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Biomedical subjects

Z Wu

Publications and source records attributed to Z Wu.

At least 613 records · Page 34Linked to original sources
PubMed1995

Is the sphere organelle/coiled body a universal nuclear component?

We present evidence for the essential homology of four nuclear organelles that have previously been described under four different names: coiled bodies in mammalian somatic nuclei, prenucleolar bodies in nuclei assembled in vitro in Xenopus egg extract, sphere organelles in amphibian germinal vesicles (GVs), and Binnenkörper in insect GVs. Each of these organelles contains coilin or a coilin-related protein plus a variety of small nuclear ribonucleoproteins. We suggest that the sphere organelle/coiled body is a "universal" nuclear component in the sense that it is involved in common nuclear processes and hence will be found in one form or another in most eukaryotic cells. We postulate that it functions in the assembly and sorting of snRNP complexes for three RNA processing pathways: pre-mRNA splicing, rRNA processing, and histone pre-mRNA 3' end formation. Specifically, the sphere organelle/coiled body may be the initial site for assembly of processing complexes, which are then sorted to other places in the nucleus, where the actual RNA processing takes place.

Animals↗
PubMed1995

Glomerular function and structure in the sodium-replete and sodium-deplete uninephrectomized spontaneously hypertensive rat: effect of blood pressure reduction, glomerular structure, and blood pressure reduction.

To assess the effects of chronic dietary sodium restriction and blood pressure reduction on glomerular function and structure during the pathogenesis of hypertensive renal disease, experiments were conducted in uninephrectomized (UNX) spontaneously hypertensive rats (SHR) using the dihydropyridine calcium antagonist manidipine. Male SHRs underwent UNX at age 10-11 weeks and subsequently were assigned to one of four groups: sodium-replete (0.4%); sodium-replete and a predetermined antihypertensive dose of manidipine (20 mg/kg body weight); sodium-deplete (0.09%); and sodium-deplete and manidipine (20 mg/kg body weight). Twelve weeks later, renal morphologic and functional studies were performed. Sodium restriction had no significant effect on systolic blood pressure, but creatinine clearance and urinary protein excretion were decreased. Importantly, mean glomerular volume and the prevalence of mesangial expansion were lower with sodium restriction. This occurred in the presence of high concentrations of plasma and renal tissue angiotensin II. Manidipine significantly reduced systolic blood pressure in the sodium-replete and sodium-deplete UNX-SHRs. This therapy was not associated with significant changes in creatinine clearance and urinary protein excretion in the sodium-deplete or sodium-replete UNX-SHRs. The prevalence of mesangial expansion in the sodium-replete UNX-SHR was approximately 50% lower with manidipine. Plasma and renal tissue angiotensin II concentrations were not affected by the drug. In the sodium-deplete UNX-SHR, the prevalence of mesangial expansion was not reduced further by manidipine. However, plasma and renal tissue angiotensin II concentrations were increased significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗
PubMed1995

Quantitation of soluble and membrane-bound Fc gamma RIIA (CD32A) mRNA in platelets and megakaryoblastic cell line (Meg-01).

Fc gamma receptors (Fc gamma Rs) are glycoproteins on platelet surface that bind IgG-containing immune complexes. However, excessive binding of immune complexes leads to platelet activation and thrombosis or increased platelet clearance and thrombocytopenia. In this study, Fc gamma R transcripts in platelets and megakaryoblastic cell line (Meg-01) were investigated using specifically designed oligonucleotides and a new quantitative in situ hybridization assay. Platelets and Meg-01 cells were found to express only Fc gamma RII transcripts. Of Fc gamma RIIA mRNA isoforms (Fc gamma RIIA, B and C), Fc gamma RIIA mRNA predominates in these cells. Platelets and Meg-01 cells contain both alternative spliced forms of Fc gamma RIIA mRNA, those with and without the transmembrane (TM) exon and both forms were present in near equal amounts. In contrast, Fc gamma RIIA transcript with the TM exon predominates in neutrophils and monocytes, suggesting that the splicing of the TM exon is under lineage-specific control.

Antigens, CD↗
PubMed1995

Characterization of neutralization epitopes in the V2 region of human immunodeficiency virus type 1 gp120: role of glycosylation in the correct folding of the V1/V2 domain.

A number of monoclonal antibodies (MAbs) with various levels of neutralizing activity that recognize epitopes in the V1/V2 domain of LAI-related gp120s have been described. These include rodent antibodies directed against linear and conformational epitopes and a chimpanzee MAb, C108G, with extremely potent neutralizing activity directed against a glycan-dependent epitope. A fusion glycoprotein expression system that expressed the isolated V1/V2 domain of gp120 in native form was used to analyze the structural characteristics of these epitopes. A number of MAbs (C108G, G3-4, 684-238, SC258, 11/68b, 38/66a, 38/66c, 38/62c, and CRA3) that did not bind with high affinity to peptides immunoprecipitated a fusion glycoprotein expressing the V1/V2 domain of HXB2 gp120 in the absence of other human immunodeficiency virus sequences, establishing that their epitopes were fully specified within this region. Biochemical analyses indicated that in the majority of V1/V2 fusion molecules only five of the six glycosylation signals in the V1/V2 domain were utilized, and the glycoforms were found to be differentially recognized by particular MAbs. Both C108G and MAbs directed against conformational epitopes reacted with large fractions of the fully glycosylated molecules but with only small fractions of the incompletely glycosylated molecules. Mutational analysis of the V1 and V2 glycosylation signals indicated that in most cases the unutilized site was located either at position 156 or at position 160, suggesting the occurrence of competition for glycan addition at these neighboring positions. Mutation of glycosylation site 160 destroyed the C108G epitope but increased the fraction of the molecules that presented the conformational epitopes, while mutation of the highly conserved glycosylation site at position 156 greatly diminished the expression of the conformational epitopes and increased expression of the C108G epitope. Similar heterogeneity in glycosylation was also observed when the HXB2 V1/V2 fusion glycoprotein was expressed without most of the gp70 carrier protein, and thus, this appeared to be an intrinsic property of the V1/V2 domain. Heterogeneity in expression of conformational and glycan-dependent epitopes was also observed for the natural viral env precursor, gPr160, but not for gp120. These results suggested that the closely spaced glycosylation sites 156 and 160 are often alternatively utilized and that the pattern of glycosylation at these positions affects the formation of the conformational structures needed for both expression of native epitopes in this region and processing of gPr160 to mature env products.

Amino Acid Sequence↗
PubMed1995

Premarital cohabitation and postmarital cohabiting union formation.

"Previous research has indicated that premarital cohabitation decreases marital stability. This study examined the role of premarital cohabitation as a determinant of cohabitation after marital disruption. The author proposed that people who cohabited with their first spouse prior to marriage have a greater propensity to cohabit after marital disruption than people who did not cohabit before their first marriage. Event history analysis of the postmarital union experiences of women and men from the Canadian 1990 Family and Friends Survey (FFS) supports this proposition. It was found that the hazard rate of postmarital cohabitation was over 50% higher for premarital cohabitants than for noncohabitants."

Americas↗
PubMed1995

Effects of the new class III antiarrhythmic drug MS-551 and d-sotalol on canine coronary ligation-reperfusion ventricular arrhythmias.

The antiarrhythmic effects of a new class III antiarrhythmic agent, MS-551 [1,3-dimethyl-6-(2-[N-(2-hydroxyethyl)-3-(4-nitrophenyl) propylamino]ethylamino)-2,4(1H,3H)-pyrimidinedione hydrochloride], were investigated using canine coronary ligation-reperfusion arrhythmia models under slow and fast heart rate conditions and compared with those of d-sotalol. Slow and fast heart rate conditions were produced by using different anesthetics; i.e., halothane anesthesia for the slow heart rate condition and pentobarbital Na anesthesia for the fast heart rate condition. MS-551 prolonged QTc and suppressed the occurrence of fatal ventricular fibrillation (VF) on coronary reperfusion under either halothane or pentobarbital anesthesia. However, it also showed proarrhythmic effects, i.e., induction of torsades de pointes-like arrhythmia in 1 of 6 halothane anesthetized dogs before coronary ligation. d-Sotalol did not suppress the reperfusion VF in halothane anesthetized animals, nor did it show proarrhythmic effects. However, in the pentobarbital anesthetized animals, d-sotalol suppressed reperfusion VF accompanied by proarrhythmic effects in 1 of 7 dogs. d-Sotalol did not show reverse rate dependent QT prolongation. These results indicate that although both these class III drugs have similar electrophysiological properties, such as QTc prolongation, they have different antiarrhythmic effects. Also, antifibrillatory effects of class III drugs on coronary reperfusion apparently can not be explained solely by their QT prolonging effects.

Animals↗
PubMed1995

Influence of steam-flaked sorghum grain and supplemental fat on performance of dairy cows in early lactation.

Effects of sorghum grain processing and fat supplementation on milk yield and composition and nutrient digestibilities were studied. Thirty-six Holstein cows were assigned at 5 d of lactation for 91 d to treatment: 1) dry-rolled sorghum, no added fat; 2) dry-rolled sorghum plus Ca salts of long-chain fatty acids; 3) steam-flaked sorghum, no added fat; and 4) steam-flaked sorghum plus Ca salts of long-chain fatty acids. Fat increased ether extract in diets from 5.7 to 7.5% of DM. Milk yield was 4.0 kg/d (12%) higher for cows fed steam-flaked than dry-rolled sorghum. Fat tended to decrease milk yield because of lower DMI, and feed efficiencies increased 15%. Milk protein decreased .14% on dry-rolled sorghum with added fat, but only .01% on the steam-flaked diet. Milk protein yield was higher for cows fed flaked than rolled sorghum. Flaking decreased milk fat percentage, but not yield. Added fat decreased shorter chain fatty acids in milk (C4 to C14), but oleic acid increased. Flaking increased C10, C12, and C14, but decreased oleic acid. Digestibilities for DM, CP, starch, and ether extract were higher for flaked and fat-supplemented diets. Flanking of sorghum prevented the milk protein decrease reported for early lactation cows fed added fat.

Animal Feed↗
PubMed1995

Effect of enzyme treatment or steam-flaking of sorghum grain on lactation and digestion in dairy cows.

Effects of addition of a fungal enzyme (reported to have amylolytic and proteolytic activities) to dry-rolled or steam-flaked sorghum grain (40% of dietary DM) were tested for 70 d with 36 lactating Holstein cows in a 2 x 2 factorial arrangement of treatments. Compared with dry-rolling, steam-flaking resulted in increased yield of milk, milk protein, and 3.5% FCM; percentage of milk protein; and efficiency of feed utilization (FCM/DMI). Milk casein (as a percentage of milk N) was not altered, but milk urea N was lower, for cows fed steam-flaked sorghum. With steam-flaking, milk fat percentage decreased, short-chain fatty acids (C8 to C14) increased, but long-chain fatty acids (C16 to C18) were not affected. No yield parameters were altered by enzyme addition, except that the percentage of lactose in milk increased (5.02 vs. 4.96%). Steam-flaking of sorghum grain increased digestibilities of DM, OM, and starch (63 vs. 57%; 66 vs. 59%; and 98 vs 83%, respectively) compared with dry rolling. Enzyme addition did not affect starch digestibility, but digestibilities of DM, OM, CP, and NDF were greater than flaked grain was treated with enzyme, resulting in significant interaction effects. This study demonstrated higher milk and milk protein yields for cows fed steam-flaked sorghum than for cows fed dry-rolled sorghum, but addition of a sorghum-specific enzyme had no significant effect.

Animal Feed↗
PubMed1995

[Simultaneous assay of Ca(2+)-ATPase and Na+, K(+)-ATPase activities of hemolysate by malachite green colorimetric method].

Activities of Ca(2+)-ATPase and Na+, K(+)-ATPase of hemolysate were simultaneously determined by a colorimetric method with malachite green dye. In the presence of Ca2+, EGTA or ouabain, inorganic phosphate released from ATP by hypotonic saponin-treated red cell lysate was used to estimate the activities of Ca(2+)-ATPase and Na2+, K(+)-ATPase. The method is simple, sensitive and stable for at least 4 h. The effects of concentration of saponin and Ca2+, the storage of hemolysate, and the activator and inhibitor of the enzymes on activity were discussed.

Calcium-Transporting ATPases↗
PubMed1995

Stroke in the People's Republic of China. I. Geographic variations in incidence and risk factors.

BACKGROUND AND PURPOSE: Stroke is a major cause of death in the People's Republic of China (PRC), and the geographic distribution of stroke death varies substantially. We conducted an ecological analysis to investigate the relationship of prevalence of hypertension and other risk factors with stroke incidence and mortality in the PRC. METHODS: The relationship between prevalence of risk factors and stroke incidence and mortality in the PRC was assessed in 29 provinces by examining risk factor data from PRC national surveys and incidence and mortality from the 1986 PRC National Stroke Study. RESULTS: A highly statistically significant correlation between prevalence of hypertension and stroke incidence (r = .838, P < .001) and mortality (r = .841, P < .001) was observed. Prevalence of hypertension explained over 70% of the geographic variability in stroke incidence (partial R2 = .703) and mortality (partial R2 = .707) in the PRC. There was a north-south gradient, with a higher prevalence of hypertension and stroke incidence and mortality in the north compared with the south of the country. In multiple Poisson regression analysis, a 10% increase in the prevalence of hypertension was associated with a 2.80-fold higher incidence and 2.68-fold higher mortality from stroke, whereas a 10% increase in the prevalence of alcohol consumption was associated with a 29% higher incidence and a 16% higher mortality from stroke. A 10% increase in the prevalence of cigarette smoking was associated with a 19% higher mortality from stroke. CONCLUSIONS: In the PRC, the prevalence of hypertension is strongly associated with the risk of stroke, and the geographic variation in stroke incidence and mortality is due mainly to differences in the prevalence of hypertension.

Adolescent↗
PubMed1995

Stroke in the People's Republic of China. II. Meta-analysis of hypertension and risk of stroke.

BACKGROUND AND PURPOSE: In the People's Republic of China (PRC), stroke accounts for over 1 million deaths per year, more than three times the number of deaths from ischemic heart disease. To quantify the effect of hypertension on stroke in the PRC, we conducted a meta-analysis and estimated the population attributable risk of stroke due to hypertension. METHODS: We searched the Chinese Medical Literature Index and MEDLINE databases to identify studies on the relationship between hypertension and stroke conducted in the PRC. The overall relative risk of stroke in hypertensive persons and the population attributable risk of stroke due to hypertension were calculated by pooling the risk estimates from individual studies. RESULTS: A total of 12 epidemiological studies with 2379 stroke cases was identified. The overall relative risk of stroke associated with hypertension was 5.43 (95% confidence interval [CI], 4.62 to 6.39). The relative risk was similar for hemorrhagic (5.44; 95% CI, 3.99 to 7.40) and ischemic (5.25; 95% CI, 3.95 to 6.98) stroke. On the basis of data from the 1990 PRC population census, vital statistics, and the 1991 PRC National Hypertension Survey, the excess annual mortality from stroke due to hypertension was estimated to be at least 545,000 deaths, with a population attributable risk of 49.5%. CONCLUSIONS: Our data suggest that hypertension is an important risk factor for stroke in the PRC and that hypertension may account for about half of all deaths from stroke in that country. Treatment and prevention of hypertension should be an important societal goal in the PRC.

Adult↗
PubMed1995

[Effect of intralipid on patients with acute necrotic pancreatitis: a prospective clinical study].

17 patients with acute necrotic pancreatitis were proved by CT or operation. These patients were randomly assigned to fat-glucose-based group (n = 9) and glucose-based group (n = 8). Their PN regimen consisted of nonprotein calories (NPC) 35-40KJ (146-167KJ)/kg/d and nitrogen 0.19-0.29g/kg/d. NPC was supplied by either dextrose or dextrose and intralipid. The PN duration was 2 weeks. The following measurements were performed: triglyceride, chorestrol, HDL, LDL, Apo-A, Apo-B and free fatty acids. The results showed that there was no hypertriglyceridemia developed after fat emulsion was administered for two weeks. It confirmed that fat emulsion could be rapidly oxidigzed. In our group, the patients with hyperglycemia were 64% at the admission time, and hyperglycemia was difficult to control in early period (10 days). But hyperglycemia was easly to control when patients received fat emulsion. There was no harmful effect on liver function during 2 weeks of intralipid administration. The data showed no difference between the two groups on conventional measurements, lysosomal enzymes and blood gas analysis. Intralipid infusion did not make ANP deterioration. These results indicated long-term intravenous intralipid in patients with ANP was safe and useful.

Acute Disease↗
PubMed1995

[Stability of amino acids and vitamins in total nutrient admixture].

We reported a formula of total nutrient admixture (TNA) used in our patients. During 24 hours of storage shaded from daylight at 4 degrees C and at room temperature (25 degrees C), the concentrations of 17 kinds of amino acids and vitamin A, E, B1, B2 in the TNA prepared in EVA plastic bag were not changed significantly. A patient who has been on this TNA for parenteral nutrition for more than 8.5 years is in a good nutritional status, with no clinical manifestations in difficiency of vitamins and proteins. 42 patients receiving this TNA on TPN for a period ranging from 31 to 93 days were improved significantly in their nutritional status.

Acute Disease↗
PubMed1995

Effects of losartan on the renin-angiotensin-aldosterone axis in essential hypertension.

Twelve essential hypertensive patients were entered into a prospective study assessing the effect of losartan, a non-peptide specific angiotensin II receptor antagonist, on blood pressure, the renin-angiotensin-aldosterone axis and renal function. Specifically monitored prior to and following 12 weeks of therapy at 6 (peak) and 24 (trough) h after dosing, were blood pressure, plasma renin activity (PRA), plasma aldosterone, and plasma angiotensin II (Ang II), creatinine clearance and urinary albumin excretion (UAE). In this small sample of hypertensive patients, losartan monotherapy and losartan-hydrochlorothiazide (HCTZ) combination therapy were associated with modest reductions in systolic, diastolic and mean arterial BPs; significant changes were observed only at the peak dosing interval. Losartan, given as either monotherapy or combination therapy, was associated with an increase in the 'trough' values of PRA; significant changes in the 'trough' values of plasma Ang II and plasma aldosterone were not observed. In contrast, PRA and plasma Ang II were stimulated, and plasma aldosterone was depressed, 6 h after dosing. There were significant negative correlations between both PRA and plasma Ang II reactivity (difference between PRA or plasma Ang II values obtained 6 h after placebo dosing and 6 h after drug dosing) and the change in systolic, diastolic and mean arterial BPs. Of interest, losartan/HCTZ combination therapy was associated with a decrease in the creatinine clearance; UAE was not significantly altered. Losartan appears to be an effective anti-hypertensive agent in patients with mild to moderate hypertension. Its peak BP effect appears to be at the dosing interval corresponding to pharmacological blockade of angiotensin II receptors. Furthermore, this anti-hypertensive agent may be more efficacious in patients with a reactive renin-angiotensin system.

Aldosterone↗
PubMed1995

[Protective effects of methanolic extract of Oenanthe stolonifera (Roxb.) Wall. ex DC. on myocardial injury induced by ischemia and reperfusion in rats].

The methanolic extract Oenanthe stoloni fera iv, pretreatment can significantly prevent the arrhythmias induced by myocardial ischemia and reduce the myocardial infarct size in rats. It can also markedly prevent myocardial ischemia and reperfusion-induced arrhythmias. In addition, the methanolic extract of Oenanthe stoloni fera (100 mg/kg i.v.) helps significantly to decrease the MDA content and preserve the SOD activity in plasma.

Animals↗
PubMed1995

Circulating soluble interleukin-2 receptor alpha and beta chain in inflammatory bowel disease.

OBJECTIVES: Inflammatory bowel disease is characterized by T cell activation. Activated T cells shed interleukin-2 receptors (IL-2R) in a soluble form. A positive correlation between sIL-2R alpha (CD25) and disease activity in inflammatory bowel disease has been shown previously, whereas IL-2R beta (CD122) has never before been investigated in this respect. Serum from 27 patients with ulcerative colitis (UC), 31 with Crohn's disease (CD), and 29 healthy volunteers was obtained. METHODS: Disease activity was scored according to a semiquantitative score for UC and by Crohn's disease activity index for CD. sIL-2R alpha and -beta chains were assessed by a sandwich ELISA technique using monoclonal antibodies specific for CD25 and CD122, respectively. RESULTS: The median concentration of sIL-2R alpha was 4424 pg/ml in healthy controls, 6460 in UC (p < 0.004), and 6371 in CD (p < 0.01). The corresponding value of sIL-2R beta in healthy volunteers was 605 pg/ml; in active UC, significantly lower levels were found at 233 pg/ml (p < 0.01), whereas in inactive UC, no such difference was observed at 725 pg/ml (p > 0.05). In CD, the levels were 839 pg/ml in inactive and 920 pg/ml in active disease stages (p > 0.05 vs controls). A positive and significant correlation existed between sIL-2R levels of alpha and beta chains in CD (r = 0.64; p < 0.01) but not in UC (r = -0.32; p > 0.05) or in healthy volunteers (r = 0.16; p > 0.05). CONCLUSION: Future longitudinal studies will be necessary to learn whether this newly assessed sIL-2R beta (CD122), which may interfere with IL-15R, could be used to predict disease exacerbation and to monitor anti-inflammatory therapy in UC.

Adult↗
PubMed1995

[CT examination for renal vein thrombosis in nephrotic syndrome and the effect of thrombolytic therapy].

Renal vein thrombosis (RVT) was diagnosed in 12 of 60 patients with nephrotic syndrome with CT scan and confirmed by selective renal angiography. Of the 60 patients, 50 had primary glomerulonephritis with various pathological findings and 10 lupus nephritis. CT is valuable in screening renal vein thrombosis. Renal vein and cubital vein blood in the 12 patients were drawn for assay of FDP, AT III, VIIIR: AG, fibrinogen; the results indicated the presence of a state of hypercoagulation. Of these, 7 were given 200,000 units of urokinase (UK) in divided doses into renal vein within one hour and 5,200,000 units UK into renal artery in the same way. Patients also received 2.5mg/d warfarin and 75mg/d persantine. Except for the 3 with focal sclerosis, patients received 40mg/d prednisone. After 1 month CT and blood fibrinogen, FDP, AT III, VIIIR: AG studies were repeated. RVT in patients with intraarterial UK had complete dissolution of their thrombi. Complete dissolution occurred in 2 of the 7 receiving UK by renal vein and there was partial dissolution in the other 5. It seems that intraarterial injection yielded better results. Hypercoagulation state was alleviated in all patients with UK therapy.

Adult↗