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Biomedical subjects

Li He

Publications and source records attributed to Li He.

At least 37 records · Page 2Linked to original sources

[Advances of study on the relationship between vascular endothelial growth factor and ischemic cerebral vascular disease].

Vascular endothelial growth factor is a potent inducer of angiogenesis identified in recent years, and its relationship with ischemic cerebral vascular diseases is a hotspot for many investigators at present. In this review, we focus on the recent evidence for VEGF expression, biological effect and its role in the treatment and prognostication of ischemic cerebral vascular disease.

Angiogenesis Inducing Agents↗

[Urinary S100B protein and lactate/creatinine ratio measurements: a tool for the early identification of neonatal hypoxic-ischemic encephalopathy].

OBJECTIVE: To investigate the value of urinary S100B protein and lactate/creatinine ratio determination in early identification of neonatal hypoxic-ischemic encephalopathy (HIE). METHODS: The levels of urinary S100B protein and urinary lactate/creatinine ratio were detected in 58 full-term newborn infants with HIE on the first, second and third day after birth. The severity of clinical manifestations, including the degree of encephalopathy, was assessed within 7 days after birth. Twenty five normal neonates were enrolled into the control groups. RESULTS: (1) The urinary S100B level of HIE neonates was significantly higher in samples collected throughout the monitoring period than those of the normal control groups (all P < 0.001). The urinary lactate/creatinine ratio of the HIE neonates was also significantly higher than that of normal control groups within the first day (P < 0.001). (2) A significantly positive correlation was found between the level of urinary S100B protein within three days and the urinary lactate/creatinine ratio within the first day and between the level of urinary S100B protein within three days and clinical degree (P < 0.05). (3) When S100B concentration was 0.47 microg/L and urinary lactate/creatinine ratio was 0.55, the sensitivity and specificity of detecting the third day urinary S100B alone, were respectively 90.4%, 91.9%. Detecting it associated with the first day urinary lactate/creatinine ratio could increase the sensitivity and specificity (respectively 98.8% and 97.4%) for predicting development of HIE. CONCLUSION: On the basis of clinical manifestations of asphyxic neonatals, detecting the level of urinary S100B within three days and the first day urinary lactate/creatinine ratio may be of important value in early diagnosis and grading of HIE.

Apgar Score↗

[Algorithm for automatic quantification of brain atrophy with computed tomography].

In this paper, a new, fully-automatic method for the quantification of brain atrophy based on CT volume data is put forward by taking advantage of the characteristics of cerebral CT images in combination with the prior medical knowledge. This algorithm has been verified through the calculation of 2388 cases of normal and brain atrophy subjects.

Adolescent↗

Antithrombotic activity of dermatan sulfate in heparin cofactor II-deficient mice.

Heparin cofactor II (HCII) is a plasma protein that inhibits thrombin rapidly in the presence of dermatan sulfate or heparin. We previously reported that the time to thrombotic occlusion of the carotid artery after photochemical injury was shorter in HCII-deficient mice than in wild-type control animals. In this paper, we describe the antithrombotic activity of dermatan sulfate in wild-type and HCII-deficient mice. Intravenous administration of porcine skin dermatan sulfate induced a dose-dependent prolongation of the carotid artery occlusion time in HCII(+/+) mice that was not observed in HCII(-/-) animals. Pharmacokinetic studies suggested that porcine skin dermatan sulfate expresses antithrombotic activity after being transferred from the plasma to sites in the vessel wall. Using invertebrate dermatan sulfate preparations, we showed that N-acetylgalactosamine-4-O-sulfate residues are required for the HCII-dependent antithrombotic effect. Furthermore, the invertebrate dermatan sulfates, which have higher charge densities than mammalian dermatan sulfate, slightly prolonged the thrombotic occlusion time of HCII(-/-) mice. These results indicate that HCII mediates the antithrombotic effect of porcine skin dermatan sulfate after injury to the carotid arterial endothelium in mice, whereas more highly charged dermatan sulfates possess weak antithrombotic activity independent of HCII.

Animals↗

Investigation of T-cell receptor-gamma gene rearrangement in gastrointestinal lymphomas by PCR-SSCP analysis.

AIM: To analyze the characterization of T-cell receptor-gamma (TCR-gamma) gene rearrangement in the gastrointestinal lymphomas and evaluate the value of PCR-SSCP analysis in gastrointestinal lymphomas investigation. METHODS: TCR-gamma gene rearrangement segments of gastrointestinal lymphomas were cloned and sequenced. Single clone plasmid and mixed clone plasmids were subsequently submitted to PCR-SSCP analysis to investigate the relationship between the number of amplified clones and band patterns of the amplified products. The PCR products of TCR-gamma gene rearrangement of 40 gastrointestinal lymphomas were electrophoresed on agarose gels and the positive cases on agarose gels were studied by SSCP analysis. RESULTS: The sequencing showed that TCR-gamma gene rearrangement of the gastrointestinal lymphomas included functional gene and pseudogene with extensive variety in the junctional regions. In SSCP analysis, the number of the single-stranded bands was about two times of the number of amplified clones, and double-stranded band became broad with the increased number of the amplified clones. Thirteen of the 25 B-cell gastrointestinal lymphomas and 14 of the 15 gastrointestinal T-cell lymphomas were positive detected on agarose gel electrophoresis. Of the positive cases detected by SSCP analysis, 3 B-cell lymphomas and 13 T-cell lymphomas showed positive bands. The other cases showed only smears. The rearranged pattern included 13 monoallelic gene rearrangements and 3 biallelic or oligoclonal gene rearrangements. CONCLUSION: The pattern of TCR-gamma gene rearrangement in gastrointestinal lymphomas are similar to that of the nodular lymphomas. PCR-SSCP analysis for TCR-gamma gene rearrangement can be applied both for adjuvant diagnosis of gastrointestinal lymphomas and analysis of the gene rearrangement pattern. The ratio of TCR-gamma gene rearrangements occurred in T-cell gastrointestinal lymphomas is significantly higher than that in B-cell gastrointestinal lymphomas. The gene rearrangement pattern involves monoallelic and biallelic (or oligoclonal) gene rearrangement.

Base Sequence↗

Organ distribution of severe acute respiratory syndrome (SARS) associated coronavirus (SARS-CoV) in SARS patients: implications for pathogenesis and virus transmission pathways.

We previously identified the major pathological changes in the respiratory and immune systems of patients who died of severe acute respiratory syndrome (SARS) but gained little information on the organ distribution of SARS-associated coronavirus (SARS-CoV). In the present study, we used a murine monoclonal antibody specific for SARS-CoV nucleoprotein, and probes specific for a SARS-CoV RNA polymerase gene fragment, for immunohistochemistry and in situ hybridization, respectively, to detect SARS-CoV systematically in tissues from patients who died of SARS. SARS-CoV was found in lung, trachea/bronchus, stomach, small intestine, distal convoluted renal tubule, sweat gland, parathyroid, pituitary, pancreas, adrenal gland, liver and cerebrum, but was not detected in oesophagus, spleen, lymph node, bone marrow, heart, aorta, cerebellum, thyroid, testis, ovary, uterus or muscle. These results suggest that, in addition to the respiratory system, the gastrointestinal tract and other organs with detectable SARS-CoV may also be targets of SARS-CoV infection. The pathological changes in these organs may be caused directly by the cytopathic effect mediated by local replication of the SARS-CoV; or indirectly as a result of systemic responses to respiratory failure or the harmful immune response induced by viral infection. In addition to viral spread through a respiratory route, SARS-CoV in the intestinal tract, kidney and sweat glands may be excreted via faeces, urine and sweat, thereby leading to virus transmission. This study provides important information for understanding the pathogenesis of SARS-CoV infection and sheds light on possible virus transmission pathways. This data will be useful for designing new strategies for prevention and treatment of SARS.

Adult↗

Effects of serum from aplastic anemia patients on the expression of cyclin D3 isoform in umbilical cord blood CD34+ cells.

The pathogenesis of aplastic anemia (AA) was explored and the effects of AA serum on the expression of crucial cyclin D isoform (cyclin D3) in umbilical cord blood hematopoietic stem/progenitor cells were observed. The CD34+ cells were isolated from the cord blood with MIDI-MACS Semi-solid methylcellulose culture technique was used to measure the formation of CFU-GM; The expression level of cyclin D3 was assayed by semi-quantitative RT-PCR and Western-blot after the hematopoietic stem/progenitor cells were incubated in AA serum. The results showed that the AA serum could inhibit the formation of CFU-GM and down regulate the expression level of the cyclin D3 at the mRNA and protein level respectively. In conclusion, the AA serum could inhibit the proliferation of hematopoietic stem cells and down regulate level of cyclin D3, which might be one mechanism of hematopoiesis inhibition in AA.

Anemia, Aplastic↗

Touch-down PCR and single-strand conformation polymorphism for detecting clonal T cell receptor gamma gene rearrangement in lymphoid leukemia.

OBJECTIVE: To explore the value of detecting clonal T cell receptor gamma (TCR-gamma) gene rearrangement with touch-down PCR and single-strand conformational polymorphism analysis (SSCP) in the diagnosis of lymphoid leukemia. METHODS: The DNA of peripheral blood leucocytes from lymphoid leukemia patients were extracted for amplification of the TCR-gamma gene rearrangement with the consensus primers and touch-down PCR. The PCR products were analyzed by agarose gel electrophoresis, direct DNA sequencing and SSCP analysis. The positive control cell line DNA was mixed in different proportions with the DNA extracted from reactive lymphoid tissue to test the sensitivity of the touch-down PCR. RESULTS: Fifteen of 18 T lymphoid leukemia and 2 of the 4 B lymphoid leukemia patients were identified to be positive by agarose electrophoresis. The positive PCR products were further analyzed by SSCP analysis, which showed discrete bands. Direct DNA sequencing confirmed the clones to be TCR-gamma gene rearrangement, and the sensitivity of touch-down PCR was 1%. CONCLUSION: Consensus primers for studying TCR-gamma gene rearrangement in combination with touch-down PCR can effectively amplify the clonal TCR-gamma gene rearrangement in T lymphoid leukemia.

Gene Rearrangement, gamma-Chain T-Cell Antigen Rec↗

[Feasibility of telephone screening interview in a validity and reliability study of telephone interview to assess dietary intake in Beijing, Shanghai and Hong Kong].

OBJECTIVE: To understand the feasibility of telephone interviews to achieve recruitment of subjects to assess the validity and reliability of the telephone interview in eliciting dietary intake. METHODS: A multi-phase study was conducted in Beijing, Shanghai and Hong Kong in 2002. RESULTS: Three hundred eligible women aged from 20 to 49 years old were recruited in those cities. In the screening interview, 2462 random telephone numbers were dialed with 95% of dials completed within 5 times of attempts. The average number of dial for the completion was two calls, the rates of completion and refusal conversion were not improved remarkably by the increase of calls although some calling attempts reached 20 times. Regarding the processing of the sampling pools in those three cities, Beijing had a lower efficiency rate but a satisfactory completion rate, Shanghai was good in both indicators, and Hong Kong had a good efficiency rate but lower completion rate. The overall telephone screening interview completion rate was 42%, with Hong Kong having the lowest rate (32%) compared with Beijing and Shanghai (47% and 50%, respectively, P < 0.001). CONCLUSION: The telephone interview method could successfully reach the target of urban Chinese women and earn their cooperation with a satisfactory completion rate.

Adult↗

[The protective effect of dachuanxiongwan on the rats with focal cerebral ischemia and reperfusion].

OBJECTIVE: Studying the protective effect of dachuanxiongwan (DCXW) on the rats with focal cerebral ischemia and reperfusion. METHODS: The ischemia and reperfusion model was established by blocking the rat's middle cerebral artery with a pre-set nylon thread and removing it from the internal carotid artery 2 hours after occlusion. 20 healthy male Sprague-Dawley rats following middle cerebral artery occlusion (MCAO) were randomly divided into two groups: Group A, transient ischemia, for control; Group B, transient ischemia treated with DCXW via gavage, 4.13 g/kg x d, twice a day for 3 days, while group A being given the same volume of saline. Seventy-two hours after reperfusion, the neurological function of all rats was evaluated according to Longa, and the rats were sacrificed. All the samples of cerebrum were processed and embedded in paraffin and cut into sections. The sections were stained with Hematoxylin & Eosin to measure the infarction volume and evaluate the effects of DCXW. RESULTS: The grade of neurological function of the treatment group (1.5+/-0.71) was lower than that of the control group (2.3+/-0.82), there was a statistically significant difference between the two groups (P=0.032); the infarction volume of the treatment group was smaller than that of the control group, there was a statistically significant difference between the two groups (P=0.000). CONCLUSION: The findings suggest that DCXW has a protective effect on the cerebrum undergoing ischemia and reperfusion.

Animals↗

[Trend of seasonal change on intake of nutrients in a year of the residents in both northern and southern China].

OBJECTIVE: To study the change of intake of nutrients in a year, and determine whether there is any change of intake of nutrition according to different seasons of the people in both northern and southern China. METHODS: The method of 24-hour diet history recall was used to study about 300 healthy adults in three areas, a rural area in the northern and rural plus urban areas in the southern. The study was carried out once per two month, and each time last 3 days. Based on the amount of food intake, the amount of both nutrition and energy per person and per day was calculated. RESULTS: The amount of energy, protein, carbohydrate, fat intake of the residents in three areas was adequate. There was almost no significant difference of intake of energy and three major nutrients (protein, fat and carbohydrate) both in the southern and northern part of China among different seasons, as well as the seasonal intake of thiamin, riboflavin, vitamin E, niacin, and zinc. While the difference of intake of retinol (microg RE), ascorbic acid, potassium and calcium were significant among different seasons. CONCLUSION: This study showed that, in rural areas, any dietary survey should avoid January and July, which is either slack or busy season for farmers. In urban areas, any time of a year should not influence the results of a dietary survey.

Adult↗

The contributions of the alpha 2 beta 1 integrin to vascular thrombosis in vivo.

The alpha 2 beta 1 integrin serves as a receptor for collagens, laminin, and several other nonmatrix ligands. Many studies have suggested that the alpha 2 beta 1 integrin is a critical mediator of platelet adhesion to collagen within the vessel wall after vascular injury and that the interactions of the platelet alpha 2 beta 1 integrin with subendothelial collagen after vascular injury are required for proper hemostasis. We have used the alpha 2 beta 1 integrin-deficient mouse to evaluate the contributions of the alpha 2 beta 1 integrin in 2 in vivo models of thrombosis. Studies using a model of endothelial injury to the carotid artery reveal that the alpha 2 beta 1 integrin plays a critical role in vascular thrombosis at the blood-vessel wall interface under flow conditions. In contrast, the alpha 2 beta 1 integrin is not required for the formation of thrombi and pulmonary emboli following intravascular injection of collagen. Our results are the first to document a critical in vivo role for the alpha 2 beta 1 integrin in thrombus formation at the vessel wall under conditions of shear following vascular injury.

Animals↗

The clinical pathology of severe acute respiratory syndrome (SARS): a report from China.

In order to investigate the clinical pathology of severe acute respiratory syndrome (SARS), the autopsies of three patients who died from SARS in Nan Fang Hospital Guangdong, China were studied retrospectively. Routine haematoxylin and eosin (H&E) staining was used to study all of the tissues from the three cases. The lung tissue specimens were studied further with Macchiavello staining, viral inclusion body staining, reticulin staining, PAS staining, immunohistochemistry, ultrathin sectioning and staining, light microscopy, and transmission electron microscopy. The first symptom was hyperpyrexia in all three cases, followed by progressive dyspnoea and lung field shadowing. The pulmonary lesions included bilateral extensive consolidation, localized haemorrhage and necrosis, desquamative pulmonary alveolitis and bronchitis, proliferation and desquamation of alveolar epithelial cells, exudation of protein and monocytes, lymphocytes and plasma cells in alveoli, hyaline membrane formation, and viral inclusion bodies in alveolar epithelial cells. There was also massive necrosis of splenic lymphoid tissue and localized necrosis in lymph nodes. Systemic vasculitis included oedema, localized fibrinoid necrosis, and infiltration of monocytes, lymphocytes, and plasma cells into vessel walls in the heart, lung, liver, kidney, adrenal gland, and the stroma of striated muscles. Thrombosis was present in small veins. Systemic toxic changes included degeneration and necrosis of the parenchyma cells in the lung, liver, kidney, heart, and adrenal gland. Electron microscopy demonstrated clusters of viral particles, consistent with coronavirus, in lung tissue. SARS is a systemic disease that injures many organs. The lungs, immune organs, and systemic small vessels are the main targets of virus attack, so that extensive consolidation of the lung, diffuse alveolar damage with hyaline membrane formation, respiratory distress, and decreased immune function are the main causes of death.

Adrenal Glands↗

Immunohistochemical detection of Kikuchi's lymphadenitis.

OBJECTIVE: To evaluate significance of immunohistochemistry in Kikuchi's lymphadenitis (KFD). METHODS: Biopsy specimens were obtained from 42 KFD cases for microscopic examination after the sections were stained with haematoxylin and eosin, and the immunohistochemical features were analyzed by monoclonal antibodies (CD20, CD8, CD45RO, CD57, CD68) and polyclonal antibody (myeloperoxidase, MPO). RESULTS: Morphologically, the lymph node lesions comprised various histiocytes, plasmacytoid monocytes, immunoblasts, small lymphocytes and nuclear fragments. In all the cases, the histiocytes were invariably observed and most of them were positive for CD68 and MPO. Immunoblasts and plasmacytoid monocytes were easily observed in proliferative stage. Immunohistochemical examination revealed strong focal T-cell positivity for the antibodies but with scarce B cell (CD20) and NK cell (CD57) positivity in the lesion area, where few or virtually no neutrophils were seen. CONCLUSION: Immunohistochemical analysis can be crucial for the differential diagnosis of KFD.

Adolescent↗

[An epidemiological study on factors affecting serum thyroglobulin levels].

OBJECTIVE: To investigate the effects of several factors affecting serum thyroglobulin (TG) levels among people aged 14 or more. METHODS: We selected Panshan with median urinary iodine (MUI) 83.45 micro g/L as a deficient iodine intake community, Zhangwu with MUI 242.85 micro g/L as a sufficient iodine intake community and Huanghua with MUI 650.87 micro g/L as an excessive iodine intake community. Serum TG and thyroid stimulating hormone (TSH) were measured in 3,335 subjects whose thyroglobulin antibody (TGAb) were negative and thyroid volume were examined using B-ultrasound. RESULTS: In the population with MUI of 80 - 650 micro g/L, serum TG levels presented a "V" curve. An elevated serum TG was found in both the communities with deficient iodine intake and excessive iodine intake. The same trend was shown in the groups with different levels of serum TSH. An elevated serum TG was found in both the groups of TSH < 0.3 mU/L and TSH > 4.8 mU/L. The serum TG levels was positively correlated with thyroid volume and was higher in female subjects than in male. An increased serum TG was found in subjects of aged 50 in the community with deficient iodine intake. CONCLUSION: Serum TG level is affected by gender, amount of iodine intake, serum TSH level and thyroid volume.

Adolescent↗

[Detection of cell apoptosis in the pathological tissues of patients with SARS and its significance].

OBJECTIVE: To explore the role and mechanism of apoptosis in severe acute respiratory syndrome (SARS). METHODS: Klenow-FragELTM DNA Fragmentation Detection Kit and immunohistochemical alkaline phosphatase detection reagent kit were used to detect cell apoptosis and expressions of CD68, CD20, CD4, CD8 and CD45RA in the pathological tissues of SARS patients. RESULTS: Apoptotic cells increased significantly in the spleen, lung and lymph nodes of SARS patients as compared with normal tissues. The apoptotic cells included pneumocytes, lymphocytes and monocytes, and CD68+ monocytes were observed in abundance in the lung, spleen and lymph nodes of SARS patients. In the lung tissue of the patients, few CD20+/CD45RA+ B cells and CD4+/CD8+ T cells were spotted, and CD20+/CD45RA+ B cells along with CD4+/CD8+ T cells were also significantly decreased in the spleen and lymph nodes, where few conserved B and T cells underwent apoptosis. CONCLUSIONS: Apoptosis is a general phenomenon in SARS, and the invasive cells in the pathological tissues are primarily monocytes, suggesting that apoptosis and invasion of monocyte play important roles in the progression of SARS. The cell apoptosis and decreased number of T cell and B cells in the lungs and CD4+/CD8+ T cells and CD20+/CD45RA+ B cells in the spleen and lymph nodes indicate that the SARS virus may exercise immune cell-killing effect to some extent during its pathogenesis.

Alkaline Phosphatase↗

[Expression of immune cells and their roles in the involved tissues of SARS patients].

OBJECTIVE: To study the expression of the immune cell markers and their active antigens in the involved tissues of patients with severe acute respiratory syndrome (SARS). METHODS: Specimens of the lungs, spleens and lymph nodes were obtained from autopsy of 3 SARS cases to investigate the expression of the immune cells and their activities with double immunohistochemical staining (DAB and AP) by using 14 immune cell markers and their active antigens. RESULTS: A large quantity of proliferated macrophages could be observed in the lungs, spleens and lymph nodes of the SARS patients, some of which were positive for CD25 marker (active macrophages). In the lungs of the 3 patients, localized necrosis occurred where infiltration of CD45RO (+) T lymphocytes was observed, with only scarce Ki67 (+) T lymphocytes (active T lymphocytes) and B lymphocytes. In the lymph nodes, scattered T lymphocytes positive for Ki67 and CD45RO markers (active T lymphocytes) were seen, but the T lymphocytes subpopulations were obviously decreased, which was especially so with CD4+ and CD8+ T lymphocytes and NK cells. CONCLUSION: Significantly enhanced activity of the macrophages occurs in SARS as the major reactive cells, but T lymphocyte subsets are obviously decreased, indicating the important roles of the macrophages and T lymphocytes in the pathogenesis of SARS.

Humans↗