Toripalimab plus axitinib versus sunitinib as first-line treatment for advanced renal cell carcinoma: RENOTORCH, a randomized, open-label, phase III study

BACKGROUND

Immune checkpoint inhibitors in combination with tyrosine kinase inhibitors are standard treatments for advanced clear cell renal cell carcinoma (RCC). This phase III RENOTORCH study compared the efficacy and safety of toripalimab plus axitinib versus sunitinib for the first-line treatment of patients with intermediate-/poor-risk advanced RCC.

PATIENTS AND METHODS

Patients with intermediate-/poor-risk unresectable or metastatic RCC were randomized in a ratio of 1 : 1 to receive toripalimab (240 mg intravenously once every 3 weeks) plus axitinib (5 mg orally twice daily) or sunitinib [50 mg orally once daily for 4 weeks (6-week cycle) or 2 weeks (3-week cycle)]. The primary endpoint was progression-free survival (PFS) assessed by an independent review committee (IRC). The secondary endpoints were investigator-assessed PFS, overall response rate (ORR), overall survival (OS), and safety.

RESULTS

A total of 421 patients were randomized to receive toripalimab plus axitinib (n = 210) or sunitinib (n = 211). With a median follow-up of 14.6 months, toripalimab plus axitinib significantly reduced the risk of disease progression or death by 35% compared with sunitinib as assessed by an IRC [hazard ratio (HR) 0.65, 95% confidence interval (CI) 0.49-0.86; P = 0.0028]. The median PFS was 18.0 months in the toripalimab-axitinib group, whereas it was 9.8 months in the sunitinib group. The IRC-assessed ORR was significantly higher in the toripalimab-axitinib group compared with the sunitinib group (56.7% versus 30.8%; P < 0.0001). An OS trend favoring toripalimab plus axitinib was also observed (HR 0.61, 95% CI 0.40-0.92). Treatment-related grade ≥3 adverse events occurred in 61.5% of patients in the toripalimab-axitinib group and 58.6% of patients in the sunitinib group.

CONCLUSION

In patients with previously untreated intermediate-/poor-risk advanced RCC, toripalimab plus axitinib provided significantly longer PFS and higher ORR than sunitinib and had a manageable safety profile TRIAL REGISTRATION: ClinicalTrials.gov NCT04394975.

[Study on flow field characteristics of dust airflow in vibrating screen and optimization of dust removal system]

In order to solve the problem of dust hazard of vibrating screen machine and difficult treatment in catalyst production process, computational fluid dynamics software Fluent was used to carry out numerical simulation calculation of the local exhaust dust removal system for the main dust dispersing points of the vibrating screen machine, including fine/coarse particles outlet and product outlet blowing and cleaning the dust points. The optimal design scheme and key technical parameters of local ventilation and dust removal system of vibrating screen machine were proposed. The results showed that the dust diffusion could be prevented by setting up an upper suction hood without air blowing, but the exhaust air volume needed to be calculated accurately. On the premise of purge, it is necessary to control the air volume to form a wind speed band of 8 m/s with a height of 15 cm at the feed port, so as to effectively remove the dust on the surface of solid particles of catalyst products and ensure that the catalyst products will not be blown away when falling into the feed barrel. The simulated design was applied to the vibrating sieve powder machine of a catalyst company, and the maximum dust concentration in the workplace was reduced from 45.80 mg/m(3) to 5.46mg/m(3), which effectively improved the working environment in the workplace.

[Establishment and validation of a new predictive equation with multiple risk factors for the development of cardiorenal syndrome type 1 in patients with acute myocardial infarction]

Objective: To investigate the independent risk factors of cardiorenal syndrome type 1 (CRS1) in patients with acute myocardial infarction (AMI) and to build a predictive equation for the development of CRS1 in these patients. Method: Consecutive inpatients with AMI, who hospitalized from January 2017 to December 2018 in the Hunan Provincial People's Hospital, were enrolled in this case-control study. Patients were divided into CRS1 group and non-CRS1 group according to the presence or absence of CRS1.The clinical data were collected through the electronic medical record system of Hunan Provincial People's Hospital. The matching process was conducted with a minimum-distance scoring method and a 1∶1 match between the CRS1 group and the no-CRS1 group, the propensity score was calculated through the logistic regression model. Factors with statistically significant differences in univariate analysis were included in the multivariate logistic regression model to analyze the risk factors of AMI patients with CRS1, then the independent risk factors were used to establish a predicting equation for CRS1 by logistic regression function for model building. Area under the curve (AUC) value and the best cut-off value of the combined predictors was determined according to the ROC curve. Python 3.8 software was used to perform 10-fold cross-validation on modeling samples. Results: A total of 942 patients were included, there were 113 cases in CRS1 group and 829 cases in non-CRS1 group. Ultimately, 99 CRS1 patients were successfully matched to 99 non-CRS1 patient using 1∶1 matching. After propensity score matching, the baseline age and sex along with heart rate, mean arterial pressure, percentage of people with a history of diabetes, hypertension, ST-segment elevation myocardial infarction, myocardial ischemia time, angiotensin converting enzyme inhibitors or angiotensin Ⅱ receptor blockers use, and β receptor blocker use were similar between the two groups(all P>0.05). The contrast agent dosage was also similar between the two groups (P=0.266). The peak cardiac troponin I (cTnI), N-terminal pro-brain natriuretic peptide(NT-proBNP), white blood cell count, base estimated glomerular filtration rate (eGFR), albumin and hemoglobin levels were statistically significant between the two groups (all P<0.05). Multivariate logistic regression analysis showed that decreased baseline eGFR, increased NT-proBNP, peak cTnI concentrations and white blood cell count were independent risk factors of CRS1 in AMI patients (all P<0.01).The predicting equation of the combined predictor was established by transforming the logistic model equation, L=0.031×cTnI+0.000 2×NT-proBNP-0.024×eGFR+0.254×white blood cell count, where L represented the combined predictor. ROC curve analysis indicated that the AUC of the peak cTnI, NT-proBNP, baseline eGFR, white blood cell count, and combined predictor were 0.76, 0.85, 0.79, 0.81, and 0.92 respectively (all P<0.05), and the cutoff value of combined predictor was 2.6. The AUC of ROC curve after the model's ten-fold cross validation was 0.89. Conclusions: Decreased baseline eGFR, increased NT-proBNP, peak cTnI concentrations and white blood cell count are the independent risk factors for CRS1 in AMI patients. The combined predictor equation based on the above 4 biomarkers presents a good predictive value for CRS1 in AMI patients.

[Research advances in neonatal hyperbilirubinemia and gene polymorphisms]

Hyperbilirubinemia is a prevalent disease in neonates and is also a main reason for hospitalization within the first week after birth, and this disease is mainly caused by the imbalance between production and elimination of bilirubin. Uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1), organic anion transporter polypeptide 2 (OATP2), heme oxygenase 1 (HO-1), and biliverdin reductase A (BLVRA) play crucial roles in the metabolism of bilirubin. More and more studies have revealed the association between the variation of the encoding genes for these enzymes and hyperbilirubinemia. This article reviews the research advances in the association between the gene polymorphisms of bilirubin metabolic enzymes and hyperbilirubinemia.

[Analysis of mortality and leading causes of death in Chinese children under 5-year-old between 2010 and 2016]

We collected death data of children under 5-year-old in China from the national child mortality surveillance system from 2010 to 2016. The change of mortality rate and causes of death were described. The mortality rate of Chinese children under 5-year-old decreased from 16.4‰ to 10.2‰ in all areas between 2010 and 2016, from 20.1‰ to 12.4 ‰ in rural areas and from 7.3‰ to 5.2‰ in urban areas, respectively, with a greater average annual decreasing rate in rural areas than urban area. During these years, in addition to traffic accidents and sepsis, other 8 cause-specific mortality rates showed a downward trend. There were substantial decreases of mortality rates of premature birth or low birth weight, birth asphyxia and neural tube defects. In urban areas, the mortality rate of premature birth or low birth weight, birth asphyxia decreased, and the mortality rate of congenital heart disease and diarrhea substantially decreased. However, there was a substantial increase of mortality rate of septicemia in urban areas. In rural areas, the change of major cause-specific mortality rates were consistent with the national trend.

[Current status of hearing loss and related influencing factors in workers with noise exposure in refining and chemical industry]

Objective: To investigate the current status of hearing loss and related influencing factors in workers with noise exposure in refining and chemical industry. Methods: From August 2015 to March 2016, the investigation method of collecting the data of past occupational health examinations and measuring noise in working environment was used to enroll 8 672 male workers. Results: Of all workers, 11.6% were diagnosed with hearing loss. There were significant differences in the distribution of hearing impairment among workers exposed to noise at different ages, device types and types of work (χ(2)=17.80, 77.80 and 30.53, all P<0.05) . The level of noise exposure≥85 dB (A) (OR=5.79, 95%CI 3.70-8.81) , working years with noise exposure (OR=1.57, 95%CI 1.05-2.43) , and 25 years (OR=3.29, 95%CI 2.08-5.71) were risk factors for hearing loss in workers with noise exposure in refining and chemical industry. Conclusion: The level of noise exposure and working years with noise exposure are main influencing factors for hearing loss in workers with noise exposure in refining and chemical industry.

[Efficacy and safety of oseltamivir in children with suspected influenza: a multicenter randomized open-label trial]

Objective: To evaluate the efficacy and safety of oseltamivir in the treatment of suspected influenza in children. Method: A multicenter, randomized and open-label trial was conducted among 229 individuals with suspected influenza which were collected from the clinic of 5 hospitals in Guangdong province (Guangzhou Women and Children's Medical Center, Shenzhen Baoan District Maternity and Child Care Service Center, the Second Affiliated Hospital of Shantou University Medical College, Dongguan Maternity and Child Care Service Centre, Yuexiu District Children's Hospital of Guangzhou) from April to July 2015. They were randomized either to oseltamivir group (oseltamivir 30-75 mg, twice daily for 5 days) or control group who were given symptom relief medicines for 5 days. Result: No significant difference was found between two groups in influenza symptoms of the patients before the treatment(P>0.05). Altogether 229 individuals (114 in oseltamivir group, 115 in control group) were analyzed for efficacy, in which 73 individuals (42 oseltamivir, 31 control), 31.9%, were identified as influenza-infected through laboratory test. No significant difference was found between the two groups in the duration of fever although shortened. In the 229 individuals , the cumulative alleviation proportion between oseltamivir and control group was not significantly different (P>0.05): the median duration of illness was 69.9 hours (95% CI 65.3-91.5) in oseltamivir group and 75.4 hours (95%CI 63.9-91. 7) in control group; the median duration of fever was 40.4 hours (95%CI 31.5-53.4) in oseltamivir group and 44.0 hours (95%CI 33.2-50.0) in control group. In the 73 individuals, the cumulative alleviation proportion between oseltamivir and control group was significantly different (P<0.05). The median duration of illness was 61.2 hours (95%CI 48.0-121. 0) in oseltamivir group, being significantly shorter than that of 116.0 hours (95%CI 91.5-175.0) in control group. But it was not significantly different that the median duration of fever was 32.8 hours (95%CI 24.0-47.0 ) in oseltamivir group and 55.8 hours (95%CI 43.6-78.3 ) in control group (P>0.05). And the median duration of fever in 60 individuals (38 oseltamivir, 22 control) was significantly different between two groups(P<0.05), who had finished a course of taking oseltamivir in the 73 individuals, 34.8 hours (95%CI 24.0-48.5 ) in oseltamivir group being significantly shorter than that of 53.3 hours (95%CI 43.6-104.0 ) in control group. There was certain difference in side effects rate between the two groups (oseltamivir 10%, control 2%, P<0.05). The main side-effects were gastrointestinal symptoms (stomachache, diarrhea, poor appetite, vomiting). Conclusion: The duration of illness and fever in suspected influenza patients treated with oseltamivir was shorter than those in the patients treated with no oseltamivir, the difference was not statistically significant, when 31.9% was confirmed with positive result of virus test in suspected influenza in children. But in these patients with positive result of virus test, the duration of illness was significantly shortened with treatment with oseltamivir as compared with no treatment with oseltamivir, and it would be better if full oseltamivir course was completed for reducing the duration of fever. Oseltamivir treatment was safe with mild side effects.

[Association between CDH23 gene polymorphisms and susceptibility to noise-induced hearing loss in the Chinese population: a meta-analysis]

Objective: To investigate the association between cadherin-23 (CDH23) gene polymorphisms and susceptibility to noise-induced hearing loss (NIHL) in the Chinese population through a meta-analysis. Methods: In June 2016, CNKI, VIP, Wanfang Data, and PubMed were searched for studies on the association between CDH23 gene polymorphisms and susceptibility to NIHL in the Chinese population. The articles were screened according to inclusion and exclusion criteria and related data were extracted. RevMan 5.3 was used for the meta-analysis. Results: A total of three Chinese articles were included. For CDH23-rs1227049, the risk of NIHL in people with C allele was 0.82 times (95%CI 0.39-1.73) that in people with G allele, the risk of NIHL in people with CG+CC genotype in the dominant model was 0.70 times (95%CI 0.34-1.43) that in people with GG genotype, the risk of NIHL in people with CC genotype in the recessive model was 1.23 times (95%CI 0.28-5.43) that in people with CG+GG genotype, and the risk of NIHL in people with CC genotype in the additive model was 1.05 times (95%CI 0.20-5.44) that in people with GG genotype (all P>0.05) . For CDH23-rs1227051, the risk of NIHL in people with T allele was 0.98 times (95%CI 0.71-1.37) that in people with C allele, and the risk of NIHL in people with CT+CC genotype in the dominant model was 1.09 times (95%CI 0.75-1.57) that in patients with TT genotype (both P>0.05) . Conclusion: There is still no enough evidence for the determination of CDH23-rs1227049 and CDH23-rs1227051 to be the susceptibility gene loci of NIHL.

Generating orthogonally circular polarized states embedded in nonplanar geometric beams

We experimentally demonstrated the generation of orthogonally circular polarized states embedded in nonplanar geometric beams. Experimental results revealed that the production of circularly polarized beams, induced by crystal birefringence, is quantized. Numerical analyses of the polarization and the spatial morphology are consistent with the experimental results.

Synthesis, Structures, and Catalytic Properties of Two Silver(I) Coordination Polymers Constructed from 1,4-Bis(benzimidazolyl)butane

Using a hydrothermal synthesis method, two silver(I) complexes, [Ag(bbbm)(1,3-HBDC)]n (1) and [Ag(bbbm)(1,2-HBDC)]n (2) (bbbm = 1,1´-(1,4-butanediyl)bis-1H-benzimidazole, 1,3-H2BDC = 1,3-benzenedicarboxylic acid, 1,2-H2BDC = 1,2-benzenedicarboxylic acid), have been synthesized and characterized by elemental analysis, IR spectra, thermogravimetric (TG) analysis and singlecrystal X-ray diffraction. The silver centers display different environments with a distorted T-shaped geometry in 1, and a linear geometry in 2. Both chain structures of 1 and 2 are bridged by bbbm in a bis-monodentate coordination mode. 1 is further linked to generate a 3D supramolecular architecture via p-p stacking interactions and intermolecular O-H· · ·O hydrogen bonding. In 2, the ribbon-like chains are additionally assembled by two p-p stacking modes to form a layer motif. The photoluminescence of 1 and 2 was investigated in the solid state. 1 and 2 possess a remarkable activity for degradation of methyl orange by persulfate in a Fenton-like process.

1,1′-[1,4-Phenylenebis(methylene)]bis(2-methyl-1H-imidazol-3-ium) 2,4-dicarboxybenzene-1,5-dicarboxylate monohydrate

In the dication of the title compound, C₁₆H₂₀N₄²⁺·C₁₀H₄O₈²⁻·H₂O, the dihedral angles formed by mean planes of the imidazolium rings and the benzene ring are 69.05 (18) and 89.1 (2)°. In the crystal, the components are linked into a three-dimensional network by inter­molecular N—H⋯O and O—H⋯O hydrogen bonds.

Bis(2-propyl-1H-imidazol-3-ium) bis(pyridine-2,6-dicarboxylato-κ3O2,N,O6)cadmate(II)

The title salt, (C₆H₁₁N₂)₂[Cd(C₇H₃NO₄)₂], displays a discrete mononuclear structure, in which the central Cd^II atom is six-coordinated in a distorted octa­hedral coordination geometry by two N and four O atoms from two different pyridine-2,6-dicarboxyl­ate anions in an O²,N,O⁶-tridentate chelation mode. The crystal packing is stabilized by N—H⋯O hydrogen bonds and π–π inter­actions [centroid–centroid distance = 3.576 (5) Å].

Poly[[(1,10-phenanthroline)(μ-l-tartrato)zinc] hexa-hydrate]

The title compouand {[Zn(C₄H₄O₆)(C₁₂H₈N₂)]·6H₂O}_n, has a linear chain structure parallel to [100] with Zn(C₄H₄O₆)(C₁₂H₈N₂) repeat units; the asymmetric unit consists of one Zn²⁺ cation, one l-tartrate dianion, one 1,10-phenanthroline and six free water mol­ecules. The Zn atom is in a distorted octa­hedral ZnN₂O₄ coordination environment. The crystal structure is stabilized by O—H⋯O hydrogen bonds and π–π stacking of the phenanthroline units [centroid–centroid distances in the range 3.552 (2)–3.625 (2)Å] occurs between the chains. The title compound is isotypic with the Cu and Mn analogues.

Hexa-kis-(1-benzyl-1H-imidazole-κN)manganese(II) bis-(perchlorate)

In the title compound, [Mn(C₁₀H₁₀N₂)₆](ClO₄)₂, the Mn^II ion, located on an inversion center, is coordinated by six N atoms from three pairs of symmetry-related 1-benzyl-1H-imidazole ligands in a distorted octa­hedral geometry. In the crystal, weak inter­molecular C—H⋯O hydrogen bonds link the complex cations and perchlorate anions.

[μ-1,4-Bis(1,2,4-triazol-1-ylmeth-yl)benzene]-bis-[aqua-(pyridine-2,6-dicarboxyl-ato)copper(II)] monohydrate

The title compound, [Cu₂(C₇H₃NO₄)₂(C₁₂H₁₂N₆)(H₂O)₂]·H₂O, displays a discrete dinuclear structure, in which the central Cu^II atom is five-coordinated in a distorted square-based pyramidal coordination geometry and the flexible ligand 1,4-bis­(1,2,4-triazol-1-ylmeth­yl)benzene adopts a bis-monodentate bridging mode linking the Cu^II atoms. It is further assembled by O—H⋯O hydrogen-bond inter­actions involving both the coordinated and uncoordinated water molecules. The latter exhibits half-occupancy.

Disruption of the Saccharomyces cerevisiae cell-wall pathway gene SLG1 causes hypersensitivity to the antitumor drug bleomycin

Bleomycin is an antitumor drug that damages DNA via a free radical-dependent mechanism, and yeast mutants defective in DNA repair are hypersensitive to the drug. To identify possible pathways that may contribute to bleomycin resistance in yeast, we characterized a panel of bleomycin-sensitive mutants that were previously isolated by insertion mutagenesis using the transposon miniTn3::Leu2::LacZ::AMP( R). One of these mutants harbored a single insertion in the SLG1 gene, which encodes a cell membrane protein that senses cell wall stress, and functions to maintain cell wall function by activating the protein kinase C signaling pathway. Deletion of the SLG1 gene in parental strains caused hypersensitivity to bleomycin, and this correlated with an accumulation of damaged DNA. A plasmid that expresses the native SLG1 gene or that increases PKC1 gene dosage restored bleomycin resistance to the slg1Delta mutant. Two-dimensional gel electrophoresis revealed that exposure to bleomycin triggered the expression of certain proteins, presumably to maintain cell wall function, in a Slg1-dependent manner. In addition, mutants lacking cell wall function were found to be hypersensitive to bleomycin. We conclude that mutants deficient in proteins that maintain cell wall function are severely compromised in their ability to limit bleomycin entry into the cell. Therefore, these mutants are burdened with increased genotoxicity upon exposure to bleomycin in the medium. Our results show that major mechanisms other than DNA repair are operating in yeast to mediate bleomycin resistance.

Crystal structure of human epidermal growth factor and its dimerization

Epidermal growth factor (EGF) is a typical growth-stimulating peptide and functions by binding to specific cell-surface receptors and inducing dimerization of the receptors. Little is known about the molecular mechanism of EGF-induced dimerization of EGF receptors. The crystal structure of human EGF has been determined at pH 8.1. There are two human EGF molecules A and B in the asymmetric unit of the crystals, which form a potential dimer. Importantly, a number of residues known to be indispensable for EGF binding to its receptor are involved in the interface between the two EGF molecules, suggesting a crucial role of EGF dimerization in the EGF-induced dimerization of receptors. In addition, the crystal structure of EGF shares the main features of the NMR structure of mouse EGF determined at pH 2.0, but structural comparisons between different models have revealed new detailed features and properties of the EGF structure.

Identification of activating transcription factor 4 (ATF4) as an Nrf2-interacting protein. Implication for heme oxygenase-1 gene regulation

Nrf2 regulates expression of genes encoding enzymes with antioxidant (e.g. heme oxygenase-1 (HO-1)) or xenobiotic detoxification (e.g. NAD(P)H:quinone oxidoreductase, glutathione S-transferase) functions via the stress- or antioxidant-response elements (StRE/ARE). Nrf2 heterodimerizes with small Maf proteins, but the role of such dimers in gene induction is controversial, and other partners may exist. By using the yeast two-hybrid assay, we identified activating transcription factor (ATF) 4 as a potential Nrf2-interacting protein. Association between Nrf2 and ATF4 in mammalian cells was confirmed by co-immunoprecipitation and mammalian two-hybrid assays. Furthermore, Nrf2.ATF4 dimers bound to an StRE sequence from the ho-1 gene. CdCl(2), a potent inducer of HO-1, increased expression of ATF4 in mouse hepatoma cells, and detectable induction of ATF4 protein preceded that of HO-1 (30 min versus 2 h). A dominant-negative mutant of ATF4 inhibited basal and CdCl(2)-stimulated expression of a StRE-dependent/luciferase fusion construct (pE1-luc) in hepatoma cells but only basal expression in mammary epithelial MCF-7 cells. A dominant mutant of Nrf2 was equally inhibitory in both cell types in the presence or absence of CdCl(2). These results indicate that ATF4 regulates basal and CdCl(2)-induced expression of the ho-1 gene in a cell-specific manner and possibly in a complex with Nrf2.

Crystallization and preliminary X-ray diffraction studies of human epidermal growth factor

Human epidermal growth factor (hEGF), a 6.2 kDa protein of 53 amino acids with three internal disulfide bridges, has been crystallized by the hanging-drop method. hEGF crystallizes in space group P3(1)21 (or P3(2)21) using MgCl(2) as precipitant, with unit-cell parameters a = b = 61.4, c = 87.0 A. Another type of crystal, obtained using NaCl as precipitant, belongs to a tetragonal point group and has unit-cell dimensions a = b = 102.5, c = 166.6 A. The trigonal crystals with the smaller unit cell diffract X-rays better and a native data set from a single crystal has been collected to 3.0 A resolution.

An allele of the yeast RPB7 gene, encoding an essential subunit of RNA polymerase II, reduces cellular resistance to the antitumor drug bleomycin

Bleomycin is an antitumor drug that kills cells by introducing lesions in DNA. Thus, normal cells exposed to bleomycin must rely on efficient DNA repair mechanisms to survive. In the yeast Saccharomyces cerevisiae, the transcriptional activator Imp2 is required to fend off the toxic effects of bleomycin. However, it remains unclear whether Imp2 controls the expression of a protein that either repairs bleomycin-induced DNA lesions, or detoxifies the drug, and or both. To gain further insight into the mechanisms by which yeast cells mount a response towards bleomycin, we began to sequentially characterize the genetic defect in a collection of bleomycin-sensitive mutants that were previously isolated by mini-Tn3 transposon mutagenesis. A rescue plasmid designed to integrate at the site of the mini-Tn3 insertion was used to identify the defective gene in one of the mutant strains, HCY53, which was not allelic to IMP2. We showed that in strain HCY53, the mini-Tn3 was inserted at the distal end of an essential gene RPB7, which encodes one of the two subunits, Rpb4-Rbp7, that forms a subcomplex with RNA polymerase II. Since rpb7 null mutants are nonviable, it would appear that the rpb7::mini-Tn3 allele produces a protein that retains partial biological function thus permitting cell viability, but which is unable to provide bleomycin resistance to strain HCY53. The defective phenotype of strain HCY53 could be corrected by a plasmid bearing the entire RPB7 gene. Two dimensional gel analysis revealed that the expression of several proteins were diminished or absent in the rpb7::mini-Tn3 mutant when challenged with bleomycin. These results are in accord with our previous report that bleomycin resistance in yeast is controlled at the transcriptional level.

A new furofuran mono-lactone from Forsythia suspensa

A new furofuran mono-lactone, named forsythenin, was isolated from the fruits of Forsythia suspensa, together with the known compounds, ocotillone, ocotillol monoacetate, (6'-O-palmitoyl)-sitosterol-3-O-beta-D-glucoside and palmitic acid. The structure of the new compound was elucidated on the basis of spectroscopic means and X-ray crystallography.

[The structural elucidation of new polyoxygenated cyclohexenes from Uvaria grandiflora]

Four new polyoxygenated cyclohexenes, named uvarigranol A(1), B(2), E(3) and F(4), along with the known zeylenol were obtained from the roots of Uvaria grandiflora Roxb (Annonaceae). Based on spectral and X-ray analysis as well as Mosher methodology, their structures and absolute configuration were established.

[Current status of HIV infection in Yunnan Province of China]

In cooperation with the Chinese Academy of Preventive Medicine and Yunnan Province Provincial Office for AIDS Control and Prevention, we studied the current status of HIV infection intravenous drug users (IVDUs) and other high risk groups in Yunnan province of China. As of the end of 1995, 1,807 HIV cases were officially reported (Positive rate was 0.6%), of which 1,278 (77.9%) were IVDUs, and 24 were their spouses. The majority of cases were found among the Dai minority male farmers near Ruili which borders on Myammar, but HIV also appears to be spreading among the Han people. HIV antibody positive rates among commercial sex workers, pregnant women and blood donors were 0.2%, 0.07% and 0.04%, respectively. A system for surveillance of HIV has been developed, but preventive strategies to cope with HIV epidemic are not sufficient. As HIV/AIDS is now a global issue, (1) the integration and coordination of such preventive strategies in cooperation with community health workers, (2) general health education for condom use promotion and (3) care of psychological vulnerable person such as IVDUs, should be developed.

A Saccharomyces cerevisiae phleomycin-sensitive mutant, ph140, is defective in the RAD6 DNA repair gene

The antibiotic bleomycin is used as an anticancer agent for treating a variety of tumours. The antitumour effect of bleomycin is related to its ability to produce lesions such as apurinic/apyrimidinic sites and single- and double-strand breaks in the cellular DNA. Phleomycin is a structurally related form of bleomycin, but it is not used as an anticancer agent. While phleomycin can also damage DNA, neither the exact nature of these DNA lesions nor the cellular process that repairs phleomycin-induced DNA lesions is known. As a first step to understand how eukaryotic cells provide resistance to phleomycin, we used the yeast Saccharomyces cerevisiae as a model system. Several phleomycin-sensitive mutants were generated following gamma-radiation treatment and among these mutants, ph140 was found to be the most sensitive to phleomycin. Molecular analysis revealed that the mutant ph140 harbored a mutation in the DNA repair gene RAD6. Moreover, a functional copy of the RAD6 gene restored full phleomycin resistance to strain ph140. Our findings indicate that the RAD6 protein is essential for yeast cellular resistance to phleomycin.

Functional mitochondria are essential for Saccharomyces cerevisiae cellular resistance to bleomycin

The antitumor activity of bleomycin is associated with its ability to produce DNA lesions. The cellular process that repairs bleomycin-induced DNA lesions is not entirely clear. To understand how these DNA lesions are repaired in eukaryotic cells, we used mini Tn3 : : LEU2 :: LacZ transposon mutagenesis to isolate yeast mutants that were hypersensitive to bleomycin. One of the mutants, HCY69, was characterized further and found to be 4- and 3-fold more sensitive, respectively, to bleomycin and hydrogen peroxide, as compared to the parent. The mutant displayed parental resistance to a variety of other DNA-damaging agents. Plasmid rescue and DNA sequence analysis revealed that the transposon interrupted the OXA1 gene, which encodes a protein required to process one of the subunits, cox II, of the cytochrome oxidase complex in mitochondria. A plasmid carrying the native OXA1 gene fully restored drug resistance to strain HCY69. Our data strongly suggest that functional mitochondria are required for cellular protection against the toxic effects of bleomycin.

Rearranged taxoids from Taxus yunnanensis

Two rearranged 2(3-->20)abeotaxanes were isolated from the leaves and stems of Taxus yunnanensis, and designated as taxin B and 2-deacetyltaxin B. The structure of taxin B with a unique 6/10/6 skeleton was deduced on the basis of 1H-NMR, 13C-NMR, 1H-1H COSY, DEPT, NOE, and mass spectra and confirmed by X-ray crystallographic analysis. The structure of 2-deacetyltaxin B is elucidated by analog.

[Clinical study of sperm intro-fallopian transfer]

To explore the new technique of assistant pregnancy, we transferred sperm into fallopian tubes by laparoscopy Via an operation named sperm intra-fallopian transfer (SIFT). Twenty-nine infertile women (eighteen patients in natural menstrual cycle group, the others in the group of stimulated ovulation cycle) had their fallicle development with B ultrasonic scanning monitored. Patients were examined by laparoscopy before ovulation, then prepared sperm was transferred into fallopian tubes. Amony twenty-nine patients who had SIFT, three were pregnant in the operation month. The rate of pregnancy in operation month was 10. 3%, The rate of pregnancy during six months after SIFT was 31.0% (9 cases). Amony fifteen patients with "real" unexplained infertility, the rate of pregnancy during six months after SIFT was 46.7%. This preliminary result, showed that on the basis of skilled technique of laparoscopy, SIFT is a new, simple, safe, economic and effective method in treating infertility.

Pharmacokinetic study of RU 486 and its metabolites after oral administration of single doses to pregnant and non-pregnant women

RU 486 and three of its metabolites (RU 42633-monodemethyl, RU 42848-didemethyl, and RU 42698-hydroxymetabolite) were determined by HPLC in plasma from nine non-pregnant and 36 pregnant women. Each non-pregnant subject took an oral dose of RU 486 (25, 100, 400 and 600 mg consecutively) once per menstrual cycle. Six of the nine women also received a dose of 200 mg. The 36 pregnant women were randomized into four groups which were given a single dose of 25, 100, 400 or 600 mg RU 486. Blood samples were taken up to 120 h after dosing. Peak concentrations of RU 486 occurred on most occasions within 2 h. Plasma concentrations at 1 h and at 24 h increased in proportion to log dose. There was a wide variability (up to ten-fold) in the pharmacokinetic parameters within each dose group. Plasma concentrations of RU 42633 were similar to those of RU 486 but concentrations of RU 42848 and RU 42698 were much lower. As with RU 486, the plasma concentrations of the metabolites were maintained at high levels for up to 48-72 h after dosing. The findings were consistent with a rapid metabolism of RU 486 to RU 42633; removal of the second methyl group leading to RU 42698 occurred much more slowly and to a much less extent than removal of the first. There appeared to be no significant differences between the non-pregnant and pregnant women in either the plasma concentrations or pharmacokinetic parameters of RU 486 and its metabolites.

A multicenter clinical study on two types of levonorgestrel tablets administered for postcoital contraception

Contraceptive efficacy, cycle control and side effects of two types of 0.75 mg levonorgestrel tablets taken postcoitally during the periovulatory period of one cycle were studied in a multicenter trial involving 361 women. No significant differences were found between the two types of levonorgestrel pills in terms of contraceptive efficacy, cycle control and side effects. The failure rate observed (1.4% per treated cycle) was similar to that reported for other hormonal approaches to emergency postcoital contraception. Intermenstrual bleeding or spotting occurred in 11.5% of the cycles and anovulation as assessed from BBT charts in 14.4% of cycles. One or more side effects were reported by 22.2% of subjects. The relatively frequent occurrence of cycle disturbances and subjective side effects make it unlikely that the repeated postcoital use of levonorgestrel would be an acceptable routine method of contraception for most women.

Comparative cross-over pharmacokinetic study on two types of postcoital contraceptive tablets containing levonorgestrel

A pharmaceutical and pharmacokinetic study was carried out on levonorgestrel tablets from two different sources (Hungarian- and Chinese-made). Both preparations contained 0.75 mg levonorgestrel and had been shown to have similar contraceptive efficacy and side effects when used for postcoital contraception. Absorption and bioavailability of the Hungarian-made tablets were greater as evidenced by higher serum concentrations of levonorgestrel, a greater area under the concentration-time curve during the first 24 hours, and a more marked suppressive effect on SHBG levels. These differences most probably reflect differences in their pharmaceutical formulation, in particular the extent of tablet dissolution and the degree of micronisation of levonorgestrel.

Isolation and structure elucidation of armillaricin1

From the petroleum ether extracts of the artificially cultured mycelium of ARMILLARIA MELLEA, a novel sesquiterpenoid aromatic ester named armillaricin has been isolated by silica gel column chromatography. Its structure was deduced from spectral data and confirmed by single-crystal X-ray analysis.

Pharmacokinetic study of orally administered RU 486 in non-pregnant women

A method based on HPLC was devised for the estimation of RU 486 in blood and utilised to study the pharmacokinetics of a single dose of 50 mg RU 486 administered orally to 12 women on day 7 of the cycle. The dose was rapidly absorbed with peak plasma concentration between 1 and 2 hours. Distribution was also rapid (mean t1/2 alpha: 1.4h), whereas elimination was slow (mean t1/2 beta: 28.3 h). RU 486 was still detectable in some women at 72 h after administration. The plasma concentrations fitted the equation for a two-compartment open model from which the pharmacokinetic parameters were calculated. The mean total plasma clearance was 3.0 l/h, and the comparison of our data with those published studies suggests that the pharmacokinetics of RU 486 in Chinese women are similar to those of other populations.

Pharmacokinetic study of levonorgestrel used as a postcoital agent

The pharmacokinetics and pharmacodynamics of levonorgestrel (LNG) were studied in six women given 0.75 mg LNG orally for seven days during the periovulatory phase of the menstrual cycle. Steady-state concentrations of LNG were reached within three days and serum LNG concentrations at various times on day 7 were generally lower than on day 1, presumably due to a reduced serum level of SHBG. On day 7 the volume of distribution was significantly increased and Co significantly decreased and both the clearance and elimination half-life were higher on day 7 than on day 1. Half-lives varied from 5.6 to 25.1 hours. The day-to-day intra-subject variations in serum LNG concentrations ranged from 23% to 80%. Serum concentrations of pituitary and ovarian hormones suggested that ovulation was not inhibited in four of the six subjects and was delayed in the remaining two. No significant changes in serum prolactin levels were observed.

Structure determination of kanglemeisu A by X-ray diffraction method

Kanglemeisu A (C50H63O19B.CH3OH) is the product of an actinomyces species from a soil sample gathered in China Kanglemeisu A belongs to the triclinic system, space group P1, unit cell: a = 12.760(3), b = 10.287(2), c = 9.926(2) A, alpha = 88.39(2), beta = 78.64(2), gamma = 89.14(2). RANTAN direct method is used to solve the structure. The final discrepancy factor is R = 0.0689, after atom coordinates and temperature factors have been refined with full matrix least squares. The structure skeleton consists of four parts, the naphthalene nucleus connected to the 5-membered ring, a 17-membered ring connected to C2, a dimethyl butane diacid extended out from C20, beta-D-3,4-OO' methylenedigitoxose passing through an oxygen bridge O6 and linked to C27 of ansa ring.

Pharmacokinetics of norethisterone in humans

The pharmacokinetics of a dose of 1mg norethisterone administered with 50 micrograms ethynyloestradiol was studied in 83 subjects. The dose was rapidly absorbed and there were wide variations in the serum NET concentrations at any particular time after dosing; the concentrations at 24 h varied from 100 to 1700 pg/ml. There was a significant negative correlation between the serum NET concentration and the time after dosing in all women. There were large inter-subject variations in the pharmacokinetic parameters, the elimination half-life and bioavailability showing 3- and 5- fold variability, respectively. Mean values for the parameters were t1/2, 7.6 h; bioavailability, 53.6 ng/ml/h; C max, 4.63 ng/ml; clearance, 22.6 l/h; and Vd 2361. There were a number of statistically significant correlations between the pharmacokinetic parameters and analysis of the correlations suggested that clearance was an important determinant of the bioavailability and of C max whereas the elimination half-life was the determinant of the NET concentration at 24 h. The pharmacokinetics of NET are compared with those of ethynyloestradiol. The wide variation in pharmacokinetics is likely to be important in determining inter-subject variations in efficacy and, particularly, side-effects of oral contraceptives especially now that low-dose formulations are widely used.

PD 116,152, a new phenazine antitumor antibiotic. Structure and antitumor activity

A new, highly substituted phenazine with antitumor activity was isolated from the culture broth of a Streptomyces sp. This compound, whose structure was determined by spectroscopic methods and verified by X-ray diffraction analysis, was found to be methyl 6-formyl-4,7,9-trihydroxy-8-methyl-1-phenazinecarboxylate.