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Biomedical subjects

X Qin

Publications and source records attributed to X Qin.

At least 109 records · Page 6Linked to original sources
PubMed1997

[Quantitative study of calcitonin gene methylation in myelodysplastic syndromes].

OBJECTIVE: To investigate the role of calcitonin gene hypermethylation in the transformation from myelodysplastic syndromes (MDS) to acute myeloid leukemias (AML). METHODS: The methylation rate of calcitonin gene (CTMR) in the genomic DNA extracted from bone marrow cell of 27 MDS patients and 6 AML patients with antecedent MDS were studied by PCR amplification of Hpa I digested DNA, with external reference of undigested and Msp I digested DNA and internal reference of 112bp fragment containing N-ras-61. Intensity of silver-stained PCR products was measured by densitometer and analysed using the computer program. RESULTS: The CTMR was significantly higher in MDS (33.65% +/- 23.37%) than in control group (P<0.001), in 9 RAEB(T) (58.35% +/- 17.44%) than in the control and RA groups. Five RA patients who have survived three to ten years without leukemia, have a normal CTMR. Seven of 8 RAEB(T) patients who had a high CTMR of more than 30% evolved into AML in two months. CONCLUSION: CTMR might be a useful marker for predicting the evolution of MDS into AML.

Adolescent↗
PubMed1997

[Liquid chromatographic separation of pepsinogens].

In this work, we reported a method for the purification of pepsinogens from human gastric mucosa with high pressure gel filtration chromatography (HPLC) and medium pressure anion exchange chromatography (MPLC). First, the two fractions of Pg1 and mixture of PGI and PGII were separated from pepsinogens with HPLC on a Bio-Sil SEC-125 column within 50min. Then the mixture of fractions of PGI and PGII was further separated with MPLC on a Bio-Scale Q2 column within 30min.

Chromatography, High Pressure Liquid↗
PubMed1997

[Dynamic study on blood lead levels of pregnant women and infants in a district of Beijing].

Under strict quality control, the authors investigated the levels of PbB among 270 women from early pregnancy to delivery and their infants. The mean PbB levels of the first three months of pregnancy and delivery is 45.0 microg/L and 64.8 microg/L respectively. Analysis shows an increase of mean PbB level in the period of gestation, and a significant increase in the last three months. The mean PbB level of umbilical cord is 51.9 microg/L (10.4% umbilical cord PbB > 100 microg/L). The mean PbB level of infants increases with the months, it increases significantly after six months. Regression analysis confirmed the positive correlation between the PbB levels of first three and second three months of gestation, the PbB of delivery and umbilical cord, the PbB of umbilical coral and infants. The correlation coefficient of the PbB level of delivery and umbilical cord, the PbB level of infants at six months and at twelve months is 0.80 and 0.47 respectively.

China↗
PubMed1997

Long-term prognosis of percutaneous transluminal coronary angioplasty in 229 cases.

OBJECTIVE: To evaluate long-term efficacy of percutaneous transluminal coronary angioplasty (PTCA) and the factors affecting its efficacy in Chinese patients. METHODS: Two hundred and twenty-nine patients who underwent successful PTCA in this institution were followed-up by direct interview or letters. The rate of follow-up was 95%. The period of follow-up were 0.5-8.4 (with mean of 2.3 +/- 1.8 years). RESULTS: Angina Pectoris recurred in 76 (33.2%) of the patients. Cox regression analysis revealed that the relative risk of recurrence of angina pectoris was increased among the patients with triple vessel disease and with history of hypertension. During the period of follow-up, 2 (0.9%) patients died, 6 (2.6%) had non-fatal acute myocardial infarction, 4 (1.7%) had coronary artery bypass graft surgery and 29 (12.7%) had repeat PTCA. The cardiac event-free survival rate calculated by Kaplan-Meier method was 84.8% at the first year and 70.5% at the eighth year. Cox regression analysis revealed that there were positive correlation between the relative risks of cardiac events and stenosis of lesions before PTCA and residual stenosis of LAD after PTCA. CONCLUSION: The long-term efficacy of PTCA in Chinese patients was good. The results of this study suggest that to decrease the residual stenosis of LAD during procedures could probably decrease the relative risk of cardiac events during follow-up.

Adult↗
PubMed1996

Detection of ultraviolet photoproducts in mouse skin exposed to natural sunlight.

In the present study, we for the first time investigated the formation of ultraviolet (UV) photoproducts, cyclobutane pyrimidine dimers (CPDs), pyrimidine-pyrimidone (6-4) photoproducts (64PPs) and Dewar isomers, in vivo in shaved and depilated C3H/HeN mouse skin exposed to natural sunlight (NSL) at noon for 5 min to 1 h in mid-summer, using a highly sensitive immunohistochemical method. This method permits the quantitative analysis of UV-photoproducts in formalin-fixed, paraffinembedded sections with specific antibodies against CPDs, 64PPs and Dewar isomers. We demonstrated that the induction of CPDs in vivo in mouse skin by NSL was exposure time-dependent, but the accumulation of 64PPs or Dewar isomers was comparatively low in the skin sections from mice exposed to NSL in vivo. The results indicate that CPDs are the main photoproducts in vivo induced by sunlight and that their formation and repair may be important in connection with carcinogenesis in sun-exposed areas of human skin.

Animals↗
PubMed1996

Transcriptional regulation of the Bacillus subtilis menp1 promoter.

The Bacillus subtilis men genes encode biosynthetic enzymes for formation of the respiratory chain component menaquinone. The menp1 promoter previously was shown to be the primary cis element for menFD gene expression. In the present work, it was found that either supplementation with nonfermentable carbon sources or reutilization of glycolytic end products increased menp1 activity in the late postexponential phase. The effect on menp1 activity by a particular end product (such as acetoin or acetate) was prevented by blocking the corresponding pathway for end product utilization. Alteration of a TGAAA motif within the promoter region resulted in unregulated menp1 activity throughout the culture cycle, irrespective of the carbon source added.

Bacillus subtilis↗
PubMed1996

[Construction of Chinese genomic cosmid library].

A Chinese genomic library has been constructed using SuperCos1 cosmid vector. 6.09 x 10(5) clones were obtained with an everage insert size of 40 kb ranging from 32 to 45 kb, which cover approximately 8.12 fold human genomic DNA. DNA pools prepared from the total library were screened with 6 known markers distributed on different chromosomes, which all were tested positive.

Asian People↗
PubMed1996

[Observation on therapeutic effect of megestrol acetate on patients with chronic obstructive pulmonary disease at remission stage].

It has been reported that malnutrition is common in stable chronic obstructive pulmonary disease (COPD) patients. In order to observe the effects of Megestrol Acetate (MA) on nutritional status, respiratory muscle strength and immunological parameters in stable COPD patients, 31 stable COPD patients were divided into two groups at random--a treatment group of 16 cases and a control group of 15 cases. Before and after treatment all parameters were recorded, including food and energy intake, body weight, triceps skinfolds (TSF), pre-albumin, transferrin, albumin. Lung function, respiratory muscle and handgrip strength were examined and immunological parameters also determined. After taking MA 160 mg/day orally for two weeks, the treatment group got benefits as follows: heat energy and protein intake increased fro 6977.9 +/- 1136 kJ/d and 44.65 +/- 13.75 g/d to 9854.0 +/- 2355.3 kJ/d and 84.80 +/- 20.23 g/d respectively. With the increase of daily energy and protein intake, body weight increased from 48.27 +/- 8.61kg to 50.34 +/- 8.76 kg, TSF from 11.75 +/- 4.50 mm to 15.06 +/- 4.73 mm, serum pre-albumin from 306.6 +/- 33.7 mg/L to 332.6 +/- 1 mg/L, transferrin from 3.09 +/- 0.21 g/L to 3.46 +/- 0.32 g/L, albumin from 38.00 +/- 1.73 g/L to 42.64 +/- 3.36 g/L, MIP from 4.77 +/- 2.14 kPa (1 kPa = 7.5 mmHg) to 6.31 +/- 2.87 kPa, MEP from 6.21 +/- 2.90 kPa to 7.20 +/- 3.67 kPa and 6 minutes walking distance from 280.2 +/- 76.4 m to 370.6 +/- 81.5 m. Handgrip strength also improved. Blood lymphocyte transformation rate elevated too. (The changes of all these parameters indicated above were statistically significant, P < 0.01). However, parameters of lung function, blood gas analysis, serum immunoglobulin and complement 3 did not change significantly. In 15 control patients all the parameters did not change significantly. There were few side effects; only one case complained of nausea and vomiting. It was shown that MA can stimulate appetite and increase dietintake, improve nutritional status, elevate respiratory muscle strength, and enhance immunity. MA is a safe and effective drug which exerts a beneficial influence on stable COPD.

Aged↗
PubMed1995

Allotransplantation of whole spleen in patients with hepatic malignant tumors or hemophilia A. Operative technique and preliminary results.

BACKGROUND: It has been reported that the spleen performs a vital function in the fight against malignant tumors. The spleen is the primary producer of tuftsin, which can directly or indirectly kill tumor cells or inhibit their growth. The spleen is also believed to produce coagulating factor VIII. Therefore, allotransplantation of the spleen can be used in the treatment of patients with malignant tumors and hemophilia A. DESIGN: Heterotopic allotransplantation of whole spleen was performed in six patients with advanced hepatocellular carcinoma and hemophilia A. An adjuvant immunotherapy with interferon alfa was simultaneously administered in the patients with liver cancer. SETTING: Tongji Hospital, Tongji Medical University, Wuhan, China. RESULTS: Among six cases of allografting of whole spleen, five grafts were successful; one failed because of torsion of the splenic hilum. Three patients with hepatocellular carcinoma survived 9, 11, and 5 months after transplantation. Marked shrinkage of hepatic tumors and reduced serum alpha-fetoprotein levels were observed in these patients. On 5-year follow-up, three patients with hemophilia who had undergone splenic allografts were alive, and two had experienced substantial clinical improvement. In these two patients, when the grafts were functioning well and the recipients were free of acute rejection or graft-vs-host reaction, the mean plasma factor VIII activity remained between 30% and 36%, with peak factor VIII activities of 53.7% and 66.6%. We also evaluate operative technique and posttransplantation complications. CONCLUSION: Our results strongly imply that the spleen is one of the primary sites of synthesis of factor VIII and that the spleen has an inherent ability to fight malignant diseases. Allografting of whole spleen may be a promising technique for the treatment of patients with unresectable hepatocellular carcinoma and severe hemophilia A.

Adult↗
PubMed1995

Effect of estrogen on egg production, shell quality and calcium metabolism in molted hens.

Force-molted White Leghorn laying hens were implanted with 0.25, 0.5, 1 and 3 Compudose 200 pellets (24 mg 17 beta estradiol/pellet). Plasma estradiol increased with increasing E2 dosages in a linear manner and decreased over time in a quadratic manner (P < 0.01). E2 treatment had a nonlinear effect on total plasma calcium. Oviduct weight, shell thickness and egg weight were not significantly affected by exogenous estradiol whereas tibial bone ash percentage was increased at only one dose (P < 0.05:0.5 pellet group). Physiological supplementation with estradiol does not improve shell quality.

Animals↗
PubMed1995

Inhibitory effect of probucol on nephrotoxicity induced by ferric nitrilotriacetate (Fe-NTA) in rats.

Effects of dietary probucol on renal damage induced by a renal carcinogen, ferric nitrilotriacetate (Fe-NTA), in male Wistar rats were quantitatively investigated with a computer-mediated image analyzer. The kidneys of rats fed a 1% probucol diet were protected from necrosis and lipid peroxidation induced by a single i.p. treatment with Fe-NTA solution at 5 mg Fe/kg body wt and were significantly resistant to a higher dose. For the parameter of lipid peroxidation, Schiff's staining method was utilized to demonstrate the extent of formation of aldehydes, products of lipid peroxidation. Thus following injection of Fe-NTA solution at 10 mg Fe/kg body wt the average areas of tubular necrosis were 85.8% versus 56.9% and the positive areas for Schiff's staining were 15.3% versus 5.6% in the renal cortices of rats fed control of 1% probucol diets respectively. These results indicate that probucol provides protection against Fe-NTA-induced nephrotoxicity through its antioxidant properties. In addition to being a cholesterol-lowering drug, useful for the control of hypercholesterolemia, probucol may therefore be beneficial for prevention and treatment of various pathogenic processes including those leading to carcinogenesis.

Animals↗
PubMed1995

Inhibitory effect of probucol on benzo[a]pyrene induced lung tumorigenesis.

The effects of probucol, a clinically used cholesterol lowering and antioxidant drug, on benzo[a]pyrene (B[a]P) induced pulmonary and forestomach tumorigenesis as well as induction of colonic aberrant crypt foci (ACF) in female A/J mice was investigated. Diet containing 1% probucol fed prior to, during and after 8 bi-weekly 1 mg/mouse oral intubations of B[a]P, reduced the number of pulmonary adenomas by 52% (P < 0.001) and the number of forestomach tumors by 31%. The 0.06% probucol diet also resulted in decreased tumor formation but the differences did not reach statistical significance. Both probucol diets significantly reduced the numbers of large ACF, putative preneoplastic lesions of the colon mucosa, but showed no effects on the total numbers of ACF. The results of this study suggest that probucol may also be useful as a chemopreventive agent, in addition to being a cholesterol lowering and anti-atherogenic drug with low toxicity.

Animals↗
PubMed1995

Quantitative detection of ultraviolet light-induced photoproducts in mouse skin by immunohistochemistry.

UVB-induced cyclobutane pyrimidine dimers (CPDs) and pyrimidine-pyrimidone (6-4)photoproducts [(6-4)photoproducts] in mouse skin DNA were quantitatively measured using an immunohistochemical approach with a computer-aided color image analyzer. The skins of the C3H/HeN mice were irradiated with ultraviolet B (UV-B, 280-320 nm), and processed to give conventional formalin-fixed, paraffin-embedded histologic sections. Routine immunohistochemistry clearly demonstrated a dose-dependent induction of both photoproducts. CPDs were detectable at doses > or = 125 J/m2, while for (6-4)photoproducts, the minimal dose at which they were detectable was 250 J/m2 in the present study. A time course study showed that the repair of (6-4)photoproducts was more rapid than that of CPDs, and that epidermal cells had a higher capacity for their removal than dermal cells. About half of the (6-4)photoproducts were excised within the first 24 h after the irradiation, and the process was essentially complete by 72 h. In contrast, there was no apparent removal (less than 10%) of CPDs in the first 24 h and they only completely disappeared from the epidermal cells at 120 h after irradiation. The effect of DNA dilution due to increased turnover of epidermal cells after UV-B irradiation was evaluated by quantitative immunohistochemical measurement of the time course of bromodeoxy-uridine (BrdUrd) incorporated into nuclei at 2 days post irradiation when the proliferation reaches a peak. The removal of photoproducts was more marked than the decrease in BrdUrd staining. Our results suggest that mouse skin cells can repair both (6-4)photoproducts and CPDs, but with considerably lower efficiency, especially in the latter case, then human or monkey skin cells.

Animals↗
PubMed1995

Exotic collagen gradients in the byssus of the mussel Mytilus edulis.

Byssal threads of the common mussel Mytilus edulis contain collagenous molecules from which two pepsin-resistant fragments have been isolated and characterized. These show a complementary distribution along the length of the thread, such that one predominates distally (Col-D) and the other proximally (Col-P). Both fragments contain three identical alpha-like chains with molecular masses of 50 kDa (Col-P) and 60 kDa (Col-D) and have typically collagenous amino acid compositions; for example, 35% glycine and almost 20% proline plus 4-trans-hydroxyproline. Hydroxylysine and 3-hydroxyproline were absent. Col-P sequences are also typical of collagen in consisting of tandem repeats of the triplet Gly-X-Y in which X and Y generally represent any amino acid. When proline occurs, it is hydroxylated to 4-trans-hydroxyproline only in the Y position. Seven instances where X is glycine have been detected in Col-P. Specific polyclonal anti-Col antibodies were used to isolate the precursors of Col-P and Col-D from the mussel foot. PreCol-P has a molecular mass of 95 kDa and contains 36% glycine but a lower imino acid content (13%). It has a complementary distribution with another precursor (preCol-D, 97 kDa) along the length of the foot. The two precursor compositions suggest resilin-like and silk-fibroin-like structures, respectively, in the noncollagenous domains of preCol-P and preCol-D. Immunogold labelling studies indicate that Col-P is associated with the coiled fibers of the inner core in the proximal portion of the thread, whereas Col-D is localized to the straight fiber bundles of the distal thread as well as to the outer core of the proximal thread.

Amino Acid Sequence↗
PubMed1995

[The effect of platelet-activating factor antagonists on early bacteria translocation of rat after burn injury].

30% third degree burn model of Wistar rat was used in this experiment. The animals were divided randomly into three groups (normal control, burn, and platelet-activating factor antagonist treatment). After poured E. coli which labelled with acridine orange into intestine, the rats were killed at 6, 12, 24, and 48 hrs postburn, the bacteria in mesentery lymph node (MLN), liver and pulmonary organisms were cultured and counted, also observed by fluorescent microscopy directly. The results showed that, in PAF antagonist (WEB2170) treatment group, the quantity of bacteria in MLN, liver and lung were decreased significantly (P < 0.001). The labelled bacteria in MLN, liver and lung of burn group were 100%, 80.0%, and 50.0% respectively compared with 40.0%, 30.0%, and 20.0% in treatment group. It is suggested that WEB 2170 could protect the intestine from bacteria translocation after burn injury.

Animals↗
PubMed1995

A two-year experience with laparoscopic cholecystectomy--a report of 1475 cases from Kunming, China.

Over a 2-year period, from 12 September 1991 to 11 September 1993, laparoscopic cholecystectomy was performed on 1475 patients with benign gallbladder disease in Kunming General Hospital, Yunnan, China. Of these, 28 cases (1.9%) were converted to open surgery. Various complications were documented in 27 instances including extrahepatic bile duct injury in 4 cases (0.3%), postoperative haemorrhage requiring laparotomy in 3 cases (0.2%) and bile leak from cystic duct stump in 1 case (0.07%). There was 1 (0.07%) death in the series. The junction between the gallbladder infundibulum and the cystic duct is an important landmark which laparoscopic surgeons must identify in the course of the procedure. Because the junction remains a comparatively constant landmark, in difficult laparoscopic cholecystectomy, excessive dissection of the bile duct would be unnecessary. During dissection of the hepatic hilus, blund dissection is recommended and the blind use of cautery and haemostasis should be avoided.

Bile Ducts, Extrahepatic↗