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Biomedical subjects

Z C Yang

Publications and source records attributed to Z C Yang.

At least 37 records · Page 2Linked to original sources
PubMed1995

A preliminary exploration of the relationship between tumour necrosis factor (TNF) and monocytic in vitro production of interleukin-1 (IL-1) and internal organ dysfunction in severely burned patients.

Biological assays were adopted in this study to examine the changes in serum tumour necrosis factor (TNF) activity and blood monocytic in vitro production of interleukin 1 (IL-1) in 24 severely burned patients. The myocardial and hepatic enzymes (which included aspartate aminotransferase (AST), creatine kinase (CPK), lactate dehydrogenase (LDH), alpha hydroxybutyric dehydrogenase (alpha-HBDH) and alanine amino-transferase (ALT) and some indices of biochemical metabolism (including lactic acid (LA), total protein (TP), albumin (Alb) and colloid osmotic pressure (COP)) were simultaneously measured. The results showed an evident increase in serum TNF activity and a decrease in in vitro production of IL-1 postburn; all the changes in TNF and IL-1 were correlated significantly with those of myocardial and hepatic enzymes in MOF patients. Furthermore, there were marked fever, hypoproteinaemia, tissue ischaemic and hypoxic symptoms such as hyperlacticaemia, and signs reflecting tissue hypercatabolic states. These all suggested that TNF and IL-1 might play important roles in the development of MOF.

Adolescent↗
PubMed1995

Effects of nimodipine, felodipine, and verapamil on isolated human arteries.

AIM: To evaluate whether there might be some difference in the action modes of nimodipine (Nim) and felodipine (Fel). METHODS: Compare the inhibitory effects of Nim and Fel with that of verapamil (Ver) as a representative of phenylalklamine on norepinephrine (NE)- and CaCl2-evoked contractions of human arteries. RESULTS: In Ca(2+)-free and high K+ depolarized solution, inhibitory effects of Nim, Fel, and Ver were more potent on CaCl2-induced contractions on isolated human arteries than those on NE-induced contractions. In CaCl2-induced contraction, the pD2 values for Nim, Fel, and Ver were 7.5, 7.42, 6.35 on uterine arteries; 7.38, 7.65, 7.20 on mesenteric arteries and 7.87, 9.10, 7.32 on renal arteries, respectively. Ver inhibited 2 components of NE-evoked contraction, while Nim and Fel only inhibited extracellular Ca(2+)-dependent contractions. CONCLUSION: The result indicates that Fel has a selective action on human renal arteries.

Adult↗
PubMed1994

Clinical significance of the change of blood monocytic interleukin-1 production in vitro in severely burned patients.

Biological methods were employed to measure the dynamic changes in the in vitro IL-1 production by blood monocytes in 24 severely burned patients. The serum myocardial and hepatic enzymes (C-reactive protein) (CRP), plasma lactic acid (LA), etc. were simultaneously measured. The results showed an obvious decrease in blood monocyte IL-1 production in vitro and increases in CRP, LA and serum enzymes. These changes were more evident in patients complicated with organ injury, multiorgan failure and systemic infection. It is suggested that blood monocytes are superstimulated postburn in vivo and produced large amounts of IL-1 leading to exhaustion of monocyte function. These changes might promote the development of severe systemic infection and internal organ injury even multiple organ failure.

Adolescent↗
PubMed1994

The significance of changes in serum tumour necrosis factor (TNF) activity in severely burned patients.

In order to explore the pathogenesis of postburn internal organ injury (OI) and multiple organ failure (MOF), serum TNF activity was measured by biological assay in 24 severely burned patients. Parameters related to internal organ functions were simultaneously measured. The results showed an obvious increase in serum TNF activity accompanied by increased serum myocardial and hepatic enzymes, plasma lactate and aggregations of WBC in internal organ tissues. Serum protein levels decreased substantially. These changes were more marked in patients suffering from both OI and MOF. It is suggested that large amounts of TNF are produced postburn and might have an important role in the development of OI and MOF.

Adolescent↗
PubMed1994

Identification of beta-adrenoceptors in mouse myometrium by radioligand binding study.

The binding of radioligand to cell membrane prepared from mouse myometrium was used to identify the characteristics of beta-adrenoceptors. Uteri were taken from mature mice (Kunming Strain) weighing 40 +/- 5 g pretreated with estradiol benzoate 1 mg.kg-1.d-1 ip for 2 d. The binding of [3H]dihydroalprenolol ([3H]DHA) to uterine membrane was saturable, having a Bmax of 378 fmol/mg protein and a KD of 3.1 nmol.L-1. The slope of Hill plot (nH = 1.03) indicated the absence of cooperative interactions. IC50 and K1 values of l-norepinephrine (NE), dl-propranol (Pro), d-timolol (d-Tim), and l-Tim competed for the [3H]DHA binding sites were 171 +/- 10, 10.3 +/- 4.3, 6.5 +/- 2.1, 0.40 +/- 0.23 nmol.L-1 and 113 +/- 6, 6.3 +/- 2.8, 4.0 +/- 1.3, 0.25 +/- 0.14 nmol.L-1, respectively. These 4 agents competed for the [3H]DHA binding sites in an order of potency: l-Tim > d-Tim > Pro > NE. Atenolol (Ate) did not compete for [3H]DHA binding sites. The results suggested that these binding sites for [3H]DHA in mouse myometrium appeared to be beta 2-adrenoceptor.

Animals↗
PubMed1994

[Adenomyomatosis of the gallbladder: report of 42 cases].

This article reported 42 cases of adenomyomatosis of the gallbladder diagnosed by postoperative pathology. Since adenomyomatosis is often asymptomatic and accompanied by cholecystitis and gallstone, it is difficult to diagnose correctly before operation. Seven cases out of this group (16.7%) was diagnosed preoperatively. Correct diagnosis is based on alertness to this disease and cholecystogram. Cholecystectomy is the effective treatment. The relationship between the pathological types and Cholecystogram are discussed.

Adenomyoma↗
PubMed1994

Effects of endothelin-1 on isolated uterine horns in estrogen-primed and pregnant mice.

Mouse uterine horns from 4 states (estrogen-primed and early-, mid-, and late-pregnancy) were used to study the effect of endothelin-1 (ET) vs carboprost (Car) and oxytocin (Oxy). In K(+)-Krebs (KCl 40 mmol.L-1) solution, ET (1-300 nmol.L-1), Car (0.002-20 mumol.L-1), and Oxy (0.6-60 nmol.L-1) evoked concentration-dependent increases in tension of the uterine horns from 4 different states. Emax for ET were 1.12 +/- 0.26, 1.27 +/- 0.18, and 1.49 +/- 0.13 g in early-, mid-, and late-pregnancies, respectively. Emax for Car in mid- was twice that in late-pregnancy, whereas Emax for Oxy in late- was thrice that in mid-pregnancy. EC50 for ET were 9.6, 5.8, and 6.3 nmol.L-1 in early-, mid-, and late-pregnancies, respectively, and were only 2% to 7% of that for Car and 3-15 times of that for Oxy in various gravid stages. The results suggest that the contractile activity of pregnant mouse uterus to ET is more potent than that of Car while slightly weaker than that of Oxy.

Animals↗
PubMed1993

Cardiac electric activity of 1-(2-[(6-methoxyl)-naphthylmethyl])-1-methyl-N-piperidinylacethyl-6,7- dimethoxyl-1,2,3,4-tetrahydroisoquinoline in SHR and WKY rats.

1-(2-[(6-Methoxyl)-naphthylmethyl)])-1-methyl-N-piperidinylacethyl -6,7- dimethoxyl-1,2,3,4-tetrahydroisoquinoline (CPU-23), a substituted tetrahydroisoquinoline, reduced the voltages of P wave and J point, prolonged PR interval, and slowed sinus rhythm of ECG in spontaneously hypertensive rats (SHR) and age-matched normotensive WKY rats. The effects of CPU-23 on cardiac electric activity were stronger in SHR than in WKY rats (P < 0.05 or P < 0.01). The results suggest that CPU-23 have a calcium antagonistic activity on rat hearts and that calcium antagonists may exert a stronger inhibition of the cardiac electric activity in hypertensive rats than in normotensive rats.

Animals↗
PubMed1993

Effects of tetrandrine on functions and ultrastructure of alveolar macrophages in smoke inhalation-injured rabbits.

A rabbit model with severe smoke inhalation injury was used to explore the effects of tetandrine (Tet) on the release of inflammatory mediators and the level of [Ca2+]i in alveolar macrophages (AM) as well as on the ultrastructural changes. It was found that Tet reduced the number of white blood cells (WBC) in bronchoalveolar lavage fluid, inhibited the release of LTB4 and O2-. from AM, and increased the [Ca2+]i in AM. The changes in size, pseudopod, and lysosome evacuation in AM treated with Tet were smaller than those in the AM from the untreated. These results suggest that Tet may alleviate the pulmonary injury through inhibiting the activation of AM.

Alkaloids↗
PubMed1993

[Effect of splenectomy on disorder of cellular immunoregulation in patients with advanced schistosomiasis].

The peripheral blood natural killer (NK) cell activity, the percentage of E-CabR rosettes, phagocytosis of neutrophil and lymphocyte blastogenesis were studied to assess the cellular immunoregulation in patients with advanced schistosomiasis. The results showed that the NK cell activity and the percentage of E-CabR rosettes were significantly lower in patients with splenomegaly than in patients who had undergone splenectomy and in normal subjects. The phagocytic index of neutrophil and lymphocyte blastogenesis was reduced in patients with advanced schistosomiasis, but no significant difference was found between the patients with and without splenectomy. These results suggested that splenectomy not only reduce the portal hypertension but also improve the regulatory functions of cellular immunity which may enhance the patient's resistance against pathogens.

Adolescent↗
PubMed1993

Determination of beta-adrenoceptor subtypes in human pulmonary artery and thoracic aorta by radioligand binding.

The beta-adrenoceptors of human pulmonary artery (PA) and thoracic aorta (TA) were studied by the use of a high specific activity radioligand [125I]pindolol (Pin). To identify the subtypes of beta-adrenoceptors in the 2 blood vessels, the competitive inhibition curves of [125I]Pin by beta 1-antagonist atenolol and beta 2-agonist salbutamol were analyzed using a computer program LIGAND of a mathematical model of the ligand-binding system. The Bmax (15.3 +/- 1.2 fmol/mg protein) and the dissociation constant Kd (44 +/- 4 pmol.L-1) for PA were similar to those for TA (Bmax, 12.8 +/- 1.2 fmol/mg protein, Kd, 45 +/- 4 pmol.L-1). Competitive inhibition analysis showed that the beta 1- and beta 2-adrenoceptor subtypes coexisted in human PA and TA, with beta 1 adrenoceptor dominant. The ratios of beta 1:beta 2 in PA and TA were 2.9:1.0 and 2.1:1.0, respectively.

Albuterol↗
PubMed1992

Structure-retention index relationships for derivatized monosaccharides on non-polar gas chromatography columns.

A gas chromatographic method for predicting the retention index of a derivatized monosaccharide is presented. The procedures are especially useful to detect and predict minute quantities of sugars in biological or chemical samples. Monosaccharides are first converted to the alditols and then derivatized by acetylation, permethylation or silylation. The derivatized monosaccharide structure-retention index relationship that has been developed is useful in the identification of unknown monosaccharides that can be readily confirmed by gas chromatography-mass spectrometry.

Acetylation↗
PubMed1992

Dynamic balance changes between elastase and antiprotease in the early stages after smoke inhalation injury.

Following the use of a rabbit smoke inhalation injury model established in this institute, there were marked reductions in elastase activities in neutrophils and alveolar macrophages; rapid increases in elastase activity in broncho-alveolar lavage fluid (BALF); reductions of serum trypsin inhibitory capacity; a decrease of Pao2 and an increase of PaCO2, and marked increases of lung water volume. Significant correlations were found between the increased extravascular lung water content and the rising elastase activity in BALF. It seems probable that the imbalance between elastase and antiprotease played an important role in the development of acute lung injury after smoke inhalation.

Animals↗
PubMed1992

Clinical studies on postburn multiple organ failure: its aetiological factors and monitoring.

This study demonstrated that multiple organ failure (MOF) developed in 16 of 57 severely burned patients (28.1 per cent). When expressed as a percentage of the 590 patients admitted during the same period, the incidence became 2.7 per cent. Fifteen of the 16 MOF cases died, with a mortality of 93.8 per cent. In those patients with TBSA over 80 per cent with inhalation injury, severe shock and systemic infection, the incidence of MOF was significantly higher. Systemic infection and severe shock were the most important complications. These results indicated that the severity of the burn is the prime prerequisite of MOF, while severe shock and systemic infection are secondary but very important factors in the genesis and development of postburn MOF. The circulatory platelet aggregate ratio (CPAR) started to decrease significantly at 12 h postburn, remaining at low levels and declining further at 5-7 days postburn. However the values of the myocardial enzyme spectrum (MES) remained at significantly higher levels, indicating significant and continuous increases of microaggregate formation and the continuous existence of visceral and tissue ischaemia and cellular destruction. Changes of CPAR and MES in MOF patients were directly related to the development of MOF. It is advisable to use CPAR and MES to monitor the possible development of postburn MOF.

Adult↗
PubMed1992

A prospective clinical study on the pathogenesis of multiple organ failure in severely burned patients.

This study has shown that multiple organ failure (MOF) is one of the major causes of death in patients with severe burns. Both the plasma and visceral levels of TXB2 and the TXB2/6-keto-PGF1 alpha ratio were significantly increased. The changed plasma levels of TXB2 and the TXB2/6-keto-PGF1 alpha ratio paralleled the deterioration of the general condition in MOF patients. The circulatory platelet aggregation ratios (CPAR) in the MOF patients initially declined then dropped profoundly at 5-7 days postburn, indicating more microaggregate formation. CPK, LDH and GOT had increased markedly by 1 day, were elevated further at 2-3 days, and remained at supranormal levels for the first 7 days postburn. Degeneration, destruction, oedema, haemorrhage and thrombosis were observed in tissues from patients who died due to heart, lung, renal and hepatic failure. Clinically, 13 of the 16 MOF cases developed organ failure and 11 died between 3 and 7 days postburn. These findings confirmed that the increases of TXA2 and the TXA2/PGI2 ratio in plasma and visceral tissues can be an important factor in the genesis and development of postburn MOF.

6-Ketoprostaglandin F1 alpha↗
PubMed1992

Roles of thromboxane and prostacyclin in the pathogenesis of acute respiratory failure in burn patients combined with inhalation injury.

Forty-one severely burned patients were divided into inhalation injury and non-inhalation injury groups. It was found that in the inhalation injury group, TXB2 level and TXB2/6-keto-PGF1 alpha ratio in both plasma and lung tissues were significantly elevated, circulatory platelet aggregate ratio markedly decreased, and blood viscosity greatly increased. Histopathologically, congestion, oedema, haemorrhage and thrombosis were observed in lung tissues taken from patients succumbing to respiratory failure. The changes in TXB2 and TXB2/6 keto-PGF1 alpha ratio accorded with the clinical course of the development of respiratory failure in burn patients with inhalation injury. It is proposed that the imbalance of TXA2/PGI2 plays an important role in the pathogenesis of respiratory failure in severely burnt patients complicated with inhalation injury.

Acute Disease↗
PubMed1992

[Clinical study of the pathogeneses of multiple organ failure after burns].

51 burned patients with TBSA over 30% were studied prospectively. MOF developed in 17 of them. Postburn MOF occurred mainly in those with TBSA over 70%. Mortality of MOF was directly proportional to the number of organs involved. The incidence of pulmonary failure was the highest, and the highest mortality was attributed to renal failure. MOF occurring in the early stage was more related to burn shock, and those occurring in the late stage was predisposed mainly by infection. Oxygen free radicals play an important role in the genesis and development of postburn MOF. In this study, it was revealed that antiperoxidation ability declined, active oxygen was increased, and lipid peroxidation became excessive after the burn injury. It was also found that oxygen free radical-mediated effects produced more serious damages in patients with MOF than those without, and also more in those died than the survivors. The hypoxanthine-xanthine oxidase system was a significant source of oxygen radicals after the burn injury. There were also significant changes in plasma TXA2 and PGI2 levels postburn. The marked increase in TXA2/PGI2 ratio indicated imbalance between TXA2 and PGI2, which was correlated well with burn size and closely related to the development of postburn MOF. The excessive production of TXA2 might trigger or accelerate the formation of microaggregates and thromboxane, subsequently leading to visceral damages and failure.

6-Ketoprostaglandin F1 alpha↗