Biomedical subjects

S Hu

Publications and source records attributed to S Hu.

At least 91 records · Page 5Linked to original sources

PubMed2001

Apoptosis within mouse eye induced by Toxoplasma gondii.

OBJECTIVE: To investigate apoptosis induced by Toxoplasma gondii (T. gondii) in eyes of C57BL/6 (B6) mice. METHODS: Apoptosis was detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) technique and pathological changes within eyes were analyzed at different time points after intraocular inoculation of either 50 or 500 of tachyzoites. RESULTS: In eyes that received 50 tachyzoites, a few apoptotic inflammatory cells in the anterior chamber and keratocytes in the cornea were seen at days 1 and 2, but no apoptosis was detected 4 days after inoculation. Significantly greater apoptosis of inflammatory cells was observed in the anterior chamber and in the vitreous of eyes injected with 500 parasites. Apoptosis of inflammatory cells in the anterior chamber and of keratocytes in the cornea was seen at day 1. The apoptotic stromal keratocytes strikingly increased at day 4. There were a number of apoptotic inflammatory cells in the vitreous at day 2, and a few apoptotic retinal cells along the internal limiting membrane and the nerve fiber layer of the retina 4 days after inoculation. CONCLUSION: These results suggest that apoptosis of inflammatory cells infiltrated eye infected with this parasite may be a mechanism of eliminating the organism.

Animals↗

PubMed2001

[The impact of early diagnosis and thrombolytic-anticoagulant therapies on outcome of pulmonary embolism].

OBJECTIVE: To investigate the effect of early diagnosis and thrombolytic followed by anticoagulant therapy in pulmonary embolism (PE). METHODS: 46 patients diagnosed as PE were retrospectively analyzed. All the patients were treated with thrombolytic followed by anticoagulant therapy. Therapeutic effect was compared between two groups of patients with symptoms more or less than two weeks before establishment of diagnosis. RESULT: 36 patients were documented as PE by lung scan, 13 of 46 patients (28.3%) were misdiagnosed as other heart or lung diseases. All the patients had accompanying diseases, including leg deep vein thrombosis (DVT) (33/46, 71.7%) heart or lung diseases other than PE(23/46, 50%), and history of surgery (6/46, 3%). 93.1% of the patients with clinical history less than 2 weeks showed improvement, whereas only 52.9% of those with clinical history exceeding 2 weeks improved. There was significant difference between them. CONCLUSION: In order to diagnose PE early, we should pay more attention to the risk factors of PE, especially DVT. The success of thrombolysis appears to depend on the interval between the onset of symptoms and start of thrombolytic therapy. Patients with clinical symptoms less than 2 weeks show better improvement.

Adult↗

PubMed2001

[Evaluation of p53, p21waf1, and PCNA in the diagnosis on lung cancer].

OBJECTIVE: To evaluate the diagnostic value of p53, p21waf1 and PCNA on diagnosis of lung cancer. METHODS: One hundred and fourteen lung cancer patients and 89 cases with benign pulmonary diseases were studied on the expression of p53, p21waf1 and PCNA by immunohistochemical staining. The differences of p53, p21waf1 and PCNA expression status between these two groups were compared and the diagnostic value of these three markers was evaluated. RESULTS: (1) The positive rates of p53, p21waf1 and PCNA expression in lung cancer were 47.37%, 75.44% and 80.70%, all significantly higher than that in benign pulmonary diseases (P < 0.001), with odds ratio 39.15, 5.75, 6.76 respectively. (2) The positive likelihood ratio of p53 was 21.08, higher than that of p21waf1 and PCNA. Specificity and Youden index were also higher than those of p21waf1 and PCNA, but the sensitivity of p53 was low. (3) The sensitivity and specificity of p53 and PCNA parallel test were 89.47% and 60.67% respectively. CONCLUSIONS: (1) The expression of p53, p21waf1 and PCNA in lung cancer cases were all upregulated. These three markers all seemed to have strong links with lung cancer. (2) p53 was shown a good marker for lung cancer diagnosis. (3) The diagnostic value of p53 and PCNA parallel test was rather high.

Biomarkers, Tumor↗

PubMed2001

[Enteral feeding of glucose increases intestinal mucosal blood flow during intestinal ischemia/reperfusion injury].

OBJECTIVE: To explore the relationship between enteral nutrition and the change in intestinal mucosal blood flow during intestinal ischemia/reperfusion injury. METHODS: Thirty-six Sprague-Dawley rats were randomly divided into alanine (12 rats), glucose (14 rats) and mannitol control (10 rats) groups. Jejunal sac was prepared with the filling of either 10 mM alanine, glucose or mannitol in the three groups. The laser doppler probe and intestinal mucosal tonometry were placed at the both ends of the sac. The superior mesenteric artery was occluded by arterial clamp for 60 mins and released thereafter for another 60 mins. Intestinal mucosal blood flow and regional pressure of CO(2) (PrCO(2)) were determined every 30 mins. RESULTS: During the process of ischemia/reperfusion, the intestinal mucosal blood flow in glucose group increased evidently and the PrCO(2) in glucose group decreased obviously (P < 0.01) when comparcd with those in mannitol group. CONCLUSION: During the process of ischemia/reperfusion, enteral feeding of glucose could increase intestinal mucosal blood flow, which provided guarding effects on the intestine suffering from ischemic/reperfusion injury.

Animals↗

PubMed2001

[Studies on chemical constituents from the flower of Citrus aurantium].

The chemical constituents from the flower of Citrus aurantium were studied. 11 compounds were isolated and identified including neohesperidin(I), synephrin(II), 5,8-epidioxyergosta-6,22-dien-3 beta-ol(III), adenosine(IV), asparagine(V), tyrosine(VI), valine(VII), isoleucine(VIII), alanine(IX),beta-sitosterol(X) and beta-daucosterol(XI).

Citrus↗

PubMed2001

[Detection of S-100 protein in laryngeal carcinoma].

OBJECTIVE: To study the relationship between S-100 protein and prognosis of laryngeal carcinoma. METHOD: S-100 protein was observed by immunohistochemical methods using anti-S-100 protein antibody in 68 laryngeal carcinoma and 21 non-cancer laryngeal tissues. RESULT: The result showed that S-100 protein positive were found 43 (63.24%) in 68 laryngeal carcinoma. S-100 protein positive cells were interspersed among the tumor cells and in the stroma. S-100 protein were rare in non-cancer laryngeal tissues. The five-year survival rate in patients with S-100 protein positive was significantly higher than that in patients with S-100 protein negative. CONCLUSION: Our result indicated that the detection of S-100 protein is of value for the prognostic analysis in patients with laryngeal carcinoma.

Humans↗

PubMed2001

[A review of research actuality on age-related macular degeneration].

A research actuality on Age-related Macular Degeneration(AMD) is reviewed, including epidemiology, pathogeny, mechanism, and the therapy of western or traditional chinese medicine. The pathogeny of AMD is linked with age, race, the history of heredity, smoking and environment. The mechanism of AMD is concerned with the metabolic disturbance of RPE and the chronic nonspecific inflammation. The main therapies for treating AMD include laser photocoagulation, photodynamic therapy, surgery, radiotherapy, drug and gene therapy. Using traditional chinese medicine to treat AMD is an exploratory direction which deserves to be mentioned due to the present situation of no effective treatments to AMD.

Aged↗

PubMed2001

Comparative experimental study of Ho-Yag laser and true-cut biopsy needle in myocardial revascularization.

OBJECTIVE: To study the mechanism and effects of blood perfusion on acute ischemic region of myocardium through channel created by Ho-Yag laser and True-cut biopsy needles with myocardial contrast echocardiography. METHODS: We partially ligated the left anterior descending coronary artery of canine hearts between the 1st and 2nd diagonal branches to produce two groups of acute myocardial ischemia models and then performed transmyocardial revascularization (TMR) on this region with Ho-Yag laser and True-cut biopsy needles. Myocardial contrast echocardiography was performed with a new generation of ultrasound contrast agent and second harmonic imaging of this region before, during ischemia and after revascularization. Pictures were taken with "R" wave trigger skill. RESULTS: Acoustic density (dB) in the ischemic region (anterior wall) with myocardial contrast echocardiography decreased obviously after the left anterior descending artery was ligated (Laser group: 5, 40 +/- 1.81, Needle group: 7.11 +/- 2.51) compared with that before (Laser group: 11.69 +/- 1.61, Needle group: 12.96 +/- 2.88, P < 0.01). dB increased remarkably after TMR by either laser or True-cut biopsy needle (Laser group: 11.02 +/- 2.01, Needle group: 10.01 +/- 4.45. P < 0.01) compared to that during ischemia and approximated to that before ischemia (P > 0.05). We found that the acoustic density of the contrast developed one picture (one cardiac cycle) ahead in the transmyocardial revascularization region than that in the lateral and other region of the left ventricle wall in the scan of both groups. CONCLUSIONS: Acute ischemic myocardium can be perfused immediately by oxygenated blood from the left ventricle through channels created with both Ho-Yag laser and True-cut biopsy needles. Evidence of blood perfusion through these channels mainly during systolic phase was detected, and myocardial contrast ultrasound using intravenous perfluorocarbon-exposed sonicated dextrose albumin was regarded as a reliable method in the study of transmyocardial revascularization.

Animals↗

PubMed2001

[Operative outcome of patients with left ventricular giant aneurysm: mid-term follow-up in 49 patients].

OBJECTIVE: To assess the mid-term outcome of the patients with left ventricular aneurysm repaired, and analyze the factors influencing early and late mortality and morbidity. METHODS: From January 1992 to November 1998, 58 patients underwent surgical repair for postischemic left ventricular aneurysm. In the 56 survivals, 49 patients (87.5%) were followed-up for an average of 47.6 months (the longest time was 90.0 months). RESULTS: Early mortality rate was 3.4% (2 patients). In the follow-up period (mean 47.6 +/- 22.4 months), 10 patients died. The 5-year survival rates were 63.7%. The left ventricular end-diastolic diameter and left ventricular ejection fraction were improved significantly 29.0 months after operation. There was significant improvement in mean NYHA (from class 2.5 +/- 0.7 to 1.3 +/- 0.5). Of the survivors, 43 (87.8%) were free from angina, and 7 had arrhythmias. Multivariate analysis showed that left ventricular end-diastolic diameter larger than 70 mm and left ventricular ejection fraction lower than 35% were independent risk factors. 33% patients were free from drugs. CONCLUSION: Left ventricular aneurysm repair is an important therapeutic intervention and can be performed successfully. Patients who could benefit from the operation are those with a normal postoperative contraction pattern. Cardiac surgical procedures;

Adult↗

PubMed2000

Separation of proteins by sodium dodecylsulfate capillary electrophoresis in hydroxypropylcellulose sieving matrix with laser-induced fluorescence detection.

Sodium dodecyl sulfate capillary electrophoresis by using hydroxypropylcellulose as the sieving matrix was developed for separation of proteins. 3-(2-furoyl)quinoline-2-carboxaldehyde, a fluorogenic dye, was used as the pre-column reagent to label proteins, which allows the use of laser-induced fluorescence to improve the detection sensitivity. Five standard proteins within the molecular mass range of 14,000-97,000 were used to test this method and a calibration curve was obtained between the molecular mass of these proteins and their peak migration times. This method was also applied to the separation of proteins from HT29 human colon adenocarcinoma cell extracts, and, typically, nearly 30 protein components could be resolved in a 20-min separation. Similar separation patterns were observed for the cell extract proteins when three running buffer systems were employed, indicating that buffer composition did not have much influence on the separation based on HPC sieving.

Cellulose↗

PubMed2000

Methyl-beta-cyclodextrin modified micellar electrokinetic capillary chromatography with laser-induced fluorescence for separation and detection of phospholipids.

Micellar electrokinetic capillary chromatography (MECC) with laser-induced fluorescence detection was applied to the separation of amino group-containing phospholipids including phosphatidylethanolamine (PE), phosphatidylserine (PS), lysophosphatidylethanolamine (LysoPE), and lysophosphatidylserine (LysoPS). A fluorogenic dye, 3-(2-furoyl)quinoline-2-carboxaldehyde (FQ), was successfully used to fluorescently label these phospholipids. 4-Fluoro-7-nitrobenzofurazan only produced fluorescent product from LysoPE and PE; signals were not observed from LysoPS and PS. A borax buffer containing sodium deoxycholate modified with methyl-beta-cyclodextrin (methyl-beta-CD) was an excellent MECC system for these phospholipids. Under the optimum conditions, four FQ-labeled phospholipid classes were separated within 8 min. Moreover, each of the PE, PS, LysoPE and LysoPS peaks split into two components corresponding to subclasses with different lengths of the fatty acid chains, but these subclasses were completely resolved only for LysoPE. Detection limits ranged from 0.18 to 1.1 fg (10(-9) - 10(-10) M), which was four- to five-orders of magnitude superior to previously reported CE methods.

Chromatography, Micellar Electrokinetic Capillary↗

PubMed2000

dFADD, a novel death domain-containing adapter protein for the Drosophila caspase DREDD.

Apoptotic cell death occurs through activation of procaspases, the precursors of a group of aspartate-specific cysteine proteases known as caspases. Procaspase activation is mediated by death adapter proteins such as the mammalian proteins FADD and Apaf-1 and the Caenorhabditis elegans protein CED-4. These adapters bind to procaspases and facilitate oligomerization and subsequent auto-proteolytic processing of the zymogens. Here we report cloning and characterization of dFADD, a FADD homologue in Drosophila. dFADD contains a death domain that is highly homologous to the FADD death domain, and it also shares a novel domain with a Drosophila caspase DREDD, which we call death-inducing domain. dFADD binds to DREDD through the death-inducing domain and enhances the cell death activity and proteolytic processing of DREDD. dFADD and DREDD are stabilized by their interaction. The structural and functional similarities between dFADD and FADD suggest the existence of a FADD-like apoptosis pathway in Drosophila.

3T3 Cells↗

PubMed2000

Effect of thalidomide on chemokine production by human microglia.

Thalidomide, a psychoactive drug that readily crosses the blood-brain barrier, has been shown to possess immunomodulatory attributes, including the inhibition of cytokine production by monocytes and microglia. In this study, we investigated the effect of thalidomide on chemokine production by human microglial cells. Microglial cells were stimulated with lipopolysaccharide, a key cell-wall component of gram-negative bacteria responsible for meningitis, and production of chemokines (regulated upon activation normally T cell expressed and secreted [RANTES], monocyte chemoattractant protein [MCP]-1, macrophage inflammatory protein [MIP]-1beta, and interleukin [IL]-8) was examined by ELISA. Thalidomide treatment was found to cause potent and selective inhibition of IL-8 production in a dose-responsive manner. This inhibition was associated with decreased intracellular IL-8 staining as well as reduced transcription of IL-8 mRNA. In addition, thalidomide treatment of lipopolysaccharide-stimulated microglia inhibited the activation of protein NF-kappaB, a transcription factor known to be important for IL-8 production. These results suggest thalidomide could have a therapeutic role in acute bacterial meningitis through inhibition of IL-8-mediated neutrophil chemotaxis.

Cells, Cultured↗

PubMed2000

The agent of human granulocytic ehrlichiosis induces the production of myelosuppressing chemokines without induction of proinflammatory cytokines.

Infection by human granulocytic ehrlichiosis (HGE) is characterized clinically by cytopenias out of proportion to the number of cells seen to be infected directly. To study the pathogenic role of inflammatory mediators in HGE infection, cytokine production by untreated and dimethyl sulfoxide-treated HL-60 cells, which demonstrate enhanced infection because of granulocytic differentiation, and by normal bone marrow cells was measured using modified sandwich ELISA assays on samples obtained sequentially after inoculation with the HGE agent. All infected cells produced physiological concentrations of CC (monocyte chemotactic protein-1, macrophage inflammatory protein-1alpha and -beta, and RANTES) and CXC (interleukin [IL]-8) chemokines in amounts significantly greater than those produced by uninfected controls. In contrast, infected cells did not secrete the classic proinflammatory cytokines IL-1, IL-6, or tumor necrosis factor-alpha. The striking production of chemokines, powerful leukocyte chemoattractants capable of suppressing hematopoiesis, by susceptible target cells, is likely to be of pathogenic importance both in the observed cytopenias and in mediation of inflammation and host defenses during infection.

Bone Marrow Cells↗

PubMed2000

Hemispheric interaction, metacontrol, and mnemonic processing in split-brain macaques.

These experiments explored the interactions remaining between the cerebral hemispheres in two split-brain macaques. The 'split' was earlier confirmed by showing that one hemisphere was incapable of identifying visual images seen by the other. The critical tests for residual interactions were intermingled with control trials in a continuous recognition task. These tests were of two kinds: 'parallel processing', to determine how simultaneous viewing by both hemispheres affected subsequent recognition by one of them alone; and 'conflict', where opposite responses were demanded from the two hemispheres, thus assessing the issue of metacontrol. Two types of stimuli were also employed: ART, in which each hemisphere saw essentially the same image; and BIPARTITE, in which images were entirely different for each hemisphere. Since, with either type of stimulus, performance was best when viewed by both hemispheres at both encoding and retrieval, 'parallel processing' was highly efficient. However, when both hemispheres viewed initially and only one was subsequently queried, performance was significantly worse than when each hemisphere acted alone on each occasion. It is thus reasoned that when both hemisphere view together, the resultant memory trace somehow reflects the bilaterality, a conclusion concordant with observations of Marcel on blindsight. Processing different images (BIPARTITE) was somewhat more disruptive in this regard than if the same image was viewed by each hemisphere. This was particularly true in the conflict situation, where for one hemisphere the item seen was NEW and for the other it was OLD. A response of 'OLD' was, at first, consistently rewarded. When this well-established protocol was changed, the hemispheres in each animal were gradually able to revise their joint behavior. This, together with the effect of disparate images, and the deficiency evoked when the animals were forced to recognize unilaterally an image first viewed under bilateral conditions, all manifest considerable, and complex, interaction between the hemispheres despite absence of the forebrain commissures. The superior colliculus seems a likely focal point for such interhemispheric effects.

Animals↗

PubMed2000

Deletion of phenylalanine 508 causes attenuated phosphorylation-dependent activation of CFTR chloride channels.

In cell-attached patches stimulated with cAMP agonists, the single-channel open probability (Po) of the phenylalanine 508-deleted cystic fibrosis transmembrane conductance regulator (DeltaF508-CFTR) channel, the most common disease-associated mutation in cystic fibrosis, was abnormally low (a functional defect). To investigate the mechanism for the poor response of DeltaF508-CFTR to cAMP stimulation, we examined, in excised inside-out patches, protein kinase A (PKA)-dependent phosphorylation activation and ATP-dependent gating of wild-type (WT) and DeltaF508-CFTR channels expressed in NIH3T3 mouse fibroblasts. For WT-CFTR, the activation time course of CFTR channel current upon addition of PKA and ATP followed a sigmoidal function with time constants that decreased as [PKA] was increased. The curvilinear relationship between [PKA] and the apparent activation rate suggests an incremental phosphorylation-dependent activation of CFTR at multiple phosphorylation sites. The time course of PKA-dependent activation of DeltaF508-CFTR channel current also followed a sigmoidal function, but the rate of activation was at least 7-fold slower than that with WT channels. This result suggests that deletion of phenylalanine 508 causes attenuated PKA-dependent phosphorylation of the CFTR chloride channel. Once DeltaF508-CFTR channels were maximally activated with PKA, the mutant channel and WT channel had indistinguishable steady-state Po values, ATP dose-response relationships and single-channel kinetics, indicating that DeltaF508-CFTR is not defective in ATP-dependent gating. By measuring whole-cell current density, we compared the number of functional channels in WT- and DeltaF508-CFTR cell membrane. Our data showed that the estimated channel density for DeltaF508-CFTR was approximately 10-fold lower than that for WT-CFTR, but the cAMP-dependent whole-cell current density differed by approximately 200-fold. We thus conclude that the functional defect (a decrease in Po) of DeltaF508-CFTR is as important as the trafficking defect (a decrease in the number of functional channels in the plasma membrane) in cystic fibrosis pathogenesis.

3T3 Cells↗

PubMed2000

Micellar electrokinetic capillary chromatographic separation and fluorescent detection of amino acids derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole.

Another method has been developed for the separation of amino acids (1 min derivatization plus 22 min separation) by micellar electrokinetic capillary chromatography (MECC) with laser-induced fluorescence detection. Interestingly enough, such work has never been performed on essential amino acids derivatized by 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F). Fifteen L-amino acid standards were labelled with NBD-F at 60 degrees C for 1 min, and separated in a buffer system containing 20 mM borate, 25 mM sodium cholate, 10 mM Brij 35 and 2.5% methanol. Methanol was employed to expand the MECC migration time window; whereas Brij 35 was used to improve the fluorescence intensity of amino acid derivatives. This method also indicates that bile salt is effective for MECC separation of ionic analytes. Surprising though, improvements in resolution, sensitivity and speed for amino acids analysis are obtained in this work, which are not initially apparent in just employing another derivatizing reagent. Under optimal conditions, 15 amino acids were separated in a short 22 min analysis time, the shortest ever reported, and detection limits of nanomolar concentration and attomole mass were obtained. Furthermore, RSDs of migration time and peak height are better than 1% and 1.8%, respectively, again the smallest ever reported in the literature.

4-Chloro-7-nitrobenzofurazan↗

PubMed2000

Association between the serotonin transporter promoter polymorphism and personality traits in a primarily female population sample.

The serotonin transporter (5-HTT) regulates serotonergic neurotransmission and is thought to influence emotion. A 5-HTT-linked polymorphic region (5-HTTLPR) has two common variants, short (s) and long (l). We previously found population and within-family associations between the lower-expressing s allele and neuroticism, a trait related to anxiety, hostility, and depression, on a standard measure (the NEO Personality Inventory, Revised [NEO-PI-R]) in a primarily male population (n=505), and that the s allele was dominant. We investigated this association in a new sample (n=397, 84% female, primarily sib-pairs). The results robustly replicated the 5-HTTLPR neuroticism association, and the dominance of the s allele. Combined data from the two studies (n=902) showed a highly significant association between the s allele and higher NEO Neuroticism both across individuals and within families. Association between genotype and a related measure, Anxiety on the 16PF inventory, was replicated in the new population and within families in the combined sample. Association to another trait, estimated TPQ Harm Avoidance, was not replicated in the new sample but found only within the combined sibship group. Another association found in our original study, between the s allele and lower scores on NEO-PI-R Agreeableness, was also replicated and was more robust in the current and the combined samples. Associations between the functional 5-HTTLPR polymorphism were similar in women and men. These results help to define specific personality features reproducibly associated with 5-HTTLPR genotype. Such associations were strongest for traits defined by the NEO, enhancing the attractiveness of the five-factor personality model in genetic research on complex behavioral dimensions. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:202-216, 2000. Published 2000 Wiley-Liss, Inc.

Adolescent↗