Independent and combined associations of upper and lower limb strength with all-cause mortality in community-based older adults: findings from the Chinese Longitudinal Healthy Longevity Survey

OBJECTIVE

With the acceleration of aging progress, China is projected to have the largest older population globally. This study aimed to examine the association of upper limb strength (ULS) and lower limb strength (LLS) with all-cause mortality based on the Chinese Longitudinal Healthy Longevity Survey (2012-2018).

STUDY DESIGN

This is a prospective cohort study.

METHODS

Participants were 2442 older adults (aged 84.98 ± 11.94 years) recruited from eight longevity areas in China. Limb muscle strength was evaluated using handgrip strength and objective physical examinations. Cox proportional hazards regression was used to analyze the association of limb muscle strength with all-cause mortality. Demographic characteristics, health status, and biological markers were included as confounders.

RESULTS

Over a median follow-up period of 42.2 months, 993 older people died. After adjusting for all covariates, low ULS was associated with higher mortality risk (hazard ratio [HR] = 1.51, 95% confidence interval [CI] = 1.25-1.84), and the association of low LLS with all-cause mortality was only significant in women (HR = 1.36, 95% CI = 1.04-1.79). Participants with combined low ULS and low LLS had the highest risk of mortality than those with normal limb muscle strength (hazard ratio = 2.06, 95% confidence interval = 1.61-2.63). The combined association of ULS and LLS with mortality was robust in subgroup and sensitivity analyses.

CONCLUSION

Low ULS and low LLS were independently and synergistically associated with higher all-cause mortality risk. Considering the high prevalence of limb muscle weakness among Chinese older adults, especially the oldest-old, limb strength could be considered as a potential doable mortality predictor for community health care.

[A retrospective safety study on screening of the samples in the clinical biobank of Beijing Hospital]

To investigate whether the laboratory specimens preserved in Beijing Hospital Biobank during a specific period had been contaminated by SARS-Cov-2 through a cross-sectional study, and to establish a retrospective biobank safety screening system. Laboratory specimens were collected from the Department of Respiratory and Critical Care Medicine and the Fever Clinic of Beijing Hospital from November 1, 2019 to January 22, 2020, nucleic acid and serological antibody testing were performed for SARS-CoV-2 in these specimens (including 79 serum, 20 urine, 42 feces and 21 bronchoalveolar lavage fluid specimens). The safety of the stored samples during this period was defined by negative and positive results. Both the nucleic acid test and serological antibody test showed negative for SARS-CoV-2, indicating that these specimens were safely stored in the biobank. High-risk specimens collected in our hospital during the early stage of the COVID-19 outbreak are free of SARS-CoV-2, and a safety screening strategy for the clinical biobank is established to ensure the biosafety of these samples.

Analysis of the chemical components of Qixianqingming granules and their metabolites in rats by UPLC-ESI-Q-TOF-MS

Qixianqingming granules (QXQM) comprise a traditional Chinese medicine (TCM) formula that was developed based on the combination of TCM theory and clinical practice. This formula has been proven to effectively treat asthma. In this study, an analytical procedure using ultraperformance liquid chromatography, coupled with electrospray ionization quadrupole time-of-flight mass spectrometry, was established for the rapid separation and sensitive identification of the chemical components in QXQM and its metabolites in serum of rats. Seventy-two compounds were systematically identified in QXQM, including flavonoids, terpenoids, anthraquinones, phenylethanoid glycosides, stilbenes, alkaloids, and organic acids. Thirteen prototype compounds and 29 metabolites were detected in the serum of rats. The results provided fundamental information for further studying the mechanisms and clinical application of QXQM.

Selective HDAC6 inhibition decreases early stage of lupus nephritis by down-regulating both innate and adaptive immune responses

We have demonstrated previously that histone deacetylase (HDAC6) expression is increased in animal models of systemic lupus erythematosus (SLE) and that inhibition of HDAC6 decreased disease. In our current studies, we tested if an orally active selective HDAC6 inhibitor would decrease disease pathogenesis in a lupus mouse model with established early disease. Additionally, we sought to delineate the cellular and molecular mechanism(s) of action of a selective HDAC6 inhibitor in SLE. We treated 20-week-old (early-disease) New Zealand Black (NZB)/White F₁ female mice with two different doses of the selective HDAC6 inhibitor (ACY-738) for 5 weeks. As the mice aged, we determined autoantibody production and cytokine levels by enzyme-linked immunosorbent assay (ELISA) and renal function by measuring proteinuria. At the termination of the study, we performed a comprehensive analysis on B cells, T cells and innate immune cells using flow cytometry and examined renal tissue for immune-mediated pathogenesis using immunohistochemistry and immunofluorescence. Our results showed a reduced germinal centre B cell response, decreased T follicular helper cells and diminished interferon (IFN)-γ production from T helper cells in splenic tissue. Additionally, we found the IFN-α-producing ability of plasmacytoid dendritic cells was decreased along with immunoglobulin isotype switching and the generation of pathogenic autoantibodies. Renal tissue showed decreased immunoglobulin deposition and reduced inflammation as judged by glomerular and interstitial inflammation. Taken together, these studies show selective HDAC6 inhibition decreased several parameters of disease pathogenesis in lupus-prone mice. The decrease was due in part to inhibition of B cell development and response.

Renal-infiltrating CD11c+ cells are pathogenic in murine lupus nephritis through promoting CD4+ T cell responses

Lupus nephritis (LN) is a major manifestation of systemic lupus erythematosus (SLE), causing morbidity and mortality in 40-60% of SLE patients. The pathogenic mechanisms of LN are not completely understood. Recent studies have demonstrated the presence of various immune cell populations in lupus nephritic kidneys of both SLE patients and lupus-prone mice. These cells may play important pathogenic or regulatory roles in situ to promote or sustain LN. Here, using lupus-prone mouse models, we showed the pathogenic role of a kidney-infiltrating CD11c⁺ myeloid cell population in LN. These CD11c⁺ cells accumulated in the kidneys of lupus-prone mice as LN progressed. Surface markers of this population suggest their dendritic cell identity and differentiation from lymphocyte antigen 6 complex (Ly6C)^low mature monocytes. The cytokine/chemokine profile of these renal-infiltrating CD11c⁺ cells suggests their roles in promoting LN, which was confirmed further in a loss-of-function in-vivo study by using an antibody-drug conjugate (ADC) strategy targeting CX₃ CR1, a chemokine receptor expressed highly on these CD11c⁺ cells. However, CX₃ CR1 was dispensable for the homing of CD11c⁺ cells into lupus nephritic kidneys. Finally, we found that these CD11c⁺ cells co-localized with infiltrating T cells in the kidney. Using an ex- vivo co-culture system, we showed that renal-infiltrating CD11c⁺ cells promoted the survival, proliferation and interferon-γ production of renal-infiltrating CD4⁺ T cells, suggesting a T cell-dependent mechanism by which these CD11c⁺ cells promote LN. Together, our results identify a pathogenic kidney-infiltrating CD11c⁺ cell population promoting LN progression, which could be a new therapeutic target for the treatment of LN.

[Population-based study on infection and genotype distribution of high-risk human among women in rural areas of China, 2014]

Objective: To explore the epidemiologic characterization of high-risk human papillomavirus (HR-HPV) infection and genotype distribution of HR-HPV among women in rural areas of China. Methods: This study used multiple layers of stratified cluster random sampling method. During January to December in 2014, 117 counties of 27 provinces were selected as the HPV test screening pilot project counties. The women aged 35-64 years with rural areas Hukou in these project counties were selected as the study subjects. A total 457 799 women received HPV DNA test. Among them, 118 237 women from 32 counties in 11 provinces received qualified HPV DNA test by fluorescent PCR to detect HPV genotypes. Results: Among 118 237 rural women, the overall HR-HPV positive infection rate was 7.8% (9 249/118 237). The infection rate increased with age and reached an infection peak at the 60-64 age groups (9.9%, 831/8 394). The HR-HPV positive infection rate in western regions (6.9%, 2 144/31 130) was statistical significantly lower than in central regions (8.2%, 1 894/23 023) and eastern regions (8.1%, 5 211/64 084) (χ(2)=51.46, P<0.001). Among 9 249 women with specific genotypes of HR-HPV, 6 496 (97.6%) cases were infected with single HR-HPV type, and 163 cases (2.4% ) were infected with multiple types. HR-HPV type 52, 16 and 58 were the most common infection types in rural areas of China. The single infection rates were 20.9% (1 355/6 496), 18.7% (1 215/6 496), and 11.2% (725/6 496), respectively. The multiple infection rates were 47.2% (77/163), 17.8% (29/163), and 18.4% (30/163), respectively. Conclusion: The HR-HPV positive infection rate in rural areas of Chinese woman was 7.8%, western region has lower infection rate compared with central and eastern regions. HPV 52 was first of the most common genotypes in rural areas of China.

Fine structure characterization of martensite/austenite constituent in low-carbon low-alloy steel by transmission electron forward scatter diffraction

Transmission electron forward scatter diffraction and other characterization techniques were used to investigate the fine structure and the variant relationship of the martensite/austenite (M/A) constituent of the granular bainite in low-carbon low-alloy steel. The results demonstrated that the M/A constituents were distributed in clusters throughout the bainitic ferrite. Lath martensite was the main component of the M/A constituent, where the relationship between the martensite variants was consistent with the Nishiyama-Wassermann orientation relationship and only three variants were found in the M/A constituent, suggesting that the variants had formed in the M/A constituent according to a specific mechanism. Furthermore, the Σ3 boundaries in the M/A constituent were much longer than their counterparts in the bainitic ferrite region. The results indicate that transmission electron forward scatter diffraction is an effective method of crystallographic analysis for nanolaths in M/A constituents.

[Clinical characteristics of orthostatic hypertension with hemodynamic response of vasovagal syncope and postural orthostatic tachycardia syndrome in children and adolescents]

OBJECTIVE

To analyze the clinical characteristics of orthostatic hypertension (OHT) with hemodynamic response of vasovagal syncope (VVS) and postural orthostatic tachycardia syndrome (POTS) in children and adolescents.

METHOD

Children and adolescents admitted to the Second Xiangya Hospital from July 2008 to April 2015 were included, and divided into three groups according to the results of head-up tilt test (HUTT): OHT group, OHT+ VVS group, OHT+ POTS group. The clinical characteristics were analyzed.

RESULT

Totally 629 cases were included, 300 cases in OHT group, 264 cases in OHT+ VVS group and 65 cases in OHT+ POTS group. Syncope and dizziness were the main symptoms of the three groups, and the proportion of patients complaining syncope in OHT+ VVS group was higher than that in OHT group (49.6% vs. 35.7%, χ(2)=11.211, P<0.05) and in OHT+ POTS group (49.6% vs. 27.7%, χ(2)=10.123, P<0.05). Baseline heart rate (HR)((78±14) beat/min vs. (77±12) beat/min, t=2.570, P<0.05), HUTT 3 min HR ((100±14) beat/min vs. (94±13) beat/min, t=17.464, P<0.05) and ΔHR ((22±12) beat/min vs. (17±9) beat/min, t=19.303, P<0.05) were higher in OHT+ VVS group than in OHT group. When compared with OHT group, baseline systolic blood pressure (SBP) ((105±10) mmHg(1 mmHg=0.133 kPa) vs. (103±10) mmHg, t=4.918, P<0.05), HUTT 3 min SBP((114±10) mmHg vs. (113±11) mmHg, t=4.046, P<0.05), baseline diastolic blood pressure (DBP)((64±6) mmHg vs. (63±7) mmHg, t=2.618, P<0.05), HUTT 3 min DBP((78±8) mmHg vs. (77±8) mmHg, t=3.302, P<0.05), HUTT 3 min HR ((107±14) beat/min vs. (94±13) beat/min, t=24.229, P<0.05) and ΔHR ((32±11) beat/min vs. (17±9) beat/min, t=39.146, P<0.05) in OHT+ POTS group were significantly higher, and baseline HR((75±14) beat/min vs. (77±12) beat/min, t=-4.221, P<0.05)in OHT+ POTS group was lower.

CONCLUSION

OHT with higher supine HR, upright HR and HR change is more susceptible to being complicated with VVS, while OHT with higher supine and upright SBP, higher supine and upright DBP and lower supine HR is more susceptible to being accompanied by POTS.

Cloning and characterization of up-regulated HbSINA4 gene induced by drought stress in Tibetan hulless barley

Hulless barley is an important crop cereal in Tibetan, China. Drought is a major abiotic stress in barley production. In this study, we cloned the drought-related HbSINA4 gene from the variety 'Himalaya 10' and analyzed its expression patterns under different drought and rehydration conditions. The cDNA of HbSINA4 was 1052 bp long, including an open reading frame of 771 bp that encoded a protein of 256 amino acids. The molecular weight of HbSINA4 protein was predicted to be 29.53 kDa and the theoretical pI was 8.32. Bioinformatic analysis showed that the HbSINA4 gene contained a protein kinase domain profile family signature motif, with high similarity to that of Oryza sativa and Brachypodium distachyon. Real-time polymerase chain reaction (PCR) assays revealed that gene expression declined rapidly with increasing drought stress; in contrast, its expression increased after rehydration treatment. Therefore, the HbSINA4 gene responds to the drought stress and plays an important role in barely drought resistance. Furthermore, our results provide information which may be useful in other temperate crop studies and in aiding resistance to drought.

Genetic diversity and relationship of chicory (Cichorium intybus L.) using sequence-related amplified polymorphism markers

Chicory is a crop with economically important roles and is cultivated worldwide. The genetic diversity and relationship of 80 accessions of chicories and endives were evaluated by sequence-related amplified polymorphism (SRAP) markers to provide a theoretical basis for future breeding programs in China. The polymorphic rate was 96.83%, and the average polymorphic information content was 0.323, suggesting the rich genetic diversity of chicory. The genetic diversity degree of chicory was higher (GS = 0.677) than that of endive (GS = 0.701). The accessions with the highest genetic diversity (effective number of alleles, NE = 1.609; Nei's genetic diversity, H = 0.372; Shannon information index, I = 0.556) were from Italy. The richest genetic diversity was revealed in a chicory line (NE = 1.478, H = 0.289, I = 0.443) among the 3 types (line, wild, and cultivar). The chicory genetic structure of 8 geographical groups showed that the genetic differentiation coefficient (GST) was 14.20% and the number of immigrants per generation (Nm) was 3.020. A GST of 6.80% and an Nm of 6.853 were obtained from different types. This observation suggests that these chicory lines, especially those from the Mediterranean region, have potential for providing rich genetic resources for further breeding programs, that the chicory genetic structure among different countries obviously differs with a certain amount of gene flow, and that SRAP markers could be applied to analyze genetic relationships and classifications of Cichorium intybus and C. endivia.

Animal models of gastrointestinal inflammation and cancer

Inflammation and cancer are the two major disorders in the gastrointestinal tract. They are causally related in their pathogenesis. It is important to study animal models' causal relationship and, in particular, to discover new therapeutic agents for such diseases. There are several criteria for these models in order to make them useful in better understanding the etiology and treatment of the said diseases in humans. In this regard, animal models should be similar as possible to human diseases and also be easy to produce and reproducible and also economic to allow a continuous replication in different laboratories. In this review, we summarize the various animal models for inflammatory and cancerous disorders in the upper and lower gastrointestinal tract. Experimental approaches are as simple as by giving a single oral dose of alcohol or other noxious agents or by injections of multiple dosages of ulcer inducing agents or by parenteral administration or in drinking water of carcinogens or by modifying the genetic makeups of animals to produce relatively long-term pathological changes in particular organs. With these methods they could induce consistent inflammatory responses or tumorigenesis in the gastrointestinal mucosa. These animal models are widely used in laboratories in understanding the pathogenesis as well as the mechanisms of action for therapeutic agents in the treatment of gastrointestinal inflammation and cancer.

Calponin expression in laryngeal myoepithelial carcinoma and its prognostic implications: a case report and literature review

A case report of laryngeal myoepithelial carcinoma (MEC) is presented and the literature concerning prognostic factors in MEC is reviewed. A 61-year old man was admitted to hospital with hoarseness and progressive dyspnoea. On examination, both vocal cords were fixed in the midline with a glottic fissure of only 3 mm. No tumour was seen, but the subglottis was not completely visible. A computed tomography scan showed a soft mass below the right vocal cord obstructing two-thirds of the larynx. On suspension laryngoscopy, a dull mass (1.5 x 1.5 cm) was seen below the right vocal cord, which was malignant on frozen biopsy. A total laryngectomy was performed and the patient received radiotherapy. He died of recurrence 25 months later. The tumour was positive for cytokeratin 14, S-100 protein and calponin. MEC of the larynx is extremely rare. The clinical behaviour of MEC is variable and prognostic factors have been poorly analysed. Calponin expression may be a prognostic factor, but other factors also affect the outcome in MEC.

Prognosis and Expression of Lambda Light Chains in Solitary Extramedullary Plasmacytoma of the Head and Neck: Two Case Reports and a Literature Review

Two cases of extramedullary plasmacytoma (EMP) of the head and neck, an uncommon plasma cell neoplasm, were studied. Both patients had good outcomes and have been followed for 17 and 12 years without recurrence or systemic disease. In these two cases, the tumours measured were 4 cm and 0.3 cm, and both cases were positive for lambda light chain restriction on immunohistochemistry. Prognostic factors were considered, based on a review of EMP of the head and neck, including published reports and the authors' clinical experience. Of all plasma cell tumours, EMP has the best prognosis, especially when located in the head and neck region. Variation in the biological behaviour of EMP and the limited number of documented cases make it difficult to determine prognostic factors. Some series have found that age, tumour size, site of origin (extramedullary versus bone), grade, M-protein, light chains and radiotherapy dose all influence the outcome in EMP patients.

Chicken keel cartilage as a source of chondroitin sulfate

Chondroitin sulfate is used extensively as a treatment for osteoarthritis. This study was conducted to evaluate whether chondroitin sulfate could be isolated from chicken keel cartilage in sufficient quantities and of requisite quality to make it a feasible source of chondroitin sulfate. Proteoglycans were extracted from chicken keel cartilage obtained immediately after slaughter by using 3 M MgCl2 at room temperature. The extract was then dialyzed and digested with papain to remove proteins. Glycosaminoglycans were obtained by ethanol precipitation, lyophilized, and characterized by using gel filtration on Sepharose CL-6B columns. Guanidine-HCI extraction was also used as a control to investigate the efficiency of extraction using MgCl2. Results showed that, from every gram of wet or non-lyophilized keel cartilage, 32.9 +/- 4.8 mg (dry weight) of glycosaminoglycans could be obtained following MgCl2 extraction. Analyses revealed that 75.5 +/- 4.2% of these glycosaminoglycans were chondroitin sulfate. Chromatographic analyses showed a single symmetrical peak, which could be almost entirely removed by prior digestion with chondroitinase ABC, indicating that the material in the peak was in fact chondroitin sulfate. The average molecular weight (also called relative molecular mass, Mr) of the glycosaminoglycans was also estimated (Mr 48,500). Characterization using polyacrylamide or agarose gel electrophoresis showed diffuse bands containing chondroitin sulfate, which could be entirely removed by prior digestion with chondroitinase ABC. This study shows that chicken keel cartilage is a readily available source of chondroitin sulfate.

[In vitro culture of modified neonatal pig islets]

A cell-isolation-and-cell-culture-in-vitro method which can produce a mass of new-born pig islet-like clusters was introduced. The new-born pig pancreas were incubated in V-type collagenase (0.5-1.0 mg.ml-1) for 8-12 minutes, and then cultured in vitro for 7 days before large amount of highly purified porcine islets were produced. The neonatal pig islets had good insulin secretion and normal sub-cell structure. The results suggest that the neonatal pig islets are probably a fine donor source for clinical xenotransplantation of islets.

A 3D structural model of memapsin 2 protease generated from theoretical study

AIM

To build a 3D structural model of memapsin 2 (M2) protease for theoretical study and drug design.

METHODS

Structural alignment was performed based on multiple and pairwise sequence alignment of three templates. After the initial model was generated, energy minimization was completed by applying molecular mechanics method. Molecular dynamics (MD) technique was used to do further structural optimization.

RESULTS

The 3D structural model of memapsin 2 was constructed. The model is reasonable according to several validation criteria. The active-site motifs of M2 are structurally supported by a beta-sheet rich domain and linked together with this domain through alpha helices. Tyr132 contained in beta-hairpin is a general characteristic of aspartic protease. The Calpha atom superimposing result is a direct verification that M2 is structurally unique but still belongs to the aspartic protease superfamily.

CONCLUSION

The 3D-structure model from our study is informative to guide future molecular biology study about M2 and drug design based on database searching.

Building three-dimensional structures of HIV-1 coreceptor CCR5 and its interaction with antagonist TAK779 by comparative molecular modeling

AIM

To study the mechanism of interaction of CCR5 receptor with its antagonist TAK779.

METHODS

Comparative molecular modeling has been used to develop the 3D-structural models of CCR5 receptor and its complex with TAK779. Molecular mechanics has been applied to optimize the above molecular models. Quantum mechanics has been utilized to calculate the structural information of TAK779. DOCK4.0 program is employed to dock the TAK779 molecular into the binding site of CCR5 receptor.

RESULTS

The 3D-structural model of CCR5 receptor is constructed using the 3D-model of frog rhodopsin as a template. The binding pocket is situated in the transmembrane helices 3, 5, 6, and 7, and it is composed of conserved residues of Tyr108, Gly111, Ser114, Glu283, Gly286, and Cys290, and conservatively varied residues including Thr105, Leu107, Phe112, Gly115, Lys197, and Met287. O1, N7, N17, and O19 of TAK779 are the active center of TAK779. The pyran cycle and the aminium group of TAK779 interact with residues in the binding pocket of CCR5 receptor, the other part of TAK779 interacts with residues from the extracellular loops of CCR5. The binding energy of TAK779 with CCR5 is -51.606 kcal/mol.

CONCLUSION

The model constructed and the interaction mode reported in the present study are useful in further understanding the molecular mechanism of receptor-virus recognition and designing new inhibitors of HIV-1 infection.

Comparative molecular modeling on 3D-structure of opioid receptor-like 1 receptor

AIM

To build the three-dimensional structure of opioid receptor-like 1 (ORL1) receptor.

METHODS

Structural elements of ORL1 receptor were predicted from sequence alignments of opioid and related receptors of G protein-coupled receptor (GPCR) based on (i) the consensus, biophysical interpretations of alignment-derived properties, and (ii) tertiary structural homology to frog rhodopsin; The extracellular loops of ORL1 were built by self-constructed database searching based on geometrical constraints; initial model was refined computationally with energy minimization by molecular mechanics method.

RESULTS

The calculated structure of ORL1 receptor has clusters of hydrogen bonds existing in interhelices and extracellular loops; the ORL1 receptor has a possible ligand-binding "crevice" situated on the extraside of the transmembrane domains between helices 3, 5, 6, and 7, which is partially covered by the extracellular loop 2 (EL-2); The binding cavity may consist of a "highly conserved region" involving the residues of Asp130, Tyr131, and an outer "conservatively variable region" containing the residues near the interface of transmembrane (TM) helices-EL loops; The molecular model obtained is qualitatively consistent with ligand affinities, hybrid peptide studies, and other experimental data.

CONCLUSION

The structural model of ORL1 receptor from this study is helpful for clarifying experimental observations of ligands interacting with opioid receptors, and for designing new biological investigations.

Study on mechanism of interaction of nociceptin and opioids binding with opioid receptor-like 1 receptor

AIM

To study the mechanism of interaction of nociceptin and opioids with ORL1 receptor.

METHODS

Molecular dynamics study was carried out before nociceptin was manually docked into the binding site of ORL1 receptor; DOCK4.0 program was applied to dock four stereoisomers of lofentanyl and etorphine into the binding pocket of ORL1 receptor; Binding energies were calculated, the relationship between binding energy and binding affinity was studied.

RESULTS

Nociceptin fits well into the binding pocket, the N-terminal FGGF tetrapeptide is located in the inner region of the binding cavity, the nociceptin (5-7) interacts with the conservatively variable residues near the other end of binding pocket, and maybe determines selectivity of ORL1 receptor over dynorphin A, the positively charged core of nociceptin (8-13) binds predominantly with negatively charged EL-2 loop, which is thought to be able to mediate receptor activation. The shortest fully active analogue of nociceptin (1-13) is also discussed. The main difference between these two opioids and nociceptin exists in the kinds and the number of conserved and variable residues in the binding pocket and thereafter in the strength of their interaction. Prediction for binding affinities of four stereoisomers of lofentanyl has been performed based on their binding energies, the similar pharmacophore of lofentanyl and other fentanyl analogs, and the good correlation between binding energies and their experimental binding affinities (-log Ki values).

CONCLUSION

Ligand docking results from this study are helpful in clarifying experimental observations of ligands interaction with opioid receptors, thus furthering biological investigations.

[Chemically induced (streptozotocin-alloxan) diabetes mellitus in dogs]

To evaluate the efficiency and toxic and side effect of the combined chemical inducer for Type I diabetes mellitus, Type I diabetes in 9 adult dogs were induced with alloxan(50 mg.kg-1) and streptozotocin (30 mg.kg-1) with vein injection. After 7-14 days, the blood glucose of 5 male dogs was kept on high levels [mean value was (22.7 +/- 3.2) mmol.L-1], exogenous insulin was (21.4 +/- 2.4) U.day-1. Three female dogs died in 7 days after they had been injected with the combined inducers. Alloxan-streptozotocin combination administration reduced the dosage of each drug, and decreased the toxic and side effect of each drug. The results suggest that this method has a high rate of success to induce Type I diabetes male dogs.

Molecular modeling on solvent effect and interaction mechanism of fentanyl analogs to mu-opioid receptor

AIM

To do theoretical study about solvation effect and interaction mechanism of fentanyl analogs (FA) to mu opioid receptor (microOR).

METHODS

Flexible docking (FlexiDock) was performed by using the possible active conformations of FA and optimized 3D structure of mu opioid receptor. Binding energies were calculated. Comparative molecular force field analysis (CoMFA) and quantitative structure activity relationship (QSAR) studies were carried out based on results of flexible docking. Solvation effects were considered by studying interaction of FA with water molecules. Partial least square (PLS) analysis was used to calculate regression equation for analgesic activities using binding energies as descriptive factor.

RESULTS

1) Binding conformations of these analogs derived by flexible docking were reasonable. 2) It was most possible for the FA to exist in water solution in the form of binding conformations. 3) Energetic calculation and QSAR analysis showed a good correlation between the calculated binding energies of FA and their analgesic activities. 4) Based on the 3D-model, the possible interaction mechanism of FA with mu opioid receptor can be illustrated reasonably.

CONCLUSION

The nature of the correlation between the binding affinities and analgesic activities of FA was explained by our modeling result.

[Cloning and sequences comparison of promoters from Aspergillus niger]

An Aspergillus niger (A. niger) genomic library was constructed in a promoter-trap vector, which contains a Hygromycin B (Hy) phosphotransferase-encoding gene (hph) and screened for DNA fragments with promoter activity by applying the sib selection procedure. A functional promoter PX27 was identified. Both DNA strands of this fragment were sequenced and showed no significant homology to the sequence already in the database. Comparison of the sequences of all known promoters from A. niger revealed a consensus CTTCTC, as a novel motif of the A. niger promoters.

[Effects of tea polyphenols on microcirculation and antioxidation in aircrew]

OBJECTIVE

To study the effects of tea polyphenols (TP) on bulbi conjunctiva microcirculation (BCM) and antioxidation in aircrew and find out the proper antioxidant for the health protection of aircrew.

METHOD

Fourty healthy aircrew were divided into TP group (TP 600 mg/d.po) and control group (placebo) randomly. The effects of TP on microcirculation and antioxidation in aircrew were tested after 20 days.

RESULT

Red blood cell (RBC) superoxide dismutase (SOD) activity and GSH-PX (Whole blood glutathione peroxidase)/MDA (serum malondialdehyde) ratio in TP group were significantly higher than those in control (P<0.01), and serum MDA level was significantly decreased after TP administration (P<0.05). The numbers of capillaries and blood flow in micrangium were significantly increased, RBC aggregation, ischemia area and A (arteriole)/V (venule) ratio were remarkably decreased in TP group (P<0.01). The total integral value of microcirculation in TP group was significantly reduced in comparison with that in the control group.

CONCLUSION

TP can significantly increase the antioxidative ability of aircrew, decrease the BCM disturbance and improve the microcirculatory function.

Induction of preneoplastic lesions by sodium arsenite in human fetal respiratory epithelia in organ culture

The effects of sodium arsenite (As) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on epithelia of human fetal trachea and bronchiolar epithelia of human fetal lung were studied by using organ-cultured explants. In epithelium of human fetal trachea, 34 microM MNNG induced hyperplasia, metaplasia, and dysplasia; 1 microM As induced hyperplasia; and 3-9 microM As induced hyperplasia and cellular atypia. In glandular epithelium of human fetal trachea, 34 microM MNNG induced hyperplasia and metaplasia; 1 microM As did not induce obvious changes; and 3-9 microM As induced hyperplasia and epidermoid metaplasia with nuclear atypia. In bronchiolar epithelium of human fetal lung, the induction of dysplasia was observed for 1 microM As. Arsenic-induced preneoplastic lesions support the conclusion of epidemiological studies that arsenic is carcinogenic to human lung.

Effects of arsenic on DNA damage and repair in human fetal lung fibroblasts

Previous studies suggest that arsenic may be both mutagenic and co-mutagenic. In this report, we examined the effects of sodium arsenite (As) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on unscheduled DNA synthesis (UDS) in human fetal lung fibroblasts (2BS cells) by 3H/14C double-labeling and liquid-scintillation counting techniques. Arsenic at concentrations of 1, 5 and 10 microM increased UDS value, indicating that arsenic directly damaged DNA and did not inhibit DNA repair. In addition, UDS induced by 34 microM MNNG in combination with arsenic was significantly increased by 3 microM As and not affected by 0.1, 0.5, 1.0 and 5 microM As, also indicating that arsenic did not inhibit the excision and polymerization steps of DNA repair. Based on the results and a previous study that 3 microM As is more efficient than 1 and 5 microM As in the induction of DNA-protein crosslinks, we proposed that arsenic may enhance the mutagenicity of other compounds by inducing DNA-protein crosslinks rather than inhibiting DNA repair.

Inhibition of the transforming ability of cigarette smoking condensate-treated human fetal lung DNA induced by oltipraz

Rat-1 cells transfected by genomic DNA of human fetal lung explants treated with 100 micrograms/ml of oltipraz (5-(2-pyrazimyl)-4-methyl-1, 2-dithiol-3-thione) for 14 hr or 100 micrograms/ml of cigarette smoking condensate for 6 hr formed 0 to 8 transformation foci, respectively. If 100 micrograms/ml of oltipraz was added to culture of human fetal lung explants 8 hr prior to the treatment of cigarette smoking condensate, the Rat-1 cells transfected by genomic DNA of human fetal lung explants formed only two foci. In addition, the growth speed of Rat-1 cells transfected by genomic DNA of human fetal lung treated with both oltipraz and cigarette smoking condensate was lower than that transfected by cigarette smoking condensate-treated human fetal lung DNA. Our results indicate that oltipraz can block the irreversible change of human fetal lung DNA caused by cigarette smoking condensate, and the results suggest the possibility of using oltipraz as control in the experimental initiation of human lung carcinogenesis.

Specific overexpression of P53 in sarcoma derived from Rat-1 cells transformed by cigarette smoking condensate-treated human fetal lung DNA

The p53 protein is highly expressed in fibrosarcoma derived from Rat-1 cells transfected with cigarette smoke condensate-treated human fetal lung DNA but expressed low in the counterparts of nitroso-N-methylurea and dimethyl sulfoxide groups. Our results denoted that a high expression of p53 protein specifically contributes to the initiation of human lung carcinogenesis induced by cigarette smoke condensate. High expression and missense mutation of p53 may probably be a potential biomarker of initiation of human lung carcinogenesis.

Arsenic-induced DNA-strand breaks associated with DNA-protein crosslinks in human fetal lung fibroblasts

Sodium arsenite (As)-induced DNA damage was measured in human fetal lung fibroblasts (2BS cells) by an alkaline elution technique and a fluorometric DNA assay. Sodium arsenite at 1-5 microM produced DNA-protein crosslinks, while at 10 microM this effect was not observed. Deproteinization of DNA-protein complexes revealed protein-associated DNA-strand breaks. Both DNA-protein crosslinks and DNA-strand breaks were concentration-dependent; 3 microM As was the most efficient dose. Arsenic mediated DNA-protein interactions may play a major role in arsenic carcinogenesis, and the induced protein-associated DNA-strand breaks could provide an explanation for chromosome aberrations and sister-chromatid exchanges induced by arsenic in vivo and in vitro.

[Immunohistochemical study in astrocytoma]

Seventy-four cases of human astrocytoma were studied with ABC method for GFAP and vimentin. Data indicated that all of the specimens in this series contained two different intermediate filament proteins: GFAP and vimentin. There was a negative correlation between the degree of anaplasia and the number of GFAP-positive cells, but no definite relationship was seen between the degree of anaplasia and the number of vimentin-positive cells. The ratio of V/G might be considered useful in expressing the histological differentiation of astrocytoma. Generally, two immunostainings are used in demonstrating GFAP and vimentin: one for intense perikaryo-staining and the other for cell processes. Both staining patterns are closely related to the histological type but not to the histological grade. Besides, there was a negative correlation between the cell density and the number of GFAP-positive cells.

An approach to automated detection of tumors in mammograms

An automated system for detecting and classifying particular types of tumors in digitized mammograms is described. The analysis of mammograms is performed in two stages. First, the system identifies pixel groupings that may correspond to tumors. Next, detected pixel groupings are subjected to classification. The essence of the first processing stage is multiresolution image processing based on fuzzy pyramid linking. The second stage uses a classification hierarchy to identify benign and malignant tumors. Each level of the hierarchy uses deterministic or Bayes classifiers and a particular measurement. The measurements pertain to shape and intensity characteristics of particular types of tumors. The classification hierarchy is organized in such a way that the simplest measurements are used at the top, with the system stepping through the hierarchy only when it cannot classify the detected pixel groupings with certainty.

[Measurement of the biochemical marker of smoking: urinary nicotine metabolites]

A novel, barbituric acid method of detecting urinary nicotine metabolites was evaluated for use as an objective test of smoking. Urine samples were collected from 289 male smokers and 167 male nonsmokers. The smokers recorded the number of cigarettes smoked on the previous day. This method correctly classified the subjects as smokers or nonsmokers. There was a significant positive correlation (r = 0.587, P less than 0.001) between the urinary nicotine metabolites/creatinine ratios and number of cigarettes smoked. This method can be performed very rapidly and reagent costs are very cheap. It is a good objective test of smoking and nicotine intake.

[Effect of beta-carotene on sister chromatid exchanges induced by MNNG and aflatoxin B1 in V79 cells]

In order to elucidate the mechanism of tumor prevention of beta-carotene, its effect on sister chromatid exchanges (SCE) induced by MNNG in cultured V79 cells, under condition free of the enzyme system to convert beta-carotene into vitamin A, was studied. It was found that SCE level was significantly increased by high doses beta-carotene (10(-5)-10(-4) M) and the enhancement of SCE was restored to its original level by addition of alpha-tocopherol (final concentration 2 micrograms/ml). This may be due to the latter inhibiting the oxidation of beta-carotene and reducing the amount of oxidated carotene, which is toxic for cultured cells. Combination of beta-carotene and alpha-tocopherol at low doses inhibited SCE induced by MNNG (P less than 0.05) but no protective activity was observed when used separately. It was also found that beta-carotene (2 x 10(-7) M) and retinol (16 micrograms/ml) inhibited SCE induced by aflatoxin B1, which is activated by S-9 mixture. The present data clearly show that the antitumor activity of beta-carotene may be attributed to both itself and its degraded compound vitamin A, and may take part in the initiation of carcinogenesis. Combination of beta-carotene and other cancer preventive drugs is more effective and safer than it used individually.

[Effect of molybdenum and tungsten on mammary carcinogenesis in Sprague-Dawley (SD) rats]

Virgin female rats of SD strain were given ad libitum a nutritionally adequate semipurified diet containing 0.026 ppm molybdenum and deionized water (groups 1-3) or the same diet with 150 ppm tungsten and the drinking water (group 4). Group 1 was used as control. After 15 days, all the animals in groups 2-4 received an intravenous injection of N-nitroso-N-methylurea (NMU) 5 mg/100 g body weight. One week after administration of carcinogen, 10 ppm Mo was added to the drinking water in group 3. After 125 days, the mammary cancer incidence in group 4 (79.2%) was significantly higher than that in group 2 (50.0%) or group 3 (45.5%) (P less than 0.05). After 198 days, the average number of mammary cancer in each animal and mammary cancer incidence in group 3 (1.5 and 50.0%) were obviously lower than those in group 2 (2.0 and 90.5%) or group 4 (2.6 and 95.7%). The first palpable mammary tumor was found in the W-supplemented group only 56 days after the injection of NMU, whereas in the W-unsupplemented and Mo-supplemented groups, the first mammary tumor was observed 71 and 85 days after NMU treatment. Of these 181 mammary tumors, 177 (97.8%) were adenocarcinoma or papillary carcinoma, only 4 (2.2%) fibroadenocarcinoma. The results of this study show, for the first time, the inhibitory effect of Mo on the mammary carcinogenesis and promoting effect of Tungsten, an antagonist of molybdenum, on the tumor growth.

[Effect of sodium selenite on the chromosomal aberration of V 79 cells induced in vitro by MNNG and MNU]

Effect of sodium selenite on chromosomal aberration of V 79 cells induced by MNNG and MNU was studied. Na2SeO3 alone, at the concentration of 10(-7)-10(-4) M, increased the incidence of chromosomal aberration. However, Na2SeO3 at 10(-7)-10(-5) M, having been preincubated with the cells for 4 hours, could reduce the number of cells with chromosomal aberration induced by MNNG. Na2SeO3 at 10(-7)-10(-4) M inhibited mutagenic activity of chromosomal aberration induced by MNU. The same inhibition was observed even sodium selenite was added to the medium simultaneously with this carcinogen. The results indicate that sodium selenite alone, at the concentration range used in this experiment, is an aberration-inducing agent. But when combined with the carcinogen, anti-cancer effect is obtained.

[Sister chromatid exchanges (SCE), chromosomal aberrations and micronuclei of cultured peripheral lymphocytes in patients with lung cancer, miners and non-mining workers of the tin mine in Yunnan]

Determination of SCE frequency, chromosomal aberration and micronucleus rate of cultured peripheral lymphocytes in 32 patients with lung cancer, 33 miners and 40 non-mining workers in Yunnan Tin Mine was carried out. The results showed that the cancer patients had higher SCE incidence, chromosomal aberration and micronucleus rate, the non-mining workers had the least and miners on an intermediate level. There was a significant difference of SCE, chromosomal aberrations and micronucleus rate between patients and non-mining workers (P less than 0.05-0.01). We also found that miners had a significant higher SCE and chromosomal aberration rate but not micronucleus rate as compared with the non-mining workers. We proposed that some carcinogens present in the Yunnan Tin Mine be responsible for the genetic damages in the miners. Chemical drugs may be considered to contribute to the genetic damage in cancer patients who had a tendency toward an increased SCE, chromosomal aberration and micronucleus rate as compared to the miners, though without reaching a statistical significance. We suggested that combination assay of SCE with chromosomal aberration or micronucleus be an useful index for screening of the high risk population and monitoring the chemical drug prevention of lung cancers in Yunnan Tin Mine.

Bioavailability of selenium to residents in a low-selenium area of China

For 8 wk 5 groups of 10 men each were given 0.5 g/day DL-methionine, 150 micrograms Se/day as sodium selenite with or without methionine or 150 micrograms Se/day as selenomethionine with or without methionine. Twenty subjects received placebo as controls. Initially plasma Se rose more rapidly than RBC Se. Increases in Se levels were significantly greater with selenomethionine than with the selenite supplement. In the placebo and methionine supplemented groups neither plasma nor RBC Se varied significantly over the course of the study. Supplementation with selenium resulted in marked increases in plasma and RBC GSH-Px within 2 and 4 wk, respectively. Plasma and RBC GSH-Px activity did not differ significantly between Se-supplemented groups. These studies suggest that selenomethionine-Se was more effective in raising plasma and RBC Se than was selenite-Se. Methionine supplements may increase the bioavailability of selenium in severely deficient subjects.

Selenium intake and metabolic balance of 10 men from a low selenium area of China

Selenium intake and urinary and fecal Se excretion of 10 healthy men from a low Se area in China were determined for three consecutive days, in summer, fall, and winter of 1983, and the spring of 1984 while self-selected diets were being consumed. Mean daily Se intake was 8.8 micrograms/day with a range of 2.3-35.5 micrograms/day, and was far below the recommended range of safe and adequate Se intake of 50-200 micrograms Se/day (National Academy of Sciences/National Research Council). Mean urinary and fecal Se outputs were 3.7 and 3.4 micrograms Se/day, respectively. Mean Se balance during this time was +1.8 micrograms Se/day. Apparent absorption of Se approximated 57%. The low Se intake in this area is a cause for concern since the residents of Molimo may be at risk for Se deficiency diseases.

Effects of molybdenum and tungsten on mammary carcinogenesis in SD rats

Virgin female rats of the SD strain were fed ad libitum a nutritionally adequate semipurified diet and demineralized water (groups 1 and 2), or the same diet with 10 ppm molybdenum (group 3) or 150 ppm tungsten (group 4) added to the drinking water. The animals in groups 2-4 received a single iv injection of 5 mg N-nitroso-N-methylurea (NMU; CAS: 684-93-5)/100 g body weight at 50 days of age. One hundred and twenty-five days after the NMU treatment, group 2 exhibited a 50.0% incidence of mammary carcinoma. Group 4 exhibited a significant increase in carcinoma incidence (79.2%) and the value for group 3 (45.5%) was not significantly different from that of group 2. The carcinoma incidence of group 3 (50.0%) was significantly lower than that of group 2 (90.5%) or group 4 (95.7%) 198 days after NMU treatment.

Inhibitory effects of molybdenum on esophageal and forestomach carcinogenesis in rats

Male weanling inbred SD rats were given ad libitum a nutritionally adequate semipurified diet and demineralized drinking water without or with 100 or 200 ppm tungsten (W) or 2 or 20 ppm molybdenum (Mo) added to the drinking water. The animals were gastrically intubated with a solution of N-nitrososarcosine ethyl ester (NSEE) from the 4th week twice weekly for 2-8 consecutive weeks. The addition of Mo at either the 2- or 20-ppm level significantly inhibited NSEE-induced esophageal and forestomach carcinogenesis. The 200 ppm W significantly countered the inhibitory effect of a low level of Mo naturally occurring in the diet.