PubMed Health⌕ Search

Biomedical subjects

M Fu

Publications and source records attributed to M Fu.

At least 181 records · Page 10Linked to original sources
PubMed1995

Atrial septal motion in effusive--constrictive pericarditis: transesophageal echocardiographic study and hemodynamic correlation.

Transesophageal echocardiography was performed in 7 patients with effusive-constrictive pericarditis to analyze atrial septal motion(ASM). In 3 patients, the ASM was found to be normal with atrial septum (AS) moving toward the right atrium from ventricular mid-systole to early-diastole and toward the left atrium from mid-diastole to early-systole. Respiration had little effect on the ASM. In 2 patients, a brisk inversion of ASM toward the left atrium at ventricular early-to-mid systole was noted during inspiration. In the other 2 patients, a sustained ASM toward the left atrium during ventricular systole was found. In 4 of these 7 patients, hemodynamic studies were performed simultaneously with the transesophageal echocardiography. The ASM reflected the pressure gradient between the left atrium (as measured by pulmonary arterial wedge pressure) and the right atrium. The augmented ASM toward the left atrium occurred as left atrial pressure decreased markedly during inspiration. In conclusion, the ASM in patients with effusive-constrictive pericarditis showed 3 patterns: normal, sustained systolic motion toward the left atrium and a brisk systolic displacement toward the left atrium during inspiration. The ASM reflects changes in the interatrial pressure gradient.

Adult↗
PubMed1994

Properties of G-protein modulated receptor-adenylyl cyclase system in myocardium of spontaneously hypertensive rats treated with adriamycin.

Properties of the receptor--G protein--adenylyl cyclase system were studied in spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar-Kyoto rats (WKY) treated with adriamycin (ADR, 1 mg/kg per week) for 12 weeks. An identical dosing schedule caused a significantly greater decline in body weight gain and a marked elevation of plasma norepinephrine level in SHR than in WKY. A significant increase in the messenger RNA encoding Gi-alpha 2 was found in SHR+ADR group. The activity of the adenylyl cyclase stimulated by guanyliminodiphosphate [Gpp(NH)p] was decreased by 49% in SHR and 73% in SHR+ADR. However, stimulated activities of adenylyl cyclase by both sodium fluoride and forskolin remained unchanged. Functional level of stimulatory G-protein (Gs) as measured by reconstitution assay in sarcolemmal membrane was unaltered among different groups. Furthermore, the density of beta-adrenoceptor was significantly decreased without change of its affinity. Muscarinic receptors exhibited a three-site affinity distribution in SHR+ADR whereas other groups displayed only two-site affinity distribution. These results suggest that SHR exhibited a depressed myocardial adenylyl cyclase signaling system which may not be due to the functional uncoupling of beta-adrenoceptors from Gs but to the increased inhibitory G-protein (Gi) activity as demonstrated by the increased mRNA of Gi-alpha 2, increased inhibition of Gpp(NH)p-mediated adenylyl cyclase and the super high affinity for carbachol of the muscarinic receptors. Decreased beta-adrenoceptor density and functional alteration of Gi might be regarded as the predisposing factors for the increased susceptibility of myocardium of SHR to ADR.

Adenylyl Cyclases↗
PubMed1994

Urgent/emergent percutaneous transvenous mitral commissurotomy.

Urgent/emergent percutaneous transvenous mitral commissurotomy (PTMC) was performed in 10 patients (two men and eight women, aged 21 to 60 yr). All patients had arterial hypoxemia and four required mechanical respirators. PTMC was performed in the semi-recumbent position in four patients. The seven patients with pliable valves (group 1) achieved good hemodynamic and echocardiographic results after PTMC, but one died 2 wk later because of sepsis complicating preexisting pneumonitis. The two pregnant patients uneventfully delivered normal babies at term. There was continued clinical improvement in the six surviving patients at last follow-up at 11 to 39 mon (median 26). Of the three patients with calcified valves and severe subvalvular lesions (group 2), the premoribund patient in whom last-resort PTMC created severe mitral regurgitation died 3 days later of multiple organ failure. The other two patients underwent mitral valve replacement 1-6 days later because of lack of clinical improvement due to creation of severe mitral regurgitation and ineffective mitral valve dilation, respectively. In conclusion, urgent/emergent PTMC is feasible and safe. However, its outcomes are dictated by the status of diseased mitral valve and coexisting illness.

Adult↗
PubMed1994

Immunocytochemical localization of M2 muscarinic receptors in rat ventricles with anti-peptide antibodies.

We produced antibodies against a synthetic peptide corresponding to amino acids 168-192 of the second extracellular loop of the M2 human muscarinic receptor in rabbits. In immunoblot, affinity-purified antibodies specifically recognized a major band of rat ventricular muscarinic receptor protein with a molecular weight of about 80 KD. This recognition could be blocked by pre-incubation with peptide. Moreover, with both light (LM) and electron microscopic (EM) immunocytochemistry techniques, muscarinic receptors were detected on sarcolemma and T-tubules of rat cardiomyocytes. In addition, immunoreactions were localized in membranes of capillaries. Likewise, these reactivities were abolished by pre-incubation with peptide. These results suggest that the antibodies against the second extracellular loop of human M2 muscarinic receptor could specifically recognize rat ventricular muscarinic receptor protein and could be a powerful tool to study the fate of this receptor under different pathological or physiological conditions.

Acetylcholine↗
PubMed1993

Electrochemical sensor for heparin: further characterization and bioanalytical applications.

Further studies regarding the potentiometric response to heparin of polymeric membranes doped with lipophilic quaternary ammonium salts are reported. Among a wide range of membrane formulations examined, optimum response toward macromolecular heparin is achieved using tridodecylmethylammonium chloride as the active membrane component within poly(vinyl chloride) or poly(vinyl chloride)/(vinyl acetate) films plasticized with dioctyl sebacate. Although such membranes are shown to exhibit a typical Hofmeister potentiometric selectivity pattern toward small inorganic and organic anions, a very large and reproducible response to heparin at submicromolar levels is observed in the presence of physiological saline (0.12-0.15 M NaCl), as well as in citrated whole blood. Equal response on a mass basis occurs with fragments of heparin's as small as 2500 Da. Complexation of heparin's anionic sites by macromolecules that bind heparin with high affinity (e.g., protamine and poly(L-lysine)) reduces the membrane electrode's heparin response, indicating that the electrode detects biologically available (unbound) heparin levels in solution. Quantitative potentiometric titrations of protamine with porcine mucosa heparin followed by the sensor yield stoichiometric values in good agreement with the literature. The biomedical utility of the sensor is demonstrated by measuring its response in whole blood from patients undergoing open heart surgery before and after heparin therapy and correlating such response to conventional blood clotting time measurements.

Electrochemistry↗
PubMed1993

Pulmonary valvuloplasty in adults using the Inoue balloon catheter.

This report describes a new balloon pulmonary valvuloplasty technique using the Inoue balloon catheter performed in 14 consecutive adult patients, aged 17-47 years (mean 27). The mean right ventricular systolic pressure and the pulmonary valvular peak-to-peak systolic gradient decreased from 102 +/- 41 to 52 +/- 19 mm Hg (p = 0.001) and 81 +/- 40 to 7 +/- 7 mm Hg (p = 0.0002), respectively. An infundibular peak-to-peak systolic gradient either developed (n = 13) or increased (n = 1). None of the patients were treated with beta-adrenergic blockers before or after the valvuloplasty. Eight patients underwent repeat hemodynamic study 12-30 months (mean 17) after treatment, and had no evidence of valvular restenosis. The mean right ventricular systolic pressure and the mean infundibular peak-to-peak systolic gradient decreased, compared to the values immediately after valvuloplasty (54 to 40 mm Hg, p = 0.03, and 28 to 10 mm Hg, p = 0.03, respectively). The study suggests that pulmonary valvuloplasty in adults using the Inoue balloon catheter technique is feasible, safe, and effective.

Adolescent↗
PubMed1993

Percutaneous transvenous mitral commissurotomy in patients with severe kyphoscoliosis.

Because transseptal catheterization is felt to be contraindicated in patients with severe kyphoscoliosis, there have been no reports of percutaneous transvenous mitral commissurotomy performed in such patients. This report describes percutaneous transvenous mitral commissurotomy in three patients with severe thoracic kyphoscoliosis, with special emphasis on the transseptal puncture technique. Biplane right atrial angiography and the contrast septal flush method are very useful in landmark selection for a safe transseptal puncture.

Adult↗
PubMed1993

Prognosis after a first Q-wave myocardial infarction in ethnic Chinese people: a prospective study.

The prognosis after a first Q-wave myocardial infarction was investigated in 206 Chinese patients of 65 years or younger who had a predischarge cardiac catheterization and coronary angiography. Three patients studied were lost to follow-up. In the remaining 203 patients with ages of between 28 and 65 years, 101 (49.8%) had 0- or 1-vessel disease, 56 (27.6%) had 2-, and 38 (18.7%) had 3-vessel disease. Significant left main coronary artery stenosis was noted in 8 (3.9%). During a mean follow-up of 33 months, 33 (16.3%) patients had 36 episodes of cardiac events, and 16 (7.9%) died of cardiac causes. Stepwise logistic regression analysis revealed that the left ventricular ejection fraction and left main coronary artery disease were predictors of cardiac mortality, while age and the extent of coronary artery disease were predictors of total cardiac events. There was no variable that could predict recurrence of myocardial infarction.

Aged↗
PubMed1993

[A study of accuracy of multiple-unit one-piece castings of fixed bridge].

We studied how the accuracy of the three-unit and four-unit bridges is affected by the three different sprue programmes and heat-treatment. The results of experiments are as follows. 1. In the two types of fixed bridge the accuracy of the lateral pouring sprue programme is greater than that of the top-pouring and bottom-pouring sprue programmes. 2. After the heat-treatment of the casting, the stresses are distributed again, so the accuracy of the casting becomes lesser. 3. The change in the measurement of the total and pontic lengths of multiple-unit fixed bridges generally causes a "fork shape" deformity.

Dental Casting Technique↗
PubMed1992

Familial aggregation of oesophageal cancer in Yangcheng County, Shanxi Province, China.

Oesophageal cancer is the second most common cause of cancer death in China and is particularly prevalent in northern China. Genetic factors have been studied less than environmental factors in the aetiology of this disease. This study was conducted to evaluate familial aggregation of oesophageal cancer. All households in Yangcheng County were interviewed in 1979 to determine family history of oesophageal cancer. In 1989, vital status for all family members from three Yangcheng villages was determined and re-interviews were conducted among families who reported a positive family history of oesophageal cancer in 1979. Risk of oesophageal cancer was evaluated by comparing family and individual rates of oesophageal cancer during the 1979-1989 interval stratified by the number of family members with oesophageal cancer prior to 1979. More families with prior oesophageal cancer history reported new oesophageal cancer deaths during the follow-up period than families without prior history (19% versus 5%). Oesophageal cancer rates increased with increasing positivity of family history, and adjustment for other risk factors did not substantially alter this result. We conclude that these data provide evidence for familial aggregation of oesophageal cancer.

Adult↗
PubMed1992

A strategy for isolating differentiation-inducing complementary DNAs from human esophageal cancer cell line treated with retinoic acid.

Treatment of the human esophageal cancer cell line EC8712 with retinoic acid (RA) stopped the cell growth significantly and gave rise to terminal differentiation of the cells characterized by increased expression of involucrin gene. Two cDNA libraries were constructed from the parental and RA-treated cells respectively. Repeated subtractive hybridization of single-stranded plasmid DNA prepared from pooled colonies of cDNA library of the parental cells with cDNA probe generated from the RA-treated cells exhausted sequences common to both libraries of the cell. The unhybridized cDNA probe represented, therefore, the genes activated after RA-treatment. By using these enriched cDNAs as probe to screen the cDNA library constructed from the RA-treated cells thirty-nine positive colonies were obtained, of which two were specifically due to RA-induction. One of these two cDNA clones, designated as pRA538, has undergone further analysis and shown differentiation-inducing effect on parental cancer cells. A novel strategy for cloning genes involved in terminal differentiation of cancer cells is developed.

Carcinoma, Squamous Cell↗
PubMed1992

[DNA repair capacity measurement and possibility of heterozygote detection using nucleoid sedimentation technique among members taken from 3 xeroderma pigmentosum (XP) families].

The nucleoid sedimentation test was used to analyse the DNA repair capacity in 35 members taken from 3 xeroderma pigmentosum (XP) families after their peripheral blood lymphocytes being exposed to UV irradiation or N-methyl-N-nitro-N-nitrosoguanidine (MNNG) at a dose of 2.5 microJ/mm2 and 2 micrograms/ml respectively. The results showed that the 6 XP patients all failed to repair their damaged DNA even after 20-hour incubation at 37 degrees C. The repair ratios were 0.61 +/- 0.13 for UV and 0.44 +/- 0.15 for MNNG while those of non-related normal members usually reached 0.96 +/- 0.07 and 0.71 +/- 0.07 for both UV and MNNG after 11-hour incubation. It is interesting to note that 9 obligatory heterozygotes (parents and grandparents of XP patients) and 4 highly possible heterozygotes (blood relatives of XP patients) also showed very poor DNA repair capacity: they could not accomplish their repair process even after 20-hour incubation. It has been showed that the nucleoid sedimentation test can probably be used to pick out the heterozygotes in XP families.

Adolescent↗
PubMed1991

Short- and long-term results of catheter balloon percutaneous transvenous mitral commissurotomy.

Percutaneous transvenous mitral commissurotomy (PTMC) was performed in 219 patients with symptomatic, severe rheumatic mitral stenosis. There were 59 men and 160 women, aged 19 to 76 years (mean 43). Pliable, noncalcified valves were present in 139 (group 1), and calcified valves or severe mitral subvalvular lesions, or both, in 80 patients (group 2). Atrial fibrillation was present in 133 patients (61%) and 1+ or 2+ mitral regurgitation in 59 (27%). Technical failure occurred with 3 patients in our early experience. There was no cardiac tamponade or emergency surgery. The only in-hospital death occurred 3 days after the procedure in a group 2 premoribund patient in whom last-resort PTMC created 3+ mitral regurgitation. Mitral regurgitation appeared or increased in 72 patients (33%); 3+ mitral regurgitation resulted in 12 patients (6%). There were 3 systemic embolisms. Atrial left-to-right shunts measured by oximetry developed in 33 patients (15%). Immediately after PTMC, there were significantly reduced (p = 0.0001) left atrial pressure (24.2 +/- 5.6 to 15.1 +/- 5.1 mm Hg), mean pulmonary artery pressure (39.7 +/- 13.0 to 30.6 +/- 10.9 mm Hg) and mitral valve gradient (13.0 +/- 5.1 to 5.7 +/- 2.6 mm Hg). Mitral valve area increased from 1.0 +/- 0.3 to 2.0 +/- 0.7 cm2 (p = 0.0001) and cardiac output from 4.4 +/- 1.4 to 4.7 +/- 1.2 liters/min (p less than 0.01). The results mirrored clinical improvements in 209 patients (97%). Multivariate analysis showed an echo score greater than 8, and valvular calcification and severe subvalvular lesions as independent predictors for suboptimal hemodynamic results.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗