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Biomedical subjects

J He

Publications and source records attributed to J He.

At least 307 records · Page 17Linked to original sources
PubMed1997

Mitochondrial tRNA(Leu(UUR)) gene mutation diabetes mellitus in Chinese.

OBJECTIVE: To ascertain the prevalence and clinical features of mitochondrial tRNALeu(UUR) gene nucleotide (nt) 3243 A-->G mutation diabetes mellitus in Chinese and to establish the approaches for genetic diagnosis of this subtype of diabetes during routine daily clinical practice. METHODS: Mitochondrial nt 3243 A-->G mutation was screened among 207 unrelated non-insulin-dependent diabetes mellitus (NIDDM) patients by using polymerase chain reaction (PCR)/Apa I restriction endonuclease digestion. Samples with positive result were confirmed by DNA sequence analysis. Genetic and clinical analysis were carried out in family members of the proband with positive genetic diagnosis. RESULTS: Positive results were found in two subjects during screening of unrelated NIDDM patients, which account for 2.4%-11.1% of NIDDM subjects with uncommon clinical features (with early age-of-onset, with low body-mass-index and on insulin therapy) or with positive family history of diabetes consistent with or unable to exclude from maternal inheritance. Genetic diagnosis was positive in 10 out of 25 family members in the pedigrees of these two probands. CONCLUSIONS: Mitochondrial tRNALeu(UUR) gene nt 3242 A-->G mutation should be considered in diabetic patients with the above-mentioned clinical features. The genetic diagnosis in daily clinical practice can be performed with allele specific priming amplification, or PCR/Hae III or Apa I digestion which are technically simple to perform and diagnostically easy to define.

Adolescent↗
PubMed1997

[The changes of lipid metabolism and hemorrheology in intrahepatic cholestasis during pregnancy].

OBJECTIVE: To identify the influence of the increased level of serum cholyglycine (CG) on lipid metabolism and hemorrheology in patients with intrahepatic cholestasis during pregnancy (ICP). METHODS: The concentrations of serum CG, total cholesterol (CH), triglycerides (TG), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), high shear and low shear of blood specific viscosity (HS and LS), plasma specific viscosity (PV) and hematocrit (HCT) were measured in 68 cases of primiparas with single pregnancy and 30 healthy nonpregnant women respectively. The group of ICP was composed of 35 cases with CG > 6 mumol/L, the group of normal pregnancy, 33 cases with CG < 6 mumol/L. RESULTS: The means of CG and the lipidic parameters in the two pregnant groups were significantly higher than those in the non-pregnancy group (P < 0.02-0.001) except the means of HDL-C between the groups of ICP and non-pregnancy. The levels of LDL-C, LDL-C/HDL-C, LS, PV and HCT in the ICP were significantly higher than those in the normal pregnancy group (P < 0.02-0.001). CONCLUSIONS: There are significant changes of lipid metabolism and hemorrheology in patients with ICP. However, these changes could be corrected after pregnancy termination, when the level of serum CG returned to normal. The results suggest that the pathophysiologic changes of ICP are associated with increased level of serum CG.

Adult↗
PubMed1997

[Measurement of thermal properties of living tissue in vivo].

We have adopted the TPD (thermal pulse decay) technique for determining the conductivity and blood perfusion of living tissue in vivo by using a self-heated sphere thermistor probe, which is based on the classical bioheat equation suggested by Pennes. This paper intends to discuss conduction in living tissue, to provide foundamental information for clinical medicine, and to extend application of the trapping probe measuring method.

Animals↗
PubMed1997

[Research respects and status of functional neuromuscular stimulation].

Functional Neuromuscular Stimulation (FNS) is a technique of restoring movements of paralyzed patients. This paper describes several respects of functional neuromuscular stimulation, such as stimulators, sensors, electrodes, muscle-skeletal models and control methods. Some novel control strategies are also discussed in this paper.

Electric Stimulation Therapy↗
PubMed1997

[The changes of PRA, ATII, ald, ET and ANP in patients with left ventricular diastolic heart failure and intervention with enalapril].

Fifty patients with left ventricular diastolic heart failure (LVDHF), and 35 patients with left ventricular systolic heart failure (LVSHF) diagnosed by clinical manifestation and radionuclide ventriculography were studied and 20 normal persons served as controls. Plasma renin activity (PRA), angiotensin I (AT I), aldosterone (ALD), endothelin (ET) and atrial natriuretic peptide (ANP) concentrations were measured by radioimmunoassay. Fifty patients with LVDHF were divided into treatment group and control group in a randomized, double blind, control method. Enalpril, CoQ10 and VitE were given in treatment group while only CoQ10 and VitE were given in control group. The therapeutic efficacy was evaluated after 8 weeks of treatment. The results showed that plasma concentration of PRA, AT I, ALD, ET and ANP were increased in LVDHF, but lower than those in LVSHF. After treatment with enalapril plasma PRA was increased while AT I, ALD and ET level were decreased significantly but ANP level had no change in treatment group.

Adult↗
PubMed1997

[Differentiation of benign and malignant palpable breast masses using 99mTc-MIBI imaging].

Forty-two patients with palpable breast masses were examined by 99mTc-MIBI imaging. All the results were compared with ultra-red scanning and B-ultrasongraphy. By pathological examination 26 out of 42 cases had breast carcinoma, 16 patients benign lesions. The sensitivity of 99mTc-MIBI imaging was 92.3%, the specificity was 96.0% and the accuracy 92.8%, which were higher than those of ultra-red scanning and B-ultrasound (P < 0.01). The authors consider that 99mTc-MIBI breast imaging is useful in distinguishing malignancies from benign breast masses.

Adenoma↗
PubMed1996

Effect of migration and related environmental changes on serum lipid levels in southwestern Chinese men.

To determine migration-related differences in serum lipid levels and to estimate the contribution of environmental factors to these differences, the authors conducted a cross-sectional study among 1,222 residents of southwestern China in 1988 and 1989: 521 Yi farmers living in a remote rural area, 340 Yi migrants to an urban setting, and 361 Han people living in the same urban setting. Serum total and high density lipoprotein cholesterol and serum triglyceride were measured after a 14-hour fast. Information on age, cigarette smoking, alcohol consumption, and physical activity was obtained by questionnaire. Diet was assessed by use of three 24-hour diet recalls. The Yi farmers had the lowest age-adjusted serum lipid levels among the three groups, white the Yi migrants and their Han counterparts had similar lipid levels. After adjustment for age, body mass index, cigarette smoking, alcohol drinking, and dietary nutrient intake, the difference in serum lipid profile between the Yi migrants and the Yi farmers was substantially reduced. These results indicate that rural-urban migration is associated with higher serum lipid levels. This migration-related difference in serum lipids can be partially explained by changes in lifestyle and dietary nutrient intake. The authors conclude that environmental factors are important determinants of population serum lipid levels in southwestern Chinese.

Adolescent↗
PubMed1996

Apoptosis induced by HIV-1 infection of the central nervous system.

Apoptosis plays a role in AIDS pathogenesis in the immune system, but its role in HIV-1-induced neurological disease is unknown. In this study, we examine apoptosis induced by HIV-1 infection of the central nervous system (CNS) in an in vitro model and in brain tissue from AIDS patients. HIV-1 infection of primary brain cultures induced apoptosis in neurons and astrocytes in vitro as determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and propidium iodide staining and by electron microscopy. Apoptosis was not significantly induced until 1-2 wk after the time of peak virus production, suggesting induction by soluble factors rather than by direct viral infection. Apoptosis of neurons and astrocytes was also detected in brain tissue from 10/11 AIDS patients, including 5/5 patients with HIV-1 dementia and 4/5 nondemented patients. In addition, endothelial cell apoptosis was frequently detected in the brain of AIDS patients and was confirmed by electron microscopy. Most of the apoptotic cells were not localized adjacent to HIV-1-infected cells, providing further evidence for induction by soluble factors. In six non-AIDS control patients with normal brain, apoptotic cells were absent or limited to rare astrocytes. However, TUNEL-positive neurons and astrocytes were frequently detected in seven patients with Alzheimer's disease or abundant senile plaques. These studies suggest that apoptosis is a mechanism of CNS injury in AIDS which is likely to be induced by soluble factors. The apoptosis of endothelial cells in the CNS raises the possibility that some of these factors may be blood-derived.

AIDS Dementia Complex↗
PubMed1996

F(c)gammaRI-targeted fusion proteins result in efficient presentation by human monocytes of antigenic and antagonist T cell epitopes.

A major challenge for using native or modified T cell epitopes to induce or suppress immunity relates to poor localization of peptides to antigen presenting cells (APCs) in vivo. In this study, we demonstrate enhanced presentation of antigenic and antagonistic peptides by targeting them to the type I Fc receptor for IgG (F(c)gammaRI, CD64) on human monocytes. A Th epitope of tetanus toxoid, TT830, and the antagonistic peptide for TT830, TT833S, were genetically grafted into the constant region of the heavy chain of the humanized anti-CD64 mAb 22 and expressed as monovalent fusion proteins, Fab22-TT830 and Fab22-TT833S. These CD64-targeted peptides were up to 1,000- and 100-fold more efficient than the parent peptides for T cell stimulation and antagonism, respectively, suggesting that such fusion proteins could effectively increase the delivery of peptides to APCs in vivo. Moreover, the F(c)gammaRI-targeted antagonistic peptide inhibited proliferation of TT830-specific T cells even when APCs were first pulsed with native peptide, a situation comparable with that which would be encountered in vivo when attempting to ameliorate an autoimmune response. These data suggest that targeted presentation of antagonistic peptides could lead to promising Ag-specific therapies for T cell-mediated autoimmune diseases.

Amino Acid Sequence↗
PubMed1996

Fas ligand mutation in a patient with systemic lupus erythematosus and lymphoproliferative disease.

The pathogenesis of systemic lupus erythematosus (SLE) is multifactorial and multigenetic. The apoptosis genes, fas and fas ligand (fasL), are candidate contributory genes in human SLE, as mutations of these genes result in autoimmunity in several murine models of this disease. In humans, fas mutations result in a familial autoimmune lymphoproliferative syndrome, but defects in FasL have not yet been identified. In this study, DNA from 75 patients with SLE was screened by single-stranded conformational polymorphism analysis for potential mutations of the extracellular domain of FasL. A heterozygous single-stranded conformational polymorphism for FasL, was identified in one SLE patient, who exhibited lymphadenopathy. Molecular cloning and sequencing indicated that the genomic DNA of this patient contained an 84-bp deletion within exon 4 of the fasL gene, resulting in a predicted 28 amino acid in-frame deletion. Analysis of PBMC from this patient revealed decreased FasL activity, decreased activation-induced cell death, and increased T cell proliferation after activation. This is the first report of defective FasL-mediated apoptosis related to a mutation of the human Fasl, gene in a patient with SLE and suggests that fasL mutations are an uncommon cause of the disease.

Amino Acid Sequence↗
PubMed1996

Altered expression of bcl-2 and bax mRNA in amyotrophic lateral sclerosis spinal cord motor neurons.

One of the primary neurodegenerative events occurring in amyotrophic lateral sclerosis (ALS) is the selective loss of spinal cord alpha motor neurons. To study the potential role of apoptosis in the degeneration of these motor neurons, in situ hybridization was used to measure the expression of two apoptotic cell death genes, bcl-2 and bax, in control and ALS lumbar spinal cord sections. The strongest hybridization signal for bcl-2 mRNA in neurological and nonneurological control spinal cords was found primarily in lamina IX alpha motor neurons, while a weaker hybridization signal was found in neurons of Clarke's nucleus and the proper sensory nucleus of the dorsal horn. Surviving lamina IX motor neurons in ALS spinal cord sections also expressed bcl-2 mRNA, but at levels that were significantly and selectively decreased (4.7-fold) compared with controls. bax mRNA hybridization signal was detected in several cells throughout the gray matter in control and ALS lumbar spinal cord, but was significantly and selectively increased (2.8-fold) in ALS motor neurons. Given the proposed interactive roles of these genes in apoptosis, the present findings favor a scenario in which this mode of cell death would contribute to spinal cord motor neuron degeneration in ALS.

Adult↗
PubMed1996

Quantitative assessment of stenotic aortic valve area by using intracardiac echocardiography: in vitro validation and initial in vivo illustration.

Quantitative assessment of aortic stenosis (AS) is subject to the limitations of all current noninvasive and invasive methods. The ability to obtain a direct measure of aortic valve area with high resolution by intracardiac echocardiography (ICE) could be of great benefit to catheterized patients. To provide a fixed AS area as an ideal standard for comparison, we performed ICE in 12 sheep hearts with experimentally created AS and five human AS hearts from autopsies. ICE catheters were passed retrograde across the aortic valve, and the minimal orifice area on pullback was planimetered and compared with calibrated video imaging. The entire orifice circumference could be successfully recorded in 16 (94%) hearts. Orifice area from ICE correlated well with actual values (r=0.98; standard error of the estimate [SEE] = 0.06 cm2). To illustrate the applicability in vivo, two canine models and 10 patients with AS were studied. The limiting orifice could be imaged in both animals and in 8 of 10 patients, in whom values agreed well with invasive data (r= 0.95; SEE = 0.04 cm2). ICE can therefore accurately measure AS orifice area in vitro; it can be applied in vivo as well. These validation studies laid the foundation for subsequent clinical studies and applications.

Animals↗
PubMed1996

Quantitative three-dimensional reconstruction of left ventricular volume with complete borders detected by acoustic quantification underestimates volume.

Recently a new acoustic-quantification (AQ) technique has been developed to provide on-line automated border detection with an integrated backscatter analysis. Prior studies have largely correlated AQ areas with volumes without direct comparison of volumes for agreement. By using complete AQ-detected borders as the input to a validated method for three-dimensional echocardiographic (3DE) reconstruction, we can compare an entire cavity volume measured with the aid of AQ against a directly measured volume. This would also explore the possibility of applying AQ to 3DE reconstruction to reduce tracing time and enhance routine applicability. To compare reconstructed volumes with actual values in a stable standard allowing direct volume measurement, the left ventricles of 13 excised animal hearts were studied with a 3DE system that automatically combines two-dimensional (2D) images and their locations. Intersecting 2D views were obtained with conventional scanning and AQ imaging, with gains optimized to permit 3D reconstruction by detecting the most continuous AQ borders for each view, with maximal cavity size. Reconstruction was performed with manually traced central endocardial reflections and AQ-detected borders visually reproduced the left ventricular shapes; the AQ reconstructions, however, were consistently smaller. The reconstructed left ventricular (LV) volumes correlated well with actual values by both manual and AQ techniques (r = 0.93 and 0.88, with standard errors of 2.3 cc and 2.0 cc, p = not significant [NS]). Agreement with actual values was relatively close for the manually traced borders (y = 0.93x + 0.68, mean difference = -0.8 +/-2.2 cc). AQ-derived reconstructions consistently underestimated LV volume by 39 +/- 10% (y = 0.62x-0.09, mean difference = -7.8 +/- 3.0 cc, different from manually traced and actual volumes by analysis of variance [ANOVA], F = 69, p<0.00001). The AQ-detected threshold signal was displaced into the cavity, and volume between walls and false tendons was excluded, leading to underestimation, which increased with increasing cavity volume (r = 0.76). The AQ technique can therefore be applied to 3DE reconstruction, providing volumes that correlate well with directly measured values in a stable in vitro standard, minimizing observer decisions regarding manual border placement after image acquisition. However, when the complete borders needed for 3D reconstruction are used, absolute volumes are underestimated with current algorithms that integrate backscatter and displace the detected threshold into the ventricular cavity.

Animals↗
PubMed1996

Analysis of determinants of binding and transcriptional activation of the pisatin-responsive DNA binding factor of Nectria haematococca.

Pisatin is a fungistatic isoflavonoid produced by garden pea. Field isolates of the ascomycete Nectria haematococca mating population VI (anamorph: Fusarium solani) that are highly virulent on pea have been found to possess the PDA1 gene encoding a pisatin detoxifying activity. Expression of PDA1 is specifically and highly induced by exposure of mycelia to pisatin. A pisatin-responsive DNA-binding activity has previously been identified with properties suggestive of a transcriptional regulator of PDA1. In this study, the sequence determinants for binding this pisatin-responsive factor (PRF) were localized to a 14-bp region through analysis of sequence alterations that reduced PRF binding. Using a homologous in vitro transcription system, a transcriptional activator of PDA1 was shown to be present in mycelial extracts that shared the sequence specificity characteristic of the PRF, indicating function of the DNA-binding protein in transcriptional control. A 70-kDa protein was shown to be a DNA-binding component of PRF by three independent assays for DNA-binding proteins: Southwestern (DNA-protein) blotting, UV-crosslinking, and binding to immobilized DNA. These results characterize a transcriptional activator acting on the PDA1 promoter that is responsive to a host-specific compound and provide insight into the regulation of fungal genes in response to plant flavonoids.

Base Sequence↗