Biomedical subjects

S Guo

Publications and source records attributed to S Guo.

At least 127 records · Page 7Linked to original sources

PubMed1998

Triterpenoid saponins from Quillaja saponaria.

Three new saponins were isolated from a commercial bark extract of Quillaja saponaria Molina. These compounds were also obtained as degradation products from larger saponins in this extract when treated with strong alkali. The compounds were characterized, using mainly NMR spectroscopy, mass spectrometry and chemical methods, as quillaic acid 3-O-¿beta-D-galactopyranosyl-(1-->2)-beta-D-glucopyranosiduronic acid¿, 3-O-¿alpha-L-rhamnopyranosyl-(1-->3)-[beta-D-galactopyranosyl-(1-->2)] -beta-D-glucopyranosiduronic acid¿ and 3-O-¿beta-D-xylopyranosyl-(1-->3)-[beta-D-galactopyranosyl -(1-->2)]-beta-D-glucopyranosiduronic acid¿, respectively.

Carbohydrate Conformation↗

PubMed1998

Endothelial cell loss after photorefractive keratectomy for myopia.

PURPOSE: To study the long-term effect of 193 nm excimer laser photorefractive keratectomy (PRK) on the human corneal endothelial cell density. SUBJECTS AND METHODS: One hundred and twenty-four eyes from 71 patients underwent photorefractive keratectomy for myopia or myopic-astigmatism. Endothelial cell density was examined a short time before the operation and on an average of 50 months after the operation using a contact specular microscope. A subgroup of 32 eyes from 20 patients treated only once was examined preoperatively and 7 and 52 months postoperatively. The endothelial cell densities were corrected for the changing magnification of the contact specular microscope with changing central corneal thickness and for the expected physiological cell loss with time. RESULTS: The average endothelial cell density was preoperatively 3098+/-283 cells/mm2 (mean+/-SD) and postoperatively 3048+/-294 cells/mm2 corresponding to a change of -50+/-157 cells/mm2. This was statistically significantly different from zero in a paired t-test (n=124, t=3.58, 2p<0.001). The average changes in endothelial cell density for the subgroup were -34+/-159 cells/mm2 for the postoperative time interval 0-7 months and -20+/-188 cells/mm2 for the postoperative time interval 7-52 months. These results were not statistically significantly different from zero in a paired t-test (n=32, t=1.21 and t=0.60, 2p>0.05). A statistically significant negative correlation between preoperative cell density and the change in cell density was found (n=124, r=-0.21, 2p<0.05). CONCLUSION: This study suggests a potentially harmful effect of PRK on the human corneal endothelium. It appears that most cells are lost during ablation or within the first period of time after PRK.

Adult↗

PubMed1998

Prevalence of male pattern hair loss in 18-49 year old men.

BACKGROUND: Previous studies investigating the prevalence of male pattern hair loss (MPHL) typically used biased samples of men recruited from clinical populations which may limit generalizability of findings to broader populations. OBJECTIVE: To obtain an updated and improved estimate of the occurrence of MPHL in healthy men residing in the community. METHODS: Community-based sample of healthy men aged 18-49 years participated in a study investigating the effects of MPHL. Participants completed a brief questionnaire self reporting degree of hair loss, general health-related quality of life (HRQL) and hair-loss-specific measures. A trained observer also rated each participant using standardized classification for MPHL. RESULTS: The proportion of men with moderate to extensive hair loss (type III or greater) was 42%. The proportion of men with moderate to extensive hair loss increased with increasing age, ranging from 16% for men 18-29 years of age to 53% of men 40-49. Twelve percent of the men were classified as having predominantly frontal baldness (type A variants). CONCLUSIONS: MPHL, especially frontal baldness, may be more common than previously reported.

Adolescent↗

PubMed1998

Comparison of biodegradable and metallic tension-band fixation for patella fractures. 38 patients followed for 2 years.

We compared the outcome of patella fractures fixed by biodegradable tension-band (B) with self-reinforced polyglycolide or self-reinforced poly-L-lactide plugs and polyester ligaments or by metallic tension-band (M) with Kirschner wires and metallic cerclage wire in a randomized study. 38 fractures (18 with B and 20 with M) were treated. The follow-up time was 24 (14-32) months. The fractures healed in all patients after a medium of 8 weeks. In the B group, the clinical outcome was good in 13, fair in 4, and poor in 1 patient. In the M group, the corresponding figures were 15, 3 and 2. There were no clinical or radiographic differences between the two methods. Patella fractures can be treated, successfully using biodegradable tension-band fixation with no need for a second operation to remove the implants after bone union.

Absorption↗

PubMed1998

[Clinical epidemiological research of antigastroesophageal reflux after cardiac plasty by anastomosis of esophageal mucosa and gastric wall].

A new operative method was designed for preventing gastroesophageal reflux after esophageal and cardiac cancer operation. From April, 1994 to December, 1995, sixty-one patients after resection of esophageal and cardiac cancer were randomly divided into two groups: experimental group with 34 patients and control group with the others. All patients were observed, monitored and followed up. It was found that no case in the experimental group showed symptoms of gastroesophageal reflux or marked reflux by esophagoscopy and barium meal examination. 10 patients (37%) in the control group had the symptoms of heartburn and regurgitation and inflammation and obvious gastroesphageal reflux were observed under esophagoscopy and barium meal examination. The pH values of anastomotic ostium were 7.0249 +/- 0.9996 and 4.6667 +/- 2.4573 in the experimental and control groups, respectively. Significant difference (P < 0.01) was observed between two groups with t test. The results showed that the advancement of operative method plays a key rolein prevention of gastroesophageal reflux.

Anastomosis, Surgical↗

PubMed1998

[Experimental study of the architecture of skin following tension traction and wound closure].

The experiment performed on domestic pig, was designed to investigate the architecture of the stretching skin and the effect of tension traction on the wound closure. An 7 cm x 3.5 cm was drawn at a standard position. Drawing horizontal and vertical lines on the traction area, points of 1 cm apart were tattooed on the lines. A traction force measuring device was used to draw the wound edges together. Measurements of the distances between the points were made. An 7 cm x 10 cm wound was made on identical sites of each hind leg. In the experiment the traction tension was applied on the edges of wound immediately after the wound debridement. The results showed the stretched distance in the two areas was 5-7 times the width of the wound. The gain of skin from traction was 61-89 percent in the width of the wound. The wounds from traction five days could be closed 5 days after traction. It was concluded that the skin which could be used for traction was abundant. Wound closure with the skin traction technique had many advantages, such as rapid decreasing the size of wound and early closing of wound.

Animals↗

PubMed1998

[The relationship between immunosuppression and oxygen free radicals in burned patients].

The serum immunosuppression effect and its relation to oxygen free radicals were studied in patients with thermal injury (n = 11, total body surface area 20%-83%). The serum MDA, sIL-2R increased significantly in burned patients (P < 0.01 all). The serum of burned patients depressed the IL-2 productin of normal human PBMC (P < 0.01). Antioxidants decreased the serum sIL-2R in burned patients and attenuated the suppressive effect IL-2 production of normal human PBMC (P < 0.05 all). The results suggest that oxygen free radicals participate in the serum immunosuppression effect in burned patients.

Adult↗

PubMed1998

[Nitric oxide in the treatment of COPD-induced chronic cor pulmonale: therapeutic effect and mechanism].

OBJECTIVE: To study the hemodynamic and oxygen-dynamic effects and the mechanism of nitric oxide (NO) inhalation therapy in COPD-induced chronic cor pulmonale at acute exacerbation period. METHOD: Right heart catheterization was performed in 11 cases of chronic cor pulmonale. The hemodynamic parameters and plasma endothelium-I(ET-I) level were examined and recorded before and after inhalation of 40 ppm NO for 20 minutes. The plasma level of NO and lipid peroxide Ca(2+)-Mg(2+)-ATPase(calcium pump) and Na(+)-K(+)-ATPase (natrium pump) activities of RBC membrane in 30 cases of chronic cor pulmonale and 30 healthy controls were determined synchronously. RESULTS: After NO therapy, the average pulmonary pressure (PAPM) and pulmonary vascular resistance index (PVRI) were lowered by 16.6% and 25.9% respectively (P < 0.05). Intrapulmonary shunt was lowered by 16.3% (P < 0.05). ET-I also lowered and showed a positive correlation with PAPM (r = 0.59, P < 0.05). The activities of calcium and natrium pump were lowered when NO level declined, showing a positive correlation with NO concentration and negative correlation with lipid peroxides. CONCLUSION: No inhalation therapy exerted favorable hemodynamic and oxygen-dynamic effects on COPD-induced chronic cor pulmonale in its exacerbation period. Suppression of ET-I release might be one of the important factors for pulmonary vessel relaxation. Dysfunction of calcium and natrium pump activities in the acute exacerbation period of chronic cor pulmonale were closely related to NO level.

Administration, Inhalation↗

PubMed1998

[Gene expression in vivo mediated by adenoviral vector after direct gene transfer into anastomotic rat carotid arteries].

OBJECTIVE: To observe the efficiency and time course of gene expression in vivo mediated by adenoviral vector after direct gene transfer into anastomotic rat carotid arteries. METHODS: After being soaked in high concentration of glucose solution containing Adv5-CMV (control group) or Adv5-CMV/LacZ (treatment group) for 30 minutes, soluble stents were inserted into the lumina of cut rat carotid arteries and end-to-end anastomoses were performed. On the 2nd, 7th, 14th, 28th, 60th and 90th day after surgery, the anastomotic carotid arteries of the two groups were explanted. All samples were analyzed for the presence of beta-galactosidase activity and histochemical staining. RESULTS: beta-galactosidase activity was not detected in the carotid arteries of the control group. Microscopic examination of sections from vessels of the control group revealed no X-gal staining. The treatment group revealed bluestaining in all anastomotic arteries and in all layers of the arterial wall explanted including the intima, media, and adventitia on the 7th, 14th day postoperatively. CONCLUSIONS: Adenoviral vector could make foreign effectively transfer into rat carotid arteries in vivo. Mediated by adenoviral vector after direct gene transfer into anastomotic rat carotid arteries, the high level of gene expression only persisted about one month.

Adenoviruses, Human↗

PubMed1998

[In situ hybrid detection of p16 mRNA in primary breast carcinoma: its clinicopathologic significance].

OBJECTIVE: To investigate the expression of p16 mRNA in primary breast carcinoma and its clinicopathological significance. METHODS: In vitro transcriptional RNA probe labeled with biotin and in situ hybridization method were used in this study to detect p16 mRNA in the paraffin embedded tissue of human primary breast carcinoma from 120 cases. RESULTS: 85 breast carcinomas showed expression of p16 mRNA with a positive rate of 70.8%. The p16 mRNA expression was not obviously correlated with patient age, tumor size, estrogen and progesterone receptor status (P > 0.05), but the positive rate of 54.4% for the lymph node metastasis group was significantly lower than 85.7% of the non-metastasis group (P < 0.001). Moreover, the positive rate of 58.3% for the poor differentiate invasive duct carcinoma was also lower than that 89.7% for the well differentiated (P < 0.05). The patients after operation were followed up. The mortality of 25% (21/85) in the p16 mRNA positive group was significantly lower than that of the negative group 57% (20/35) (P < 0.01). CONCLUSION: Abnormal expression of p16 mRNA may play an important role in the development of human breast carcinoma.

Adult↗

PubMed1998

[PCR/SSCP used as a complementary method for HLA oligotyping].

Seventy samples randomly selected from Hunan Han nationality normal individuals were typed for HLA DPA1 polymorphism by PCR/SSO with the primers and SSOs. Silver staining PCR/SSCP was also performed on the polymorphic second exon of all samples, which demonstrated the accurate gene frequencies of DPA1*01,02 to be 0.2632 and 0.7327, respectively. Using PCR/SSCP technique, we found that PCR/SSO mistyped a DPA1*01/02 heterozygote as single DPA1*01 gene because of weak hybridization signals. PCR/SSCP also revealed DPA1*02 in Hunan Han population to be composed of a single subtype. The results indicate that PCR/SSCP can be used to clarify the samples with atypical or irregular PCR/SSO hybridization patterns and to analyze the possible polymorphisms outside SSOs sequences. Thus this method may guarantee the accuracy of HLA oligotyping.

Gene Frequency↗

PubMed1998

[RBC-CR1 genotype polymorphism and RBC immune function in childhood ITP].

OBJECTIVE: To investigate the RBC immune functions in childhood idiopathic thrombocytopenic purpura (ITP). METHODS: RBC-CR1 polymorphism genotype, RBC immune function and its regulator function were detected in 22 ITP, 30 allergic purpura (AP) and 50 normal children by PCR and Guo Feng's method. RESULTS: 1. There were 18 cases of high expression (82%) and 4 of medium expression (18%) of RBC-CR1 genotypes in the ITP cases. The rate of the medium expression genotype was significantly higher in ITP than that in AP and normal children (P < 0.01). 2. The rates of RBC-C3bRR and RBC-C3bRFER were much lower (P < 0.01), and the rates of RBC-ICR and RBC-C3bRFIR were significantly higher in ITP than those in normal children (P < 0.01). 3. RBC-CR1 genotypes in ITP were correlated negatively with RBC-C3bRR and RBC-C3bRFER (P < 0.05), but positively with RBC-ICR and RBC-C3bRFIR (P < 0.05). CONCLUSION: RBC immune participated in the pathogenesis of ITP.

Child↗

PubMed1998

[Studies on the morphology of fruit-body developing of Polyporus umbellatus].

OBJECTIVE: Studying the fruit-body development of polyporus umbellatus to reveal the life-cycle of this medicinal fungus. METHODS: Parts of materials treated by paraffin section, and examined under a light microscope; parts of materials by ultrathin section and observation under transmission electron microscope (TEM). RESULTS: The fruit-body consists of trimitic hyphae, including generative hyphae, skeletal hyphae and binding hyphae. Generative hyphae are characterized by thin walls, dense cytoplasmic contents. Skeletal hyphae are unbranched, thick-walled, and of a narrow lumen. Binding hyphae are much-branched, tending to weave themselves among the other hyphase of flesh. The morphology of basidiospore development was also discussed in this paper. CONCLUSIONS: The trimitic hyphae are the main component parts in the different developing stages of fruit-body of polyporus umbellatus.

Plants, Medicinal↗

PubMed1998

[Effects of Chinese herbs xianzhen tablet on the deformability of erythrocyte in non-insulin-dependent diabetes mellitus patients with deficiency of both qi and yin and deficiency of kidney with blood stasis].

OBJECTIVE: To explore the effects of Xianzhen Tablet (XZT) on the hemorheology of type 2 diabetes (NIDDM) on the basis of previous studies in XZT, that have indicated its ability to deplete fasting blood glucose, to reduce the injury of free radical to the body, to improve the Na(+)-K(+)-ATPase in the erythrocyte membrane of NIDDM. METHODS: Erythrocyte deformability and aggregation were studied with Ektacytometer in a total of 60 type 2 diabetes who were randomly divided into two groups. One was ZXT treated group, another was placebo group. RESULTS: (1) The erythrocyte deformability of type 2 diabetes was lower than that in normal subjects (P < 0.001), but the erythrocyte aggregation increased abnormally than that of health people (P < 0.001). The correlation test indicated there were negative correlation with plasma fibronogen and positive correlation with blood cholesterol (P < 0.05). (2) The erythrocyte deformability in the ZXT treated group with 30 patients improved after 8 weeks treatment (P < 0.01), with the decreased fasting blood glucose and plasma fibrinogen (P < 0.05). Compared with placebo group, there was significant statistical difference (P < 0.01). CONCLUSIONS: XZT could improve the erythrocyte deformability in the type 2 diabetes.

Aged↗

PubMed1998

[Selection of key biological components (KBC) for Controlled Ecological Life Support System (CELSS)].

Biological components are key parts in Controlled Ecological Life Support System (CELSS), the future experimental success will depend to a large extent on the suitability of selected KBCs. For this purpose, 15 KBCs including 4 higher plants(vegetables), 5 microorganisms, 5 microalgae and 1 lower plant were selected from lots of biological species for CELSS. These results laid a solid foundation for our studies of CELSS.

Ecological Systems, Closed↗

PubMed1998

[The role of pro-UK gene in protecting vein graft from thrombosis].

OBJECTIVE: To study the role of Pro-UK gene in protecting vein graft from thrombosis. METHODS: 42 Wister rats underwent implantation of reversed autologous jugular vein interposition grafts in the common carotid artery. Jugular veins were exercised and distended with solution containing either Adv5-CMV(control group) or Adv5-CMV/Pro-UK(treatment group) for 30 minutes, then the jugular veins were reversed and interposed into the divided carotid arteries. Proximal and distal anastomoses were performed in an end to end fashion with interrupted 11-0 polypropylene sutures. 14 days after surgery, the vein graft of two groups were explanted to examine the presence of Pro-UK gene expression. The amount of 51 Cr-labeled platelet of the two groups was counted 24 hours postoperatively. Segment of grafts of both group was explanted 14 days after surgery for histologic analysis. RESULTS: Pro-UK activity was not detected in the vein graft of the control group. In the treatment group, the amount of Pro-UK gene express was 308 IU/g tissue. The amount of 51Cr-labeled platelet of the two groups was (123.7 +/- 19.4) x 10(6)/gdrywt. (34.4 +/- 5.3) x 10(6)/gdrywt. The amount of the control group was prominent over the treatment group(P < 0.01). On the 14th day after surgery, the thrombosis rate and occlusion rate of the vein graft in the control group were 30%, 10% respectively. In the treatment group, all vein grafts were patent and free of thrombosis. CONCLUSIONS: Mediated by adenoviral vector after direct gene transfer into vein graft, Pro-UK gene expression could protect graft from thrombosis. Therefore, this method could effectively enhance venous graft patency.

Animals↗

PubMed1998

[Synthesis and application of novel acrylic resin as enteric coating].

The pH sensitive two- and three-component acrylic resins were synthesized by radical solution copolymerization of methyl methacrylate (MMA), methacrylic acid (MAA) and/or butyl acrylate (BA) and their acid values were measured by acid-base titration. The dissolution of naproxen pellets coated with the synthesized resins in dissolution medium of different pH value was studied. The results show that the acrylic resin with different acid value can be prepared by adjusting the monomer ratios (MMA:MAA or MMA:MAA:BA). The smaller the acid value of the resin is, the higher pH sensitive value it has. The release of naproxen from pellets coated with these resins is greatly influenced by the pH value of the dissolution medium and the pH sensitive value of the coating resin. The three-component resins are plastic and can be used as coating material without adding plastisizers.

Acrylic Resins↗

PubMed1998

[Development of new ambulatory monitor for multi-channel gastroesophageal pH combining with cardiogram].

A new ambulatory monitor for multi-channel gastroesophageal pH combining with cardiogram is introduced in this paper. Key techniques of the monitor, design of hardware and software, clinical significance are described. Clinical application shows that the monitor advantages the diagnoses of functional diseases of upper digestive tract, especially is significant to distinguish the chest pain of cardiac origin and esophageal origin.

Chest Pain↗