Biomedical subjects

G Xu

Publications and source records attributed to G Xu.

At least 181 records · Page 10Linked to original sources

PubMed2000

[Effects of acute hypobaric hypoxia on the distribution of somatostatin contents in lower gastrointestinal tract of rats].

OBJECTIVE: To examine the effects of acute hypobaric by hypoxia on the distribution of Somatostatin (SS) contains in lower gastrointestinal tract of rats. METHOD: 36 Wistar [correction of Wister] male rats were divided into 6 groups. Three were control groups, three were ulcerous groups. Each group contains ground, 5000 m above sea level and 10000 m above sea level. SS contents were determined with radioimmunoassay [correction of radioimmunoassy] methods. RESULT: Statistically significant difference was exhibited among each group. There was no significant difference of SS contents in each altitude between model and control. SS contents were significantly increased in intestine of control in 5000 m groups, in caecum in 5000 m groups, compared with that in ground (P<0.05). It was also significantly increased in intestine of model in 5000 m groups, in caecum in 5000 m groups, compared with that in ground (P<0.01). SS contents was significantly increased in caecum of model in 10000 m groups compared with that in ground (P<0.05). Except this, There was no significant difference of ss contents in lower gastrointestinal tract among each group. CONCLUSION: SS contents in lower gastrointestinal tract were significantly increased in acute hypobaric hypoxia rats. This result suggested that ss contents in lower gastrointestinal tract may play an important protective role in acute hypobaric hypoxia rats.

Altitude↗

PubMed2000

[Re-evaluation of proteinuria and qualitive methods for diagnosis of diabetic nephropathy].

This study was aimed to re-evaluate the proteinuria quantitative and qualitative methods for diagnosis of diabetic nephropathy (DN). 136 cases were divided into two groups of proteinuria negativeness and postiveness by the results of urine routine examination. The clinical and biochemical indices and the frequencies of other diabetic complications of the two groups were compared. The results showed that the blood glucose and glycated Hb in the two groups were increased, especially in the proteinuria negative group (P < 0.01 and 0.05, respectively). There was a high prevalence of hypertension and other diabetic complications in the two groups, and it was higher in the positive group than in the negative group (P < 0.05 and 0.01, respectively). The frequencies of hyperlipoproteinemia in the two groups were over 40%, but no significant defference was observed between them (P > 0.05). There was correlation between hypertension and proteinuria (P < 0.01) but no correlation between diabetic retinopathy and proteinuria. The prevalence of azotemia in the proteinuria negative group was 17.07%. These suggest that the amount of proteinuria can not completely reflect the duration and severity of DN. Negative proteinuria in routine examination cannot rule out DN. For diagnosis of DN, it is necessary to think about all data on blood glucose, blood lipid, blood pressure and the change in fundus oculi.

Adolescent↗

PubMed2000

[Influence of chronic sinusitis on middle ear function].

OBJECTIVE: To study the effect of range size and duration of chronic sinusitis on middle ear function. METHOD: Eustachian tube function, tympanogram and air hearing threshold were measured with an acoustic impedance audiometer and pure tone audiometer in 56 patients (112 ears). RESULT: Eustachian tube function was disturbed in 48.3% cases, tympanogram was abnormal in 42.0% cases, and air hearing threshold was increased in 33.9% cases. Comparison of middle ear function between anterior sinusitis and pan-sinusitis showed significant difference (P < 0.01), middle ear function between the course of less 5 years and of more than 5 years had significant difference (P < 0.05). CONCLUSION: The damage of middle ear function become more serious with the extent of lesion and with the longer course of disease in paranasal sinuses.

Acoustic Impedance Tests↗

PubMed2000

[Study on the mechanism of pulmonary edema after seawater drowning in rabbit].

To study the mechanism of pulmonary edema after seawater drowning (PE-SWD), the indexes of blood-gas and acid-base in rabbits artery blood were measured by the blood-gas analyser. The activity of Na(+)-K(+)-ATPase, cytochrome oxidase(CYTO) and alkaline phospharase(ALP) in the lungs were measured and analysed by computer image system. C-fos mRNA and Fos protein in the lungs were respectively determined by situ hybrioization and immunohisto chemical techniques. The distribution of phospholipid and Ca2+ of rabbits lungs was quantitatively analysed by ultrastructural location method. The results showed that, five parameters of PaO2, oxygen saturation(SaO2), pH, actual bicarbonite(AB) and base excess(BE) and the activity of Na(+)-K(+)-ATPase and CYTO decreased remarkably in PE-SWD. Both c-fos mRNA and Fos protein expression in pulmonary epithelial cells in PE-SWD were significantly elevated compared with the normal controls(P < 0.01). The phospholipids products in the pulmonary alveolar type II epithelial cells were decreased, however, the Ca2+ precipitate pellets inside the lung capillary endothelial cells and the pulmonary alveolar type I and II epithelial cells increased obviously. The arthors suggest that the injuny action of the seawater, hypoxia and metabolic acidosis may be the mian three mechanisms of the pulmonary edema induced seawater drowning. The lowering activity of Na(+)-K(+)-ATPase and CYTO in the lungs and calcium overload in the cells are not only evil consequence resulted from above three factors, but also the importent causes leading to the worse of PE-SWD. The transmiting line of Ca(2+)-fos may be also a key link to bring about the worse of PE-SWD.

Acidosis↗

PubMed2000

[Intranasal endoscopic treatment of chronic sinusitis in children].

OBJECTIVE: To explore the curative effect of endoscopic sinus surgery (ESS) and the factors associated with surgery effect for treating children with chronic sinusitis. METHOD: Thirty-one children with a median age of 10 years (range 5-14 years) who suffered from chronic sinusitis or/and nasal polyps and were operated via ESS from May 1996 to January 1999 were retrospectively analyzed. RESULT: According to the therapeutic evaluation standard (ESS-1997, Haikou), twelve cases (38.7%) were completely cured, fifteen cases (48.4%) were improved and four children (12.9%) showed no change with a general effective rate of 87.1% without any severe operative complication. CONCLUSION: The results suggested ESS is a safe and effective method in the treatment of children with chronic sinusitis or/and nasal polyps. Furthermore, meticulous postoperative endoscopic care and medication are also important for securing optimal long-term results.

Adolescent↗

PubMed2000

[Pharmacognostical studies on the roots of Stellera chamaejasme and S. chamaejasme f. chrysantha].

Morphological and histological characters of the roots of Stellera chamaejasme L. and S. chamaejasme L. f. chrysantha S. C. Huang, used as the origins of the Chinese medicine Langdu, were described and illustrated with line drawings. TLC analyses of the above two drugs were also undertaken. These studies provide referencial informations for the quality control, development and identification of these two drugs.

Chromatography, Thin Layer↗

PubMed2000

[Pharmacognostical studies on the roots of Euphorbia fischeriana].

Morphological and histological characters of the roots of Euphorbia fischeriana Steud., used as one of the origins of traditional Chinese medicine Langdu, were described and illustrated with line drawings. TLC analysis of the above drug was also undertaken. These studies provide referencial informations for clinics, quality control, development and identification of this crude drug.

Chromatography, Thin Layer↗

PubMed2000

[Partial laryngectomy plus radiotherapy versus partial laryngectomy alone for laryngeal carcinoma].

OBJECTIVE: To investigate the effect of radiotherapy in the combined treatment of laryngeal cancer with partial laryngectomy. METHODS: One hundred and seventy-one cases of laryngeal cancer were randomly separated into three groups of partial laryngectomy, partial laryngectomy with preoperative radiotherapy (dose 40-50Gy) and partial laryngectomy with postoperative radiotherapy(dose 51-70 Gy). The surgical procedures included cordectomy, vertical partial laryngectomy, horizontal partial laryngectomy and near total laryngectomy. RESULTS: The overall 5-year survival rate was 82% (123/150). The 5-year survival rates for surgery alone group (56 cases), surgery with preoperative radiotherapy group(65 cases) and surgery with postoperative radiotherapy group(50 cases) were 85.7%, 80.7% and 79.5% respectively. There was no significant difference among the groups(chi 2 = 0.703, P = 0.704). Analysis of survival rates revealed a significant difference among the different stages(chi 2 = 12.248, P = 0.007). All 171 cases except 3 that had near total laryngectomy achieved satisfactory phonation. CONCLUSION: Neither preoperative radiotherapy nor postoperative radiotherapy can improve the 5-year survival rate of laryngeal cancer with partial laryngectomy. All patients with partial laryngectomy got satisfactory phonation.

Adolescent↗

PubMed2000

[The concentration and expression of IL-5 in human nasal polyp tissue].

OBJECTIVE: To study the concentration and expression of IL-5 in nasal polyp tissues and explore its significance in the micro-environment differentiation of eosinophils accumulation and clarify the conception of nasal polyposis. METHODS: The concentration and expression of IL-5 in nasal polyp tissues of 40 patients were determined by ELISA and immunohistochemistry, and inferior turbinate mucosa from patients with nasal polyps and healthy volunteers was used as control. RESULTS: 1. IL-5 concentration in the polyp tissues was significantly higher than that in inferion turbinate mucosa(P < 0.05). There was no significant difference in inferion turbinate mucosa between the patients with nasal polyps and healthy volunteers (P > 0.05). IL-5 concentration in polyp tissues was markedly higher in patients with extensive polypoid change of nasal mucosa, history of previous polypectomy and allergic rhinitis compared with those without these features (P < 0.05). IL-5 concentration had no correlation with age and sex (P > 0.05). 2. 80.1% of the eosinophils were positive for IL-5 and 90.9% of IL-5 positive cells were eosinophils. Only 3.7% of the lymphocytes and neutrophils were IL-5 positive, and IL-5 was not detectable in epithelial cells. IL-5 expression in eosinophils of polyp tissues was remarkably stronger than that of the turbinate mucosa (P < 0.05). There was no significant difference in inferion turbinate mucosa between the patients with nasal polyps and healthy volunteers (P > 0.05). IL-5 expression of eosinophils in polyp tissues was significantly stronger in patients with extensive polypoid change of nasal mucosa, history of previous polypectomy and allergic rhinitis compared with those without these features (P < 0.05). There was no significant difference in IL-5 expression in lymphocytes and neutrophils between polyp tissues and inferior turbinate nasal mucosa (both P > 0.05). CONCLUSION: IL-5 is a key protein in eosinophilic pathologic mechanisms in nasal polyp tissues.

Adult↗

PubMed2000

[Diagnosis and nasal endoscopic surgery of rhinogenic optic function damage].

OBJECTIVE: To explore the diagnosis and the surgical treatment of rhinogenic optic function damage through transnasal endoscopic approach. METHODS: The clinical characteristics and the results of transnasal endoscopic surgery of 32 cases(32 eyes) with rhinogenic optic function damage were analyzed. RESULTS: Eleven eyes were cured, 20 eyes were improved, 1 eye failed, No recurrence was found within 6 months to 3 years after operation. CONCLUSION: The sinus inflammatory disease might injure optic function. Early diagnosis as is important and the endoscopic sinus surgery combined with appropriate medical drug administration are in effective.

Adolescent↗

PubMed2000

[Treatment of traumatic cerebrospinal rhinorrhea in frontal sinus].

OBJECTIVE: To evaluate the indication, operative technique and advantages of the treatment of traumatic cerebrospinal rhinorrhea in frontal sinus by intranasal endoscopic surgery. METHOD: Treatment of 6 cases of traumatic cerebrospinal rhinorrhea in frontal sinus by intranasal endoscopic surgery was reported. We adopt a procedure to open and enlarge the nasofrontal duct under direct vision by intranasal endoscopic surgery firstly and find the fistula, then repair it with its own smashed muscle, and support it with muscular membrane and gelfoam, iodoform Sponges. RESULTS: Four cases were repaired successively in one procedure with intranasal endoscopic surgery, 2 cases were solved by combined external and intranasal procedure. CONCLUSIONS: The advantages of treatment of traumatic cerebrospinal rhinorrhea in frontal sinus by intranasal endoscopic surgery included easily operation, easily confirmation of fistula and high success rate, combination of frontal sinus incision may deal with its demerit to the un-reach-able site sometimes.

Adult↗

PubMed2000

[Study on spectra pretreatment in near infrared spectroscopy analysis using charger coupled device detector].

The effects of spectra pretreatment method and parameters to signal noise ratio and calibration models quality in near-infrared spectroscopy analysis using charger coupled device(CCD) detector have been studied and discussed. To attain higher signal noise ratio, in the range of 700-1,100 nm, using 2048 pixels CCD, we suggest that the optimal gaps of smoothing first derivative treatment of spectra are 9 points, and the gap of second derivative treatment is 19 points.

English Abstract↗

PubMed2000

[Development of modern near infrared spectroscopic techniques and its applications].

The historical progresses, characteristics and determined principle of near infrared spectroscopy are presented briefly. The development of modern near infrared spectroscopic instruments, chemometrics problems and applications are reviewed. Some results developed on instrument, chemometrics methods and applications of petroleum industries in our laboratory are presented briefly.

Spectroscopy, Near-Infrared↗

PubMed2000

[Orientation of H-bonds revealed by cryogenic FTIR spectroscopy].

We propose a new way to reveal structural arrangement of hydrogen bond network using FTIR spectroscopy. When KBr pellet and fluorolube mull methods are used to prepare samples for IR measurements, the resultant spectra sometimes show significant differences, sometimes not. The reason is unknown. We use cryogenic FTIR spectra to prove pressure effect accounts for spectral variation in different sampling process. The sensitivity of the FTIR spectra to external pressure is related to the three-dimensional arrangement of hydrogen bonding network in the sample. When hydrogen bonds are in one plane, they can not resist external pressure applied perpendicular to that plane. Consequently, large differences appear between the spectra obtained using KBr pellet and fluorolube mull methods. On the other hand, when hydrogen bonds orientate towards various directions, the hydrogen bonding system can resist pressure from any directions. Thus, the FTIR spectra exhibit little variation using different sampling methods. We propose that the spectral variation obtained using above methods is a criterion to judge whether the hyrogen bonds orientate toward various directions in three-dimensional space or not.

Cholesterol↗

PubMed1999

Glutathione levels discriminate between oxidative stress and transforming growth factor-beta signaling in activated rat hepatic stellate cells.

Reactive oxygen species are implicated in the pathogenesis of several diseases, including Alzheimer's disease, multiple sclerosis, human immunodeficiency virus, and liver fibrosis. With respect to liver fibrosis, we have investigated differences in antioxidant enzymes expression in stellate cells (SCs) and parenchymal cells from normal and CCl(4)-treated rat livers. We observed an increase in the expression of catalase in activated SCs. Treatment with transforming growth factor-beta (TGF-beta) increased the production of H(2)O(2). Treatment with catalase decreased TGF-beta expression. Addition of H(2)O(2) resulted in increased TGF-beta production. 3-Amino-1,2,4-triazole abolished the capacity of SCs to remove H(2)O(2). A paradoxical increase in capacity was observed when the cells were pretreated with diethyl maleate. Treatment with 3-amino-1, 2,4-triazole increased TGF-beta production. A paradoxical decrease of TGF-beta production was observed with diethyl maleate. Treatment of the cells with N-acetylcysteine resulted in increased TGF-beta production. TGF-beta decreased the capacity of the SCs to remove H(2)O(2.) An increase in the capacity to remove H(2)O(2) was observed when TGF-beta was removed by neutralizing antibodies. In conclusion, our results suggest: 1) a link between cellular GSH levels and TGF-beta production and 2) that cellular GSH levels discriminate whether H(2)O(2) is the result of oxidative stress or acts as second messenger in the TGF-beta signal transduction pathway.

Acetylcysteine↗

PubMed1999

The effects of pain severity on health-related quality of life: a study of Chinese cancer patients.

BACKGROUND: The health-related functioning of patients with cancer is compromised by several factors, including the disease process, treatment, and the various symptoms that are produced by both disease and treatment. This study was designed to specify the relationship between patients' pain severity and their self-reported quality of life. METHODS: The study enrolled 216 consecutive consenting adult patients from 2 Chinese cancer centers with pathologically-diagnosed metastatic cancer who could understand and complete the self-report measures. The majority had cancer-related pain and were receiving analgesics. The Chinese version of the Brief Pain Inventory was used to assess the severity and interference of pain. A Chinese translation of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) was used to assess health-related functional status. Patients' physicians completed a form that indicated characteristics of the patients' cancer, Eastern Cooperative Oncology Group performance status, pain, and current pain treatment. RESULTS: Increasing severity of pain was associated with worsening health-related functioning, even when an estimate of disease severity was taken into account. The correlation between pain severity and impairment was nonlinear. The functional health and well-being of cancer patients with no or mild pain was significantly less impaired than that of patients with moderate or severe pain. The impairment of patients with moderate and severe pain did not differ. CONCLUSIONS: Pain severity is an important variable to be taken into account when quality of life outcome measures are considered. The functioning of cancer patients with well-controlled (mild) pain did not differ significantly from that of patients without pain. Providing pain relief should significantly improve the functional status of cancer patients.

Adolescent↗

PubMed1999

Reversed-phase high-performance liquid chromatographic investigation of urinary normal and modified nucleosides of cancer patients.

Post-transcriptional modifications in RNA give rise to free modified ribonucleosides circulating in the blood stream and excreted in urine. Due to their abnormal levels in conjunction with several tumor diseases, they have been suggested as possible tumor markers. The developed RP-HPLC method has been applied to analyze the urinary nucleosides in 34 urinary samples from 15 kinds of cancer patients. The statistical analyses showed the urinary nucleoside excretion, especially modified nucleoside levels, in cancer patients were significantly higher than those in normal healthy volunteers. Factor analysis was used to classify the patients with cancer and normal healthy humans. It was found that using 15 urinary nucleoside levels or only five modified nucleoside levels as data vectors the factor analysis plot displayed two almost separate clusters representing each group.

Chromatography, High Pressure Liquid↗

PubMed1999

Tumor necrosis factor alpha-induced pancreatic beta-cell insulin resistance is mediated by nitric oxide and prevented by 15-deoxy-Delta12,14-prostaglandin J2 and aminoguanidine. A role for peroxisome proliferator-activated receptor gamma activation and inos expression.

Recent studies have identified a beta-cell insulin receptor that functions in the regulation of protein translation and mitogenic signaling similar to that described for insulin-sensitive cells. These findings have raised the novel possibility that beta-cells may exhibit insulin resistance similar to skeletal muscle, liver, and fat. To test this hypothesis, the effects of tumor necrosis factor-alpha (TNFalpha), a cytokine proposed to mediate insulin resistance by interfering with insulin signaling at the level of the insulin receptor and its substrates, was evaluated. TNFalpha inhibited p70(s6k) activation by glucose-stimulated beta-cells of the islets of Langerhans in a dose- and time-dependent manner, with maximal inhibition observed at approximately 20-50 ng/ml, detected after 24 and 48 h of exposure. Exogenous insulin failed to prevent TNFalpha-induced inhibition of p70(s6k), suggesting a defect in the insulin signaling pathway. To further define mechanisms responsible for this inhibition and also to exclude cytokine-induced nitric oxide (NO) as a mediator, the ability of exogenous or endogenous insulin +/- inhibitors of nitric-oxide synthase (NOS) activity, aminoguanidine or N-monomethyl-L-arginine, was evaluated. Unexpectedly, TNFalpha and also interleukin 1 (IL-1)-induced inhibition of p70(s6k) was completely prevented by inhibitors that block NO production. Western blot analysis verified inducible NOS (iNOS) expression after TNFalpha exposure. Furthermore, the ability of IL-1 receptor antagonist protein, IRAP, to block TNFalpha-induced inhibition of p70(s6k) indicated that activation of intra-islet macrophages and the release of IL-1 that induces iNOS expression in beta-cells was responsible for the inhibitory effects of TNFalpha. This mechanism was confirmed by the ability of the peroxisome proliferator-activated receptor-gamma agonist 15-deoxy-Delta12, 14-prostaglandin J2 to attenuate TNFalpha-induced insulin resistance by down-regulating iNOS expression and/or blocking IL-1 release from activated macrophages. Overall, TNFalpha-mediated insulin resistance in beta-cells is characterized by a global inhibition of metabolism mediated by NO differing from that proposed for this proinflammatory cytokine in insulin-sensitive cells.

Animals↗