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1.
Zhonghua Gan Zang Bing Za Zhi ; 26(5): 365-370, 2018 May 20.
Article in Chinese | MEDLINE | ID: mdl-29996205

ABSTRACT

Objective: To observe the changes of γδT cells in the peripheral blood of patients with chronic hepatitis B (CHB) during pegylated interferon α-2a treatment, and to analyze the correlation between clinical indicators and curative effects. Methods: Peripheral blood of hepatitis B e antigen (HBeAg)-positive CHB patients were collected at different time points of Peg-IFNα-2a treatment, including 17 patients at 0 weeks, 20 patients at 12 weeks, 20 patients at 24 weeks, and 16 patients at 48 weeks. From these 11 patients, blood samples were frequently observed at 0, 12, 24, and 48 weeks of treatment. The frequencies of γδT and its subpopulation cells Vδ1T, Vδ2T, effector memory γδT (γδTem), central memory γδT (γδTcm), initial γδT (γδTnaive) and terminal differentiation effect γδT (γδTeff) cells in peripheral blood were detected by flow cytometry. Liver function, serum HBV markers and HBV DNA levels were measured simultaneously. SPSS 23.0 statistical software was used to analyze the differences in cell proportions at each treatment time point, and the correlation between cell proportions and alanine aminotransferase (ALT), HBsAg, HBeAg or HBV DNA levels. In addition, the correlation between the proportions of γδT and its subpopulation cells and the response to Peg-IFNα-2a treatment in the 11 patients with continuous follow-up were analyzed. Results: The percentage of γδT and Vδ2T cells in peripheral blood of patients with CHB decreased gradually during the period of 0-48 weeks of Peg-IFNα-2a treatment. The percentages of γδT cells and Vδ2T cells at 48 weeks were 6.89% (5%, 8.15%), 4.61% (2.16%, 6.50%), respectively; significantly lower than the 0 week [12.5% ​​(7.73%, 19%), 6.59% (3.86%, 13.62%)], the differences were statistically significant (P < 0.05). The proportions of Vδ1T, γδTem, γδTcm, γδTnaive, or γδTeff subpopulations were not statistically different at each time points (all P > 0.05). At the same time, the levels of ALT, HBsAg, HBeAg or HBV DNA were positively correlated with the ratio of γδT or Vδ2T cells (P < 0.05). Among the 11 patients with continuous followed- up, the proportion of γδTem cells in responders was significantly lower than that of non-responders at each time points, and the difference was statistically significant (P < 0.05). There was no statistically significant difference between the two groups (all P > 0.05). Conclusion: The proportion of γδT cells in the course of CHB treatment with Peg-IFNα-2a reduces the liver inflammation by decreasing the replication of HBV virus. Chronic hepatitis B patients with a lower proportion of effector memory (γδTem) cells may be more likely to get better response with Peg-IFNα-2a.


Subject(s)
Hepatitis B, Chronic , Alanine Transaminase , Antiviral Agents , Biomarkers , Hepatitis B Surface Antigens , Hepatitis B e Antigens , Humans , Interferon-alpha , Polyethylene Glycols , Receptors, Antigen, T-Cell, gamma-delta , Recombinant Proteins , T-Lymphocytes , Treatment Outcome
2.
Eur Rev Med Pharmacol Sci ; 22(4): 1102-1105, 2018 02.
Article in English | MEDLINE | ID: mdl-29509262

ABSTRACT

OBJECTIVE: We aimed to investigate the heart rate variability in children with myocarditis presenting with ventricular arrhythmias. PATIENTS AND METHODS: The study compared the characteristics of heart rate variability (HRV) among 67 children with viral myocarditis (VMC), presenting with (n=35) and without (n=32) ventricular arrhythmias and a control group of 30 healthy children. RESULTS: Compared with the control group, the HRV time-domain indicators of children with VMC were significantly lower (p<0.05); also, the indicators of children with ventricular arrhythmias were significantly lower than those of children without ventricular arrhythmias (p<0.05). Equally, during both the lucid and sleep periods, the time-domain indicators of HRV were significantly lower in patients with VMC and arrhythmias than in either the control group (p<0.05) or the group with VMC but no ventricular arrhythmias (p<0.05). CONCLUSIONS: We conclude that the HRV of children with VMC probably decreased because of impaired vagal nerve function, with ventricular arrhythmias developing only when the decrease was most significant. Thus, HRV can be a useful predictive indicator for ventricular arrhythmias in children with VMC.


Subject(s)
Heart Rate/physiology , Myocarditis/diagnosis , Myocarditis/physiopathology , Ventricular Fibrillation/diagnosis , Ventricular Fibrillation/physiopathology , Arrhythmias, Cardiac/complications , Arrhythmias, Cardiac/diagnosis , Arrhythmias, Cardiac/physiopathology , Child , Child, Preschool , Diagnosis, Differential , Female , Humans , Male , Myocarditis/complications , Ventricular Fibrillation/complications
3.
Eur Rev Med Pharmacol Sci ; 21(15): 3447-3451, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28829496

ABSTRACT

OBJECTIVE: We analyzed the relationship between Mink-S27 gene polymorphism and children with cardiac insufficiency. PATIENTS AND METHODS: From April 2013 to April 2015, we enrolled 73 cases of children with cardiac insufficiency for this study, and all 73 were placed in the observation group. 76 normal cases were selected for the control group. Restriction fragment length polymorphism (RFLP) was used to make polymorphism analysis of the Mink-S27. RESULTS: Our results showed no significant differences in Mink-S27 genotype and allele distribution in both observation and control groups (p>0.05). In lesion samples collected from children with cardiac insufficiency, we detected significant difference in AA, CC genotype frequency and allele frequency between the observation group and the control group (p< 0.05) (X2 = 15.43, p<0.05; X2  = 16.27, p<0.05). Further studies on samples obtained from both groups revealed certain differences of AA, CC, AC genotype frequency and allele frequency in the observation group. The proportion of homozygote (AA, CC) in children with severe cardiac insufficiency was relatively high. CONCLUSIONS: GNAS2 gene polymorphism was associated with the prevalence of cardiac insufficiency in children. And also the patients' condition was correlated to the frequency of different genotypes and alleles.


Subject(s)
Heart Failure/genetics , Potassium Channels, Voltage-Gated/genetics , Alleles , Case-Control Studies , Child , Child, Preschool , Female , Gene Frequency , Genotype , Humans , Male , Polymorphism, Genetic , Polymorphism, Restriction Fragment Length
4.
Eur Rev Med Pharmacol Sci ; 20(9): 1814-8, 2016 05.
Article in English | MEDLINE | ID: mdl-27212174

ABSTRACT

OBJECTIVE: To explore the role of microparticles produced by endothelial cells in the injury of vascular endothelial cells. MATERIALS AND METHODS: We stimulated human umbilical vein endothelial cells (HUVEC) with TNF-α in vitro, analyzed the change of cellular morphology, and measured EMP level in the supernatant with a flow cytometer. Then, we evaluated the corresponding clinical indicators and the role of EMP in endothelial injury. RESULTS: The endothelial cellular morphology underwent significant changes, and a large number of microparticles were secreted. In turn, these microparticles blocked cell cycle and induced apoptosis. CONCLUSIONS: The microparticles produced by endothelial cells play an important role in the injury of vascular endothelial cells.


Subject(s)
Cell-Derived Microparticles , Endothelial Cells , Mucocutaneous Lymph Node Syndrome , Cells, Cultured , Child , Endothelium, Vascular/drug effects , Human Umbilical Vein Endothelial Cells/drug effects , Humans , Tumor Necrosis Factor-alpha/metabolism
5.
J Dairy Sci ; 97(11): 6785-91, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25218752

ABSTRACT

Pathogenic Yersinia enterocolitica is involved in yersiniosis through expression of chromosome-borne or plasmid-borne virulence factors. Yersinia enterocolitica is a cold-tolerant pathogen frequently isolated from refrigerated or frozen foods. However, little attention has been focused on the prevalence of pathogenic Y. enterocolitica in refrigerated or frozen dairy samples in China. In this study, we developed a new duplex PCR targeting the plasmid-borne virF gene and chromosome-borne ail gene for detection of pathogenic Y. enterocolitica isolates. We established a detection limit for the duplex PCR of 6.5 × 10(2)cfu/mL in artificially contaminated dairy samples. In addition, the duplex PCR could detect directly 4.5 to 5.7 cfu of Y. enterocolitica in 5 mL of brain heart infusion broth after 6 h of enrichment at 28 °C. A newly developed dot hybridization assay further confirmed specificity of the duplex PCR for detection of virulent Y. enterocolitica. Furthermore, 13 Y. enterocolitica and 5 pathogenic strains, from 88 commercial frozen or refrigerated dairy products, were detected successfully by the China National Standard method (GB/T4789.8-2008) and the duplex PCR, respectively. Finally, biotypes and serotypes of pathogenic Y. enterocolitica strains were further characterized. The duplex PCR developed here is reliable for large-scale screening, routine monitoring, and risk assessment of pathogenic Y. enterocolitica in refrigerated or frozen dairy products.


Subject(s)
Bacterial Outer Membrane Proteins/genetics , Dairy Products/microbiology , Food Contamination/analysis , Yersinia enterocolitica/isolation & purification , China , Cold Temperature , DNA, Bacterial/genetics , Food Microbiology , Limit of Detection , Nucleic Acid Hybridization , Plasmids/genetics , Polymerase Chain Reaction , Sensitivity and Specificity , Virulence Factors/genetics , Yersinia enterocolitica/genetics
6.
Gen Comp Endocrinol ; 173(1): 139-47, 2011 Aug 01.
Article in English | MEDLINE | ID: mdl-21624370

ABSTRACT

To understand how the social and physical environment influences behaviour, reproduction and survival, studies of underlying hormonal processes are crucial; in particular, interactions between stress and reproductive responses may have critical influences on breeding schedules. Several authors have examined the timing of breeding in relation to environmental stimuli, while others have independently described endocrine profiles. However, few studies have simultaneously measured endocrine profiles, breeding behaviour, and offspring survival across seasons. We measured sex and stress hormone concentrations (oestrogens, testosterone, and corticosterone), timing of breeding, and chick survival, in Adelie penguins (Pygoscelis adeliae) at two colonies in two different years. Clutch initiation at Cape Bird South (CBS; year 1, ~14,000 pairs) occurred later than at Cape Crozier East (CCE; year 2, ~ 25,000 pairs); however, breeding was more synchronous at CBS. This pattern was probably generated by the persistence of extensive sea ice at CBS (year 1). Higher corticosterone metabolite and lower sex hormone concentrations at CBS correlated with later breeding and lower chick survival compared to at CCE - again, a likely consequence of sea ice conditions. Within colonies, sub-colony size (S, 50-100; M, 200-300; L, 500-600; XL, >1000 pairs) did not influence the onset or synchrony of breeding, chick survival, or hormone concentrations. We showed that the endocrine profiles of breeding Adelie penguins can differ markedly between years and/or colonies, and that combining measures of endocrinology, behaviour, and offspring survival can reveal the mechanisms and consequences that different environmental conditions can have on breeding ecology.


Subject(s)
Reproduction/physiology , Spheniscidae/physiology , Animals , Breeding , Corticosterone/metabolism , Endocrinology , Estrogens/metabolism , Feces/chemistry , Female , Immunoenzyme Techniques , Male , Spheniscidae/metabolism , Testosterone/metabolism
7.
J Fish Biol ; 77(8): 1983-92, 2010 Nov.
Article in English | MEDLINE | ID: mdl-21078101

ABSTRACT

New Zealand has a freshwater fish fauna characterized by high levels of national and local endemism and which is threatened by anthropogenic stressors including habitat destruction or deterioration, commercial harvest, pollution and interactions with invasive exotic species. Significant expansion of New Zealand's dairy production has recently created further deterioration of lowland water quality and greater pressure for water allocation in drier eastern regions of the South Island. New Zealand has large freshwater resources and its climate is predicted to experience less dramatic changes in mean annual temperature and precipitation than many other regions of the world as a result of anthropogenic climate change. Predicted changes in regional climate and further expansion of the dairy industry, however, will impose similar pressures on freshwater resources in northern New Zealand to those already acting to threaten freshwater biodiversity in the eastern South Island.


Subject(s)
Climate Change , Fishes/physiology , Fresh Water , Animals , New Zealand , Population Dynamics , Socioeconomic Factors
8.
J Comp Physiol B ; 180(1): 83-94, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19609534

ABSTRACT

Physiological measurements of both stress and sex hormones are often used to estimate the consequences of natural or human-induced change in ecological studies of various animals. Different methods of hormone measurement exist, potentially explaining variation in results across studies; methods should be cross-validated to ensure that they correlate. We directly compared faecal and plasma hormone measurements for the first time in a wild free-living species, the Adelie penguin (Pygoscelis adeliae). Blood and faecal samples were simultaneously collected from individual penguins for comparison and assayed for testosterone and corticosterone (or their metabolites). Sex differences and variability within each measure, and correlation of values across measures were compared. For both hormones, plasma samples showed greater variation than faecal samples. Males had higher mean corticosterone concentrations than females, but the difference was only statistically significant in faecal samples. Plasma testosterone, but not faecal testosterone, was significantly higher in males than females. Correlation between sample types was poor overall, and weaker in females than in males, perhaps because measures from plasma represent hormones that are both free and bound to globulins, whereas measures from faeces represent only the free portion. Faecal samples also represent a cumulative measure of hormones over time, as opposed to a plasma 'snapshot' concentration. Our data indicate that faecal sampling appears more suitable for assessing baseline hormone concentrations, whilst plasma sampling may best define immediate responses to environmental events. Consequently, future studies should ensure that they select the most appropriate matrix and method of hormone measurement to answer their research questions.


Subject(s)
Corticosterone , Feces/chemistry , Spheniscidae , Testosterone , Animals , Antarctic Regions , Corticosterone/analogs & derivatives , Corticosterone/analysis , Corticosterone/blood , Corticosterone/metabolism , Female , Immunoenzyme Techniques , Male , Reproducibility of Results , Seasons , Sex Characteristics , Spheniscidae/blood , Statistics as Topic , Stress, Physiological , Testosterone/blood , Testosterone/metabolism
9.
Biochemistry ; 47(24): 6301-10, 2008 Jun 17.
Article in English | MEDLINE | ID: mdl-18498174

ABSTRACT

We used recombinant techniques to create a two-chain form (residues 1-345 and residues 346-758) of the vitamin K-dependent gamma-glutamyl carboxylase, a glycoprotein located in the endoplasmic reticulum containing five transmembrane domains. The two-chain carboxylase had carboxylase and epoxidase activities similar to those of one-chain carboxylase. In addition, it had normal affinity for the propeptide of factor IX. We employed this molecule to investigate formation of the one disulfide bond in carboxylase, the transmembrane structure of carboxylase, and the potential interactions among the carboxylase's transmembrane domains. Our results indicate that the two peptides of the two-chain carboxylase are joined by a disulfide bond. Proline 378 is important for the structure necessary for disulfide formation. Results with the P378L carboxylase indicate that noncovalent bonds maintain the two-chain structure even when the disulfide bond is disrupted. As we had previously proposed, the fifth transmembrane domain of carboxylase is the last and only transmembrane domain in the C-terminal peptide of the two-chain carboxylase. We show that the noncovalent association between the two chains of carboxylase involves an interaction between the fifth transmembrane domain and the second transmembrane domain. Results of a homology model of transmembrane domains 2 and 5 suggest that not only do these two domains associate but that transmembrane domain 2 may interact with another transmembrane domain. This latter interaction may be mediated at least in part by a motif of glycine residues in the second transmembrane domain.


Subject(s)
Carbon-Carbon Ligases/chemistry , Cell Membrane/enzymology , Disulfides/chemistry , Peptide Fragments/chemistry , Proline/chemistry , Vitamin K , Amino Acid Sequence , Amino Acid Substitution/genetics , Carbon-Carbon Ligases/genetics , Carbon-Carbon Ligases/metabolism , Humans , Models, Molecular , Molecular Sequence Data , Peptide Fragments/genetics , Peptide Fragments/metabolism , Proline/genetics , Protein Structure, Tertiary , Recombinant Proteins/chemistry , Sequence Homology, Amino Acid , Structure-Activity Relationship , Vitamin K/chemistry
10.
J Clin Periodontol ; 34(2): 103-10, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17214737

ABSTRACT

BACKGROUND: Oxidative stress is implicated in the pathogenesis of periodontitis. The total antioxidant capacity (TAOC) of gingival crevicular fluid volume (GCF) and plasma appears compromised in periodontitis, but it is unclear whether this predisposes to, or results from the inflammatory process. AIM: To investigate longitudinal changes in GCF and plasma TAOC following reductions in periodontal inflammation with successful non-surgical therapy. MATERIALS AND METHODS: Two longitudinal studies were run in series on non-smokers with chronic periodontitis (CP). Study-1 (n=17) assessed index sites with mild disease; Study-2 (n=18) investigated deep sites. GCF sampling and clinical measures were performed at baseline and 3 months post-therapy. Plasma and GCF TAOC was determined by enhanced chemiluminescence and 32 age/sex-matched periodontally healthy controls were used. RESULTS: Therapy improved clinical outcomes consistent with the literature. There were no differences in plasma TAOC between periodontitis patients (507+/-92 microMTeq) and controls (520+/-100 microMTeq; p=0.57) at baseline, but GCF TAOC was lower (p<0.0001) in CP patients (680+/-371 microMTeq) than controls (1129+/-722 microMTeq). Successful periodontal therapy did not alter plasma TAOC (p=0.56), but GCF TAOC increased (by 449+/-722 microMTeq, p<0.001) to control subject levels (p=0.47) CONCLUSIONS: Local total antioxidant capacity in CP appears to reflect increased oxygen radical activity during periodontal inflammation and can be restored to control subject levels by successful non-surgical therapy.


Subject(s)
Antioxidants/metabolism , Gingival Crevicular Fluid/metabolism , Periodontitis/metabolism , Reactive Oxygen Species/metabolism , Adult , Case-Control Studies , Chronic Disease , Cross-Sectional Studies , Dental Care , Female , Humans , Longitudinal Studies , Male , Matched-Pair Analysis , Middle Aged , Oxidative Stress/physiology , Periodontal Index , Periodontitis/blood , Periodontitis/therapy , Reactive Oxygen Species/blood , Reference Values , Sex Factors
11.
Peptides ; 26(11): 2294-301, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16269355

ABSTRACT

We investigated the effect of melanocortin 4 receptor (MC4) antagonists on food intake in mice. Food intake during the light phase was significantly increased by ICV administration of mixed MC3/MC4 antagonists (AgRP and SHU9119) or MC4 selective antagonist peptide [(Cyclo (1-5)[Suc-D-Nal-Arg-Trp-Lys]NH2] (MBP10) and the small molecule antagonists THP and NBI-30. Both mixed and selective antagonists significantly reversed anorexia induced by ICV administration of the MC4 agonist (c (1-6) HfRWK-NH2) and the cytokine IL-1beta. These findings provide pharmacological evidence that the MC4 receptor mediates the effects of melanocortin agonists and antagonists on food intake in mice, and support the idea that selective small molecule MC4 antagonists may be useful as therapeutics for cachexia.


Subject(s)
Anorexia/drug therapy , Hyperphagia/drug therapy , Interleukin-1/administration & dosage , Melanocyte-Stimulating Hormones/administration & dosage , Peptides, Cyclic/administration & dosage , Receptor, Melanocortin, Type 4/agonists , Receptor, Melanocortin, Type 4/antagonists & inhibitors , Animals , Anorexia/chemically induced , Cachexia/drug therapy , Female , Melanocyte-Stimulating Hormones/adverse effects , Mice
12.
Arch Environ Contam Toxicol ; 48(4): 520-9, 2005 May.
Article in English | MEDLINE | ID: mdl-15886890

ABSTRACT

Juvenile rainbow trout (Oncorhynchus mykiss) were exposed to 0, 10, 30, and 70% (v/v) of a secondary-treated, integrated thermomechanical-bleached kraft pulp and paper mill effluent. The immunological parameters oxidative burst and phagocytosis of head kidney macrophages and total and differential circulating leukocytes were measured after 21 d of exposure. General parameters of stress and exposure including erythrocyte counts, numbers of degenerating erythrocytes, splenic pigmented macrophage aggregates (PMAs), spleen size, bile chemistry, and hepatic EROD activity were also assessed. Contrary to parallel chronic studies on the same effluent, EROD induction did not occur. Analyses of bile indicated uptake and accumulation of resin acids and some sterols. There was no measurable macrophage-related immunological dysfunction. However, circulating leukocytes, specifically lymphocytes, were reduced. The density of splenic PMAs increased over the exposure period, possibly in association with degenerating blood cells. There were statistical differences between staggered days of sampling in head kidney oxidative burst, white and mature red blood cell counts, and spleen size, indicating that relatively minor capture and handling stress could result in rapid changes in some parameters. Overall, it was concluded that the observed minor, indirect alterations in the immune response were likely the result predominantly of a nonspecific mechanism such as a cortisol-mediated stress response.


Subject(s)
Industrial Waste , Oncorhynchus mykiss/physiology , Water Pollutants, Chemical/toxicity , Animals , Bile/chemistry , Blood Cell Count , Industrial Waste/analysis , Kidney/immunology , Macrophages/drug effects , Macrophages/immunology , Muramidase/blood , New Zealand , Oncorhynchus mykiss/blood , Oncorhynchus mykiss/immunology , Paper , Phagocytosis/drug effects , Respiratory Burst , Rivers , Spleen/immunology , Waste Disposal, Fluid , Water Pollutants, Chemical/analysis
13.
Biochemistry ; 43(12): 3670-8, 2004 Mar 30.
Article in English | MEDLINE | ID: mdl-15035637

ABSTRACT

CC chemokine receptor 7 (CCR-7) is expressed on mature dendritic cells and T-cells. Its ligands, CCL-19 (MIP-3beta) and CCL-21 (SLC), play an important role in the migration of these cells to secondary lymphoid organs where they are predominantly expressed. For most chemokines, the N-terminal domain preceding the first two conserved cysteines is involved in stabilizing the active conformation of its cognate receptors. We have chemically synthesized N-terminal analogues of CCL-19 with the aid of a native chemical ligation method to investigate structure function requirements of this ligand domain by performing ligand binding, GTP-gammaS binding, and chemotaxis assays. Successive truncations of the N-terminus of CCL-19 reduced the affinity of the receptor for the ligand in a size-dependent manner. Furthermore, Ala substitutions of Asn(3), Asp(4), and Asp(7) show that the side chains of these residues are important for high-affinity binding of CCL-19 to CCR-7. The effects observed were mirrored in both GTP-gammaS binding and chemotaxis assays, highlighting the functional importance of this ligand domain. We also describe two partial agonists of CCR-7 ([Nle(72)]CCL-19(6-77) and Ac-[Nle(72)]CCL-19(7-77)), and identify the first analogue of CCL-19 (Ac-[Nle(72)]CCL-19(8-77)) that acts as a functional antagonist in vitro (K(B) approximately 350 nM for GTP-gammaS binding assays). As mutations of both Glu(6) and Asp(7) to Ala did not dissociate effects on ligand binding from receptor activation, it is likely that the backbone of these two residues is crucial for agonist activity.


Subject(s)
Chemokines, CC/chemistry , Peptide Fragments/chemistry , Receptors, Chemokine/metabolism , Acetylation , Alanine/genetics , Amino Acid Sequence , Amino Acid Substitution/genetics , Animals , CHO Cells , Cell Line, Tumor , Cell Migration Inhibition , Chemokine CCL19 , Chemokine CCL21 , Chemokines, CC/genetics , Cricetinae , Humans , Ligands , Methionine/genetics , Molecular Sequence Data , Norleucine/genetics , Peptide Fragments/genetics , Protein Binding/genetics , Receptors, CCR7 , Receptors, Chemokine/antagonists & inhibitors , Receptors, Chemokine/chemistry , Receptors, G-Protein-Coupled/metabolism , Sequence Deletion
14.
Proc Biol Sci ; 270 Suppl 2: S195-7, 2003 Nov 07.
Article in English | MEDLINE | ID: mdl-14667381

ABSTRACT

Water movements, of both abiotic and biotic origin, provide a wealth of information for fishes. They detect these water movements by arrays of hydrodynamic sensors located on the surface of the body as superficial neuromasts and embedded in subdermal lateral line canals. Recently, the anatomical dichotomy between superficial and canal neuromasts has been matched by demonstrations of a corresponding functional dichotomy. Superficial neuromasts are sensitive to water flows over the surface of the fish and are the sub-modality that participates in orientation to water currents, a behaviour known as rheotaxis. The canal neuromasts are sensitive to water vibration and it is this sub-modality that determines the localization of artificial prey. Recently, however, it has been shown that the complex behaviour of natural prey capture in the dark requires input from both lateral line sensory submodalities and here we show that the ability of trout to hold station behind a stationary object in fast flowing water also requires integration of information from both sub-modalities.


Subject(s)
Oncorhynchus mykiss/physiology , Orientation/physiology , Sensory Receptor Cells/physiology , Water Movements , Animals , Predatory Behavior , Rheology
15.
J Med Chem ; 44(23): 4001-10, 2001 Nov 08.
Article in English | MEDLINE | ID: mdl-11689087

ABSTRACT

Insulin-like growth factors (IGF-I and II) play an important role in metabolic and mitogenic activities through stimulation of the IGF-I receptor on the cell surface. Although the concentration of IGF in blood and cerebrospinal fluid is quite high (>100 nM), this large pool of IGF is biologically inactive because of its association with six distinct binding proteins, which form high-affinity complexes with IGF. Thus, inhibitors of IGF-binding proteins (IGFBPs), especially IGFBP-3, could potentially alter the distribution between the "free" and "bound" forms of IGF and thereby elevate biologically active IGF-I to exert a beneficial effect on those patients with diseases that respond to the application of exogenous IGF-I. Whereas IGF-I peptide variants, which bind to IGFBPs but not the IGF-I receptor, have been shown to be potent IGF/IGFBP inhibitors, small molecule nonpeptide IGF/IGFBP inhibitors have the potential advantages of oral bioavailability and flexible dosing regimen. Here we report the discovery of several isoquinoline analogues, exemplified by 1 and 2, which bind IGFBP-3 as well as other IGFBPs at low nanomolar concentrations. More importantly, both compounds were shown to be able to release biologically active IGF-I from the IGF-I/IGFBP-3 complex. These results point to the feasibility of developing orally active therapeutics to treat IGF-responsive diseases by optimization of the lead molecules 1 and 2.


Subject(s)
Insulin-Like Growth Factor II/metabolism , Insulin-Like Growth Factor I/metabolism , Isoquinolines/chemical synthesis , Receptor, IGF Type 1/antagonists & inhibitors , Receptor, IGF Type 2/antagonists & inhibitors , 3T3 Cells , Animals , Binding, Competitive , Cell Division/drug effects , Isoquinolines/chemistry , Isoquinolines/pharmacology , Magnetic Resonance Spectroscopy , Mice , Receptor, IGF Type 1/metabolism , Receptor, IGF Type 2/metabolism , Structure-Activity Relationship
16.
J Biol Chem ; 276(35): 32419-22, 2001 Aug 31.
Article in English | MEDLINE | ID: mdl-11445558

ABSTRACT

Insulin-like growth factor-I (IGF-I) has both metabolic and mitogenic activities mediated through interaction with the type 1 IGF receptor. The circulation of IGF-I in blood and interstitial fluid is not free but bound mostly to a family of six high affinity IGF-binding proteins, which form stable complexes with IGF and neutralize its bioactivity. Therefore, displacement of this large pool of endogenous IGF from the binding proteins could elevate "free" IGF levels to elicit beneficial effects in diabetes and other IGF-responsive diseases comparable with those produced by administration of exogenous IGF-I. We report here the identification of a nonpeptide ligand NBI-31772, which displaces IGF-I from all six IGF-binding proteins at low nanomolar concentrations from screening of the in-house chemical libraries. Furthermore, the released free IGF-I was shown to be biologically active in an in vitro bioassay. Thus, NBI-31772 could serve as a valuable lead molecule for the design of novel therapeutics to treat diabetes and other IGF-responsive diseases.


Subject(s)
Catechols/pharmacology , Insulin-Like Growth Factor Binding Proteins/drug effects , Insulin-Like Growth Factor Binding Proteins/metabolism , Insulin-Like Growth Factor I/metabolism , Isoquinolines/pharmacology , Animals , Binding, Competitive , Cell Line , Humans , Insulin-Like Growth Factor Binding Protein 1/metabolism , Insulin-Like Growth Factor Binding Protein 2/metabolism , Insulin-Like Growth Factor Binding Protein 4/metabolism , Insulin-Like Growth Factor Binding Protein 5/metabolism , Insulin-Like Growth Factor Binding Protein 6/metabolism , Iodine Radioisotopes , Kinetics , Ligands , Molecular Structure , Radioligand Assay , Recombinant Proteins/metabolism , Spodoptera , Transfection
17.
Neuroreport ; 12(6): 1231-4, 2001 May 08.
Article in English | MEDLINE | ID: mdl-11338197

ABSTRACT

Intracerebroventricular (i.c.v.) administration of corticotropin-releasing factor (CRF) peptide fragments with low affinity for CRF receptors reportedly improves cognitive performance without producing anxiety. These compounds are hypothesized to act by displacing endogenous peptide from the CRF-binding protein (CRF-BP). To test this hypothesis, the present study determined whether the performance-enhancing potency of CRF fragments was related to their affinity for the CRF-BP. Rank ordering of the optimal doses of these compounds for facilitating spatial navigation corresponded to their affinity for the CRF-BP. i.c.v. pretreatment with performance-enhancing doses of r/h CRF(1-41)-OH (5 micrograms) or r/h CRF(6-33) (25 micrograms) did not increase emotionality. These findings replicate the dissociability of the cognition- and anxiety-related effects of CRF-related compounds and suggest that CRF fragments facilitate performance via the CRF-BP.


Subject(s)
Carrier Proteins/antagonists & inhibitors , Carrier Proteins/metabolism , Corticotropin-Releasing Hormone/pharmacology , Emotions/drug effects , Maze Learning/drug effects , Motor Activity/drug effects , Animals , Corticotropin-Releasing Hormone/metabolism , Emotions/physiology , Ligands , Male , Maze Learning/physiology , Motor Activity/physiology , Rats , Rats, Wistar
18.
Cancer Res ; 61(4): 1432-8, 2001 Feb 15.
Article in English | MEDLINE | ID: mdl-11245447

ABSTRACT

Individuals affected with either acute or chronic diseases often show disorders of nutrient balance. In some cases, a devastating state of malnutrition known as cachexia arises, brought about by a synergistic combination of a dramatic decrease in appetite and an increase in metabolism of fat and lean body mass. Stimulation of the hypothalamic melanocortin 4 receptor (MC4-R) produces relative anorexia and increased metabolic rate, even in a relatively starved state. Here we demonstrate that cachexia induced by lipopolysaccharide administration and by tumor growth is ameliorated by central MC4-R blockade. MC4-R knock-out mice or mice administered the MC3-R/MC4-R antagonist, agouti-related peptide, resist tumor-induced loss of lean body mass, and maintain normal circadian activity patterns during tumor growth. The final tumor mass is not affected in these animals, providing further support for the potential role of MC4-R antagonism in the treatment of cachexia in disease states.


Subject(s)
Cachexia/prevention & control , Receptors, Peptide/antagonists & inhibitors , Agouti-Related Protein , Animals , Cachexia/chemically induced , Cachexia/etiology , Carcinoma, Lewis Lung/complications , Eating/drug effects , Eating/physiology , Intercellular Signaling Peptides and Proteins , Lipopolysaccharides/antagonists & inhibitors , Lipopolysaccharides/toxicity , Mice , Mice, Inbred C57BL , Mice, Knockout , Motor Activity/drug effects , Motor Activity/physiology , Proteins/pharmacology , Receptor, Melanocortin, Type 3 , Receptor, Melanocortin, Type 4 , Receptors, Corticotropin/antagonists & inhibitors , Receptors, Peptide/genetics , Receptors, Peptide/physiology , Sarcoma, Experimental/complications , Signal Transduction/physiology
19.
Endocrinology ; 142(3): 992-9, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11181511

ABSTRACT

Although there is considerable information regarding the role of brain CRF in energy balance, relatively little is known about the role of urocortin (UCN), which is an equally potent anorexic agent. Therefore, the effects of intracerebroventricular (icv) administration of UCN (0.01-1 nmol/day) on food intake and body weight were assessed over a period of 13 days and compared with data from CRF-infused counterparts. Although both peptides dose dependently reduced food intake and weight gain, the effects of CRF were much greater in magnitude than those of UCN, particularly on body weight. Pair-feeding studies suggested that, while the effects of CRF on body weight could not be completely explained by appetite suppression, the effects of UCN appeared to be due to its initial impact on food intake. CRF increased brown adipose fat pad and adrenal weights, whereas it reduced thymus and spleen weights. CRF also increased serum corticosterone, triglyceride, FFA, and cholesterol levels, whereas it reduced glucose. UCN did not produce any consistent changes in any of these indices of sympathetic nervous system activation. Concurrent administration of the CRF(2)-selective antagonist, antisauvagine-30 (ASV-30) (30 nmol/day) completely reversed or attenuated the effects of UCN and CRF (1 nmol/day) on food intake and body weight. ASV-30 did not significantly attenuate any of the above CRF-induced changes in tissue weights or serum chemistry. These data suggest that the central CRF(2) receptor may primarily mediate the anorexic, but not the metabolic effects of CRF.


Subject(s)
Corticotropin-Releasing Hormone/metabolism , Energy Metabolism , Receptors, Corticotropin-Releasing Hormone/metabolism , Animals , Blood/metabolism , Body Weight/drug effects , Corticotropin-Releasing Hormone/pharmacology , Dose-Response Relationship, Drug , Eating/drug effects , Male , Organ Size/drug effects , Protein Isoforms/metabolism , Rats , Rats, Long-Evans , Urocortins
20.
J Clin Invest ; 107(2): 173-80, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11160133

ABSTRACT

The 9-23 amino acid region of the insulin B chain (B9-23) is a dominant epitope recognized by pathogenic T lymphocytes in nonobese diabetic mice, the animal model for type 1 diabetes. We describe herein similar (B9-23)-specific T-cell responses in peripheral lymphocytes obtained from patients with recent-onset type 1 diabetes and from prediabetic subjects at high risk for disease. Short-term T-cell lines generated from patient peripheral lymphocytes showed significant proliferative responses to (B9-23), whereas lymphocytes isolated from HLA and/or age-matched nondiabetic normal controls were unresponsive. Antibody-mediated blockade demonstrated that the response was HLA class II restricted. Use of the highly sensitive cytokine-detection ELISPOT assay revealed that these (B9-23)-specific cells were present in freshly isolated lymphocytes from only the type 1 diabetics and prediabetics and produced the proinflammatory cytokine IFN-gamma. This study is, to our knowledge, the first demonstration of a cellular response to the (B9-23) insulin epitope in human type 1 diabetes and suggests that the mouse and human diseases have strikingly similar autoantigenic targets, a feature that should facilitate development of antigen-based therapeutics.


Subject(s)
Diabetes Mellitus, Type 1/immunology , Insulin/pharmacology , Peptide Fragments/pharmacology , Prediabetic State/immunology , T-Lymphocytes/drug effects , Adolescent , Adult , Cells, Cultured , Diabetes Mellitus, Type 1/blood , Female , Humans , Immunodominant Epitopes/pharmacology , Interferon-gamma/immunology , Lymphocyte Activation/drug effects , Male , Prediabetic State/blood , Risk Factors , T-Lymphocytes/immunology
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