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Biomedical subjects

X Su

Publications and source records attributed to X Su.

At least 127 records · Page 7Linked to original sources
PubMed1995

Preoperative segmental localization of focal hepatic lesion on MRI.

In order to evaluate the accuracy of preoperative segmental localization of hepatic mass lesions, 68 cases were prospectively studied and evaluated by the correlation of magnetic resonance imaging (MRI) and surgical findings. Right, middle and left hepatic veins were seen in 100%, 97% and 94% of the subjects respectively on MRI. The right and left portal veins were seen in 100% and 95.6% respectively. The accuracy in determining the segmental location of hepatic lesions was 89.7%. The accuracy could be increased to 91.3% if the lesion was located at single segment whereas it was only 86.4% when the lesion extended across several segments. It is possible to say that MRI is an important modality in the preoperative segmental localization of masses.

Adolescent↗
PubMed1995

[Comparative study on pharmacological effects of various species of Pueraria].

Through comparative studies on the acute toxicity of four species of Pueraria, it was found that the toxicity of P. peduncularis was the highest, followed by P. lobata and P. omeiensis, and that of P. thomsonii was the lowest. The inhibitory effects of P. lobata, P. omeiensis and puerarin on the fever induced by 2,4-dinitrophenol in rats were very fast and significant, maintaining for about 8 hours, while the effect of P. thomsonii is relatively weak. As for influence upon the degrees of myocardiac ischemia induced by pituitrin, P. omeiensis appeared to be the most potent, and P. thomsonii the least one, while P. lobata and puerarin were intermediate between the above two. Summarily, the antipyretic and anti-myocardiac ischemia effects of P. lobata and P. omeiensis are stronger than those of P. thomsonii, and puerarin is one of their effective components.

2,4-Dinitrophenol↗
PubMed1994

Cloning and expression of a novel, highly truncated phosphoinositide-specific phospholipase C cDNA from embryos of the brine shrimp, Artemia.

A novel, highly truncated form of a cDNA encoding Artemia phosphoinositide-specific phospholipase C (PLC), designated PLC-beta x, was isolated from a brine shrimp cDNA library. The full-length cDNA is of the beta-type, it is 2855 base pairs long, and it contains an open reading frame encoding 489 amino acids. The deduced amino acid sequence of PLC-beta c cDNA shows novel features. It lacks several hundred amino acids at the 5' end, as compared to PLC-beta s in the higher species. It contains conserved domains X and Y, but domain X is highly truncated at the 5' end (only 14-25 conserved amino acids as compared to about 150 amino acids in the higher eukaryotic organisms). Northern blot hybridization showed that the PLC-beta x cDNA corresponds to a 4.4-kilobase mRNA. Northern blot hybridization with a cDNA probe from the 5' end and PCR performed upstream from domain Y showed that PLC-beta x is not a cloning artifact due to fusion of an unrelated clone into the coding region of the PLC-beta homologue. A functional PLC and new protein bands on SDS-PAGE were observed after subcloning full-length PLC-beta x cDNA, as well as a fragment containing the conserved regions, into expression plasmid vectors and transfecting into Escherichia coli. 1 mM lithium markedly stimulated expression in E. coli.

Amino Acid Sequence↗
PubMed1994

Prenatal diagnosis of unusual hemoglobinopathies.

While analyzing 280 hemoglobinopathy kindreds with prescribed molecular tests, 3 unusual mutations were observed that required additional characterization. In the first case, the hypervariable region flanking the alpha-globin genes generated an intermediate length 8.2 kb psi zeta-globin gene fragment on a Southeast Asian chromosome with two deleted alpha-globin genes. Rehybridization of the Southern blot with alpha-globin probe distinguished the mutation unambiguously. In the second case, restriction enzyme analysis of a PCR amplified black beta-globin gene detected a novel beta-83 point mutation adjacent to a promoter element. In the third case, which was uninformative with available allele specific oligonucleotides (ASOs), total genomic PCR amplification and sequencing identified a single basepair insertion in codon 36/37 of an Iranian beta-globin gene that shifted the reading frame and obliterated gene activity. Developing additional region-specific ASOs will further diminish the number of cases that must be characterized by genomic PCR sequencing.

Anemia, Sickle Cell↗
PubMed1994

Effect of inhaled 3% CO2 on Cheyne-Stokes respiration in congestive heart failure.

Cheyne-Stokes respiration (CSR) in severe stable congestive heart failure (CHF) may be associated with significant nocturnal arterial oxygen desaturation and sleep disruption. Previous investigations of inhaled CO2 in CSR have been uncontrolled and of short duration, sleep has not been monitored electroencephalographically, and most patients studied have had neurological disease with or without cardiac disease. The purpose of our study was to document the effects of inhaled CO2 on CSR in patients with severe stable CHF (left ventricular ejection fraction < 35% and NYHA class 3 or 4 dyspnea) in controlled all-night polysomnographic studies. Six patients were studied for 3 nights and days: adaptation, control and inhalation of CO2. These patients received a constant F1CO2 = 0.03 in air (with a 4-5 mm Hg increase in PaCO2) on night 3. This caused virtual abolition of CSR as reflected by CSR duration/total sleep time (62-2.2%; p = 0.0012) and CSR duration/nonrapid eye movement (NREM) sleep time (73-2.4%; p = 0.00064), and NREM apnea index was reduced from 33.5 to zero (p = 0.026). The apparatus used to accurately control F1CO2, however, was intrusive and some features of sleep structure such as sleep latency were adversely affected. We conclude that inhalation of CO2 with a constant F1CO2 = 0.03 virtually eradicates CSR in all-night polysomnographically monitored studies in patients with severe stable CHF. The clinical significance of these findings remains to be determined.

Administration, Inhalation↗
PubMed1994

[The complications of senile patients with diabetic retinopathy].

From December, 1990 to June, 1992, 114 patients with diabetic retinopathy were treated ambulatorally in our department. Among them 109 cases (42 males and 67 females) were older than 45 years with 210 diseased eyes. 65 eyes suffered from simple diabetic retinopathy, 145 eyes proliferative one. The visual acuity of 105 eyes (50%) was lower than 0.3, 65 eyes (30.95%) was lower than 0.05. 100 cases (91.74%) were complicated with cardiovascular diseases, 5 cases (4.5%) with cerebrovascular accident, 56 cases (51.40%) with hyperlipemia, 42 cases (61.76%) with high viscosity of the blood. Among the ophthalmic complications, macular disease occurred in 122 eyes, cataract in 88 eyes, central retinal vein obstruction in 15 eyes, neovascular glaucoma in 5 eyes.

Aged↗
PubMed1994

[The clinical observation of China-made ofloxacin eye drops in the treatment of bacterial infection of the external eye].

Ninety patients with extraocular infection were observed. After bacteriological examination on all of the patients, we found that staphylococcus epidermidis was the main pathogen and accounted for 43.3%. Next to it were staphylococcus aureus (31.1%), saprophytic staphylococcus was (5.6%), diplococcus catarrhus (3.3%) and moraxella sp. (2.2%). All the patients were treated with Ofloxacin eye drops produced in Guangzhou. The bacteriological examination showed negative in 98.9% of the patients, which proved this medicine has high antibiotic power.

Adult↗
PubMed1994

Optimized chemiluminescent detection of DNA amplified in the exponential phase of PCR.

We describe a procedure for quantitative detection of nucleic acids by coupling PCR with improved chemiluminescent detection techniques. After performing PCR in the exponential phase in the presence of a trace amount of digoxigenin-11-dUTP, the amplified products are transferred to a positively charged nylon membrane. The membrane is cleaned with a modified method involving sodium dodecyl sulfate and ethanol washing steps to ensure low backgrounds in chemiluminescent detection. The membrane is exposed to two stacked x-ray films to increase the dynamic response in a film exposure. This sensitive and quantitative procedure is useful for molecular biology studies.

Base Sequence↗
PubMed1994

Effect of low dose radiation on intracellular calcium and protein kinase C in lymphocytes.

It is first reported in the present paper that whole-body irradiation (WBI) with low dose X-rays could increase intracellular calcium ions ([Ca2+]i) and stimulate protein kinase C (PKC) activity of mouse lymphocytes. Following WBI of male Kunming mice with 75 mGy X-rays at a dose rate of 12.5 mGy/min the mobilization of [Ca2+]i with Con A in CD4+ and CD8+ Cells in the thymus and spleen was potentiated and the amplitude of [Ca2+]i mobilization in thymocytes in response to anti-CD3 monoclonal antibody increased with time from 4 to 24 h following low dose radiation. The PKC activity in the homogenate of spleen was markedly stimulated 12 h after WBI with 75 mGy, reaching its peak value at 24-48 h and coming down to lower than normal on day 7. However, the PKC activity in the separated T lymphocytes reached its peak value at 12 h and that in the B lymphocytes reached its peak value on day 4, both coming down to below control on day 7. The implications of this facilitation of signal transduction in T lymphocytes in the mechanism of immunoenhancement after low dose radiation were discussed.

Animals↗
PubMed1993

[Effect of extraoral facemask appliance in 48 cases of malocclusion and dentofacial deformity in class III].

Malocclusion and dentofacial deformity in class III is always characterized by maxillary skeletal retrusion and/or mandibular protrusion. It affects function and facial esthetics. An orthopedic mask appliance with class III extraoral traction made by the authors was applied in 48 cases from Aug. 1985 to Oct. 1991. The study population included 5 patients with deciduous dentition, 30 with permanent dentition, and 13 with mixed dentition. The second deciduous molars or permanent first molars are a class III relationship. These exhibited bilateral crossbites and negative overjet greater than 5 mm severe arch length discrepancies existed in both arches, maxillary skeletal retrusion and/or mandibular protrusion. The results of these 48 cases were very satisfactory. The relationship between maxillary and mandibular second deciduous molar or permanent first molar all showed centric occlusal position. Dentofacial orthopedics therapy is one of the most important treatments of malocclusion and dentofacial deformity. The choice of therapy and orthodontic force must follow the age and endurance of the patient. Also, exercise of the tongue muscle must be considered.

Adolescent↗
PubMed1992

Excitation energy transfer from phycocyanin to chlorophyll in an apcA-defective mutant of Synechocystis sp. PCC 6803.

A greenish mutant of the normally blue-green cyanobacterium Synechocystis sp. PCC 6803, designated UV6p, has been isolated and characterized. UV6p possesses functional photosystems I and II (PSI and PSII) but lacks normal light harvesting phycobilisomes because allophycocyanin is absent and core-specific linker proteins are almost entirely absent. The mutation responsible for the UV6p phenotype has been identified; it is a base substitution which results in the creation of a termination codon within the coding region of the apcA gene. Phycocyanin (PC) and phycobilisome rod linker proteins are present in UV6p and, despite the absence of core components, at least 35% of the PC is associated with rod linker proteins. At 77 K, light absorbed by PC of UV6p elicits PSI fluorescence comparable to that of wild type cells but produces greatly diminished PSII fluorescence. The results indicate that the assembly of rods is independent of cores and that light energy absorbed by rods can be transferred principally and directly to PSI. This energy transfer pathway, which may also be present in wild type, may have a regulatory role in maintaining the balance of input of excitation energy into PSI versus PSII during photosynthesis.

Amino Acid Sequence↗
PubMed1992

Monoclonal antibodies to porcine tumor necrosis factor alpha: development of an enzyme-linked immunosorbent assay.

Five hybridomas (4F4, 14H1, 9B4, 6E10, and 8G7) secreting antibodies to porcine tumor necrosis factor alpha (PTNF-alpha) were obtained from one fusion. Four of the 5 monoclonal antibodies (Mab) recognized recombinant PTNF-alpha (rPTNF-alpha) on western blot and were able to neutralize both rPTNF-alpha and native (released by porcine macrophages) PTNF (nPTNF-alpha, only 4F4, 14H1, and 9B4 tested for the neutralization of nPTNF-alpha) in vitro. A sandwich enzyme-linked immunosorbent assay (ELISA) for PTNF-alpha was developed using Mab 4F4 and purified rabbit polyclonal antibodies against PTNF-alpha. The test detected PTNF-alpha concentrations as low as 400 pg/ml and did not cross react with native porcine TNF-beta, recombinant human TNF-alpha, recombinant mouse TNF-beta or native mouse TNF-alpha. The Mabs and the ELISA should be useful for assessing PTNF-alpha levels in swine serum during disease processes and possibly for alleviation of toxic effects of TNF-alpha.

Animals↗
PubMed1992

Equine tumor necrosis factor alpha: cloning and expression in Escherichia coli, generation of monoclonal antibodies, and development of a sensitive enzyme-linked immunosorbent assay.

We describe the production and purification of recombinant equine tumor necrosis factor alpha (rETNF alpha), generation and characterization of murine monoclonal antibodies (Mabs) and rabbit polyclonal antibodies (Pabs) against ETNF alpha, and development of a sensitive enzyme-linked immunosorbent assay (ELISA). Genomic-derived DNA sequences encoding mature ETNF alpha were reconstructed by the polymerase chain reaction (PCR) and oligonucleotide-directed mutagenesis and were cloned into the vector pFLAG-1 for expression in Escherichia coli. rETNF alpha was purified by anti-FLAG immunoaffinity chromatography and then used as immunogen for production of murine Mabs and rabbit Pabs. Three Mabs (6H4, 9B10, and 12F6) were obtained from one fusion. All three Mabs recognized rETNF alpha on western blots. Mabs 6H4 and 9B10 recognized similar epitopes on rENTF alpha and neutralized both rETNF alpha and native ETNF alpha (nETNF alpha) in a WEHI cell cytotoxicity assay. A sensitive ELISA was developed using Mab 6H4 and biotin-labeled rabbit Pabs. The ELISA was shown to detect levels of ENTF alpha as low as 100 pg/ml and was used to demonstrate the induction of ETNF alpha in horses with experimental endotoxemia. The rETNF alpha, antibodies, and ELISA developed in this report should be useful tools for studies of TNF-mediated diseases in horses.

Animals↗