Biomedical subjects

X Gao

Publications and source records attributed to X Gao.

At least 109 records · Page 6Linked to original sources

PubMed2001

[Effects of phenytoin on structural aberration of human sperm chromosomes in vitro].

OBJECTIVE: To detect the mutagenic effects of phenytoin on human sperm chromosomes. METHODS: The mutagenic effects of phenytoin at 10, 20 and 40 microgram/ml were tested by an in vitro testing system of human sperm chromosomes, with leomycin A5 as a positive control and mutagen-free solution as the blank control. RESULTS: The frequencies of sperm with structural chromosomal aberrations and breakages of sperm chromosomes in the groups of 10 microgram/ml, 20 microgram/ml and 40 ug/ml of phenytoin were all higher than those in the blank control, but only in the group of 40 ug/ml, the elevated frequencies were statistically significant (P<0.005, P<0.05). CONCLUSION: Phenytoin has probably mutagenic potential effect on human sperm cells.

Adult↗

PubMed2001

[Effect of composition in plaque fluid on evaluation of individual caries risk].

OBJECTIVE: To study the association of composition in plaque fluid after sugar challenge with caries susceptibility in order to find predictors of identifying individual caries risk. METHODS: Children aged 6-7, caries free 12, high caries 6 and low caries 7 were studied. Plaque composition were determined by capillary electrophoresis. RESULTS: Contents of lactic acid and lower pKa acids were significantly lower in caries free group than in low caries (P = 0.002) and high caries (P = 0.01) groups. It demonstrated by multiple regression and Logistic regression that lactic acid content could be a predictor of individual caries risk. CONCLUSIONS: Content of lactic acid in plaque fluid 7 minutes after sugar challenge could be a predictor of individual caries risk.

Child↗

PubMed2001

Expression of 5-HT2A receptor mRNA in rat nucleus raphe magnus neurons after peripheral inflammation.

AIM: Examine the expression of 5-HT2A receptor mRNA and co-localization of 5-HT2A receptor mRNA with 5-HT immunoreactivity in nucleus raphe magnus (NRM) neurons following carrageenan inflammation. METHODS: In situ hybridization (ISH) and combining fluorescent ISH with immunofluorescent histochemical double staining technique were used in the present study. RESULTS: 5-HT2A receptor mRNA was expressed in moderate level in NRM neurons. Following carrageenan inflammation, the expression of 5-HT2A receptor mRNA in NRM was greatly increased. The peak occurred at 3 - 8 h and then there was a clear decrease at 24 h after injection of carrageenan. Only a few 5-HT2A receptor mRNA and 5-HT immunoreactive double labeled cells were observed in NRM, and the number of the double labeled cells had no obvious change following carrageenan inflammation. CONCLUSION: The synthesis of 5-HT2A receptor was increased in non-serotonin rather than serotonin neurons of NRM during peripheral inflammation.

Animals↗

PubMed2001

[Ultrasonic removal of organic pollutants in tannery waste water].

The effect of ultrasonic treatment on flocculating settling of tannery effluent was studied, removal of COD in particular was did. The influences of irradiation method and duration of ultrasonic as well prescription of coagulants on the efficiency of minimizing organic chemicals in waste water were investigated. The results show that: 1. when waste water was treated only by ultrasonic for 60s, the removal rate of COD was 40.6%; 2. when total concentration of coagulants increased to 100 mg/L, the highest removal rate of COD was achieved; 3. when waste water was firstly treated with ultrasonic for 60s, then flocculated with coagulants, the removal rate of COD came to 73.2%, 10% higher than the control without ultrasonic. Thus the treatment of tannery waste water with flocculating settling technology can be effectively strengthened by ultrasonic.

Industrial Waste↗

PubMed2001

[Effect of fluoride release on flexural strength of fluoride-containing composites].

OBJECTIVE: To study fluoride release and its impact on flexural strength of fluoride-containing composites. METHODS: Experimental composite resins containing 0.3%, 0.6% and 1.2% fluoride (w/w) respectively and non-fluoride control composites were selected, including a compomer and its control composites. The amount of fluoride release in vitro was determined with fluoride ion-sensitive electrode in a 30 day consecutive period. The flexural strength was measured by Autograph Machine before and after releasing fluoride in water. RESULTS: The amount of fluoride release increased (0, 21.98, 43.98 and 99.91 micrograms.cm-2 respectively) and the flexural strength decreased (101.70, 94.29, 82.03 and 79.84 MPa respectively) while fluoride-contents in resins increased (0%, 0.3%, 0.6% and 1.2% respectively). With fluoride release, the flexural strength decreased significantly (P < 0.05). CONCLUSION: Fluoride release affects mechanical properties of fluoride-containing composites.

Composite Resins↗

PubMed2001

Determination of the dominant language hemisphere by functional MRI in patients with temporal lobe epilepsy.

OBJECTIVE: To determine the dominant language hemisphere in patients with intractable temporal lobe epilepsy before surgical treatment by using functional MRI (fMRI). METHODS: Twelve patients underwent fMRI. Among them, 4 patients also underwent the Wada test. Anterior temporal lobectomy was performed on patients with epileptic focus on the non-dominant hemisphere, and selective amygdalo-hippocampectomy on patients with epileptic focus on the dominant hemisphere. RESULTS: Ten patients had left dominance, and 2 right dominance. The fMRI results were concordant with Wada test results in the 4 patients who accepted the Wada test. Seven patients underwent anterior temporal lobectomy, and 5 underwent selective amygdalo-hippocampectomy. There was no post-operative dysphasia. CONCLUSION: fMRI is an alternative method of noninvasive functional mapping for language dominance in patients with temporal lobe epilepsy.

Adult↗

PubMed2001

Diagnosis and surgical treatment of temporal lobe epilepsy.

OBJECTIVE: To discuss the diagnosis and surgical treatment of temporal lobe epilepsy. METHODS: From 1996 to 1998, 36 patients presenting with medically intractable temporal lobe epilepsy were identified by EEG and MR, including volumetric MR, for hippocampal formation. Among them, 16 patients underwent anterior temporal lobectomy, while 20 patients accepted selective amygdalohippocampectomy. The results of surgical operation and follow-up are analyzed. RESULTS: With respect to seizure outcome, all patients benefited from surgery. The surgical results were satisfactory in 24 cases, notable in 11 cases, and good in 1 case, and there were no complications. CONCLUSION: MR is beneficial for the localization of epileptic foci. Surgery is an effective method for the treatment of temporal lobe epilepsy; selective amygdalohippocampectomy is the first choice for medial temporal lobe epilepsy. The transzygmatic-temporal lobe base approach presented in this study improved the safety of the surgery.

Adolescent↗

PubMed2001

Gynecological procedures under gasless laparoscopy.

OBJECTIVE: To evaluate gasless laparoscopy in treating gynecological conditions. METHODS: With Kirschner wire lifting, transversely or longitudinally introduced into abdominal wall subcutaneously, we exposed the operative field and pelvic organs with routine operative instruments under epidural anesthesia. When a dense pelvic adhesion was confronted, we used the temporarily low-pressured pneumolaparoscopy to dissect it. RESULTS: All procedures were carried out without organ injury, hematoma, or other complications. The operative field can be clearly seen with this method. The mean time for appendagectomy was one hour and for laparoscopic assisted vaginal hysterectomy 80 minutes. CONCLUSION: Gasless laparoscopy avoids the complications which occur in the routine laparoscopy such as subcutaneous or mediastinal pneumatoma, hypercarbonemia, air embolism, cardiopulmonary dysfunction. Our lifting method is simple, convenient, time and money saving, as well as more flexible for treating gynecological conditions.

Adult↗

PubMed2001

[Bispecific McAb mediated multiple tumor cytotoxicity in gastric cancer].

OBJECTIVE: McAb against CD3 and McAb against TNP were combined into bispecific McAb by chemical methods. With this bispecific McAb, human peripheral blood lymphocytes (PBLS) were introduced to in vitro and in vivo cytotoxic test of any tumor cells by different TNP-McAb against gastric cancer. METHODS: The activity of bispecific McAb prepared by chemical method, was detected by enzyme-linked immunosorbent assay (ELISA). The bispecific McAb was identified by bridge ELISA. Ouchterlony test and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Cytotoxic test of tumor cells in vitro and tumor growth inhibition test in vivo were performed for the bispecific McAb function. RESULTS: Anti-CD3 and Anti-TNP McAbs were successfully combined into bispecific McAb which could conjugate any TNP-McAb against gastric cancer and induce PBLS to cytotoxic test of gastric cancer cells in vitro and in vivo. CONCLUSION: The bispecific McAb may very will be useful in the immuno-biotherapy of tumors.

Animals↗

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

[Characteristics of nitrogen and phosphorus pollution in the middle and small creeks, suburban Shanghai].

1. The middle and small creeks in suburban Shanghai were under heavy eutropic condition, with high loadings of nitrogen, phosphorus and organic pollutants. KN, TP and CODCr of the surface water of them were several times greater than the critical values of Types V, the worst level of water. 2. Spatial variations of N and P pollution were observed, as the creeks in different places accepted different types and amounts of pollutants. Affected by domestic sewage, the creeks nearby residential areas were often heavily polluted by NH4+ and P. The creeks in agricultural fields were more easily polluted by NO3- than by NH4+ and phosphorus. The creeks nearby livestock farms often witnessed sudden soaring of NH4+ and P. 3. N and P loadings of the creeks were also affected by the seasonal evolvement of ecological environment. With the increase of temperature and biomass, NH4+ and NO3- in the surface water were largely consumed and decreased as a result; while organic N and particle P increased as the enhancement of suspending biological particles. NO2- in the surface water increased with temperature as nitrifying bacteria became active. Total P and water soluble P also showed the trend of enhancement with the intensification of biological activities, however, they were also controlled by the condition of pH and DO in the water. 4. At the height of the summer, the surface and bottom water of the creeks differed in N and P loadings. NH4+, soluble P and total reactive P in the bottom water were higher than those in the surface; while NO3- and NO2- in the surface were higher than those in the bottom. Such water-quality stratification inevitably resulted from the enhancement of phytoplankton in the surface water and intensified release of NH4+ and P from the sediments. In the autumn, as-the temperature decrease, such phenomenon declined gradually.

China↗

PubMed2001

[A matched case-control study on direct economic costs of four kinds of nosocomial infections].

OBJECTIVE: To evaluate the direct economic costs of four major kinds of nosocomial infections such as nosocomial pneumonia, urinary tract infection, deep surgical wound infection and intracranial infection. METHODS: A matched case-control study was conducted among 95 pairs of hospitalized patients to investigate the direct economic costs of nosocomial infections. RESULTS: The average medical cost for patients in the case group was 38 741 RMB Yuan, 20 365 Yuan more than that in the control group patients (P < 0.0001). The largest part of extra costs was found in drug expenses, taking up 62.07%, while other extra costs such as non-drug therapies, blood transmission and laboratory examinations, accounted for 10.32%, 7.40% and 5.72% respectively. Extra economic burden caused by nosocomial infections varied in different degrees with different departments, with the heaviest found in the department of tumourology and hematology at an average extra cost of 34 944 Yuan. The average extra charges in case group caused by nosocomial pneumonia, urinary tract infection, deep surgical wound infection and intracranial infection were 31 940 Yuan, 7 436 Yuan, 17 332 Yuan and 17 349 Yuan respectively. The average length of hospital stay was 50.57 days in case group and 25.22 days in control group, showing a 25.53 extra days (P < 0.0001) of hospitalization due to nosocomial infections. CONCLUSION: Nosocomial infections had significantly added to the economic burden of managing the underlying diseases, led to prolonged hospitalization of the patients and lowered the turnover rate of hospital bed. There is a need to call for better infection control program, which would bring tremendous social and economic profits.

Case-Control Studies↗

PubMed2001

[Clinical study of detenia cecal-ascending colon continent cutaneous urinary reservoir].

OBJECTIVE: To construct a good continent urinary diversion which is easy to be performed and has a low incidence of complications. METHODS: 26 cases of bladder cancer were given radical cystectomy before the cecal-ascending colon was excluded and 15-20 cm of the cecal-ascending colon was isolated. The colon teniae were then incised at the interval of 0.5-1.0 cm to construct the detenia cecal-ascending colon continent urinary diversion open to the umbilicus. RESULTS: All the patients were followed up for 21.1 +/- 10.1 months. Reliable continence was achieved in all with a low incidence of complications. The capacity of the reservoirs reached 350-600 ml 6 month after operation. Self catherizations were carried out every 3 to 6 hours, Urodynamic data showed a mean maximum filling pressure of 58.7 +/- 24.5 cmH2O, and a mean maximum urethral (efferent) closure pressure of 104.3 +/- 33.8 cmH2O. CONCLUSION: Detenia cecal-ascending colon continent urinary diversion is an ideal method.

Adult↗

PubMed2001

[Developmental toxicity of Al(NO3)3 on rat embryos].

The developmental toxicity and its mechanism of Al(NO3)3 on embryos in SD rats were studied. On the 9.5th day of gestation, the embryos were incubated in a whole-embryo culture system with Al(NO3)3 at concentrations of Al3+ from 0.6 to 9.0 micrograms/ml in culture media for 48 hrs. Viable embryos were evaluated by Brown's morphological scoring system, and the diameter of yolk sac, crown-rump, head length and the dry weight of embryos were measured. There was a dose-dependent relations of decreasing embryo development with increasing concentrations of Al3+. Yolk sac diameter, head length, dry weight and heart, forelimb as well as neural tube scores decreased significantly at 1.2 micrograms/ml (P < 0.05). When embryos were exposed to Al3+ at > or = 3.0 micrograms/ml, the embryonic development and morphological differentiation were obviously inhibited(P < 0.05); meanwhile, the incidence of dysmorphogenesis significantly increased, including neural tube defects and dorsiflexion teratogenesis. The results suggested that aluminum might be a developmental toxicant and dysmorphogenesis agent.

Aluminum Compounds↗

PubMed2001

[Studies on the fingerprint of radix notoginseng and its preparation].

OBJECTIVE: A fingerprint of raw material, extracted and injections of radix notoginseng has been studied and provides the quality information. METHOD: Polaris C18-A column was used, with mixtures of acetonitrile and water as mobile phase in a gradient mode. The wavelength of measurement was 203 nm. RESULT: According to the selected chromatographic conditions, a good fingerprint of radix notoginseng and its extract, preparation has been described. CONCLUSION: The method is simple, accurate with good reproducibility. It may be practical value for the quality control of sample for radix notoginseng and its preparation.

Chromatography, High Pressure Liquid↗

PubMed2001

[The blood drainage of Langerhans islets with special reference to the functional and clinical significance of pancreatic exocrine part].

OBJECTIVE: This study sought to gain an insight into the blood drainage of Langerhans islets with special reference to the functional and clinical significance of pancreatic exocrine part. METHODS: Observations were carried out in 11 human dead bodies, 40 monkeys, 24 dogs, 62 rats and 24 rabbits by scanning electron microscopy and light microscopy with the technique of retaining microcirculatory dynamic and tissular information in the static specimens, microvascular serial reconstruction, and/or by intravital fluorecence microscopy with FITC-labeled erythrocytes. RESULTS: Three patterns of islet drainage channels drained into different acinar regions with different features and insulo-insular drainage channels observed in the primates were found in this study. The authors suggest that these patterns might be termed as follows: 1. Continuous drainage vessels. All islets possessed these capillary-sized portal vessels which ran a short distance, and then drained into the peri-islet acinar region. 2. Convergent drainage vessels. Some islets possessed one or two, occasionally more, of these portal vessels, which were relatively long and/or thick and drained into the acinar region far away from the islet in the lobule. 3. Translobular drainage vessels. These portal vessels crossed the interlobular septum into an adjacent lobule where sometimes no islet existed, and then drained into the exocrine acinar region 4. Insulo-insular drainage vessels. Some islets in the monkey and human, possessed these vessels which drained into an adjacent small islet through the insulo-insular drainage vessels. CONCLUSION: Langerhans islets possessed the consummate drainage system which drained into different exocrine acinar regions, suggesting that the release of islet hormones is in some way necessary for the exocrine secreting function, and that the reduction of local insular hormone levels in insuloacinar portal circulation and the impairment of insular drainage vessels would be the morphological basis of the pancreatic exocrine pathologic lesion in human diabetes.

Adult↗

PubMed2001

[Screening and sequence analysis of the adult stage-specific gene of Trichinella spiralis].

OBJECTIVE: To obtain the sequence of the adult stage-specific gene of Trichinella spiralis. METHODS: An adult T. spiralis cDNA library was screened using an adult T. spiralis stage-specific probe. The gene sequence was analyzed by DNAstar software and GenBank database. RESULTS: A cDNA clone of 1,629 bp was obtained by screening the library with an adult stage-specific probe. The clone contained one open reading frame composed of 1,464 bp encoding 487 amino acids. GenBank searching revealed that no identical cDNA was found. Two zinc fingers located at the positions within amino acids 207-270. Some possible antigen epitopes were predicted within the amino acids 52-64, 108-116, 137-163 and 226-260. CONCLUSION: A novel stage-specific gene of adult T. spiralis encoding the protein containing certain predicted antigen epitopes was obtained.

Amino Acid Sequence↗

PubMed2001

[Green electroluminescence generated from a new rare earth complex: Tb(asprin)3phen].

Pure Green and narrow bandwidth emission from organic electroluminescent device was presented by using a new rare earth complex Tb(asprin)3phen as emissive layer. The structure of the device was ITO/PVK:Tb(asprin)3phen/Al, where PVK was used to improve the film-forming ability and conductivity of Tb(asprin)3phen. The electroluminescent property of the device was studied. It proved that this new kind of rare earth complex has excellent optoluminescent and electroluminescent properties. The electroluminescent mechanism of the device was proposed by measuring and analyzing the emission and excitation spectra of the emissive layer. The excitation spectrum of Tb(asprin)3phen-dispersed PVK film was very similar to that of the PVK. We proposed that the excited carriers of PVK and Tb(asprin)3phen were captured by Tb3+ and light was emitted when the electrons and holes recombined at Tb3+.

Chelating Agents↗