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Biomedical subjects

W Gao

Publications and source records attributed to W Gao.

At least 181 records · Page 10Linked to original sources
PubMed1996

Single bailout stenting for threatened coronary closure complicating balloon angioplasty: acute and mid-term outcome.

BACKGROUND: Emergency stent implantation for the treatment of failed balloon angioplasty has been limited by a 3-33% incidence of early stent thrombosis and a paucity of information on restenosis. Accordingly, the objective of this study is to determine both the acute and midterm results following single bailout stenting for threatened closure after failed balloon angioplasty. METHODS: Single stent placement with either a Gianturco-Roubin or Palmaz-Schatz stent for the treatment of threatened closure complicating conventional single-vessel balloon angioplasty of de novo native coronary lesions was carried out in 16 and 24 patients, respectively. RESULTS: Successful stent implantation was achieved in 39 patients (97.5%), reducing the diameter stenosis from 90 +/- 7% before 6 +/- 8% after the procedure. No early stent closure, myocardial infarction, or need for emergency coronary bypass surgery was observed. Furthermore, except for one death due to massive intracranial hemorrhage 1 1/2 weeks after a successful stent implantation, there was no mortality directly related to the procedure. Repeat angiographic study performed at a mean of 5 +/- 3 months after stenting in 30 (86 %) eligible patients revealed in-stent restenosis (> 50% diameter stenosis) in six patients (20%). Five had successful repeat balloon angioplasty. Restenosis rate was significantly higher in patients with diabetes mellitus (83 versus 21% in nondiabetics, P = 0.0047), who had small (< 3 mm diameter) stent (reflecting small vessel diameters) implanted (40 versus 10% for > or = 3 mm stents, P = 0.0528) and those who had received stents to rectify vessel recoil (60 versus 12% for dissection, P = 0.0264). During a follow-up period of 12 +/- 8 months, clinical benefits were maintained in most patients, with none requiring bypass surgery, and no myocardial infarction or death encountered. CONCLUSION: Our study suggests that single bailout stenting for threatened closure in selected patients is associated with a favorable short and mid-term outcome, with minimal risk of early stent closure and a low restenosis rate. Restenosis rate, however, remains high in diabetic patients, stent placement for vessel recoil indication and those receiving < 3 mm diameter stents.

Angioplasty, Balloon, Coronary↗
PubMed1996

Epidermal abnormalities may distinguish type 2 from type 1 and type 3 of Gaucher disease.

A major clinical challenge in Gaucher disease is the early and presymptomatic discrimination of type 2 (acute neuronopathic) from milder type 1 and type 3 Gaucher patients to enable appropriate management and counseling. Although most patients with Gaucher disease do not have skin abnormalities, a subset of patients with severe type 2 Gaucher disease display ichthyosiform skin. Analogous findings occur in the skin of type 2 (null allele) Gaucher mice. Ultrastructural and functional studies of epidermis from these mice reveal that glucocerebrosidase is required to generate functionally competent membranes for normal epidermal barrier function. We have extended our studies by examining the epidermal lipid content and ultrastructure in all three types of Gaucher patients. Only the type 2 Gaucher patients, some of whom had clinical ichthyosis, demonstrated an increased ratio of epidermal glucosylceramide to ceramide as well as extensive ultrastructural abnormalities, including the persistence of incompletely processed lamellar body-derived contents throughout the stratum corneum interstices. These epidermal alterations may provide a means for early differentiation of type 2 Gaucher disease.

Animals↗
PubMed1996

Immediate and long-term results of percutaneous Inoue balloon mitral commissurotomy with use of a simple height-derived balloon sizing method for the stepwise dilation technique.

OBJECTIVE: To assess the short- and long-term efficacy of Inoue balloon percutaneous transvenous mitral commissurotomy (PTMC) with use of our simple balloon sizing method based on patient height. DESIGN: Data from 105 consecutive patients with symptomatic mitral stenosis who underwent 107 PTMC procedures between October 1991 and April 1995 at our hospital were analyzed. RESULTS: All PTMC procedures were successfully completed with no instances of cardiac perforation, systemic embolism, severe mitral regurgitation (grade 3 or more angiographically), or death. The mean mitral valve area increased from 0.8 +/- 0.2 cm2 to 1.7 +/- 0.4 cm2 (P = 0.0001), as assessed echocardiographically. Optimal results -- defined as an improvement in valve area of 50% or more or a final valve area of 1.5 cm2 or more without significant mitral regurgitation (an increase in mitral regurgitation of two or more grades or a final regurgitation of grade 3 or more) -- were obtained in 96% of patients. At a mean follow-up interval of 20 months, symptomatic benefit was maintained in 97% of patients. Echocardiographic evidence of restenosis (loss of more than 50% initial gain in valve area, a valve area of less than 1.5 cm2, or both) was noted in 9.8%. CONCLUSION: Inoue balloon PTMC with use of our simple balloon sizing method yielded excellent short- and long-term results in terms of mitral valve enlargement and sustained symptomatic benefit without the creation of severe mitral regurgitation.

Adult↗
PubMed1996

Technically demanding Inoue-balloon mitral commissurotomy: broadened indications for the procedure.

Although percutaneous transvenous mitral commissurotomy (PTMC) is now the preferred treatment modality for selected patients with mitral stenosis, there are certain settings where its application remains controversial or even contraindicated, mainly because of an increased risk of major complications. In this report, 3 such complex PTMC cases are described. A 39-year-old female with a rare combination of mitral stenosis and concomitant sizeable atrial septal aneurysm underwent a successful PTMC procedure. PTMC in a 60-year-old female with coexisting severe kyphoscoliosis which required major adjustments to the transseptal technique yielded an improvement in the mitral valve area from 1.0 cm2 to 1.9 cm2. In the third patient who was in her 25th week of gestation and had evidence of congestive cardiac failure, an abbreviated and expeditious PTMC procedure was carried out uneventfully. The 3 cases reported here highlight the feasibility, safety and efficacy of complex PTMC in the presence of atrial septal aneurysm, severe kyphoscollosis and pregnancy.

Adult↗
PubMed1996

Detection of alpha-hydroxyethyl free radical adducts in the pancreas after chronic exposure to alcohol in the rat.

Chronic pancreatitis is characterized by inflammation and fibrosis leading to tissue destruction; in industrialized nations, alcohol abuse is the cause of 70-80% of cases of pancreatitis in adults. The purpose of the current work was to determine whether free radical adducts are produced by the pancreas during the early phases of chronic exposure to ethanol. Accordingly, rats were chronically fed ethanol using the model of continuous enteral infusion developed by Tsukamoto et al.[Am. J. Physiol. 247: R595-R599 (1984)]. Histological evaluation revealed only mild acinar steatosis and spotty necrosis after 4 weeks of alcohol treatment; the pancreatic enzymes lipase and amylase were not elevated. Furthermore, no fibrosis was detected, nor were there differences in pancreatic collagen alpha 1(l) mRNA levels between the dietary control and ethanol-treated groups. After 4 weeks, rats were injected with the spin trap alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone (1 g/kg intravenously), and pancreatic secretions were collected over a 4-hr period. A six-line free radical adduct spectrum indicative of a carboncentered free radical was detected in pancreatic secretions and in Folch extracts of pancreatic tissue by electron spin resonance spectroscopy. Control experiments ruled out ex vivo radical formation. This study represents the first detection of radical adducts in pancreatic secretions. When [13C]ethanol (3 g/kg intragastrically) was administered, a definitive 12-line spectrum was detected in pancreatic secretions, demonstrating that the alpha-hydroxyethyl radical adduct was formed in the pancreas from [13C]ethanol. Interestingly, only a six-line signal was detected in tissue extracts under these conditions. Free radicals, therefore, are formed in the pancreas during the early phases of chronic alcohol intake in rats before the development of overt pathology.

Adult↗
PubMed1996

Safety and efficacy of percutaneous Inoue-balloon mitral commissurotomy.

BACKGROUND: Although percutaneous transvenous mitral commissurotomy (PTMC) is currently accepted as the first-line treatment modality for selected patients with mitral stenosis, technical failures and the potential risk of inadvertent cardiac perforation with tamponade, resultant severe mitral regurgitation and death associated with the procedure continue to be important issues of concern. OBJECTIVES: The purpose of this study was to assess the safety profile and acute results of Inoue-balloon PTMC in a consecutive series of 50 patients with symptomatic significant mitral stenosis who underwent the procedure between January 1993 and August 1994. RESULTS: PTMC was successfully completed in all patients without encountering cardiac perforation, cardioembolism, severe (> or = grade 3+) angiographic mitral regurgitation or death. The mitral valve area increased from 0.8 +/- 0.2 cm2 to 1.7 +/- 0.4 cm2 (p = 0.0001) as assessed echocardiographically. Optimal results defined as a valve area improvement of > or = 50% and/or a final valve area of > or = 1.5 cm2 without significant mitral regurgitation (> or = 2 grade increase in mitral regurgitation or a final regurgitation > or = 3+) was obtained in 94% of patients. CONCLUSION: We confirm that Inoue-balloon PTMC is a safe and highly effective procedure as reflected by the absence of cardiac perforation, cardioembolism, severe mitral regurgitation or death and the excellent enlargement in mitral valve area. Furthermore, in our study the clinical restenosis rate was low with the majority of patients maintaining their improved functional status over a 14-month follow-up period.

Adult↗
PubMed1996

[Clinical significance of ophthalmo-electromyography in the determination of the function of the superior levator muscle].

Preoperative electromyographic examinations of superior levator muscle were done in 36 ptotic patients using the Neurematic 2000 electromyograph. Shortening of the levator palpebrae superior was done through a combined internal and external route. In 12 patients of mild ptosis the spike voltage was all above 30 mv during contraction. When the spike voltage was above 100 mv, better operative results were obtained. In 24 patients whose ptosis was moderate or severe, the graphs of contraction generally showed simple phases with low amplitude. In 9 patients whose spike voltage was below 30 mv, their palpebral fissure did not reach the anticipated width after the operation. On the contrary, in 15 patients whose spike voltage was above 30 mv the operative results were satisfactory. It is concluded that in patients whose ptosis is moderate or severe, the operative procedure should be based on electromyographic examinations. If the spike voltage of the superior levator muscls is higher than 30 mv on contraction, simple shortening of the levator will be successful. If the spike voltage is lower than 30 mv and the graph presents simple phase or electro-tranquilization, then suspension of the frontalis muscle is preferable.

Adolescent↗
PubMed1996

[Detection of lipoarabinomannan-IgG in serum for the diagnosis of pulmonary tuberculosis].

OBJECTIVE: To ascertain the value of lipoarabinomannan-IgG (LAM-IgG) determination in the diagnosis of pulmonary tuberculosis. METHOD: LAM-IgG in sera obtained from 90 patients with active pulmonary tuberculosis, 53 patients with lung cancer and 30 healthy individuals were detected by using rapid enzyme-linked immunosorbent assay (ELISA). RESULTS: The positive rate was 82% in tuberculosis group, and the false positive rates were 8% and 3% in cancer group and healthy controls respectively. CONCLUSION: The results suggested that rapid ELISA and LAM-IgG detection was a useful supplementary tool for diagnosis of pulmonary tuberculosis.

Enzyme-Linked Immunosorbent Assay↗
PubMed1996

[Labour induction in women at term with mifepristone and misoprostol].

OBJECTIVE: To determine the efficacy of mifepristone (RU486) combined with misoprostol as an induction agent for the initiation of labour in women at term. METHODS: Our study group contained 68 pregnant women at term (gestational age: 38-41 weeks) who had clear clinical indications for labour induction. They received mifepristone either 150 mg or 200 mg respectively in the first two or three days. The shortening of the cervical length, the change of Bishop score and the change of the blood serum in oestradiol (E2) concentration and progesterone (P) concentration were observed respectively before and after medication. On the fourth day, misoprostol was added from 100 micrograms to 300 micrograms successively. The outcome of labour induction in these women was recorded. RESULTS: The cervical length of women who were given mifepristone was 1-3 cm shorter and Bishop score was 4-5 higher than those before treatment. The E2 concentration and the P concentration were significantly higher and lower respectively than those before treatment. The cervical ripening ratio was 100.00%. The incidence of the onset of labor was 93.00% and the incidence of vaginally delivery was 80.88% after misoproston was given. CONCLUSION: Mifepristone combined with misoprostol is a safe, efficient, economical and convenient induction agent for initiation of labor in women at term.

Abortifacient Agents, Nonsteroidal↗
PubMed1996

[Effect of escharectomy during burn shock stage on bacterial and endotoxic translocation from the gut].

120 SPF rats (Wistar) were randomly divided into 3 groups (1) simple skin grafting group (Group A). (2) Escharectomy during burn shock group (Group B). (3) Routine escharectomy group (Group C) Full-thickness burn of 30% TBSA was produced in Group B and Group C. One hour after scald intravenous fluid replacement was instituted. First stage escharectomy has been performed 24 hours after burn and 5 days postburn. The results demonstrated that the contents of both plasma LPS and TNF in Group B were significantly lower as compared with these in Group C. Our data indicated escharectomy during burn shock would effectively eliminate the effects of the endotoxemia. Endotoxin play an important role in the bacterial and endotoxic translocation.

Animals↗
PubMed1995

Evidence that uncharged tRNA can inhibit a programmed translational frameshift in Escherichia coli.

In the modified release factor 2 (RF2) programmed translational frameshift (with a sense codon replacing the wild-type in-frame UGA codon at the shift site), ribosomes shift +1 into the reading frame for an out-of-frame reporter fused to the frameshift sequence. Partitioning of ribosomes between the out-of-frame shift and in-frame reading depends on the codon at the shift site and on the levels of tRNA decoding the in-frame codon. Overexpression of a tRNA species cognate to the in-frame codon at the shift site significantly reduces the frequency of frame-shifting, presumably by facilitating in-frame reading, which would reduce production of the out-of-frame reporter. However, since overexpression of a tRNA increases levels of both charged and uncharged tRNA, it is possible that uncharged cognate tRNA might be able to reduce the frequency of the frameshift, by entering the A site on the ribosome. To test this, we manipulated charged and uncharged tRNA levels in vivo, using the tryptophan analog tryptophan hydroxamate, which increases the proportion of uncharged tRNA(Trp) by competing with cognate amino acid tryptophan for tryptophanyl-tRNA synthetase, thereby reducing protein synthesis. We report here that a slight but reproducible reduction in the relative frequency of the frameshift is observed when tryptophan hydroxamate is added to cells containing the modified RF2 shift with UGG (Trp codon) at the shift site. When tRNA(Trp) is overexpressed from another plasmid, the shift frequency drops three- to fourfold, as expected, however, this reduction is still seen in the presence of the analog. Thus, under conditions when most of the tRNA(Trp) is apparently uncharged, excess tRNA(Trp) still causes a significant reduction in the frameshift when UGG is at the shift site, providing evidence that uncharged cognate tRNA also can inhibit this frameshift.

Amino Acyl-tRNA Synthetases↗
PubMed1995

Primary nonfunction of fatty livers produced by alcohol is associated with a new, antioxidant-insensitive free radical species.

The formation of free radicals after orthotopic liver transplantation in the rat correlates with graft failure. Fatty livers from alcoholics transplant poorly, so these studies were designed to examine the effect of alcohol on free radical formation in a rearterialized rat liver transplantation model. Treatment of rats for 3-5 weeks with either a high-fat or an ethanol-containing liquid diet caused characteristic pericentral lipid accumulation. After storage in University of Wisconsin cold storage solution (UW) and transplantation, a reperfusion injury characterized by increased postoperative AST levels (greater than 1500 U/l in about 3 hours) was observed in rats fed high-fat or alcohol-containing diets, whereas parenchymal cell injury was seen much less in low-fat controls. Survival was around 63% in the low-fat group but decreased to 12 and 18% in the high-fat and alcohol groups, respectively. Furthermore, intracellular lipid content correlated inversely with survival. In untransplanted livers, the spin trap alpha-phenyl N-tert-butylnitrone (PBN) was infused, and blood samples were collected and extracted with chloroform:methanol. Signals indicative of carbon-centered PBN radical adducts were barely detectable in all untransplanted groups studied by electron paramagnetic resonance. In contrast, a robust 6-line complex spectrum was obtained from all groups studied immediately after 48 hours of cold storage in UW solution and transplantation. A mixture of 3 radical species was identified. Two had coupling constants similar to lipid-derived free radicals, whereas the third is a new species with unique coupling constants and is most likely oxygen derived. In low-fat controls, the signal was reduced significantly by superoxide dismutase (SOD)/catalase; however, SOD/catalase had no effect on free radicals in lipid-loaded livers. Thus, both dietary high fat and alcohol exposure produce a unique SOD/catalase-insensitive free radical species that may be involved in the mechanism of failure of fatty livers after orthotopic liver transplantation.

Alcoholism↗
PubMed1995

Antibiotics prevent liver injury in rats following long-term exposure to ethanol.

BACKGROUND/AIMS: Kupffer's cells participate in alcohol-induced liver injury, and endotoxemia is observed in human alcoholics and in a rat model. This study evaluated the effect of reducing bacterial endotoxin production by intestinal sterilization on alcohol-induced liver injury. METHODS: Male Wistar rats were exposed to ethanol continuously for up to 3 weeks via intragastric feeding. The gut was sterilized with polymyxin B and neomycin. RESULTS: Fecal culture of stool samples from ethanol-fed rats treated with antibiotics showed virtually no growth of gram-negative bacteria. Endotoxin levels of 80-90 pg/mL in plasma of ethanol-fed rats were reduced to < 25 pg/mL by antibiotics. Antibiotic treatment also completely prevented elevated aspartate aminotransferase levels and significantly reduced the average hepatic pathological score in rats exposed to ethanol. Oxygen tension on the surface of the liver measured in vivo was decreased significantly from control values of 48 +/- 1 to 39 +/- 1 mumol/L in ethanol-treated rats. This hypoxia was prevented by treatment with antibiotics. Moreover, the increase in rates of ethanol elimination due to long-term ethanol treatment was prevented by antibiotic treatment. CONCLUSIONS: Intestinal sterilization prevented alcohol-induced liver injury in the rat, supporting the idea that hypermetabolism and consequent hypoxia caused by activation of Kupffer's cells by endotoxin is involved in the mechanism.

Animals↗