ZIF-8@GMP-Tb nanocomplex for ratiometric fluorescent detection of alkaline phosphatase activity

Luminescent metal-organic frameworks (LMOFs) and their functional materials with unique characteristics can provide the basis for the construction of new analytical techniques, which can meet the continuous demand for various fields. In this work, guanosine monophosphate (GMP), terbium ion (Tb³⁺) and zeolitic imidazolate framework-8 (ZIF-8) are self-assembled to form a ZIF-8@GMP-Tb nanocomplex, which can be utilized as a ratiometric fluorescent probe to monitor alkaline phosphatase (ALP) activity. Specifically, with adding ALP, the fluorescence intensity at 547 nm (one of the characteristic emission peaks of Tb³⁺) obviously decreased. Meanwhile, the conjugated structure of GMP increased the fluorescence of ZIF-8 (located at 330 nm). The possible mechanism was proposed through the characterization of the materials. Based on the variation of the emission peaks at 330 and 547 nm, the ratiometric fluorescent sensor of ALP has a linear range of 0.25-20 U/L. Moreover, applying this sensing system to the detection of ALP in the human serum sample and ALP inhibitor investigation possesses satisfactory results. This work provides a new perspective for the utilization of ZIF-8 and lanthanide ions in manufacturing simple and sensitive sensors.

[Efficacy and safety of domestic dasatinib as second-line treatment for chronic myeloid leukemia patients in the chronic phase]

目的

探讨国产酪氨酸激酶抑制剂（TKI）达沙替尼（商品名：依尼舒）二线治疗慢性髓性白血病慢性期（CML-CP）患者的疗效及安全性。

方法

回顾性分析2016年3月至2018年7月湖北省CML协作组成员医院收治的二线服用国产达沙替尼的CML-CP患者的病例资料，统计患者治疗3、6和12个月时最佳反应率、累积完全细胞遗传学反应（CCyR）率、累积主要分子学反应（MMR）率、无进展生存（PFS）、无事件生存（EFS）情况及不良反应情况。

结果

共纳入83例CML-CP患者，中位随访时间为23（4~45）个月，达沙替尼治疗3、6、12个月最佳反应率分别为77.5%（54/71）、72.6%（61/75）、60.7%（51/69）。至随访截止，累积CCyR率、MMR率分别为65.5%（55/80）、57.1%（48/73），达CCyR和MMR的中位时间均为3个月。随访时间内，PFS率为94.0%（79/83），EFS率为77.4%（65/83）。国产达沙替尼最常见非血液学不良反应为水肿（32.5%），其次为皮疹瘙痒（18.1%）、乏力（13.3%），血液学不良反应主要有血小板减少（31.3%）、白细胞减少（19.3%）和贫血（6.0%）。

结论

国产达沙替尼二线治疗CML-CP患者具有较好的疗效及安全性，可作为CML-CP患者的治疗选择。

Relative contributions of testosterone deficiency and metabolism syndrome at the risk of reduced quality of life: A cross-sectional study among Chinese mid-aged and elderly men

Testosterone deficiency and metabolism syndrome (MetS) are universal among ageing males, and they have been suggested responsible for poorer quality of life (QoL). We aimed to evaluate the relative contributions of reproductive hormones and components of MetS at the risk of reduced QoL among Chinese mid-aged and elderly men. A cross-sectional study recruited 2,364 males aged 40-79 years, and 2,165 was included for analysis eventually. The Chinese version of ageing male symptoms scale, 36-item Short Form and Beck Depression Inventory were applied to assess QoL. Bivariate correlation analysis and multiple linear regression analysis were used to assess the relative contributions of reproductive hormones and components of MetS at the risk of reduced QoL. Testosterone deficiency and MetS contributed to poorer QoL, of which higher fasting blood glucose made the primary contribution, lower total testosterone mainly contributed to poorer physical functioning.

Inhibition of human immunodeficiency virus type 1 reverse transcriptase, protease and integrase by bovine milk proteins

Different proteins have been isolated from bovine milk including lactoferrin, lactoperoxidase, glycolactin, angiogenin-1, lactogenin, alpha-lactalbumin, lactoglobulin and casein. These proteins have been assayed for inhibitory activity against human immunodeficiency virus type 1 (HIV-1) reverse transcriptase, protease and integrase, enzymes crucial to the HIV-1 life cycle. It was found that different milk proteins inhibited the three aforementioned HIV enzymes to different extents. Lactoferrin strongly inhibited HIV-1 reverse transcriptase but only slightly inhibited HIV-1 protease and integrase. On the other hand, alpha-lactalbumin, beta-lactoglobulin and casein inhibited HIV-1 protease and integrase to an appreciable extent but did not inhibit HIV-1 reverse transcriptase. Glycolactin and angiogenin-1 suppressed the activity of HIV-1 reverse transcriptase by a moderate extent but more powerfully inhibited HIV-1 protease and integrase. In comparison with the other milk proteins glycolactin was a strong inhibitor of HIV-1 protease and integrase and a moderate inhibitor of HIV-1 reverse transcriptase. Lactogenin was a strong inhibitor of HIV-1 integrase, a moderate inhibitor of HIV-1 reverse transcriptase and a weak inhibitor of HIV-1 protease.

Use of PCR with universal primers and restriction endonuclease digestions for detection and identification of common bacterial pathogens in cerebrospinal fluid

We have designed a universal PCR capable of amplifying a portion of the 16S rRNA gene of eubacteria, including Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus pneumoniae, Enterococcus faecium, Enterococcus faecalis, Mycobacterium tuberculosis, Legionella pneumophila, Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Enterobacter cloacae, Pseudomonas aeruginosa, Acinetobacter baumannii, Proteus mirabilis, Haemophilus influenzae, and Neisseria meningitidis. The sizes of the amplified products from various bacteria were the same (996 bp), but the restriction patterns of most PCR products generated by HaeIII digestion were different. PCR products from S. aureus and S. epidermidis could not be digested by HaeIII but yielded different patterns when they were digested with MnlI. PCR products from S. pneumoniae, E. faecium, and E. faecalis yielded the same HaeIII digestion pattern but could be differentiated by AluI digestion. PCR products from E. coli, K. pneumoniae, S. marcescens, and E. cloacae also had the same HaeIII digestion pattern but had different patterns when digested with DdeI or BstBI. This universal PCR could detect as few as 10 E. coli or 250 S. aureus organisms. Compared with culture, the sensitivity of this universal PCR for detection and identification of bacteria directly from 150 cerebrospinal fluids was 92.3%. These results suggest that this universal PCR coupled with restriction enzyme analysis can be used to detect and identify bacterial pathogens in clinical specimens.

Ureaplasma urealyticum infection and apoptosis of spermatogenic cells

AIM

To study the relationship between Ureaplasma urealyticum (UU) infection and apoptosis of human spermatogenic cells.

METHODS

Spermatogenic cells were observed under light microscope with Wright-Giemsa staining and by means of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP)-biotin nick-end labeling (TUNEL) technique.

RESULTS

Apoptotic rate of UU-infected males (15.5% +/- 6.8%) was significantly higher than that of controls (5.2% +/- 2.3%).

CONCLUSION

Apoptosis of spermatogenic cells can be caused by UU infection, which provides further evidence for UU-induced male infertility.

Isolation of a trypsin inhibitor with deletion of N-terminal pentapeptide from the seeds of Momordica cochinchinensis, the Chinese drug mubiezhi

A trypsin inhibitor, MCCTI-1, with a molecular weight of 3479 Da as determined by mass spectrometry, was isolated from Momordica cochinchinensis seeds with a procedure involving extraction with 5% acetic acid, ammonium sulfate precipitation, ion exchange chromatography on CM-Sepharose and reverse-phase high performance liquid chromatography. The sequence of its first 13 N-terminal amino acid residues was ILKKCRRDSDCPG which was about 85% identical with the sequence of trypsin inhibitor MCTI-1 from Momordica charantia Linn. When compared with the sequences of most other squash family trypsin inhibitors, the sequence of MCCTI-1 was characterized by the deletion of a pentapeptide from the N-terminus. Trypsin inhibitors also existed in seeds of some hitherto uninvestigated Cucurbitaceae species.

Removal of polyphenolic compounds from aqueous plant extracts using polyamide minicolumns

An improved method for the removal of polyphenolic compounds from aqueous extracts of plants is presented. The method removes > 99% polyphenolic compounds from 5 mg of extract. The method is simple, robust and reproducible. We examined the removal of polyphenolics from 5 different aqueous extracts of Chinese medicinal herbs.

Inhibition of glycohydrolase enzymes by aqueous extracts of Chinese medicinal herbs in a microplate format

A microplate assay, for use with a variety of glycohydrolase enzymes, was developed to aid the screening of Chinese medicinal herb extracts for the presence of potential anti-viral and anti-lymphoma compounds. The microplate assay method described offers greater convenience, speed and reproducibility over existing methods. The enzymes tested were alpha-glucosidase, beta-glucosidase and beta-glucuronidase. The assay can be easily adapted for use with other glycohydrolase enzymes. Of the 12 herb extracts examined four did not inhibit any of the enzymes (< 50% inhibition), one inhibited alpha-glucosidase only (> 50% inhibition), six inhibited beta-glucuronidase only, and one inhibited both alpha-glucosidase and beta-glucuronidase. None of the extracts were capable of inhibiting beta-glucosidase to any significant extent.

A comparison of human immunodeficiency virus type 1 inhibition by partially purified aqueous extracts of Chinese medicinal herbs

A multiple screening approach to detect compounds inhibitory to various aspects of the human immunodeficiency virus type 1 (HIV-1) life-cycle has been applied to aqueous extracts of 19 herbs traditionally used in Chinese medicine as anti-viral agents. The extracts were tested for their ability to inhibit HIV-1 in a series of in vitro assays. The extracts were tested for inhibition of the interaction between HIV-1 gp120 and immobilized CD4 receptor, inhibition of recombinant HIV-1 reverse transcriptase and for inhibition of three glycohydrolase enzymes that contribute to viral protein glycosylation. Six of the herb extracts (30%) were potent inhibitors of the interaction between HIV-1 gp120 and the CD4 receptor (ID50 5.6 - 79.4 microg/ml), two extracts (10%) contained potent reverse transcriptase inhibitors (ID50 16.9 - 26.0 microg/ml) and 14 extracts (75%) were able to inhibit at least one of the glycohydrolase enzymes.

Multivariate risks among extremely premature infants

This study was designed to identify risk factors for mortality and morbidity of extremely premature infants born in the surfactant era. The study cohort included 194 infants born at < 29 weeks' gestation at one regional tertiary center between 1983 and 1986. Forty-one infants died. Blinded neurodevelopmental assessments were performed on 149 of 153 (97%) survivors at a mean age of 52 months. Thirty-one (21%) survivors had major impairments: 15 had mental retardation, 8 had multiple impairments, 7 had cerebral palsy, and 1 was blind. Logistic regression analysis identifies five significant risk factors for mortality: grade III or IV intraventricular hemorrhage, birth weight < 800 gm, 5-minute Apgar score < or = 3, male sex, and absence of surfactant therapy. Significant risk factors for any major impairment included sepsis (relative risks [RR] = 6.4), male sex (RR = 3.1), and nonwhite race (RR = 2.8). Hydrocephalus requiring shunting was a significant risk factor for cerebral palsy (RR = 16.4) and neonatal retardation (RR = 16.0). Nonwhite race (RR = 7.3), sepsis (RR = 6.8), and male sex (RR = 3.7) also were significant risk factors for mental retardation. Confirmation of these risk factors should facilitate development of targeted interventions for optimizing long-term outcome.

A versiconal hemiacetal acetate converting enzyme in aflatoxin biosynthesis

Conversion of the aflatoxin biosynthetic intermediate versiconal hemiacetal acetate (VHA) in a cell free extract of Aspergillus parasiticus ATCC 15517 is investigated. The enzymatic reaction is monitored by a method using high performance liquid chromatography (HPLC). The major product of the enzymatic reaction is a water soluble compound not chloroform-extractable at pH 7.5. The product becomes chloroform extractable upon acidification of the reaction medium and is separated and quantitated by reversed-phase HPLC. It is tentatively identified as 'versiconal hemiacetal alcohol,' which is converted to versicolorin C (VC) upon acid treatment.

Analysis of various indefinite self-associations of the AK type

Although we and others have developed equations to analyze for some indefinite self-associations that might be encountered, it is felt in some cases that these models, known as the sequential, equal equilibrium constant (SEK) models, might overestimate the size of aggregates encountered at higher solute concentrations. Thus, Garland and Christian proposed two attenuated equilibrium constant (AK) models that might overcome this problem. Their methods were restricted to ideal solutions and to osmometric procedures. We have removed these restrictions, and we have developed equations for analyzing four AK models that might be encountered. Various tests to aid in distinguishing these models are presented. These procedures have been tested with two simulated examples of a Type III AK indefinite self-association.

Occurrence of glycosphingolipids in chicken egg yolk

Chicken egg yolk was found to contain a unique glycosphingolipid pattern not seen in other types of tissue or cell. These glycosphingolipids were isolated in pure form and their structures established by sequential enzymic hydrolysis and permethylation analysis. The major gangliosides in chicken egg yolk are N-acetylneuraminosylgalactosylceramide, N-acetylneuraminosyl-lactosylceramide and di-N-acetylneuraminosyl-lactosylceramide. The only neutral glycosphingolipid found in chicken egg yolk is galactosylceramide.

beta-Mannosidase from the mushroom Polyporus sulfureus

beta-D-Mannosidase (EC 3.2.1.25), a useful tool for the structural studies of heterosaccharide chains, has been isolated in a highly purified form from the fruiting bodies of the mushroom Polyporus sulfureus. This mushroom is unique among reported sources of this enzyme in that it has the advantage of being almost free of alpha-mannosidase activity. The purification procedure involves ammonium sulfate fractionation followed by Sephadex G-100 filtration and chromatography on columns of DEAE-cellulose and hydroxylapatite. The final enzyme preparation gives essentially a single band on disc gel electrophoresis. The purified enzyme liberates the beta-D-mannopyranosyl unit from various natural substrates such as the core glycopeptide, Man(GlcNAc)2-Asn isolated from ovalbumin, from Taka-amylase A, and from human alpha1-acid glycoprotein. It also hydrolyzes (Man)2-GlcNAc from the urine of an alpha-mannosidosis patient, 1,4-D-mannobiose and mannotriose isolated from ivory nut mannan, 4-O-beta-D-mannopyranosyl-L-rhamnose, 6-O-beta-D-mannopyranosyl-D-galactose and 4-O-beta-D-mannopyranosyl-N-acetylglucosamine. The molecular weight of this enzyme is estimated to be about 64,000 by gel filtration. For p-nitrophenyl-beta-D-mannopyranoside, the pH optimum is between 2.4 and 3.4 and the Km is 1.6 mM.