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Biomedical subjects

J He

Publications and source records attributed to J He.

At least 109 records · Page 6Linked to original sources
PubMed2001

Effects of alcohol reduction on blood pressure: a meta-analysis of randomized controlled trials.

Alcohol drinking has been associated with increased blood pressure in epidemiological studies. We conducted a meta-analysis of randomized controlled trials to assess the effects of alcohol reduction on blood pressure. We included 15 randomized control trials (total of 2234 participants) published before June 1999 in which alcohol reduction was the only intervention difference between active and control treatment groups. Using a standard protocol, information on sample size, participant characteristics, study design, intervention methods, duration, and treatment results was abstracted independently by 3 investigators. By means of a fixed-effects model, findings from individual trials were pooled after results for each trial were weighted by the inverse of its variance. Overall, alcohol reduction was associated with a significant reduction in mean (95% confidence interval) systolic and diastolic blood pressures of -3.31 mm Hg (-2.52 to -4.10 mm Hg) and -2.04 mm Hg (-1.49 to -2.58 mm Hg), respectively. A dose-response relationship was observed between mean percentage of alcohol reduction and mean blood pressure reduction. Effects of intervention were enhanced in those with higher baseline blood pressure. Our study suggests that alcohol reduction should be recommended as an important component of lifestyle modification for the prevention and treatment of hypertension among heavy drinkers.

Adult↗
PubMed2001

Skeletal muscle lipid content and insulin resistance: evidence for a paradox in endurance-trained athletes.

We examined the hypothesis that an excess accumulation of intramuscular lipid (IMCL) is associated with insulin resistance and that this may be mediated by the oxidative capacity of muscle. Nine sedentary lean (L) and 11 obese (O) subjects, 8 obese subjects with type 2 diabetes mellitus (D), and 9 lean, exercise-trained (T) subjects volunteered for this study. Insulin sensitivity (M) determined during a hyperinsulinemic (40 mU x m(-2)min(-1)) euglycemic clamp was greater (P < 0.01) in L and T, compared with O and D (9.45 +/- 0.59 and 10.26 +/- 0.78 vs. 5.51 +/- 0.61 and 1.15 +/- 0.83 mg x min(-1)kg fat free mass(-1), respectively). IMCL in percutaneous vastus lateralis biopsy specimens by quantitative image analysis of Oil Red O staining was approximately 2-fold higher in D than in L (3.04 +/- 0.39 vs. 1.40 +/- 0.28% area as lipid; P < 0.01). IMCL was also higher in T (2.36 +/- 0.37), compared with L (P < 0.01). The oxidative capacity of muscle determined with succinate dehydrogenase staining of muscle fibers was higher in T, compared with L, O, and D (50.0 +/- 4.4, 36.1 +/- 4.4, 29.7 +/- 3.8, and 33.4 +/- 4.7 optical density units, respectively; P < 0.01). IMCL was negatively associated with M (r = -0.57, P < 0.05) when endurance-trained subjects were excluded from the analysis, and this association was independent of body mass index. However, the relationship between IMCL and M was not significant when trained individuals were included. There was a positive association between the oxidative capacity and M among nondiabetics (r = 0.37, P < 0.05). In summary, skeletal muscle of trained endurance athletes is markedly insulin sensitive and has a high oxidative capacity, despite having an elevated lipid content. In conclusion, the capacity for lipid oxidation may be an important mediator of the association between excess muscle lipid accumulation and insulin resistance.

Adult↗
PubMed2001

Skeletal muscle lipid content and oxidative enzyme activity in relation to muscle fiber type in type 2 diabetes and obesity.

In obesity and type 2 diabetes, skeletal muscle has been observed to have a reduced oxidative enzyme activity, increased glycolytic activity, and increased lipid content. These metabolic characteristics are related to insulin resistance of skeletal muscle and are factors potentially related to muscle fiber type. The current study was undertaken to examine the interactions of muscle fiber type in relation to oxidative enzyme activity, glycolytic enzyme activity, and muscle lipid content in obese and type 2 diabetic subjects compared with lean healthy volunteers. The method of single-fiber analysis was used on vastus lateralis muscle obtained by percutaneous biopsy from 22 lean, 20 obese, and 20 type 2 diabetic subjects (ages 35+/-1, 42+/-2, and 52+/-2 years, respectively), with values for BMI that were similar in obese and diabetic subjects (23.7+/-0.7, 33.2+/-0.8, and 31.8+/-0.8 kg/m2, respectively). Oxidative enzyme activity followed the order of type I > type IIa > type IIb, but within each fiber type, skeletal muscle from obese and type 2 diabetic subjects had lower oxidative enzyme activity than muscle from lean subjects (P < 0.01). Muscle lipid content followed a similar pattern in relation to fiber type, and within each fiber type, muscle from obese and type 2 diabetic subjects had greater lipid content (P < 0.01). In summary, based on single-fiber analysis, skeletal muscle in obese and type 2 diabetic subjects mani-fests disturbances of oxidative enzyme activity and increased lipid content that are independent of the effect of fiber type.

Adult↗
PubMed2001

Adenovirally-mediated transfer of E2F-1 potentiates chemosensitivity of human glioma cells to temozolomide and BCNU.

The therapeutic efficacy of standard cancer treatments such as chemotherapy may be improved if they are combined with gene-therapy. Less than 30% of patients with glioblastoma multiforme respond to adjuvant chemotherapy. Actively dividing cells are generally more sensitive to chemotherapy than are non-dividing cells. To determine whether forced cell-cycle progression selectively sensitizes tumor cells to alkylating agents, we examined the effects of overexpressing the E2F-1 protein (a positive regulator of cell-cycle progression) on the sensitivity of two malignant human glioma cell lines, U-251 MG and D-54 MG, to BCNU and temozolomide. Treating these cells with 20-35 microM BCNU or 20-30 microM temozolomide resulted in 50% growth inhibition (IC50) within 4 or 6 days, respectively. By contrast, cells that were first induced to overexpress E2F-1 protein by infection with an adenoviral vector had IC50s that were 37-50% lower. Conversely, transferring the cyclin-dependent kinase inhibitors p16 and p21 to the cells, also by adenoviral infection, produced 3 to 4-fold increases in chemoresistance. Cell-cycle analyses showed that the combination of E2F-1 overexpression and treatment with BCNU or temozolomide increased the proportion of cells in S phase, but the combination of p16 or p21 overexpression and drug treatment reduced the proportion of cells in S phase. These observations suggest that overexpression of genes that positively control cell-cycle progression may be useful for increasing the sensitivity of glioma cells to alkylating agents.

Adenoviridae↗
PubMed2001

Enhancing patterns in multiple sclerosis: evolution and persistence.

BACKGROUND AND PURPOSE: Contrast enhancement on MR images of patients with multiple sclerosis (MS) is known to be associated with abnormalities of the blood-brain barrier (BBB). However, little is known about diagnostic patterns and common features of enhanced MS lesions. This study was designed to evaluate initial enhancement patterns, changes in these enhancing patterns, and duration of enhancement in a cohort of patients with MS. METHODS: Twenty-five patients with clinically definite MS were studied retrospectively. The appearance of enhancing lesions and sequential changes in the appearance on axial contrast-enhanced spin-echo images were evaluated. The enhancing lesions were classified as nodular, ringlike, or "other" (eg, arclike). RESULTS: Of 301 new enhancing lesions, 205 (68%) showed nodular enhancement, 70 (23%) a ring pattern, and 26 (9%) a pattern neither nodular nor ringlike (eg, arclike). Two hundred eighty (93%) of 301 enhancing lesions disappeared within 6 months, and seven (2%) lesions showed persistent enhancement longer than 6 months. The other 14 (5%) lesions, which disappeared by the time of the next scan, were excluded, because the course between two examinations was longer than 6 months. Of nine persisting nodular enhancing lesions on the follow-up images, seven were decreased in size, whereas all of two persisting ringlike enhancing lesions on the follow-up images were larger than before. CONCLUSION: Nodular enhancement is the predominant enhancement pattern for new MS lesions, and the temporal course of enhancement is usually shorter than 6 months. The appreciation of the evolution of MS-enhanced lesions aids in both identifying new MS lesions and distinguishing these lesions from other pathologic entities. This may be helpful in clinically evaluating the stage of MS lesions.

Adult↗
PubMed2001

[Study of in vitro cultured microencapsulated adrenal cortical tissues of rats].

In order to investigate the growth of in vitro cultured microencapsulated adrenal cortical tissues of rats, we produced the microcapsules by using sodium alginate, calcium chloride and poly-L-lysine, etc. The adrenal glands were taken out of 24 rats, half of the adrenal glands were microencapsulated (capsule group) while the other half were left free (noncapsule group). After 36 hours' in vitro culture, the concentrations of aldosterone and cortisol in culture solution were measured by radioimmunoassay. The two groups continued to be cultured for 24 and 36 hours with ACTH stimulation. The concentrations of aldosterone and cortisol at 24 and 36 hours were detected respectively. Parts of adrenal cortical tissues were observed under light microscope and electron microscope. The results showed that the concentrations of aldosterone and cortisol in the microencapsulated adrenal cortical tissues were significantly higher than those of noncapsule group (P < 0.01). In the capsule group, the concentration of cortisol after 36 hours' ACTH stimulation was significantly higher than that before ACTH stimulation (P < 0.01). After 24 and 36 hours' ACTH stimulation, the concentrations of aldosterone and cortisol were significantly higher in the capsule group than in the noncapsule group. In the noncapsule group, regardless of ACTH stimulation, no significant change was seen in the concentration of aldosterone and cortisol (P > 0.05). The cellular structure of adrenal tissues remained intact under light microscopic and electron microscopic observations, and the cells remained alive well. These data suggest that in vitro cultured cells of microencapsulated adrenal cortical tissues remain alive well. Microcapsule has not influenced the secretory function of adrenal tissues. Microencapsulated tissues have a good response to ACTH stimulation.

Adrenal Cortex↗
PubMed2001

Cocaine-mediated apoptosis in bovine coronary artery endothelial cells: role of nitric oxide.

The present study examined the role of nitric oxide in cocaine-induced apoptosis in bovine coronary artery endothelial cells (BCAECs). Cocaine produced a time-dependent decrease in cell viability and an increase in apoptosis in BCAECs, which were blocked by the nitric oxide donors DETA-NONOate (DETA-NO) and S-nitroso-N-acetyl-penicillamine. In accordance, cocaine decreased nitric oxide production in BCAECs at each time point of the study. Cocaine significantly increased caspase-3 activity that was blocked by the inhibitors of cytochrome c release (cyclosporin A), caspase-3 (Ac-DEVD-CHO), and caspase-9 (Z-LEHD-FMK), respectively. In addition, cocaine activated caspase-9, which was blocked by cyclosporin A and Z-LEHD-FMK. Ac-DEVD-CHO only partially blocked cocaine-induced caspase-9 activity. DETA-NO (20 microM) blocked cocaine-mediated activation of both caspase-9 and caspase-3. Cocaine decreased Bcl-2 protein levels, which was partially blocked by Ac-DEVD-CHO and Z-LEHD-FMK, but not by DETA-NO. Furthermore, cocaine induced a translocation of Bax from the cytosol to the mitochondria in BCAECs, and increased Bax levels in mitochondria by 2.2-fold. In accordance, cytosolic Bax levels decreased about 42%. Neither Ac-DEVD-CHO nor DETA-NO affected cocaine-induced translocation of Bax. We conclude that cocaine-induced Bcl-2 protein down-regulation and Bax translocation to the mitochondria are upstream signals of caspase-9 activation that precedes caspase-3. Cocaine-induced attenuation of nitric oxide plays a key role in the activation of the caspase cascade in BCAECs.

Animals↗
PubMed2001

[Analysis of HIV-1 seropositive individual infected with different subtypes].

OBJECTIVE: To investigate whether there existed any individuals infected with different subtypes of human immunodeficiency virus type 1 (HIV-1) and to analyze their source of infection. METHODS: Membrane protein gene (env) of HIV-1 in uncultured single peripheral blood monocytes (PBMCs) from HIV-1 seropositive individuals found in Shenzhen was amplified by nested polymerase chain reaction (PCR). The C2-V3 region and its adjacent region (360 bp) of them were sequenced and analyzed, and their divergence rate and systematic phylogenetic tree (cladogram) were calculated. RESULTS: There existed sequences of B and C or B and E strains of HIV-1 subtype in three infected individuals in Shenzhen. Gene divergence rates between different subtypes and corresponding international subtype reference strains Bcon, Ccon and Econ were 5.07%-7.26%, 3.23% and 5.38%-5.99%, respectively, and those between different subtypes strains in the same individual were 23.52%, 20.69% and 28.44%, respectively. GPGR sequence of typical Europe and America subtype B was found in strain sz46-1 from prostitute with intravenous drug abuse, based on their tetra-peptide sequence characteristics in the crown of gp 120 V3 loop, strain sz8-2 was GPGH and other strains were GPGQ sequence characterized by Thai B (B') and E subtypes. Furthermore, phylogenetic tree analysis showed that strains sz1-2, sz8-1 and sz46-1 were clustered with international reference sequence Bcon, strain sz1-1 clustered with Econ, and strains sz1-1 and sz8-2 clustered with Ccon. CONCLUSION: These findings suggested that an individual could be simultaneously infected with different HIV-1 subtypes, which could probably be caused by his or her own multiple high-risk behavior.

Adult↗
PubMed2001

Limitations to photosynthesis of lettuce grown under tropical conditions: alleviation by root-zone cooling.

Aerial parts of lettuce plants were grown under natural tropical fluctuating ambient temperatures, but with their roots exposed to two different root-zone temperatures (RZTs): a constant 20 degrees C-RZT and a fluctuating ambient (A-) RZT from 23-40 degrees C. Plants grown at A-RZT showed lower photosynthetic CO2 assimilation (A), stomatal conductance (gs), midday leaf relative water content (RWC), and chlorophyll fluorescence ratio Fv/Fm than 20 degrees C-RZT plants on both sunny and cloudy days. Substantial midday depression of A and g(s) occurred on both sunny and cloudy days in both RZT treatments, although Fv/Fm did not vary diurnally on cloudy days. Reciprocal temperature transfer experiments investigated the occurrence and possible causes of stomatal and non-stomatal limitations of photosynthesis. For both temperature transfers, light-saturated stomatal conductance (gs sat) and photosynthetic CO2 assimilation (A(sat)) were highly correlated with each other and with midday RWC, suggesting that A was limited by water stress-mediated stomatal closure. However, prolonged growth at A-RZT reduced light- and CO2-saturated photosynthetic O2 evolution (Pmax), indicating non-stomatal limitation of photosynthesis. Tight temporal coupling of leaf nitrogen content and P(max) during both temperature transfers suggested that decreased nutrient status caused this non-stomatal limitation of photosynthesis.

Carbon Dioxide↗
PubMed2001

Retroviral vectors for gene therapy of AIDS and cancer.

Both AIDS and cancer are linked to immune dysfunctions of the body which are characterized by the persistence of disease-afflicted cells. To effect a cure with novel gene therapy approaches, these diseased cells must be eliminated either directly or indirectly using cytotoxic or suicide genes, or via activation of specific immune functional cells. Retroviral vectors are useful tools for long-term genome modification owing to their ability to integrate into host chromosomes. However, most oncoretroviruses, including murine leukemia virus (MLV), require cell division to facilitate nuclear entry; this has restricted the application of murine oncoretroviral vectors to cell targets that are actively dividing. Accordingly, gene transfer into hematopoietic stem cells (HSCs) and terminally differentiated cells such as muscles, neurons and dendritic cells (DCs) has been limited with the conventional oncoretroviral vectors. The lentiviral family of retroviruses, including human immunodeficiency virus type 1 (HIV-1), has been developed into useful gene transfer tools. Lentiviral vectors carry several nuclear entry viral proteins, and therefore can target slowly-dividing and non-dividing cells. To activate immune response against cancer or HIV infection, long-term marking of the target cells is not necessary. However, to establish intracellular defense to prevent HIV infection, prolonged genetic modification of target cells such as HSCs will be required. Due to the poor transduction efficiency and the problem of transgene silencing over time with oncoretroviral vectors, most gene therapy studies for AIDS and cancer using oncoretroviral vectors remain proof-of-concept studies. Here we will discuss recent developments in the use of retroviral vectors, including HIV-1-derived lentiviral vectors, for the treatment of AIDS and cancer, and their future therapeutic potential.

Acquired Immunodeficiency Syndrome↗
PubMed2001

[Landscape structure and greenland spatial pattern in workshop district of Wuhan Iron and Steel Company].

The landscape structure and greenland spatial pattern in the workshop district of Wuhan Iron and Steel Company were investigated and analyzed on the basis of landscape ecological theory. The results showed that the main parts of the landscape structure were the artificial landscape elements such as building and concrete covering patches, highway and railway bed corridors, and industrial reservations. All of these artificial landscape elements accounted for 74.37% of patch area and 57.70% of patch dominance. In the landscape, the building and concrete covering land had the maximum percentage of patch area (56.43%) and the maximum dominance (35.59%). The special purpose greenlands had the highest fragmentation index (5.0591 ind.hm-2) and the wide-ranging distribution. The corridor density (13.78 km.km-2) was high, and the highway had more effects on landscape than the railway. All the results reflected not only the essential landscape features of industrial region, but also the rational trend of landscape structure in the workshop district of Wuhan Iron and Steel Company. In the greenland, the road greenbelts had the maximum patch number, area percentage (66.07%), and dominance (75.31%), the shelter forests being mainly composed of tree species had high patch average area (8454.45 m2) and environmental benefit, and the ornamental greenlands had abundant plant species and varied scenery. The greenland system was initially formed by four afforestation districts, using shelter forests and ornamental greenlands in large patch as a center connected by road greenbelts. It should be attached importance to the relatively high dominance of wild grasslands, the low area percentage of shelter forests and the imperfect road greenbelts to develop the uncovered lands and to improve the quality of the greenland system.

China↗
PubMed2001

[Clinical study of P-gp, and bcl-2 protein expression in non-Hodgkin's lymphomas patients].

OBJECTIVE: To investigate the relationship between the expression of P-gp, P26-bcl-2 and the prognosis in intermediate and high grade non-Hodgkin's lymphomas (NHL). METHODS: Sixty cases of intermediate and high grade NHL were retrospectively reviewed using immunohistochemical method. All patients were received CHOP chemotherapy over 4 courses. RESULTS: P-gp was identified in 15 and P26-bcl-2 in 25 cases. The 3-year survival rates for patients with P26-bcl-2 (+) and P26-bcl-2 (-) were 37.64% and 76.80%, respectively (P < 0.005), and for patients with both positive P-gp and P26-bcl-2 and both negative were 15.38% and 48.48%, respectively (P = 0.038). CONCLUSIONS: There is direct relationship between the P-gp, P26-bcl-2 protein expression and the prognosis in intermediate and high grade non-Hodgkin's lymphoma.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

[Aminopeptidase inhibitor Bestatin induces HL-60 cell apoptosis through activating caspase 3].

OBJECTIVE: To study the variation and significance of caspase 3 activity in the process of amino-peptidase inhibitor--bestatin (BS) inducing human leukemic cell apoptosis. METHODS: Cell apoptosis was evaluated by light microscopy, TUNEL labeling and flow cytometry (FCM). Caspase 3 activity was detected by colorimetry. The mitochondrial transmembrane potentials (DeltaPsi(m)) were detected by Rhodamine123 staining. RESULTS: The apoptotic morphology, apoptotic peak on FCM and positive Annexin V(FITC) on cell membrane showed that BS could induce HL-60 cell apoptosis in a dose- and time-dependent manner. Caspase 3 activity was significantly higher in the apoptotic cells than in control cells. The apoptosis induced by BS was inhibited by AC-DEVD-CHO. The DeltaPsi(m) of cells treated with BS declined. CONCLUSION: BS induces apoptosis of human acute leukemic cells through activation of caspase 3.

Aminopeptidases↗
PubMed2001

[A study of heart rate variability in asthma].

OBJECTIVE: To study the changes of autonomic nervous function in the young adult with asthma through the heart rate variability(HRV). METHODS: Two groups of young adults, 23 healthy volunteers and 69 asthmatic young adults were divided into three groups according to the severity of asthma. Twenty-four hours Holter monitored and heart rate variability analysed. RESULTS: The HF and pNN50 that showed the vagal tone in asthma subjects increased as compared with the normal group, while the LF and SDANN that mainly showed the sympathetic tone decreased(P < 0.01). These values were remarkable in the severe asthma group (P < 0.01). CONCLUSION: Even in mormal condition when patients are free of asthmatic attack, autonomic nervous function of asthmatics differ from that of normal young adults.

Adult↗
PubMed2001

[Study on the expression of endothelial nitric oxide synthase and its mRNA in liver tissues of patients with chronic hepatitis B].

BACKGROUND: To study the expression of endothelial nitric oxide synthase (eNOS) and its mRNA in liver tissues of patients with chronic hepatitis B (CHB) and the relationship between its expression and pathological changes of hepatic tissues and the clinical significance. METHODS: 48 cases of specimens of liver tissues with CHB were observed and analyzed using immunohistochemical method and in situ nucleic acid hybridization. RESULTS: eNOS was expressed in hepatocytes, sinusiod endothelial cells and vessel endothelial cells, being predominantly expressed in hepatocytes. The number and distribution of eNOS mRNA positive cells were similiar to those of its protein. Increase in expression of eNOS was correlated with degrees of inflammatory activity and fibrosis (r=0.6855 [P<0.05]; r=0.4828 [P<0.05]; respectively), and with decreasing PA and ALB (F=3.4101 [P<0.05]; F=9.1714 [P<0.0]). Changes of expression of TGF-alpha-R were parallel to those of eNOS. CONCLUSIONS: eNOS may be involved in pathological lesion of CHB by affecting the expression of TGF-R in liver tissues with CHB.

Adult↗
PubMed2001

[Clinical study on effects of root canal instrumentation on the root canal microflora].

OBJECTIVE: To investigate the effects of instrumentation and ultrasonic treatment on the root canal flora. METHODS: A total of 21 single-rooted teeth with chronic apical periodontitis were selected and prepared using step-back/ultrasonic technique, Samples were taken before and after the step-back preparation, and after the ultrasonic treatment. RESULTS: The number and species of bacteria in the root canal were both reduced dramatically and there were significant differences among the three groups (P < 0.05). CONCLUSION: The instrumentation and ultrasonic treatment of root canal can effectively reduce the number and species of root canal microflora.

Adolescent↗