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Biomedical subjects

H Ni

Publications and source records attributed to H Ni.

At least 37 records · Page 2Linked to original sources
PubMed2001

Prospective evaluation of an outpatient heart failure management program.

BACKGROUND: Although considerable effort has been devoted to the follow-up of hospitalized patients, the effectiveness and process of heart failure outpatient management have not been well demonstrated. METHODS AND RESULTS: All new patients referred to the program from April 1997 to September 1998 were followed and managed by comprehensive strategies including preemptive hospitalization. Quality of life (QOL) and patients' self-care adherence behaviors were measured at baseline, 3 months, and 6 months. Clinical outcomes were compared for the 6 months before and 6 months after referral. A total of 108 patients were recruited. Patients' self-care knowledge score was improved over time (difference score = 0.9, P <.01). The proportion of patients weighing themselves daily increased by 24% (P =.02). The proportion of patients with New York Heart Association (NYHA) class III to IV was 67.6% at baseline and 49.1% at 6 months (P =.01). Compared with 6 months before referral, the program intervention was accompanied by a 52% reduction in the risk of hospitalization for cardiovascular causes (56.1% v 27.2%, P <.001) and a 72% reduction in emergency room visits (53.6% v 14.5%, P <.01). The total hospital admissions for cardiovascular causes decreased by 59% from 94 to 39; the total emergency room visits decreased by 77% from 83 to 19. The patients' QOL was improved over time with a change score of 11.2 (P <.001) at 3 months and 10.7 (P <.001) at 6 months. CONCLUSION: Our study shows the effectiveness of this heart failure outpatient management program.

Adult↗
PubMed2001

[Effects of volatiles from different trophic level on foraging behavior of Aphidius avenae].

The responses of female Aphidius avenae to volatiles from undamaged wheat plant, Sitobion avenae and Rhopalosiphum padi, aphids-plant complexes and aphids damaged plant were investigated in wind tunnel and Y-tube olfactometer. The volatiles from undamaged wheat plant, S. avenae and R. padi were much less attractive to A. avenae than those from aphids-plant complexes and aphids-damaged plant. Although the parasitic rate was much lower, the R. padi-plant complexes and R. padi damaged plant were also attractive to A. avenae. Identification of volatiles by GC-MS showed that the main volatiles induced by aphids feeding were 2-camphene, 6-methyl-5-hepten-2-one, 6-methyl-5-hepten-2-ol, Z-3-hexenyl-acetate, and methyl salicylate, among which, 6-methyl-5-hepten-2-one and 6-methyl-5-hepten-2-ol were more attractive to A. avenae, while methyl salicylate was not attractive.

Animals↗
PubMed2001

Analysis of the 1991-2000 influenza epidemic in Guangdong Province, China.

Influenza surveillance networks in Guangdong were established to investigate the epidemiological characteristics of influenza and influenza epidemics. Influenza activity peaked annually from March to July in Guangdong in 1991-2000; influenza H3N2 predominated in the epidemic (7 years of 10); the outbreak of influenza in 1996 was the remarkable result of antigenic drift of H3N2 strain. Ten isolates of H9N2 strains were discovered from human subjects in 1998 and 1999: chicken strains isolated after the Hong Kong fowl influenza outbreak. It was found that there was just one influenza activity season per annum in Guangdong and that the influenza H3N2 subtype still predominates in Guangdong. Further research into the pathogenicity of influenza H9N2 in humans warranted.

Animals↗
PubMed2000

Active site binding modes of HIV-1 integrase inhibitors.

Using the crystal structure of the first complex of the HIV-1 integrase catalytic core domain with an inhibitor bound to the active site, structural models for the interaction of various inhibitors with integrase were generated by computational docking. For the compound of the crystallographic study, binding modes unaffected by crystal packing have recently been proposed. Although a large search region was used for the docking simulations, the ligands investigated here are found to bind preferably in similar ways close to the active site. The binding site is formed by residues 64-67, 116, 148, 151-152, 155-156, and 159, as well as by residue 92 in case of the largest ligand of the series. The coherent picture of possible interactions of small-molecule inhibitors at the active site provides an improved basis for structure-based ligand design. The recurring motif of tight interaction with the two lysine residues 156 and 159 is suggested to be of prime importance.

Anthraquinones↗
PubMed2000

HIV gag mRNA transfection of dendritic cells (DC) delivers encoded antigen to MHC class I and II molecules, causes DC maturation, and induces a potent human in vitro primary immune response.

Dendritic cells (DC) are the major APCs involved in naive T cell activation making them prime targets of vaccine research. We observed that mRNA was efficiently transfected, resulting in superior translation in DC compared with other professional APCs. A single stimulation of T cells by HIV gag-encoded mRNA-transfected DC in vitro resulted in primary CD4(+) and CD8(+) T cell immune responses at frequencies of Ag-specific cells (5-12.5%) similar to primary immune responses observed in vivo in murine models. Additionally, mRNA transfection also delivered a maturation signal to DC. Our results demonstrated that mRNA-mediated delivery of encoded Ag to DC induced potent primary T cell responses in vitro. mRNA transfection of DC, which mediated efficient delivery of antigenic peptides to MHC class I and II molecules, as well as delivering a maturation signal to DC, has the potential to be a potent and effective anti-HIV T cell-activating vaccine.

Antigen Presentation↗
PubMed2000

Mutation of any site of N-linked glycosylation accelerates the in vivo clearance of recombinant rabbit antithrombin.

Antithrombin (AT) is a plasma protein with four sites of N-linked glycosylation. Asn 135 is incompletely glycosylated, and the resulting 3-glycan AT is cleared more rapidly in vivo than the 4-glycan form. The Asn codons in each of the four sites of glycosylation were altered in turn, to create four mutant rabbit AT cDNAs. Permanently transfected CHO cell lines were generated following transfection of the resulting constructs, encoding either the wild-type rabbit AT (AT-WT) or one of the four underglycosylated variants (AT-N96Q, AT-N135Q, AT-N155Q, and AT-N155Q). Comparison of the five resulting recombinant AT proteins revealed that the major AT species of each variant co-migrated on SDS gels, and migrated more rapidly than the major form of AT-WT. The shift in mobility, from 60 to 57 kDa, was consistent with the loss of one fully sialylated complex N-linked glycan. Neither the amount of AT secreted (range: 1.25 to 4.2 microg/10(6) cells/day) nor the kinetics of secretion differed significantly between cell lines expressing AT-WT or any of the AT variants. All forms of recombinant rabbit AT were capable of forming denaturation-resistant complexes with thrombin. Purification and radioiodination of each of the five recombinant AT proteins permitted pharmacokinetic analysis of their individual clearance in rabbits. While neither the equilibration half-life (t(0.5)alpha) nor the terminal catabolic half-life (t(0. 5)beta) differed significantly between plasma-derived rabbit AT and AT-WT, the t(0.5)beta of all the underglycosylated variants was decreased relative to that of AT-WT (maximum reduction in mean: from 70.1+/-3.2 h to 52.4+/-2.5 h). These results suggest that the overall extent of glycosylation, rather than the location within AT of the glycan chains, is a primary determinant of AT clearance.

Amino Acid Substitution↗
PubMed2000

Comparative responsiveness of Short-Form 12 and Minnesota Living With Heart Failure Questionnaire in patients with heart failure.

BACKGROUND: The Short-Form 12 (SF-12) and Living With Heart Failure Questionnaire (LHFQ) are commonly used to measure quality of life (QOL) in heart failure outcomes research. Their comparative responsiveness, however, has not been documented. METHODS AND RESULTS: A prospective cohort study was conducted among patients attending a university-based heart failure clinic between April 1997 and September 1998. All patients received comprehensive heart failure care management. QOL of patients was assessed by the SF-12 and LHFQ at baseline and 3 months. Of 87 patients completing follow-up, the mean change score was 10.1 for the LHFQ and 5.8 for the SF-12 (both Ps < .001). The change scores of the instruments were correlated (r = 0.61; P < .001). The SF-12 had a greater ability than the LHFQ to statistically detect change in physical health but was less sensitive to changes in mental health. The LHFQ performed better than the SF-12 in the ability to distinguish the differences in perceived global health transition. CONCLUSION: The LHFQ is more responsive than the SF-12 to changes in QOL. The SF-12 should not be used alone to measure the changes in QOL of patients with heart failure.

Adult↗
PubMed2000

Interaction of yellow fever virus French neurotropic vaccine strain with monkey brain: characterization of monkey brain membrane receptor escape variants.

Binding of yellow fever virus wild-type strains Asibi and French viscerotropic virus and vaccine strains 17D and FNV to monkey brain and monkey liver cell membrane receptor preparations (MRPs) was investigated. Only FNV bound to monkey brain MRPs, while French viscerotropic virus, Asibi, and FNV all bound to monkey liver MRPs. Four monkey brain and two mouse brain MRP escape (MRP(R)) variants of FNV were selected at pH 7.6 and 6.0. Three monkey brain MRP(R) variants selected at pH 7.6 each had only one amino acid substitution in the envelope (E) protein in domain II (E-237, E-260, or E274) and were significantly attenuated in mice following intracerebral inoculation. Two of the variants were tested in monkeys and retained parental neurotropism following intracerebral inoculation at the dose tested. We speculate that this region of domain II is involved in binding of FNV E protein to monkey brain and is, in part, responsible for the enhanced neurotropism of FNV for monkeys. A monkey brain MRP(R) variant selected at pH 6.0 and two mouse brain MRP(R) variants selected at pH 7.6 were less attenuated in mice, and each had an amino acid substitution in the transmembrane region of the E protein (E-457 or E-458).

Animals↗
PubMed2000

Evolutionary relationships of endemic/epidemic and sylvatic dengue viruses.

Endemic/epidemic dengue viruses (DEN) that are transmitted among humans by the mosquito vectors Aedes aegypti and Aedes albopictus are hypothesized to have evolved from sylvatic DEN strains that are transmitted among nonhuman primates in West Africa and Malaysia by other Aedes mosquitoes. We tested this hypothesis with phylogenetic studies using envelope protein gene sequences of both endemic/epidemic and sylvatic strains. The basal position of sylvatic lineages of DEN-1, -2, and -4 suggested that the endemic/epidemic lineages of these three DEN serotypes evolved independently from sylvatic progenitors. Time estimates for evolution of the endemic/epidemic forms ranged from 100 to 1,500 years ago, and the evolution of endemic/epidemic forms represents relatively recent events in the history of DEN evolution. Analysis of envelope protein amino acid changes predicted to have accompanied endemic/epidemic emergence suggested a role for domain III in adaptation to new mosquito and/or human hosts.

Base Sequence↗
PubMed2000

Persistence of platelet thrombus formation in arterioles of mice lacking both von Willebrand factor and fibrinogen.

We used intravital microscopy to observe the formation of platelet plugs in ferric chloride-injured arterioles of live mice. With this model, we evaluated thrombus growth in mice lacking von Willebrand factor (vWF) and fibrinogen (Fg), the two key ligands known to mediate platelet adhesion and aggregation. In vWF(-/-) mice, despite the presence of arterial shear, delayed platelet adhesion occurred and stable thrombi formed. In many mice, a persisting high-shear channel never occluded. Abundant thrombi formed in Fg(-/-) mice, but they detached from the subendothelium, which ultimately caused downstream occlusion in all cases. Surprisingly, mice deficient in both vWF and Fg successfully formed thrombi with properties characteristic of both mutations, leading to vessel occlusion in the majority of vessels. Platelets of these doubly deficient mice specifically accumulated fibronectin in their alpha-granules, suggesting that fibronectin could be the ligand supporting the platelet aggregation.

Afibrinogenemia↗
PubMed2000

A transient increase in CCK mRNA levels in hippocampus following audiogenic convulsions in audiogenic seizure-prone rats.

AIM: To examine the effects of a single convulsion and multiple convulsions on cholecystokinin (CCK) mRNA expression in hippocampus of audiogenic seizure-prone rats (P77PMC). METHODS: Ringing (electric bell, 100 dB, 60 s) was used to induce convulsions, hippocampal CCK mRNA expression was exhibited by in situ hybridization. RESULTS: 1) The number of CCK mRNA-positive neurons in principal hippocampus of normal rats was 34 +/- 5, which elevated markedly after a single (155 +/- 7, P < 0.01) or multiple convulsions (95 +/- 8, P < 0.01). 2) CCK mRNA levels in multiple consecutive convulsion rats were lower than that in a single convulsion rats (P < 0.01). CONCLUSION: The increased number of CCK mRNA-positive neurons in hippocampus may have important functional consequences in convulsion-associated processes.

Acoustic Stimulation↗
PubMed2000

[Clinical study in treating type 2 diabetes mellitus according to liver in TCM].

OBJECTIVE: To explore the clinical effect of Danzhi Xiaoyao powder (DZXY) in treating type 2 diabetes mellitus (DM) according to Liver in TCM. METHODS: Fifty-one type 2 DM patients were randomly divided into the treated group and the control group, 31 patients of the treated group were treated with conventional and DZXY therapy, while 20 patients in the control were treated with conventional therapy alone. Before and after treatment for 3 months, the levels of fasting blood glucose (FBG), fasting insulin, glycosylated hemoglobin (HbA1c), blood cholesterol (CH) and triglycerides (TG) were examined in all the patients. RESULTS: By the end of 3 months, the effect in treating type 2 DM in the treated group was better than that in the control group (P < 0.05). Compared with those before treatment in each group and those of the control, the levels of FBG, fasting insulin, HbA1c after DZXY treatment were reduced (P < 0.05), but levels of CH and TG in all groups had no significant difference. CONCLUSION: DZXY could soothe the Liver to relieve depression, which is effective in treating type 2 DM and could improve the symptoms of DM patients.

Aged↗
PubMed2000

[A transient increase in CCK mRNA levels in amygdala following audiogenic seizures in audiogenic seizure-prone rats].

The effects of single and multiple seizures on cholecystokinin (CCK) mRNA levels in amygdala of audiogenic seizure-prone rats (P77PMC) were examined by in situ hybridization. The main results are as follows: (1) CCK mRNA positive neurons (No/0.01 mm(2)) in amygdala showed a transient increase in number from the 8+/-1 to 58+/-5 (P<0.01) in 30 min and then returned to the control value in 2 h (9+/-2, P>0.05), and (2) in the multiple consecutive seizure rats the increase in 30 min (22+/-3) was less than that in the single seizure rats (P<0.01), and the number returned to normal in 1 h (6+/-1, P>0.05). These data indicate that the transient increase in CCK mRNA level in amygdala following single or multiple consecutive seizures of P77PMC may be involved in anti-convulsant mechanisms in response to acute seizures.

Amygdala↗
PubMed1999

Factors influencing knowledge of and adherence to self-care among patients with heart failure.

BACKGROUND: Patient education has been shown to be a key component in comprehensive heart failure management. Few data, however, are available regarding patients' knowledge of and adherence to self-care recommendations for the disease. OBJECTIVES: To assess the knowledge level of and adherence to self-care among patients with heart failure and to determine associated factors. METHODS: We conducted a needs-assessment survey among new patients visiting a heart failure clinic from April 1997 through June 1998. Multiple linear regression analysis was used to assess the factors predictive of patients' knowledge level and adherence behaviors. RESULTS: Of the 113 patients surveyed, 77% were referred by cardiologists and 60% had New York Heart Association class III or IV status. Two thirds of the patients reported receiving information or advice about self-care from health care providers. When asked how much they knew about congestive heart failure, however, 37% said "a little or nothing," 49% said "some," and only 14% said "a lot." Approximately 40% of the patients did not recognize the importance of weighing themselves daily and 27% weighed themselves twice a month or less often. Although 80% of the patients knew they should limit their salt intake, only one third always avoided salty foods. Additionally, 25% of the patients did not appreciate the risk of alcohol use and 36% believed they should drink a lot of fluids. The multiple linear regression analysis indicated that a higher knowledge score was associated with being married, prior hospitalization, and having received both advice and information about self-care from physicians or nurses. A poor adherence behavior score was associated with being unmarried, lower perceived self-efficacy, a lack of knowledge about self-care, and no prior hospitalization. CONCLUSIONS: We observed a gap between patients receiving and absorbing or retaining information on self-care for congestive heart failure supplied by health care providers. Self-care education needs to be directed to outpatients in addition to inpatients.

Adult↗
PubMed1999

The importance of coulombic end effects: experimental characterization of the effects of oligonucleotide flanking charges on the strength and salt dependence of oligocation (L8+) binding to single-stranded DNA oligomers.

Binding constants Kobs, expressed per site and evaluated in the limit of zero binding density, are quantified as functions of salt (sodium acetate) concentration for the interactions of the oligopeptide ligand KWK6NH2 (designated L8+, with ZL = 8 charges) with three single-stranded DNA oligomers (ss dT-mers, with |ZD| = 15, 39, and 69 charges). These results provide the first systematic experimental information about the effect of changing |ZD| on the strength and salt dependence of oligocation-oligonucleotide binding interactions. In a comparative study of L8+ binding to poly dT and to a short dT oligomer (|ZD| = 10),. Proc. Natl. Acad. Sci. USA. 93:2511-2516) demonstrated the profound thermodynamic effects of phosphate charges that flank isolated nonspecific L8+ binding sites on DNA. Here we find that both Kobs and the magnitude of its power dependence on salt activity (|SaKobs|) increase monotonically with increasing |ZD|. The dependences of Kobs and SaKobs on |ZD| are interpreted by introducing a simple two-state thermodynamic model for Coulombic end effects, which accounts for our finding that when L8+ binds to sufficiently long dT-mers, both DeltaGobso = -RT ln Kobs and SaKobs approach the values characteristic of binding to poly-dT as linear functions of the reciprocal of the number of potential oligocation binding sites on the DNA lattice. Analysis of our L8+-dT-mer binding data in terms of this model indicates that the axial range of the Coulombic end effect for ss DNA extends over approximately 10 phosphate charges. We conclude that Coulombic interactions cause an oligocation (with ZL < |ZD|) to bind preferentially to interior rather than terminal binding sites on oligoanionic or polyanionic DNA, and we quantify the strong increase of this preference with decreasing salt concentration. Coulombic end effects must be considered when oligonucleotides are used as models for polyanionic DNA in thermodynamic studies of the binding of charged ligands, including proteins.

Anions↗
PubMed1999

Maturation and developmental stage-related changes in fetal globin gene expression are reproduced in transiently transfected primary adult human erythroblasts.

A novel system is described, which uses transfection of primary human erythroblasts for the study of gene regulation in differentiating human red cells. This system includes a protocol for liquid culture of erythroid progenitors, which reproduces developmental differences in globin gene expression found between adult and cord blood as well as the maturation-related changes in fetal globin levels observed in adult cells. Reporter constructs driven by globin gene promoters were electroporated into adult and cord blood-derived erythroblasts at different time points during culture. Both the developmental stage and maturation-related differences in endogenous fetal and adult globin gene expression could be reproduced by the transiently transfected reporter constructs. Transfection of primary human erythroblasts during differentiation provides a previously unavailable opportunity to study dynamic aspects of erythropoiesis.

Adult↗
PubMed1999

Clinical profiles of four large pedigrees with familial dilated cardiomyopathy: preliminary recommendations for clinical practice.

OBJECTIVES: This study aimed to characterize the clinical profile of familial dilated cardiomyopathy (FDC) in the families of four index patients initially diagnosed with idiopathic dilated cardiomyopathy (IDC) and to provide clinical practice recommendations for physicians dealing with these diseases. BACKGROUND: Recent evidence indicates that approximately one-half of patients diagnosed with IDC will have FDC, a genetically transmissible disease, but the clinical profile of families screened for FDC in the U.S. has not been well documented. Additionally, recent ethical guidelines suggest increased responsibilities in caring for patients with newly found genetic cardiovascular disease. METHODS: After identification of four families with FDC, we undertook clinical screening including medical history, physical examination, electrocardiogram and echocardiogram. Diagnostic criteria for FDC-affected status of asymptomatic family members was based on left ventricular enlargement (LVE). Subjects with confounding cardiovascular diagnoses or body mass indices >35 were excluded. RESULTS: We identified 798 living members from the four FDC pedigrees, and screened 216 adults and 129 children (age <16 years). Twenty percent of family members were found to be affected with FDC; 82.8% of those affected were asymptomatic. All four pedigrees demonstrated autosomal dominant patterns of inheritance. The average left ventricular end-diastolic dimension was 61.4 mm for affected and 48.4 mm for unaffected subjects, with an average age of 38.3 years (+/- 14.6 years) for affected and 32.1 years for unaffected subjects. The age of onset for FDC varied considerably between and within families. Presenting symptoms when present were decompensated heart failure or sudden death. CONCLUSIONS: We propose that with a new diagnosis of IDC, a thorough family history for FDC should be obtained, followed by echocardiographic-based screening of first-degree relatives for LVE, assuming their voluntary participation. If a diagnosis of FDC is established, we suggest further screening of first-degree relatives, and all subjects with FDC undergo medical treatment following established guidelines. Counseling of family members should emphasize the heritable nature of the disease, the age-dependent penetrance and the unpredictable clinical course.

Adolescent↗