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Biomedical subjects

T Jiang

Publications and source records attributed to T Jiang.

At least 55 records · Page 3Linked to original sources
PubMed2001

[Clinical analysis of 68 patients with ruptured sinus of Valsalva aneurysm].

OBJECTIVE: To evaluate the clinical characteristics, diagnosis, treatment and prognosis of ruptured aneurysm of the sinus of Valsalva (ASV). METHODS: Sixty-eight cases of ruptured ASV treated in our hospital from 1986 to 1998 were retrospectively analyzed. RESULTS: The ratio of male to female was 1.8:1 in 68 patients (44 males, 24 females). The mean age was (29.5 +/- 10.7) years (8-60 years). The proportion of ruptured aneurysms originating from the right coronary and noncoronary sinus was 79.4% and 20.6% respectively. Sixty-seven point six percent of ASV ruptured into right ventricle and 32.3% into right atrium. The incidence of ventricular septal defect and aortic valve insufficiency was 48.5% and 20.6% respectively. The former only existed in those patients whose ASV originating from the right coronary sinus and rupturing into right ventricles. There was a significant correlation between sudden onset of symptoms and fistulating of ASV into right atrium and a significant difference as compared with those fistulating into right ventricle (P < 0.001). Diagnostic sensitivity and specificity of echocardiography in ruptured ASV was 97.1% and 100% respectively, but the rate of missing subarterial ventricular septal defect was 24.2%. Sixty-seven patients received operation, one died of pulmonary embolism six weeks after operation. Thirty-six patients were followed up, the mean follow-up period was 6.5 years (range 1 to 16 years). Two patients were reoperated for leak of ventricular septal defect and aortic regurgitation. The cardiac function of sixteen patients were found to be of NYHA class I, seventeen of class II and three of class III. CONCLUSION: Echocardiography in combination with aortography is an accurate diagnostic method for ruptured ASV and the prognosis in majority of the patients operated in time is good.

Adult↗
PubMed2001

[Gene rearrangement and p53 expression in defining the nature of angioimmunoblastic lymphadenopathy].

OBJECTIVE: To investigate gene rearrangement and p53 expression in defining the nature of angioimmunoblastic lymphadenopathy. METHODS: DNA was extracted from paraffin-embedded tissue blocks of 44 angioimmunoblastic lymphadenopathy (AIL) patients and analyzed with polymerase chain reaction (PCR) for IgH and TCRgamma gene rearrangement. Immunohistochemistry staining was used to detect p53 protein expression. Thirty-five cases were followed-up. RESULTS: 12 out of 44 cases (27.3%) showed TCRgamma gene rearrangement and 2 (4.5%) showed IgH gene rearrangement. Rearrangement of both IgH and TCRgamma genes were detected in 2 cases (4.5%). 14 cases (31.8%) showed p53 positive expression, among which 12 showed positive rearrangement and 2 showed negative (P < 0.01). Eight out of 11 patients of positive gene rearrangement died in one year, while only 3 patients were still alive at the eighteenth month of follow-up, three of 24 patients of negative gene rearrangement were found dead at the time of the one year follow-up, while the rest 21 patients were alive and the longest survival time was 96 months. CONCLUSIONS: Gene rearrangement can define the pathological nature of AIL. The expression of p53 is highly related to gene rearrangement, and thus an important immunological marker in research on AIL.

Follow-Up Studies↗
PubMed2001

[Clinical application of Targis veneers].

OBJECTIVE: The aim of this study was to evaluate the Targis material in the form of veneers. METHODS: Nineteen patients treated with 91 Targis veneers were involved in this study, and the clinical evaluation on veneers was conducted at the time of recall. The evaluation parameters included marginal adaptation, marginal discoloration, surface texture and color match. The periodontal status of all teeth with veneers was evaluated by gingival bleeding index and plaque index before and after the treatment. RESULTS: The mean observation period for the veneers was 14.6 months. Four veneers failed due to fracture, three because of debond, one because of discoloration. The cumulative rate of success was 91.2%. There was no significant difference in gingival bleeding index before and after treatment, but the plaque index significantly decreased after the treatment. CONCLUSION: The clinical results of Targis are satisfactory.

Adult↗
PubMed2000

[Effect of irradiation on the shelf-life of aquatic products].

The effect of irradiation at doses of 0-10 kGy on the shelf-life of aquatic products was determined. The results showed that irradiation could not prolong the shelf-life of aquatic products kept at 25 degrees C. While the aquatic products were kept at refrigerator (4 degrees C), the irradiation could prolong the shelf-life and effectively reduce the total aerobic plate count. Irradiation could effectively reduce the number of coliform to less than 300/kg and eliminate Shigella shigae, Salmonella and Vibrio parahaemolyticus inoculated on shrimp, needle fish and crucian. A dose of 2.5 kGy could delay the rising of total volatile basal nitrogen in samples.

Animals↗
PubMed2000

Intestinal blood loss during cow milk feeding in older infants: quantitative measurements.

OBJECTIVE: To determine the response, in terms of fecal hemoglobin excretion and clinical symptoms, of normal 9 1/2-month-old infants to being fed cow milk. DESIGN: Longitudinal (before-after) trial in which each infant was fed formula for 1 month (baseline) followed by 3 months during which cow milk was fed. SETTING: Healthy infants living in Iowa City, Iowa, a town with a population of about 60,000. MAIN OUTCOME MEASURES: Hemoglobin concentration in spot stools, 96-hour quantitative fecal hemoglobin excretion, stool characteristics, feeding-related behaviors, and iron nutritional status. RESULTS: Fecal hemoglobin concentration during formula feeding (baseline) was higher than previously observed in younger infants. Nine of 31 infants responded to cow milk feeding with increased fecal hemoglobin concentration. Fecal hemoglobin concentration (mean +/- SD) of the 9 responders rose from 1,395 +/- 856 microg/g of dry stool (baseline) to 2,711 +/- 1,732 microg/g of dry stool (P=.01). The response rate (29%) was similar to that in younger infants, but the intensity of the response was much less. Quantitative hemoglobin excretion was in general agreement with estimates based on spot stool hemoglobin concentrations. Cow milk feeding was not associated with recognizable changes in stool characteristics, nor were there clinical signs related to fecal blood loss. Iron status was similar, except that after 3 months of cow milk feeding responders showed lower (P= .047) ferritin concentrations than nonresponders. CONCLUSIONS: Cow milk-induced blood loss is present in 9 1/2-month-old infants but is of such low intensity that its clinical significance seems questionable. Nevertheless, infants without cow milk-induced blood loss were in better iron nutritional status than infants who showed blood loss.

Anemia, Iron-Deficiency↗
PubMed2000

Distinguishing between cellular and vasogenic edema in head injured patients with focal lesions using magnetic resonance imaging.

Having determined that edema and not vascular engorgement is the major factor leading to traumatic brain swelling, the objective of this study was to determine which type of edema, cellular or vasogenic, is responsible for increased tissue water in patients with focal lesions. Severely head injured patients (GCS 8 or less) were transported to imaging suites for measurement of brain water and apparent diffusion coefficient (ADC) using magnetic resonance technique. Cerebral blood flow by stable Xenon method was also measured in the regions of interest. Brain water was increased significantly in the hemisphere with lesion. The increase in water was associated with reduced ADC signifying a predominant cellular edema. The ADC in the contralateral hemisphere was near normal value. Cerebral blood flow values in the regions of interest were above ischemic levels suggesting that factors other than ischemia are responsible for the cytotoxic swelling in patients with focal injury.

Blood-Brain Barrier↗
PubMed2000

Proinflammatory gene expression and macrophage recruitment in the rat remnant kidney.

BACKGROUND: Macrophage (Mphi) infiltration may contribute to chronic renal injury. We therefore sought to examine the expression of genes associated with Mphi recruitment in the rat remnant kidney model. METHODS: Male Munich Wistar rats underwent 5/6 nephrectomy or sham operation (SHM, N = 18) and received no treatment (VEH, N = 18), enalapril 100 mg/L (ENA, N = 18), or candesartan 70 mg/L (CSN, N = 24) in drinking water. Competitive, quantitative reverse transcription-polymerase chain reaction was used to determine renal cortex mRNA levels for cell adhesion molecules vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1), the Mphi chemoattractant monocyte chemoattractant protein-1 (MCP-1), Mphi products interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha), and the profibrotic cytokine transforming growth factor-beta1 (TGF-beta1), at intervals post-nephrectomy. RESULTS: Glomerular and interstitial Mphi infiltration in VEH rats was associated with an early (4 week) and sustained rise in MCP-1 and TGF-beta1 mRNA levels. Progressive increases in ICAM-1, VCAM-1, IL-1beta, and TNF-alpha expression followed at 8 and 12 weeks. Immunostaining in VEH rats localized TGF-beta1 to glomeruli, tubules, and interstitium; MCP-1 to tubules and interstitial cells; ICAM-1 to glomeruli; and IL-1beta and TNF-alpha to tubules and interstitial cells. At 12 weeks, both treatments normalized systolic blood pressure (ENA, 105 +/- 6; CSN, 97 +/- 3 mm Hg) and the urinary protein excretion rate (ENA, 8.4 +/- 0.9; CSN, 5.7 +/- 0.8 mg/day), prevented renal injury (focal and segmental glomerulosclerosis: ENA, 3.3 +/- 0.9; CSN, 1.3 +/- 0.4%), and suppressed Mphi infiltration and cytokine expression (with the exception of TNF-alpha) to near SHM levels. CONCLUSIONS: These findings support the hypothesis that the coordinated up-regulation of several molecules regulating Mphi recruitment and activation is a fundamental response to renal mass ablation and is dependent on an intact renin-angiotensin system. We speculate that these responses may play a role in the pathogenesis of the ensuing glomerulosclerosis and tubulointerstitial fibrosis.

Animals↗
PubMed2000

Stochastic heuristic algorithms for target motif identification (extended abstract).

Target motifs are motifs that are "close" to one or more substrings in each sequence in one given set of sequences but are far from every substring in another given set of sequences. Target motifs have pharmaceutical applications; unfortunately, the problem of identifying target motifs is NP-hard and is thus unlikely to have efficient optimal solution algorithms. In this paper, we propose a set of simple modifications to the Gibbs Sampling heuristic for finding motifs which allows this heuristic to detect target motifs. We also present the results of several experiments relative to both simulated and real datasets which suggest that this modified heuristic is good at detecting target motifs under a variety of conditions.

Algorithms↗
PubMed2000

Dose-effect relationship of dicentric and ring chromosomes in lymphocytes of individuals living in the high background radiation areas in China.

Chromosomes of 39 healthy family members (3 generations from 13 families) living both in the high-level background radiation areas (HBRA) and the control areas (CA) were studied. Cumulative dose from birth to the time of blood sampling was estimated by calculating measured exposure rate in each individual. The cumulative doses ranged 30.9-358.9 and 6.0-59.2 mGy for HBRA and CA, respectively. Peripheral lymphocyte chromosome preparations were made according to our improved method. Dicentric and ring chromosomes (Dic + Rc) were scored in average 2,527 cells per individual in HBRA and 2,694 cells in CA under a microscope equipped with an automated stage. A positive correlation between Dic + Rc and age was found in HBRA, while no such dose relationship was clear in CA. The frequency of Dic + Rc linearly increases over lifetime due to chronic low dose exposure and it is likely that the activation of repair enzymes is not triggered in the present HBRA. Threshold dose (rate) of the induction of chromosome aberrations, if any, is below the present dose (rate) level.

Adult↗
PubMed2000

Fournier gangrene associated with Crohn disease.

A 17-year-old boy presented with Fournier gangrene associated with previously undiagnosed Crohn ileocolitis. Fournier gangrene was managed by débridement, broad-spectrum antibiotics, and hyperbaric oxygen. A diverting ileostomy was performed before skin grafting and scrotal reconstruction. Microscopy of a full-layer surgical sample from the terminal ileum revealed granulomas with multinucleated histiocytes, consistent with Crohn disease. Crohn disease was treated with mesalamine, metronidazole, 6-mercaptopurine, and infliximab. The patient was discharged on hospital day 32. At 6-month follow-up, reconstruction of his scrotum had completely healed. Ostomy output was normal.

Adolescent↗
PubMed2000

[Studies of the active site, thermostability and thermophilicity of the thermostable alkaline phosphatase by site-directed mutagenesis].

Through PCR-mediated mutagenesis, three mutants E68S, S70A and E68SS70A around active site S(69) were obtained. Their enzymatic characteristics was determined. It was found that the specific activity of E68S ascended 8 times while its optional reactive temperature climbed 20 degrees C and its Tm descended 3 degrees C; the specific activity of S70A ascended 1 time while its optional reactive temperature climbed 5 degrees C and its Tm descended 2 degrees C; the specific activity of E68SS70A descended 50% while its optional reactive temperature climbed 5 degrees C and its Tm descended 19 degrees C. These result implied that the amino acids, beside the active site, were contributed not only to enzymatic activity but also to its thermostability and thermophilicity. The work provided the direction for mutation to improve enzymatic specific activity and studying the mechanism of thermostability and thermophilicity.

Alkaline Phosphatase↗
PubMed2000

[Progress in researches on anti-tumor agent L-asparaginase for treatment of leukemia].

L-asparaginase is a very effective anti-tumor agent. To take the most advantage of enzyme treatment method, the natural L-asparaginase could be chemically modified, entrapped or immobilized into/onto other carriers. The extracorporeal shunt system with immobilized enzyme reactor deserves to receive special attention. It provides an entirely new idea for leukemia treatment and is proved to be very prospective in the future leukemia cure.

Antineoplastic Agents↗
PubMed1999

beta-Siloxy unsaturated nitriles: stereoselective cyclizations to cis- and trans-decalins.

[formula: see text] beta-Siloxy unsaturated nitriles are excellent precursors to enolate and nitrile anions that cyclize to cis- and trans-decalins, respectively. The stereoelectronic requirements of endocyclic enolates and exocyclic nitrile anions are complementary, providing cis- and trans-decalins from a common intermediate. This cyclization allows the synthesis of diastereomeric cis- and trans-decalins containing a contiguous array of quaternary-tertiary-quaternary stereocenters.

Cyclization↗
PubMed1999

[Quantitative determination of 3-nitropropionic acid by HPLC].

A reversed-phase liquid chromatographic method to determine the concentration of 3-nitropropionic acid (3-NPA) in the culture medium with Aspergillus oryzae was developed. The culture medium samples were extracted with ethyl acetate. The analytic column was Hypersil C18 and the mobile phase was CH3CN/KH2PO4(0.02 mol/L, pH 3.0) (1/3, v/v). The sample was detected at UV210 nm. The detection limit of this method was at 10 micrograms/kg level and recoveries were 90.1%-98.0.

Aspergillus oryzae↗
PubMed1999

Crystal structure of allophycocyanin from red algae Porphyra yezoensis at 2.2-A resolution.

The crystal structure of allophycocyanin from red algae Porphyra yezoensis (APC-PY) at 2.2-A resolution has been determined by the molecular replacement method. The crystal belongs to space group R32 with cell parameters a = b = 105.3 A, c = 189.4 A, alpha = beta = 90 degrees, gamma = 120 degrees. After several cycles of refinement using program X-PLOR and model building based on the electron density map, the crystallographic R-factor converged to 19.3% (R-free factor is 26.9%) in the range of 10.0 to 2.2 A. The r.m.s. deviations of bond length and angles are 0.015 A and 2.9 degrees, respectively. In the crystal, two APC-PY trimers associate face to face into a hexamer. The assembly of two trimers within the hexamer is similar to that of C-phycocyanin (C-PC) and R-phycoerythrin (R-PE) hexamers, but the assembly tightness of the two trimers to the hexamer is not so high as that in C-PC and R-PE hexamers. The chromophore-protein interactions and possible pathway of energy transfer were discussed. Phycocyanobilin 1alpha84 of APC-PY forms 5 hydrogen bonds with 3 residues in subunit 2beta of another monomer. In R-PE and C-PC, chromophore 1alpha84 only forms 1 hydrogen bond with 2beta77 residue in subunit 2beta. This result may support and explain great spectrum difference exists between APC trimer and monomer.

Amino Acid Sequence↗
PubMed1999

Structure and function of chromophores in R-Phycoerythrin at 1.9 A resolution.

The crystal structure of R-Phycoerythrin (R-PE) from Polysiphonia urceolata has been refined to a resolution of 1.9 A, based on the atomic coordinates of R-PE determined at 2.8 A resolution, through the use of difference Fourier method and steorochemistry parameters restrained refinement with model adjustment according to the electron density map. Crystallographic R-factor of the refined model is 0.195 (Rfree = 0.282) from 8-1.9 A. High resolution structure of R-PE showed precise interactions between the chromophores and protein residues, which explained the spectrum characteristic and function of chromophores. Four chiral atoms of phycourobilin (PUB) were identified as C(4)-S, C(16)-S, C(21)-S, and C(20)-R. In addition to the coupling distances of 19 A to 45 A between the chromophores which were observed and involved in the energy transfer pathway, high resolution structure of R-PE suggested other pathways of energy transfer, such as the ultrashort distance between alpha140a and beta155. It has been proposed that aromatic residues in linker proteins not only influence the conformation of chromophore, but may also bridge chromophores to improve the energy transfer efficiency.

Amino Acid Sequence↗
PubMed1999

Cow's milk and intestinal blood loss in late infancy.

OBJECTIVES: Young infants commonly show occult intestinal blood loss when fed cow's milk, but in older infants blood loss may be less common. This study examined intestinal blood loss in response to cow's milk feeding in normal 7(1/2)-month-old and 12-month-old infants. STUDY DESIGN: Infants (n = 62) were fed formula for 1 month and then pasteurized cow's milk for 2 months. Stools were collected for quantitative determination of hemoglobin. Iron nutritional status was assessed. RESULTS: Infants fed cow's milk from 7(1/2) months of age showed a significant increase in guaiac-positive stools and in stool hemoglobin concentration. These effects were largely limited to those infants who had been breast fed early in life. Infants fed cow's milk from 12 months of age at baseline had greater stool hemoglobin concentrations than 7(1/2)-month-old infants, but cow's milk produced no significant increase. In neither age group did cow's milk affect iron nutritional status. CONCLUSION: The response to cow's milk is attenuated in infants aged 7(1/2) months compared with younger infants. By 12 months of age, the response has disappeared entirely. We conclude that the gastrointestinal tract of healthy infants gradually loses its responsiveness to cow's milk.

Age Factors↗