Biomedical subjects

H Li

Publications and source records attributed to H Li.

At least 415 records · Page 23Linked to original sources

PubMed2001

[A case-control study of endogenous estrogen and risk of Alzheimer's disease].

OBJECTIVE: To investigate the risk of Alzheimer's disease (AD) associated with endogenous estrogen. METHODS: A population based, m: n matched case-control study was conducted, including 115 female AD patients identified from sample population aged 55 years or older as cases and 1,041 non-cognitive impairment individuals from same population matched for age and sex as controls. RESULTS: Age at natural menopause had significant effect on AD using multivariate analysis. The odds ratio (OR) for AD was 0.672 for individuals whose age at natural menopause were between 47 to 50 years old, compared with individuals whose age at menopause were less than 47 years old. The OR was 0.452 for individuals whose age at menopause were more than 50 years old comparing with individuals whose age at menopause were less than 47 years old (P = 0.0207). The OR for AD increased parallel to the increase of age at menarche (adjusted OR = 1.160 for each increased year, P = 0.0342). CONCLUSION: The decrease of endogenous level in postmenopausal women might serve an etiological factor for AD.

Alzheimer Disease↗

PubMed2001

[Influence of fluid shear stress on the expression of monocyte chemotactic protein-1 by vascular endothelial cells].

OBJECTIVE: To study the effect of fluid shear stress on the expression of monocyte chemotactic protein-1(MCP-1) by vascular endothelial cells and its role in the early stages of atherogenesis(AS). METHODS: Parallel plate flow chamber was used to expose vascular endothelial cells to different shear stress. Sandwich ELISA (enzyme-linked immunosorbent assay) and RT-PCR (reverse transcription polymerase chain reaction) were applied to detect MCP-1 protein and mRNA respectively. RESULTS: Under 0.72 Pa shear stress, MCP-1 mRNA expression in endothelial cells reached a high level in 5 hours, but decreased to below the control level (P < 0.001) after 12 hours. The expression of MCP-1 mRNA showed a time dependent increase, which became slower 5 hours later. When different shear stress (0.30, 0.72, 2.40 Pa) was loaded for the same period of time (5 h), MCP-1 increased to above twice the control level, while its mRNA expression increased threefold as compared to the static control. CONCLUSIONS: The expression of MCP-1 reacts strongly to fluid shear stress. The steady laminar flow down regulates the gene expression of MCP-1. These results may help to explain why AS lesions tends to occur at the site of turbulent blood flow.

Cells, Cultured↗

PubMed2001

[Malignant catarrhal fever in Switzerland: 2. Evaluation of the diagnosis].

Malignant catarrhal fever (MCF) is a mostly fatal lymphoproliferative disease of cattle. In 1995 a PCR based method was introduced for the detection of the ovine herpesvirus 2 (OvHV-2), which is regarded as the causative agent of the sheep-associated form of the disease. This PCR can be regarded as a gold standard for the in vivo diagnosis of sheep-associated MCF in cattle (Müller-Doblies et al., 1998). This semi-nested PCR was now used as a reference test for the reassessment of diagnostic criteria in the clinical and post mortem diagnosis that could previously not be quantitated. Based on 83 suspected cases with a complete clinical record the clinical signs were weighted and grouped according to their sensitivity and specificity into lead signs indicative of MCF and frequently accompanying signs supportive for the diagnosis of MCF and general clinical signs that were less reliable for the diagnosis. Differential diagnoses are discussed, which are of particular significance due to their status as OIE list A diseases e.g. foot-and-mouth disease or rinderpest. 38 PCR confirmed cattle with MCF served for the quantitative analysis of organ lesions. For the post mortem diagnosis an essential set of organ samples is defined to permit a reliable histological diagnosis, as the gross pathology often did not give any indication for the diagnosis. These criteria should help to improve the diagnostic efficiency and to select the appropriate laboratory diagnostic procedures for MCF-suspected cattle.

Animals↗

PubMed2001

Characterization of a novel hemoglobin-glutathione adduct that is elevated in diabetic patients.

BACKGROUND: Typically, a diagnosis of diabetes mellitus is based on elevated circulating blood glucose levels. In an attempt to discover additional markers for the disease and predictors of prognosis, we undertook the characterization of HbA1d3 in diabetic and normal patients. MATERIAL AND METHODS: PolyCAT A cation exchange chromatography and liquid chromatography-mass spectroscopy was utilized to separate the alpha- and beta-globin chains of HbA1d3 and characterize their presence in normal and diabetic patients. RESULTS: We report the characterization of HbA1d3 as a glutathionylated, minor hemoglobin subfraction that occurs in higher levels in diabetic patients (2.26 +/- 0.29%) than in normal individuals (1.21 +/- 0.14%, p < 0.001). The alpha-chain spectrum displayed a molecular ion of m/z 15126 Da, which is consistent with the predicted native mass of the HbA0 alpha-globin chain. By contrast, the mass spectrum of the beta-chain showed a mass excess of 307 Da (m/z = 16173 Da) versus that of the native HbA0 beta-globin chain (m/z = 15866 Da). The native molecular weight of the modified beta-globin chain HbA0 was regenerated by treatment of HbA1d3 with dithiothreitol, consistent with a glutathionylated adduct. CONCLUSIONS: We propose that HbA1d3 (HbSSG) forms normally in vivo, and may provide a useful marker of oxidative stress in diabetes mellitus and potentially other pathologic situations.

Animals↗

PubMed2001

Miller Fisher syndrome: toward a more comprehensive understanding.

PURPOSE: To review recent knowledge on the clinical features, pathology and pathophysiology, diagnosis and treatment of Miller Fisher syndrome (MFS). DATA SOURCES: Clinical and laboratory studies on MFS in the past 10 years were included. RESULTS: A viral infection preceded neurological symptoms in 71.8% of MFS patients. Typical MFS consists of the triad of ataxia, areflexia and ophthalmoplegia. Other cranial nerves are also involved, which may overlap with limb weakness in typical Guillain-Barre syndrome (GBS). Lower cranial nerve variants of GBS, atypical MFS and ataxic neuropathies may overlap, and are thought of as variant forms of MFS. Recurrence and CNS involvement is found more frequently in MFS than in GBS. Antibody to GQ1b, a tetrasyaloganglioside (GQ1b antibody) which is found in close relation to ophthalmoplegia in MFS, is also associated with Campylobacter jejuni (C. jejuni) serotype Penner 2. This suggests that C. jejuni may induce MFS via the GQ1b structure. The GQ1b antibody may lead to the failure of acetylcholine release from motor nerve terminals, which has been confirmed by clinical neurophysiological results. CONCLUSIONS: Many studies have shown similarities in the pathogenesis of MFS and GBS. However, there are still some differences between them, especially in the areas of sensory and CNS involvement. The GQ1b antibody is thought of as one of the key factors in the pathogenesis of MFS, especially with ophthalmoplegia, and it may prove a useful clinical marker in the diagnosis of MFS.

Central Nervous System↗

PubMed2001

Gene expression of glucose transporters and its regulation by glucose in mesothelial cells.

OBJECTIVE: To observe the influence of glucose on the expression of glucose transporters (GluTs) in peritoneal tissues. METHODS: Mesothelial cells (MsCs) from Sprague-Dawley (SD) rats were cultured in medium with glucose 214.4 mmol/L or 75.5 mmol/L. The normal medium with glucose 17.5 mmol/L was used as control. Total RNA was extracted from each sample after 24 hours incubation. Reverse transcript polymerase chain reaction (RT-PCR) was performed with primers corresponding to sodium-glucose transporter (SGIT1) and GluT1-GluT4. mRNA expression of the above GluTs from each sample was measured with quantitative PCR. RESULTS: GluT1 and GluT2 mRNA can be detected in MsCs from SD rats, while no positive bands can be found specifically for GluT3, GluT4 and SGiT1. Quantitating the amount of PCR products indicated that the levels of GluT1 mRNA in MsCs cultured 24 h in both 214.4 mmol/L glucose and 75.5 mmol/L glucose medium decreased dramatically compared with that in normal medium (P < or = 0.01). While under the same conditions, the levels of GluT2 mRNA in MsCs cultured 24 h in 214.4 mmol/L and 75.5 mmol/L glucose medium both increased significantly (P < 0.01). CONCLUSIONS: GluT1 is strongly expressed in MsCs under normal glucose levels and decreased dramatically under high glucose conditions, while GluT2 expressed at a low level in normal medium and increased greatly after incubation in high glucose conditions. This may play a great role in glucose absorption during peritoneal dialysis and have some connection with ultrafiltration failure due to the alteration of glucose absorption after long-term dialysis.

Animals↗

PubMed2001

Diagnosis and treatment of bronchial rupture from blunt thoracic trauma.

OBJECTIVE: To evaluate the diagnosis and management of bronchial rutpture from blunt thoracic trauma. METHODS: A group of 31 patients with bronchial rupture was involved. Chest roentgenography, tomography and bronchoscopy were performed on all patients. The surgical technique and complications were described. RESULTS: Diagnosis was confirmed by tomography and bronchoscopy in all the patients. End to end anastomosis was used in 26 patients. Four patients were operated with total pneumonectomy. One patient was repaired with an intercostal muscle and rib flap with blood supply. Of the 31 patients, one died of adult respiratory distress syndrome after operation. Most patients had excellent surgical outcomes. 81% (25/31) of the bronchial rupture were delayed in diagnosis and treatment. The classic symptoms and signs of bronchial rupture included subcutaneous emphysema, dyspnea and an intermediate coma interval. The roentgenogram showed mediastinal emphysema, pneumothorax, "drop lung" sign and marked radiodensity of hilum widened mediastinum. CONCLUSION: Bronchoscopy is a useful and accurate method to diagnose and treat the bronchial rupture, with which surgeons can easily locate the rupture site during surgery. Surgical treatment could restore pulmonary function in most patients.

Adolescent↗

PubMed2001

Effects of acidum vitamin A on tyrosinase activity.

OBJECTIVE: To investigate the effect of acidum vitamin A on tyrosinase activity and provide experimental evidence for therapy of pigment disorder of skin. METHODS: Tyrosinase activity was estimated by measuring the rate of oxidation of DL-dopa. RESULTS: The levels of tyrosinase activity in the acidum vitamin A group were significantly greater than those of the control group (P < 0.01). CONCLUSION: Tyrosinase activity can be increasingly induced by acidum vitamin A.

Humans↗

PubMed2001

[The placental immunopathology of intrauterine growth retardation].

OBJECTIVE: To observe the immune complex distribution in placenta of intrauterine growth retardation (IUGR). METHOD: Using immunohistochemical technique (SP method), authors studied the deposition of IgG and IgM in the placenta of idiopathic IUGR patients (including 8 samples of (ACA)-positive and 14 samples of ACA-negative) and patients with Pregnancy induced hypertension (PIH) complicated IUGR. RESULTS: There is no significant difference of IgG deposition in villous vessels among the three groups. The positive rate of IgM in villous vessels, the positive rate of IgG, IgM in decidual vessels and the deposition of IgM in syncytiotrophoblast of both idiopathic IUGR and PIH complicated IUGR were much higher than those of control group (P > 0.05). The positive rates of IgG, IgM in decidual vessels and villous vessels between the ACA-positive group and ACA-negative group in the idiopathic IUGR were not significantly different. CONCLUSIONS: The immunopathological lesion in placenta might play an important role in the development of IUGR. Idiopathic IUGR and PIH complicated IUGR have the similar placental immunopathological changes. The etiology of IUGR induced by ACA needs more studies.

Female↗

PubMed2001

[A comparative study of friction behaviour matching of natural tooth and new type dental prosthetic materials--titanium].

New type dental prosthetic materials Titanium not only have excellent biocompatibility, better corrosion resistance, appropriate hardness, light density approaching to human skeleton, but also good mechanical properties as those of type II, IV gold alloy recommended by ADAS, and their strength to weight ratio is 1.3 times that of aluminum, 1.5 times that of steel. Friction wear comparative tests of natural living teeth and dental Titanium materials have been carried out against Gr15 steel ball. A reciprocating movement was realized at the modified machine of fretting to simulate the pair of real tooth. The main test parameters were: slip amplitude 500 microns, normal load 20 N, frequency 2 Hz, and number of cycles 5000. The wear behavior results show that titanium is comparatively a prospective dental materials for restoration.

Child↗

PubMed2001

[The application of laser therapy plus endobronchial stenting in treatment of complete airway obstruction].

OBJECTIVE: To assess the efficacy of laser therapy plus endobronchial stenting in the treatment of complete airway obstruction. METHODS: 17 cases with complete airway obstruction were treated with Nd: YAG laser and endobronchial stenting from April 1998 to November 2000. The patients' dyspnea, airway gauge, pulmonary function and complications were observed. RESULTS: The airways were all restructured following a single or multiple laser treatment; the airway gauge enlarged and the average diameter increased (5.82 +/- 1.01) mm. Immediate relief of dyspnea was achieved in sixteen patients and dyspnea index lessened one grade in 4 patients, 2 grades in 11 and 3 grades in one. Obvious improvement of forced expiratory volume in one second (FEV(1)) was noted in all patients;the improvement averaged (0.49 +/- 0.18) L. Endobronchial stents were placed for 14 patients after laser treatment. After stent placement, the airway was further opened and the average airway gauge increased (3.50 +/- 0.94) mm further in diameter. Patients' dyspnea and FEV(1) were further improved; dyspnea index lowered one grade in eight patients and 2 grades in two patients. FEV(1) improved further (0.41 +/- 0.20) L in average. Complications after laser therapy included hypoxemia in 15 patients, hemorrhage in 2 and postoperative dyspnea in 3. Follow-up duration ranged from 2-20 months. Complications after stenting included recurrent pneumonia in 4 patients, airway obstruction due to granuloma or tumour growth in 5 and stent migration in 1. CONCLUSION: Laser therapy and endobronchial stent placement were effective in the treatment of patients with totally occluded airway. Nd: YAG laser can be first chosen to restructure the occluded airway, then endobronchial stent must be used to further enlarge the airway and maintain the therapeutic effect.

Adolescent↗

PubMed2001

[Diarrhea during mechanical ventilation].

OBJECTIVE: To identify the causes of diarrhea during mechanical ventilation. METHODS: We reviewed 56 cases, who have been mechanically ventilated for more than 48 hours, and also received both enteral and parental nutritional support in our RICU. RESULTS: 33 (57%) patients developed ventilator-associated pneumonia. 19 (33%) patients suffered from diarrhea, lasted 13 days on average. Spores with large quantities were found in stools of 8 patients, with hypha in three patients. There was imbalance of bacteria in faeces in 4 cases, manifested by decreases in rods and increases in cocci, in which E. faecalis were present in 3 patients. 9 patients suffered from diarrhea with no evidence rate of abnormalities in their faeces. Diarrhea was treated by adjustment of food temperature and rate of feeding. it is confirmed by Logistic regression that diarrhea during mechanical ventilation was correlated with ventilator associated pneumonia (VAP). CONCLUSIONS: Diarrhea in mechanical ventilated patients in our RICU were attributed mainly to improper administration of enteral nutrition, disturbances of the microenvironment of the intestines, including fungal infection, imbalance between coccus and rod, even E. faecalis colonization. Limitation of broad-spectrum antibiotics administration, VAP control, and proper administration of formula are strongly recommended.

Diarrhea↗

PubMed2001

Rapid and simple fixation-staining technique of fresh frozen cryostat sections for SIMS microscopy.

Before observing freeze-dried cryosections by ion microscopy, it is necessary to perform localization of the analysis site by light microscopy. The present study reports a rapid fixation-staining method for preparing freeze-dried or air-dried cryosections, wherein cryosections are observed after immersion in Carnoy-Lebrun fixative for 30 s and staining in undiluted Giemsa solution for 30 s. Cryostat sections of goldfish intestine and kidney tissue on the silicon wafer substratum were subsequently examined by SIMS. Positive cesium ion images showed a general histology of the intestinal villi with goblet cells. Their granules contained large amounts of sodium, magnesium, potassium and calcium on ion images. By contrast, iron, copper and CsFe ion images showed diffuse distribution throughout the sections.

Acetic Acid↗

PubMed2001

[Expression and significance of urokinase-type plasminogen activator, its receptor, and type 2 inhibitor in giant cell tumor of bone].

OBJECTIVE: To investigate the expression and significance of u-PA, u-PAR and PAI-2 mRNA in giant cell tumor of bone. METHODS: The expressions of u-PA, u-PAR and PAI-2 mRNA in 42 patients with giant cell tumor(GCT) of bone was detected with in situ hybridization. RESULTS: The expression rates of u-PA, u-PAR, and PAI-2 mRNA of multinuclear giant cells (MGC) were 64.3%, 71.4% and 40.5%. Their expression rates in the mononuclear cells (MC) were 54.8%, 45.2% and 9.5%, respectively. The expression rates of u-PA mRNA in MGC, u-PA and u-PAR mRNA in MC of grade II and III lesions were significantly higher than those of grade I and non-recurrent lesions (P < 0.05). Close positive relation was observed between the expressions of u-PA mRNA of both cells, between the expressions of u-PAR and PAI-2 mRNA in MGC and also between the expressions of u-PA and u-PAR mRNA in MC. The expression rate in MGC was higher than that of MC significantly (P < 0.05). CONCLUSION: The expressions of u-PA, u-PAR mRNA of giant cell tumor, especially in the mononuclear cells demonstrate lower differentiation and recurrent potential in giant cell tumor of bone. Mononuclear cells may be the main tumor cell in giant cell tumor of bone.

Bone Neoplasms↗

PubMed2001

Retrograde interlocking intramedullary nailing under arthroscopy for supracondylar femoral fracture.

OBJECTIVE: To evaluate the therapeutic effects of retrograde interlocking intramedullary nailing under arthroscopy on supracondylar femoral fractures. METHODS: From June 1999 to December 2000, 17 patients with supracondylar femoral fracture were treated with arthroscopically assisted implantation of retrograde interlocking intramedullary nail and close reduction. RESULTS: More than 6-month follow-up study after operation in 11 patients revealed that the average healing time was 3 months. Average range of the knee motion for all the patients was more than 90 degrees. There was no implant breakage and infection. CONCLUSIONS: This new method, combining the advantage of arthroscope and retrograde interlocking intramedullary nail, can provide a stable and reliable fixation, and meanwhile is less invasive to the soft tissue and knee, less operative time and blood loss, minimal disruption of the blood supply in fracture site. It is conducive to the fracture healing and the functional recovery of the knee joint and worthwhile to be recommended.

Adult↗

PubMed2001

Comparative observation with MRI and pathology of brain edema at the early stage of severe burn.

OBJECTIVE: To investigate the correlation between MRI features and pathology in brain edema at the early stage of severe burn (5 0% TBSA III degree) in dogs. METHODS: Fifty-two dogs were randomized into control, simple b urn (SB), burn plus sodium lactate (BSL), and burn plus glucose solution groups (BGS). The manifestation of the brain of control group was compared with that of burn groups at 6, 12, 18 and 24 hours postburn with MRI and pathological examination (gross appearance, electron microscopy and light microscopy). RESULTS: The earliest findings of brain edema were seen at 12 h ours after burn in BGS group, in which brain swelling was the main feature of MR I. The decrease of SIR on T(1)WI was not observed until it was exceeded 10%. Sig nal of T(2)WI increased by 8.29% at 24 hours after burn. It was difficult to distinguish the gray matter from the white matter at the boundary line, which became blurred later. Histological changes of brain edema were observed as early as 6 hours after burn, being accompanied by swelling of endothelial cells and peri-vescular astrocytes, and vacuolation took place in neurons at 12 hours after burn, with different degrees of necrosis of capillary endothelium, neurons, and axons. These changes became more marked with elapse of time. The BGS group showed the most obvious changes mentioned above at 24 hours after burn. CONCLUSIONS: The model of the brain edema after severe burn has the feature of both vasogenic edema and cytotoxic edema on the MRI and pathology. Positive MRI findings lagged behind that of the pathomorphological changes.

Animals↗

PubMed2001

[cDNA expression array in the differential expression profiles of p53 regulated genes in nasopharyngeal carcinoma and the human normal nasopharynx].

OBJECTIVE: To compare the gene expression map of nasopharyngeal carcinoma (NPC) tissue with that of the control tissue by cDNA array and to discuss possible reasons of TP53 accumulation in NPC tissue. METHODS: After the hybridization of Atlas human cancer cDNA expression array 7742-1, analysis of Atlas arrays by means of AtlasImage 1.01a was carried out. Then, the results of array were verified by reverse transcription-polymerase chain reaction (RT-PCR). Gene expression alteration on the protein level was verified by immunohistochemistry. RESULTS: 134 of 588 tumor-related genes were upregulated and 88 downregulated. Thirteen of 32 p53-regulated genes showed differential expression with 11 upregulated and 2 downregulated. CONCLUSION: (1) p53 dysfunction exists in NPC tissues, (2) MDM2, p21 and Bax may be involved in the regulation of nasopharyngeal carcinoma cell growth.

DNA, Complementary↗

PubMed2001

[Single topotecan or in combination with other chemotherapeutic agents for 18 recurrent advanced ovarian cancer patients].

OBJECTIVE: This study was designed to evaluate the efficacy and toxicity of topotecan hydrochloride, used singly or combined with other drugs in patients with recurrent advanced ovarian cancer. METHODS: Eighteen ovarian cancer patients who had received cytoreductive operation 1 to 3 times and 8 to 18 courses of chemotherapy but still failed in DDP-based(86.3%) and Taxol-based(32.7%) as well as combined DDP and Taxol-based(30.7%) chemotherapy, were divided into 3 groups: 1. Topotecan 1.2 mg/m2 q.d.i.v. for 5 consecutive days every 3 weeks for a total of 6 patients and 14 courses. 2. Topotecan 0.7 mg/m2 q.d.i.v. for 5 consecutive days and cis-platin 20 mg/m2 q.d.i.v. for 3 consecutive days over 4 weeks and 3. Topotecan 0.7 mg/m2 q.d.i.v. for 4 consecutive days and taxol 100 mg/m2 q.d.i.v. for one day as well as cis-platin 20 mg/m2 q.d.i.v. for 3 consecutive days totalling 12 patients and 27 courses. All together 18 courses, median 2.7 courses, were given. RESULTS: All 18 patients were evaluable. PR was achieved in 3 patients with a response rate of 16.7%. The main adverse effects were hematological toxicity, lasting for 3-27 days. Ten (55.6%) patients developed leucocytopenia Grade III-IV which occurred in 16(33.3%) courses. Six(33.3%) patients developed thrombocytopenia Grade III-IV which occurred in 8(16.7%) courses. Six(33.3%) patients developed RBC reduction Grade III which occurred in 8(16.7%) courses. Peripheral nerve inflammation was most serious in the non-hematologic toxicity. CONCLUSION: Topotecan is effective in recurrent advanced ovarian cancer patients who have failed in DDP or/and taxol-based regimes. Topotecan combined with cisplatin and taxol would be effective even if single topotecan has failed. Careful evaluation before treatment is indicated.

Adult↗