anastomosis in 5. The 5- and 10-year survival rate was 56.2% and 42.9% respectively. For squamous cell carcinoma in particular, the 5-year survival was 60%. The indications and techniques of this operation are discussed in detail. Sleeve lobectomy had the advantages of preserving as much normal lung tissue as possible while keeping the principle of radical resection uncompromised. The low operative mortality and good long-term survival warrant its popularization.

[Transabdominal termino-esophago-proximal gastrectomy for portal hypertension. An analysis of 61 cases]

The results of transabdominal termino-esophago-proximal gastrectomy in 61 patients with portal hypertension were presented. The patients were followed up for 2 to 7.5 years. Two patients died from the surgery. There was no esophageal varix rebleeding during the follow-up period. We conclude that it is a good method for controlling bleeding varices.

Group IIIA-metal hydroxides indirectly neutralize the voltage sensor of the voltage-dependent mitochondrial channel, VDAC, by interacting with a dynamic binding site

The voltage-dependent, anion-selective mitochondrial channel, VDAC, undergoes two different conformational changes from the open to a closed state under positive and negative applied electric fields. Micromolar quantities of aluminum hydroxide and other metal trihydroxides have recently been shown to be able to inhibit this voltage-dependent closure (Dill et al. (1987) J. Membr. Biol. 99, 187-196; Zhang and Colombini (1989) Biochim. Biophys. Acta 991, 68-78). It was suggested that the inhibition results from the neutralization of the positively charged voltage sensors by the metal species. In the present study, the dynamics of the metal-binding site accompanying channel closure was investigated by adding In(OH)3 to only one side of the membrane and examining its effect on the channel's gating processes. Indium added to open channels inhibited channel closure only when the metal-containing side was on the lower potential side of the applied field. If indium was added only to the higher-potential side, the channels closed and tended to remain closed after the field was abolished. The addition of metal hydroxide after closing the channels with a negative potential on the metal side did not result in channel re-opening as would be expected for sensor neutralization. Inhibition occurred immediately, however, if the channels were first allowed to open briefly. The closed-state selectivity seemed to be very similar in the absence or presence of the metal, indicating that the metal-binding sites are not located within the pore of the channel in the closed conformation. The results are consistent with a voltage-dependent translocation across the membrane of each of two metal-binding sites on VDAC. This translocation is tightly coupled with channel opening and closing.

Inhibition by aluminum hydroxide of the voltage-dependent closure of the mitochondrial channel, VDAC

Micromolar quantities of aluminum have been found (Dill et al. (1987) J. Membrane Biol. 99, 187-196) to reduce the voltage dependence of the mitochondrial outer membrane channel, VDAC, from Neurospora crassa. In the present study, various metallic and organic ions were tested for possible aluminum-like effect, and only the trivalent metals exhibited a similar ability to reduce the channels voltage dependence. However, trivalency alone was not sufficient because lanthanum (III) had no effect. Quantitative analyses with three group IIIA metals (A1, Ga, and In) showed that, of the structural characteristics examined, the ability to form sufficient M(OH)3 at experimental pH was the primary property shared by all the effective metals. While providing new insight into the nature of VDAC's sensor, these results also indicate that aluminum-cell interaction may result from the presence of AI(OH)3 in solution in addition to the widely accepted AI3+-mediated interactions. While the [AI3+] is vanishingly low at neutral pH, the trihydroxide is the major form and should be considered as an important candidate for aluminum-induced cellular effects.

Randomized clinical trial on the combination of preoperative irradiation and surgery in the treatment of esophageal carcinoma: report on 206 patients

From June 1977 to May 1985, a prospective randomized clinical trial on pre-operative radiation for esophageal carcinoma was carried out in 206 patients. Lesions under 8 cm in length and patients younger than 65 years, at least on semi-liquid diet and not contra-indicated for surgery were randomized into a combined group (104 patients) or a surgery alone group (102 patients). Eight MV X ray units were used for the pre-operative radiation using A-P portals to deliver 4,000 cGy to the whole mediastinum and the left gastroepiploic lymphatic chain. Surgery was carried out after 2 to 4 week's rest. The immediate results of the combined group and the surgery alone group were: resection rate 93% and 85%, operative mortality 5% and 6%, intra-thoracic anastomotic leak 0% and 1%, positive pathology at the esophageal stump 0% and 2%, and lymph nodes metastasis 27% and 35% respectively. The 5-year survival rates of the combined group and the surgery alone group were 35% and 30%. We have noticed that those patients with lesions showing radiation reaction of grade III gave a 5-year survival of 50% (12/24). Because intra- and extra-thoracic lymphnode metastasis caused failures (41% and 34% of these two groups), increasing the preoperative tumor dose to 60 Gy or designing post-operative irradiation to cover the bilateral supraclavicular areas was necessary. The whole mediastinum and the left gastroepiploic lymphatics could further improve the results of surgery. Further studies are needed.

[Surgical management of adenocarcinoma of the gastric cardia--experience in 937 patients]

A total of 937 patients with adenocarcinoma of the gastric cardia were operated on within a period of 27 years. The overall resectability rate was 74.5%, the operative mobility was 16.0% and the resection mortality was 1.7% (within 30 days postoperatively). The incidences of anastomotic leakage and pulmonary complications were 3.7% and 3.2%, respectively. These two major complications carried mortality rates of 19.2% and 4.8% and accounted for 50% of the post-operative death. The 1-, 3-, 5-, and 10- year survival rates were 66.9%, 30.0%, 19.5% and 10.3%, respectively. The authors advise regular subtotal proximal gastrectomy when the cancer is confined to the stomach only or extends distally within one third of the lesser curvature. The main factors influencing the long-term results are lymph node metastasis, carcinomatous invasion to gastric serosa and the type of resection, either palliative or curative.