Non-ergodic extended regime in random matrix ensembles: insights from eigenvalue spectra

The non-ergodic extended (NEE) regime in physical and random matrix (RM) models has attracted a lot of attention in recent years. Formally, NEE regime is characterized by its fractal wavefunctions and long-range spectral correlations such as number variance or spectral form factor. More recently, it's proposed that this regime can be conveniently revealed through the eigenvalue spectra by means of singular-value-decomposition (SVD), whose results display a super-Poissonian behavior that reflects the minibands structure of NEE regime. In this work, we employ SVD to a number of RM models, and show it not only qualitatively reveals the NEE regime, but also quantitatively locates the ergodic-NEE transition point. With SVD, we further suggest the NEE regime in a new RM model-the sparse RM model.

[Comparison of early postoperative effects between anterior bladder and posterior bladder approaches in robotic assisted laparoscopic radical prostatectomy]

Objective: To examine the effect of robotic assisted laparoscopic radical prostatectomy with different approaches on early postoperative effects. Methods: Totally 44 patients (average age of 65.9 years, range: 46 to 81 years) underwent robotic assisted laparoscopic radical prostatectomy by a single operator at Department of Urology, Peking Union Medical Collage Hospital from March 2018 to March 2020 were retrospectively analyzed. The mean age was 65.9 years (range: 46 to 81 years), including 24 cases in the anterior bladder approach group (anterior approach group) and 20 cases in the posterior bladder approach group (posterior approach group). The preoperative clinical data, perioperative related data and postoperative urinary control recovery were compared between the two groups by t test, χ² test or Fisher exact test. Results: In terms of clinical data, there was no difference in age, prostate volume, preoperative prostate specific antigen and Gleason score(all P>0.05). There was no significant difference in operation time ((184±43) minutes vs. (193±42) minutes, t=-0.599, P=0.55), bleeding volume ((218±88) ml vs. (225±115) ml, t=-0.244, P=0.81), postoperative stage (T2/T3: 15/9 vs. 12/8, χ²=0.029, P=0.87) and positive rate of cutting edge (29.2% (7/24) vs. 30.0% (6/20), χ²=0.004, P=0.95). In terms of postoperative urinary control, patient rates who achieved urinary control immediately after extubation was significantly higher for the posterior approach group than the anterior approach group (30.0% (6/20) vs. 4.2% (1/24), P=0.04). There was no significant difference between two groups for those who achieved urinary control 3 months after operation (6 cases vs. 11 cases, P=0.06), 6 months after operation (20 cases vs. 19 cases, P=0.36) and those who achieved urinary control 12 months after operation (23 cases vs. 19 cases, P=1). Conclusion: For robotic assisted laparoscopic radical prostatectomy, the posterior approach does not prolong the operation time, does not increase the amount of bleeding, and improves the short-term postoperative urinary control.

[Surgery treatment of ectopic adrenocorticotrophic hormone syndrome]

OBJECTIVE

To investigation the diagnosis and treatment of ectopic adrenocorticotrophic hormone (ACTH) syndrome.

METHODS

The clinical characters of 57 cases of ecotopic ACTH syndrome from Jan. 1996 to Dec. 2016 were collected and analyzed. The 57 cases included 32 males and 25 females. The age ranged from 11 to 68 years (average 32 years). ACTH levels significantly increased from 16.5 to 365.6 pmol/L, with average 77.6 pmol/L (normal range <10.1 pmol/L). The pituitary MRI did not found lesions. The CT showed that their bilateral adrenal glands diffused small nodular changes or nodular hyperplasia. The 57 cases were divided into 3 groups according to different treatment options. In the study, 25 ectopic ACTH syndrome cases (44%) were group A, without identified source of ectopic hormone, were treated with bilateral or unilateral adrenalectomy due to the severity of the disease and difficulty of operation. Group B was composed of 16 cases (28%) diagnosed as ectopic ACTH syndrome by finding ectopic ACTH tumors and surgical resection. Group C included 16 cases (28%) with nonsurgical therapy. Different treatment results and prognosis were analyzed.

RESULTS

In the study, 40 cases of the 57 had been followed up for 6 months to 10 years. In group A, of the 25 cases with bilateral or unilateral adrenalectomy, 4 died of diabetes and severe pulmonary infection, 18 survived, and 3 were lost to the follow-up, and the survival rate was 81% (18/22). In group B, of the 16 cases with radical tumor resection, 5 died of tumor recurrence 0.5-6.0 years after operation, 3 survived, and 8 were lost to the follow-up, and the survival rate was 37.5% (3/8). In group C, of the 16 non-operation patients, 4 with radiotherapy and chemotherapy died of metastases, diabetes or pulmonary infection, 6 with chemotherapy died of pulmonary infection within 1 year and the others were lost to the follow-up, and the survival rate was 0.

CONCLUSION

Ectopic ACTH syndrome is difficult to treat. Adrenalectomy is effective for the management of ectopic ACTH syndrome, especially for those patients with severe Cushing's syndrome, but the primary tumor can not be located.

[Effects of Electroacupuncture on Hippocampal nNOS Expression in Rats with Anxiety-like Behavior]

OBJECTIVE

To compare the effects of electroacupuncture (EA) preconditioning and post-conditioning on hippocampal neuronal nitric oxide synthase (nNOS) expression in rats with anxiety-like behavior, so as to explore the reasonable EA intervention time.

METHODS

Forty-two SD rats were randomly divided into 6 groups:normal 1, normal 2, anxiety model 1, an-xiety model 2, EA-pre-conditioning and EA-post-conditioning. The anxiety model was established by giving the rats with repeated foot shock stimulation (0.8 mA, 2-25 s/time, 10 times in 5 min) combined with isolation-raising. Before or after modeling, EA stimulation was applied to "Baihui" (GV 20) and "Yintang" (GV 29) for 20 min, once a day for 7 days. Elevated plus maze (EPM) tests were performed to determine the percentages of time spent in the open arms and the percentages of entries into the open arms in 5 min for evaluating the animals' anxiety-like behavioral activities. The reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect hippocampal nNOS mRNA expression and the immunohistochemical staining adopted to detect the expression of nNOS protein in the hippocampal CA 1 and CA 3 areas, respectively.

RESULTS

Compared with their own normal control group 1 and 2, both the percentage of time spent in the open arms and the percentage of entries into the open arms were significantly decreased in model group 1 and 2 (P<0.05, P<0.01). After pre- and post-conditioning of EA, the decreased proportions of time spent and entries into the open arms were considerably increased (P<0.05), suggesting an improvement of anxiety-like behavior activities after EA intervention. The expression levels of hippocampal nNOS mRNA and nNOS protein in the hippocampal CA 3 region were significantly higher in the model group 1 and 2 than in their own normal control group 1 and 2 (P<0.01), but those of nNOS protein in the CA 1 area were markedly lower in the model group 1 and 2 than in their own normal control group 1 and 2 (P<0.01). Following pre- and post-conditioning of EA, the increased expression levels of nNOS mRNA and protein of CA 3 area and the decreased level of nNOS protein of CA 1 area were all notably reversed (P<0.05, P<0.01).

CONCLUSIONS

Both pre- and post-conditioning of EA can improve anxiety-like behavior in anxiety rats, which may be associated with its effects in down-regulating hippocampal nNOS expression.

HDAC6: physiological function and its selective inhibitors for cancer treatment

Acetylation and deacetylation of histones are important in regulating gene expression and play a key role in modification of gene transcription. Specific HDACs isoforms can be regarded as a target for cancer therapy avoiding side-effects, HDAC6 with a unique physiological function and structure has become a hot issue recently. The unique isoform HDAC6 is involved in tumorigenesis, development and metastasis through tubulin, HSP90, invasin and ubiquitin-protein. Here we review the structure elements, biological function, and recent selective inhibitors of HDAC6, and study the structure-activity and structure-selectivity relationship.

A new boronic acid-based fluorescent sensor for L-dihydroxyphenylalanine

Catecholamines, such as dopamine and L-dihydroxyphenylalanine (L-DOPA), are associated with different physiological functions and diseases. In our recent studies, a novel water-soluble boronic acid compound 3c was identified as a selective fluorescent sensor for L-DOPA. This compound not only has the ability to interact with dopamine and catechol, but also has no fluorescence intensity change for L-DOPA precursors in vivo, such as L-tyrosine.

A new partial trisomy 12p with artery catheter vagus, congenital cataracts, external auditory canal, and no turbinate

We describe the prenatal diagnosis and fetal phenotype of partial trisomy 12 (p12-pter) transmitted from a maternal reciprocal translocation 6;12. Genetic analysis was conducted on umbilical cord blood for a fetus accompanied with tricuspid regurgitation and orbital hypertelorism from a 27-year-old gravida 4, para 1 after sonography at gestation 35 weeks. The karyotype was unusual, with 46, XY, der (6), t (6;12) (p24; p12) mat. The pregnancy was terminated at 37 gestational weeks. The aborted fetus displayed dysmorphic features of a round flat face with prominent cheeks and high forehead, hypertelorism, short nose, broad and depressed nasal bridge, anteverted nares, deformed philtrum, open mouth, thin upper vermilion and broad everted lower lip, low-set ears and aural atresia, broad hands with simian creases, and a short neck. Fetal anatomy showed right artery catheter vagus, congenital cataract, no turbinate and external auditory canals. Through karyotype-phenotype analysis of this patient and a review of other reported cases, we believe this is a first report that expands the database of partial trisomy 12p, and is beneficial for future clinical genetic counseling. This study supports that phenotypic variability depends on the type and extent of the associated partial monosomy.

Expression, purification, and S-nitrosylation of recombinant histone deacetylase 8 in Escherichia coli

Histone deacetylase (HDAC) 8 is a zinc ion dependent enzyme involved in removing the acetyl group from the core histones and other proteins which belong to Class I HDACs. It was reported that nitric oxide (NO) is a key regulator of HDAC function and S-nitrosylation of HDAC2 induces chromatin remodelling in neurons. This work reports the successful recombinant expression of human HDAC8 in Escherichia coli with two plasmids and the purification and S-nitrosylation in vitro. It was found that HDAC8 can be S-nitrosylated by the NO donor S-nitrosoglutathione (GSNO) in vitro, and the activity of HDAC8 was significantly inhibited when incubated with GSNO and S-nitrosocysteine in a time- and dosage-dependent manner, but sodium nitroprusside (SNP), and dithiothreitol cannot reverse this inhibition. These observations support and extend the concept that NO may regulate HDAC8 function by S-nitrosylation.

Design, synthesis, and primary activity evaluation of pyrrolidine derivatives as matrix metalloproteinase inhibitors

A series of novel pyrrolidine derivatives was designed, synthesized, and assayed to determine the derivatives' activity against matrix metalloproteinase-2 (MMP-2) and aminopeptidase N (APN)/CD13. Preliminary biological tests showed that most compounds inhibit MMP-2 in a highly selective manner compared to APN. Compounds 9d, 9e, and 9g had better inhibitory activity than LY52 and could be used as lead compounds in the future.

A microplate-based screening assay for neuraminidase inhibitors

Neuraminidase (NA) represents a highly promising new target for drug development in influenza virus genes. Rapid screening of enzyme inhibitors is a key method for the identification of leading compounds. In order to speed up the screening for enzyme inhibitors of natural and synthetic origin, effective and fast assays are needed. 2'-(4-Methylumbelliferyl)-α-D-N-acetylneuraminic acid (4-MUNANA) was selected as substrate for development of a microplate-based assay. The enzymatic reaction conditions were optimized as follows: in a 100 μL reaction mixture, the final concentrations were 32.5 mM sodium acetate (pH 3.5), 20 μM 4-MUNANA, 0.005% (w/v) bovine serum albumin, and 0.42 μg/mL NA. In the study, the doseresponse relationship of oseltamivir carboxylate to NA activity was observed. In addition, an overall Z' value of 0.8 proved the systems robustness and potential for screening. The assay system developed will be a valuable tool to discover new structures for the therapeutic inhibition of NA used to treat Influenza.

Direct effects of fascaplysin on human umbilical vein endothelial cells attributing the anti-angiogenesis activity

Novel anti-angiogenesis activity of fascaplysin via VEGF blockage was recently revealed by our previous study in addition to the reported cyclin-dependent kinase 4 (CDK4) selective inhibition. To uncover more details of this pharmacologically prospective property, this study further investigated whether fascaplysin had direct anti-proliferation effects on human umbilical vein endothelial cells (HUVEC), which might be contributing to anti-angiogenesis. The results showed that G1 cell cycle arrest was induced by 2.6 μM fascaplysin in a time-dependent manner, and exhibited more sensitive than hepatocarcinoma cells BeL-7402 and Hela cells. Approximately 56.09 ± 2.63% of the cells were arrested at the G1 phase after 24h, and 64.94 ± 2.07% after 36 h, comparing to the 22.82 ± 1.2% in methanol treated cells. Apoptosis of HUVEC cells was induced by 1.3 μM fascaplysin and indicated by the sub-G1, Hoechst staining, terminal deoxynucleotidyl transferase dUTP-mediated nicked end labeling (TUNEL) assay, and annexin-V and propidium (PI) label. This apoptosis response was further confirmed by the detection of active caspase-3 and by western blotting using antibodies against Bax, Bcl-2, procaspase-8, and Bid, indicating that apoptosis in HUVEC cells may involve a mitochondria pathway, by the demonstration of an increase in the Bax/Bcl-2 ratio. Together, our results suggest that the anti-angiogenesis activity of fascaplysin is through the direct effects of cell cycle arrest and apoptosis on HUVEC.

QSAR studies of histone deacetylase (HDAC) inhibitors by CoMFA, CoMSIA, and molecular docking

In order to develop highly potent antitumor agents, three-dimensional quantitative structure-activity relationship (3-D QSAR) studies were conducted using a series of thienyl-based hydroxamic acids. Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods were applied to provide the structural information for further chemical modification and optimization. ClogP was applied as an additional descriptor in the CoMFA analysis to study the effects of lipophilic parameters on the activity of these compounds, and it did improve the statistical significance of the model. Two molecules were designed based on the 3-D QSAR analysis, their activity values were predicted by the generated model, and their binding mode was elucidated by a docking approach compared to molecules in the dataset.

The main functions and structural modifications of tripeptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) as a chemotactic factor

Gram negative bacteria-derived and synthetic N-formyl peptides play a key role in host defense as chemotactic factors for phagocytic leukocytes. The first compound to be identified was N-formylmethionyl-leucyl-phenylalanine (fMLP) which contains highly potent leukocyte chemoattractant. Natural fMLP was subsequently purified and identified in supernatants of gram negative bacteria. Recently, much more attention has been focused on the human formyl peptide receptor (FPR) and its variant formyl peptide receptor-like 1 (FPRL1) and formyl peptide receptor-like 2 (FPRL2). Chemotactic factors such as fMLP interact with their specific cell surface receptors, which results in multiple biological responses through a G protein-coupled signal pathway. In this review, the functions and structural modifications of fMLP are discussed in view of future drug development.

Novel N-hydroxybenzamide histone deacetylase inhibitors as potential anti-cancer agents

Histone deacetylases (HDACs) are a class of Zn(2+) dependent metalloproteases that play an important role in tumorigenesis. Inhibition of HDACs may be a potential strategy for cancer therapy. This study designed and synthesized a series of novel N-hydroxybenzamide histone deacetylase inhibitors based on the structural features of suberoylanilide hydroxamic acid (SAHA), the first HDAC inhibitor that came to market. Preliminary biological evaluation in vitro found that most of the inhibitors had satisfactory inhibitory activity (IC(50) =1-17 μM) against HDACs and HCT116 tumor cells.

3D-QSAR study with pharmacophore-based molecular alignment of hydroxamic acid-related phosphinates that are aminopeptidase N inhibitors

3D-QSAR models for a series of aminopeptidase N inhibitors were developed based on comparative molecular field analysis (CoMFA) and comparative molecular similarity analysis (CoMSIA).GALAHAD, a pharmacophore generation module involving a genetic algorithm, was used to generate the pharmacophore model of the series of inhibitors. Molecules both in the training set and test set were aligned to the pharmacophore model. Values for the CoMFA model were r(2) = 0.992, q(2) = 0.586, SEE = 0.111, and F (8, 10) = 191.263. Values for the CoMSIA model were r(2) = 0.990, q(2) = 0.776, SEE = 0.123, and F (7, 11) = 156.68. This model can help not only in improving current understanding of enzyme-ligand interactions but also in predicting the activity of derivatives and designing new compounds with better potency.

China's efforts to shed its title of "Leader in liver disease"

According to Xinhua News, Chen Zhu, China's Minister of Health, mentioned at the 2007 Annual Conference of the China Association for Science and Technology (CAST) that an action plan for the diagnosis and treatment of hepatitis B could control hepatitis B virus (HBV) infection to below 1% by 2050. This plan is one of the Health Ministry's goals for middle-long-term development planning in medical science and technology that China is endeavoring to reach (http://hbv.39.net/079/18/127612.html, available as of September 18, 2007). The Ministry's strategy involves a series of action plans for other areas like HIV, tuberculosis, malignant tumor control, and mental health, but chronic HBV therapy is more important and more urgent. HBV infection is a leading cause of illness and death in China. Approximately 60% of the population has a history of HBV infection, and 9.8% of persons in China are chronically infected with HBV and at risk for premature death from liver disease. Each year, an estimated 263,000 persons in China die from HBV-related liver cancer or cirrhosis, accounting for 37%~50% of HBV-related deaths worldwide (Available as a report from the Centers for Disease Control and Prevention (CDC), 2007;56:441-445. http://www.cdc.gov/mmwr/previe / mmwrhtml/mm5618a2.htm, May 11, 2007). Besides China, HBV is highly prevalent in approximately 45% of the global population and is found in the Far East, parts of the Middle East, sub-Saharan Africa, parts of South America, and the Amazon basin, where at least 8% of the population are HBV chronic carriers (hepatitis B surface antigen [HBsAg] positivity rates > 8%) (Figure 1) (Int J Med Sci 2005;2:50-57). China seems to have become a "Leader in liver disease." Annually, more than 1,000 billion RMB is spent on HBV therapy and prevention, while the resulting indirect economic losses are inestimable. The reasons for the high rates of chronic HBV infection in China are complex. First, HBV infection has broad clinical manifestations, including asymptomatic carriers, acute hepatitis, and chronic (lifelong) hepatitis, due to different immune reactions by the host. However, little is currently known about the mechanisms for HBV's unremitting infection and long-term nonprogressive HBV infection of asymptomatic HBV carriers. Although a safe and effective vaccine against HBV has been available since 1982, there are still approximately 5~10% nonresponders to the hepatitis B vaccine. Moreover, little is known about the possible immunogenetic mechanisms of HBV-infected individuals developing cirrhosis and hepatocellular carcinoma, which are considered to be the biggest bottleneck for HBV therapy. Second, some social factors may explain the high rates of HBV infection. The public often pales at the mention of HBV infection, but they have incorrect perceptions or little knowledge about how hepatitis B is transmitted, resulting in inadequate self-prevention, unfounded prejudices, or unfair treatment of the chronically infected. Worse, even many physicians are not aware of the risk, the association between hepatitis B and liver cancer, the importance of HBV vaccination to prevent infection, and the need for carriers to have regular liver cancer screening. The latter is important because a carrier is an infected individual who does not develop the disease but can transmit the virus to others. Research has proven that the hepatitis B virus is mainly transmitted through body fluids like blood, semen, vaginal or menstrual secretions, serum, and wound exudates, and the virus has also been found in saliva, amniotic fl uid, tears, urine, feces, sweat, and mother's milk (Int J Med Sci 2005;2:50-57). Thus, people should actively acquire HBV-related knowledge, perform good hygiene, and heighten individual awareness of prevention to contain the transmission of HBV, which is of great importance to everyone. Finally, poor living habits are another important factor. In most rural areas in China, and especially in the poverty-stricken areas inhabited by smaller ethnic groups, people still lead poor lifestyles and have poor health habits, leading to their decreased immunity to HBV. This, to a certain extent, may be attributed to the inadequate public health advertising and financial input of the Government. Except in some large general hospitals, the sanitary conditions of most hospitals and rural health clinics still need to be improved, including a system of social relief and assistance. Another important aspect is attributed to people's lack of awareness concerning regular physical examinations. Many chronically infected individuals may not know that they have been infected because they feel perfectly healthy. By the time symptoms develop, however, action will be too late. The public is glad to see that a series of measures have been taken by Chinese authorities to provide effective HBV treatment and prevention. For instance, the "Wang Bao-En hepatic fibrosis research fund" was established by the China Foundation for Hepatitis Prevention and Control (CFHPC) on January 30, 2007 for the financial support of HBV research (Xinhua News, http://news.xinhuanet.com/health/2007-02/02/content 5687887.htm, available as of February 2, 2007). Similarly, the " Vaccination against Hepatitis B & Health Education Program," supported by the CFHPC, the Asian Liver Center at Stanford University, and several philanthropic foundations in Hong Kong, was formally inaugurated on August 31, 2007 to provide students of Qinghai Province with free and fullrange protection with hepatitis B vaccination (CFHPC News, http://www.cfhpc.net/CN/News/Detail.asp?gCatalogID=3&SystemID=79, available as of August 31,2007). The PRC is currently forming exceptional scientific teams, both from clinical and research institutes, to study the integrity, development, and natural history of HBV as well as mechanisms for unremitting HBV infection in terms of aspects such as the virus, host, and environment. In the meantime, researchers are endeavoring to develop novel anti-hepatitis virus drugs pursuant to the "Guideline for Prevention and Treatment of Chronic Hepatitis B" enacted at the end of 2004. As Health Minister Chen Zhu said, "China must cast its title of 'Leader in liver disease' into the Pacific Ocean because," he added, "we already have an extremely effective vaccine against HBV."

China's new drug R&D is steadily advancing

China appears to consistently lag behind developed countries like the US, Japan, and the nations of Europe in the development of pharmaceuticals, putting China in an embarrassing situation. In fact, China is still dependent on foreign imports for most highly effective cures to major diseases such as cancer, diabetes, hepatitis, and neurodegenerative disease. There is no denying the fact that governmental support, and especially a signifi cant amount of fi nancial support and political assistance to include government restructuring, is needed for the establishment of new drug Research and Development (R&D). Fortunately, China's authorities have recently recognized the importance of new drug development and have committed to implementing strong measures to help establish new drug R&D. This improvement in the government's status is showing immediate and substantial promise in the field of pharmaceuticals. On January 4, 2007, a research group directed by Wang Ming-Wei, Head of the National Center for Drug Screening, Shanghai Institute of Materia Medica (SIMM), made a breakthrough in the development of novel category I anti-diabetes drugs with the support of the Ministry of Science & Technology of China, the National Natural Science Foundation (NSFC) of China, and the Shanghai municipal government. Taking almost four years, the group finally developed a nonpeptide agonist of small molecule glucagon-like peptide 1 receptors with effi cacy in diabetic db/db mice (Proc Natl Acad Sci U S A 2007;104:943-948). As an antidiabetes drug, a peptide hormone traditionally had to be taken as an injection, which greatly limited its clinical application. In contrast, the new compound can be taken orally. This offers hope for the development of a new field of peptidomimetics for orally-available nonpeptide small molecules. Today, the ever-growing prevalence of major diseases worldwide is driving growth in new drug spending, encouraging the marketing of newly developed and effi cacious therapies. This achievement appears to have significantly boosted the field of new drug research in China. While "China's pharmaceutical firms lag far behind [their Western counterparts] in terms of biological preparations" "today's achievement, with the attention it has garnered, has important scientific signifi cance and potential social and economic value," said Chen Zhu, the minister of health PRC and also the former associate dean of the China Academy of Sciences (http://www.simm.ac.cn/News/20071417649.htm , available as of January 4, 2007). Other encouraging news came from the Shanghai Life Sciences Institute. A novel anti-HIV compound named Nifeviroc was developed with the support of the municipal government and licensed for clinical trials on April 17, 2007 (Shanghai Daily, April 17, 2007). This is expected to become the world's first oral HIV entryinhibitor. Thus far, applications to patent Nifeviroc have been submitted in 14 countries and regions, including the United States, Japan, and the European Union. Recently, Shanghai Targetdrug Pharmaceutical Company and Avexa, a Melbourne-based drug-research company in Australian, announced that they will jointly develop Nifeviroc for global distribution. Avexa will handle post-research expenses, develop the drug in the international marketplace, and share global profits with Targetdrug. Thus, China may have justified rationale and confidence to believe that the day will come when China's pharmaceutical products will boast a strong presence in the global market.

Electron microscopy study on a new phase in β-titanium alloys aged at a high temperature

In a Ti-20mass%Mo alloys aged by two steps aging at 623 and 823K, a new phase has been observed. In the first step aging, [Formula: see text] -phase crystals appear and at the second step aging, these crystals disappear and are replaced with the newly discovered phase crystals. Observations in the dark field image and analysis of composition of the new phase crystals have shown that the formation is closely related to the [Formula: see text] -phase structure. The new phase crystals have been also observed in four kinds of [Formula: see text] -type Ti alloys and a ( [Formula: see text] ) type Ti alloy aged at high elevated temperatures. Based on high-resolution electron microscope observations, the atomic structure of the new phase is assumed.

Roles of IL-4 and other factors in the trichosanthin-induced ovalbumin-specific IgE response

AIM

To study the mechanism of trichosanthin (TCS)-induced ovalbumin (OVA)-specific immunoglobulin E (IgE) response in vivo.

METHODS

To determine whether interleukin-4 (IL-4) was involved in TCS-induced IgE production, TCS and OVA co-immunized mice were treated with anti-IL-4 monoclonal antibodies (mAb) and OVA-specific serum IgE production was measured by enzyme-linked immunosorbent assay (ELISA). To distinguish whether recombinant IL-4 (rIL-4) was sufficient to support OVA-specific IgE response, OVA alone immunized mice were treated with rIL-4 and OVA-induced IgE production were examined by ELISA in the serum. To determine whether additional factors were involved in TCS-induced IgE response, th e kinetic expression of CD40 ligand (CD40L), tumor necrosis factor-alpha (TNF-alpha), and interleukin-13 (IL-13) were measured by semi-quantitative RT-PCR in draining mesenteric lymph node (MLN) from TCS-immunized mice.

RESULTS

TCS-induced OVA-specific IgE production was suppressed by anti-IL-4 antibody, whereas IL-4 alone could not induce OVA-specific IgE production. CD40L, TNF-alpha, and IL-13 all expressed high levels in MLN after both primary and secondary immune responses. Among them CD40L had the similar transient expression peak to that of IL-4.

CONCLUSION

IL-4 was indispensable for TCS-induced OVA-specific IgE production, and the other three factors examined may also be involved in, but CD40L may play a more important role.

Interleukin 20: discovery, receptor identification, and role in epidermal function

A structural, profile-based algorithm was used to identify interleukin 20 (IL-20), a novel IL-10 homolog. Chromosomal localization of IL-20 led to the discovery of an IL-10 family cytokine cluster. Overexpression of IL-20 in transgenic (TG) mice causes neonatal lethality with skin abnormalities including aberrant epidermal differentiation. Recombinant IL-20 protein stimulates a signal transduction pathway through STAT3 in a keratinocyte cell line, demonstrating a direct action of this ligand. An IL-20 receptor was identified as a heterodimer of two orphan class II cytokine receptor subunits. Both receptor subunits are expressed in skin and are dramatically upregulated in psoriatic skin. Taken together, these results demonstrate a role in epidermal function and psoriasis for IL-20, a novel cytokine identified solely by bioinformatics analysis.

PSMA mimotope isolated from phage displayed peptide library can induce PSMA specific immune response

Prostate-specific membrane antigen (PSMA) is a cell surface glycoprotein expressed predominantly in prostate secretory acinar epithelium and prostate cancer cells as well as in several extraprostatic tissues. Mouse monoclonal antibody 4G5 specific to the extracellular domain of PSMA was used to screen two phage displayed peptide libraries (9aa linear and 9aa cys library). Three 4G5-reactive phagotopes were identified. Sequence analysis of isolated clones demonstrated that the interaction motif "VDPA/SK" has high homology to 719-725aa on PSMA. Immunohistochemical staining of the prostate cancer sample with the PSMA-mimic phagotope (mimotope) immunized serum antibodies demonstrate that the mimotope isolated from the phage displayed peptide libraries can induce PSMA specific immune response in vivo.

Cloning and characterization of human protease-activated receptor 4

Protease-activated receptors 1-3 (PAR1, PAR2, and PAR3) are members of a unique G protein-coupled receptor family. They are characterized by a tethered peptide ligand at the extracellular amino terminus that is generated by minor proteolysis. A partial cDNA sequence of a fourth member of this family (PAR4) was identified in an expressed sequence tag database, and the full-length cDNA clone has been isolated from a lymphoma Daudi cell cDNA library. The ORF codes for a seven transmembrane domain protein of 385 amino acids with 33% amino acid sequence identity with PAR1, PAR2, and PAR3. A putative protease cleavage site (Arg-47/Gly-48) was identified within the extracellular amino terminus. COS cells transiently transfected with PAR4 resulted in the formation of intracellular inositol triphosphate when treated with either thrombin or trypsin. A PAR4 mutant in which the Arg-47 was replaced with Ala did not respond to thrombin or trypsin. A hexapeptide (GYPGQV) representing the newly exposed tethered ligand from the amino terminus of PAR4 after proteolysis by thrombin activated COS cells transfected with either wild-type or the mutant PAR4. Northern blot showed that PAR4 mRNA was expressed in a number of human tissues, with high levels being present in lung, pancreas, thyroid, testis, and small intestine. By fluorescence in situ hybridization, the human PAR4 gene was mapped to chromosome 19p12.

Two reactive site locations and structure-function study of the arrowhead proteinase inhibitors, A and B, using mutagenesis

The arrowhead (Sagittaria sagittifolia, Linn.) proteinase inhibitor A and B are double-headed and multifunctional, consisting of 179 amino acid residues with three disulfide bridges. Both their primary structures and cDNA sequences have been elucidated [Yang, H. L., Luo, R. S., Wang, L. X., Zhu, D. X., & Chi, C. W. (1992) J. Biochem. 111, 537; Xu, W. F., Tao, W. K., Gong, Z. Z., & Chi, C. W. (1993) J. Biochem. 113, 153; Luo, M. J., Lu, W. Y., & Chi, C. W. (1997) J. Biochem. (in press)]. Though they share 91% homology, they are different in inhibitory activities. Sequence analysis of their full-length cDNAs showed that there are seven extra residues in the C-terminal part which might be cleaved off by proteinase post-processing. To locate the reactive sites and study the structure-function relationship of the two forms A and B, the genes coding for the mature inhibitor B and its extended form were respectively cloned into the secretion expression vector, pVT102U/alpha, and expressed in Saccharomyces cerevisiae strain S-78. Both of the gene products were purified and characterized to have the same inhibitory activities as the natural one. The gene product of the extended form was a mixture with the extended C-terminal part of the inhibitor either completely or partially removed. The two previously predicted reactive site residues, Lys-44 and Arg-76 of inhibitor B, were then respectively substituted with Ala by site-directed mutagenesis and expressed. As compared with the natural inhibitor, each of the mutants could only inhibit one molecule, instead of two molecules of trypsin, and displayed an inhibitory activity against elastase, thus confirming the location of the two reactive sites in the inhibitors. The gene coding for inhibitor A, which for some reason could not be expressed in S. cereviciae, was successfully expressed in the reconstructed plasmid pET-1522bx in Escherichia coli strain BL21 with the expressed product existing in the inclusion body. After denaturation and renaturation, the active inhibitor A was obtained and purified by anhydrotrypsin affinity chromatography. Using site-directed mutagenesis, two residues of inhibitor A, namely, Ser-82 and Leu-87, prominently different from Leu-82 and Arg-87 in inhibitor B, were replaced by these two corresponding residues, respectively. As compared with the natural inhibitor A, its S82L mutant showed a lower inhibitory activity toward trypsin, whereas a higher activity was found in the L87R mutant. Meanwhile, both of their chymotrypsin inhibitory activities became weaker than the natural one. The important accessary role of the residue of position 87 in causing the difference in inhibitory properties between inhibitor A and B was discussed.

Protein and gene structure analysis of an albumin genetic variant: proalbumin Wu Yang (-2 Arg-->His)

An electrophoretically slow genetic variant of human serum albumin was isolated from a patient with bis-albuminemia in Xin Jiang who originated in the province of He Nan, county Wu Yang. Based on the FPLC-CNBr peptide profiles of the variant and normal albumins, the mutated CNBr peptide of the variant was found. Both the mutated and corresponding normal CNBr peptides were further subjected to trypsin digestion. An additional peptide peak from the mutated CNBr peptide was found in the HPLC mapping. The amino acid sequence of this peptide was determined to be Gly-Val-Phe-His-Arg corresponding to the fragment of albumin propeptide from position -5 to -1 with an -2 Arg-->His mutation. The N-terminal sequence of the mutated CNBr peptide was also determined to be Arg-Gly-Val-Phe-His*-Arg-Asp-Ala-His-Lys-, namely the N-terminal part of the mutated proalbumin. According to the known genomic structure of proalbumin, the gene fragments neighbouring the propeptide DNA sequences of the normal and variant albumins were amplified in vitro by polymerase chain reaction. The PCR products with 390 bp were then cloned into M13 vector, respectively. The nucleotide sequence analyses demonstrated that the codon CGT for -2 Arg was mutated to CAT for His. Thus, the point substitution was confirmed both at protein and gene levels. The above genetic variant of albumin was named proalbumin Wu Yang (-2 Arg-->His) being the first instance of the Lille type found in China.

Identification of a nonsense mutation at amino acid 584-arginine of platelet glycoprotein IIb in patients with type I Glanzmann thrombasthenia

Using Southern blot, the restriction digests of genomic DNAs in 11 patients with Glanzmann thrombasthenia from 10 unrelated kindreds were probed with a full-length GPIIb cDNA. An additional 2.3 kb Taq I fragment and two 1.65 kb and 0.65 kb fragments with reduced band intensity were found in the genes of two affected siblings from a family originating from the city of Huang Yan in the Zhejiang province. The Taq I digest of the abnormal gene was further probed with three portions of GPIIb cDNA, revealing that the heterozygous mutation was present in the region around exons 15-17 of the GPIIb gene. Two primers for polymerase chain reaction (PCR) were then designed, and a 394 bp PCR product was generated and sequenced, indicating that a stop codon (TGA) was substituted for an Arg codon (CGA) at amino acid position 584 of GPIIb, and resulted in a premature termination of translation and production of a shortened protein. The Western blot analysis showed that GPIIIa at the platelet surface was apparently deficient, it may be ascribed to the rapid turn-over of GPIIIa uncomplexed with the truncated GPIIb. The abnormal 2.3 kb Taq I fragment was used as a specific genetic marker to detect the carrier status of the patient family. The abnormal allele was proved to be derived from the mother, the two affected siblings are double heterozygotes, and one clinically unaffected daughter has also inherited this defective allele, while the father carries another recessive abnormal allele unidentified.

cDNA and genomic structures of arrowhead proteinase inhibitors

Arrowhead double-headed proteinase inhibitors A and B consist of 150 amino acid residues with three disulfide bonds. Based on their primary structures, three cDNA fragments of the inhibitors were amplified in vitro by the PCR method using a constructed arrowhead cDNA library as a template. With the overlapping sequences, the full-length cDNA sequences of the inhibitors were then ascertained. The open reading frame encodes a pre-inhibitor, including a 24 residue signal peptide. The deduced amino acid sequences are consistent in principle with those determined by primary structure analysis, except that there are seven extra residues in the C-terminal part of the inhibitors, which might be cleaved off by proteinase post-processing immediately after protein synthesis. It is worth pointing out that cDNAs of both inhibitors A and B contain an 87 bp intron in the AAG codon of residue Lys-97. According to the elucidated cDNA sequences, the structural genes of inhibitors A and B were amplified using the total cDNA or genomic DNA of arrowhead as a PCR template. It was indicated that both the cDNA and genomic structures of inhibitors A and B have the same sequences.