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Biomedical subjects

K Y Jiang

Publications and source records attributed to K Y Jiang.

15 recordsLinked to original sources
PubMed1999

Structure-function relationship in glycosylated alpha-chymotrypsin as probed by IMAC and IMACE.

Chemical glycosylation of bovine alpha-chymotrypsin, by a glucosamine adduct on the carboxyl group, results in the modification of its catalytic activity. The structural alterations of alpha-chymotrypsin resulting from its glycosylation are studied by immobilized metal-ion affinity chromatography (IMAC) and immobilized metal-ion affinity capillary electrophoresis (IMACE). The chemical glycosylation of alpha-chymotrypsin generates two distinct subpopulations of the protein: one which totally loses the initial affinity for IDA-Cu(II) and another which exhibits an increased affinity for the metal chelate ligand.

Animals↗
PubMed1998

Effects of tanshinone II-A sulfonate on adhesion molecule expression of endothelial cells and platelets in vitro.

AIM: To study the action of tanshinone II-A sulfonate (Tan) on adhesion molecule expression by cultured endothelial cells and platelets. METHODS: Tumor necrosis factor alpha (TNF-alpha)-induced ICAM-1 expression on the cell surface and endothelial adhesivity toward HL-60 cells were studied using human umbilical vein endothelial cells (HUVEC). Thrombin-induced expression of platelet P-selectin was studied using human blood platelets. Adhesion molecule expression on the cell surface was measured by flow cytometry. The number of HL-60 cells adhering to the HUVEC monolayer was determined by liquid scintillation spectroscopy. RESULTS: Pretreatment of HUVEC with TNF-alpha significantly enhanced ICAM-1 expression and increased HL-60 cells adhesion to HUVEC from 4.6% +/- 0.7% to 30% +/- 6%. Tan (25-200 mumol.L-1) inhibited the effects of TNF-alpha in a concentration-dependent manner. Tan also inhibited the increase of P-selectin expression of thrombin-activated platelets in a concentration-dependent manner. CONCLUSION: Tan inhibited expression of adhesion molecules (ICAM-1, P-selectin) in HUVEC and in human blood platelets.

Blood Platelets↗
PubMed1996

Esters and amides of 6-(chloromethyl)-2-oxo-2H-1-benzopyran-3-carboxylic acid as inhibitors of alpha-chymotrypsin: significance of the "aromatic" nature of the novel ester-type coumarin for strong inhibitory activity.

A series of esters and amides of 6-(chloromethyl)-2-oxo-2H-1-benzopyran-3-carboxylic acid were synthesized and evaluated in vitro for their inhibitory activity toward bovine alpha-chymotrypsin and human leukocyte elastase. Both series behaved as time-dependent inhibitors of alpha-chymotrypsin, but ester-type coumarins were clearly more efficient than the corresponding amides in inactivating the serine proteinase. The best inactivations were observed with "aromatic" esters, in particular with meta-substituted phenyl esters such as m-chlorophenyl 6-(chloromethyl)-2-oxo-2H-1-benzopyran-3-carboxylate, which appears to be one of the most powerful inactivators of alpha-chymotrypsin yet reported (kinact/KI = 760,000 M-1 S-1 at pH 7.5 and 25 degrees C). Usually, the coumarin derivatives failed to inhibit significantly human leukocyte elastase. As a result, the reported series of aromatic coumarinic esters behaves as a new chemical family of selective alpha-chymotrypsin inhibitors.

Animals↗
PubMed1995

Effects of Panax notoginseng saponins on posthypoxic cell damage of neurons in vitro.

AIM: To study cerebral protective mechanism of Panax notoginseng saponins (PNS). METHODS: Cultured neurons of chick embryo cerebral hemisphere were used as an in vitro system for investigating the effects of PNS. The hypoxic cell damage of neurons cultured were induced by NaCN. The levels of adenosine triphosphate (ATP) were determined with HPLC. PNS was added 30 min before, beginning or after hypoxia. RESULTS: PNS 50 and 100 mg L-1 retarded the break down of ATP of cultured neurons after 2-h hypoxia for 11.3 +/- 1.5 (P < 0.05) and 12.8 +/- 2.2 mumol/g protein (P < 0.01), respectively and accelerated the restoration of ATP during 30-min reoxygenation for 21.0 +/- 2.0 (P < 0.05) and 22.7 +/- 2.6 mumol/g protein (P < 0.01), respectively. PNS also reduced the release of creatine kinase (CK) from 75 +/- 8 kU L-1/g protein to 52 +/- 6 (P < 0.05) and 41 +/- 3 kU L-1/mg protein (P < 0.01), respectively and promoted the restoration of ATP of neurons 20 h after hypoxia when administered in the beginning of hypoxia from 13.0 +/- 0.9 mumol/g protein to 18.1 +/- 1.4 and 20.5 +/- 2.1 mumol/g protein (P < 0.01), respectively. PNS still promoted the restoration of ATP from 13.0 +/- 0.9 nmol/mg protein to 14.9 +/- 1.0 and 18.3 +/- 0.7 nmol/mg protein (P < 0.01), respectively and reduced (PNS 100 mg L-1) the CK release of neurons 20 h after hypoxia even when added in the recovery. CONCLUSION: The protection against hypoxic damage of PNS was related to improving energy metabolism, preserving the structural integrity of neurons.

Adenosine Triphosphate↗
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↗
PubMed1991

A full-to-empty mode controller for the pneumatically-driven blood pump.

Presented in this paper is a microprocessor-based controller developed based upon the theory of finite state automata to activate the pneumatically-driven diaphragm blood pump in the full-to-empty mode. Under normal situations, each pumping cycle of the blood pump can be divided into several phases in a proper sequence, and such phase information is contained in the driving air pressure waveform. The controller tries to match the sequential phases with the pressure waveform sampled at real time in an attempt to search for the end-ejection or end-filling of the blood pump. If either the end-ejection or the end-filling can be found, the controller sends triggering signals to the driving unit, and if the sampled pressure waveform can not be matched with the sequential phases or the controller fails to detect the end-ejection or end-filling, the controller activates the driving unit by the parameters of the last measured pumping cycle; thus, the driving unit triggers the blood pump without any stop. The result of laboratory bench tests demonstrates its ability in finding the end-ejection and end-filling points and the reliability of the fail-safe measure.

Algorithms↗
PubMed1991

A generic algorithm for finding restriction sites within DNA sequences.

This paper describes a generic algorithm for finding restriction sites within DNA sequences. The 'genericity' of the algorithm is made possible through the use of set theory. Basic elements of DNA sequences, i.e. nucleotides (bases), are represented in sets, and DNA sequences, whether specific, ambiguous or even protein-coding, are represented as sequences of those sets. The set intersection operation demonstrates its ability to perform pattern-matching correctly on various DNA sequences. The performance analysis showed that the degree of complexity of the pattern matching is reduced from exponential to linear. An example is given to show the actual and potential restriction sites, derived by the generic algorithm, in the DNA sequence template coding for a synthetic calmodulin.

Algorithms↗
PubMed1991

[Experimental study on combined treatment in smoke inhalation injury].

Forty-two healthy dogs were randomly divided equally into a control group (CG) and a treated group (TG). All were inflicted with severe smoke inhalation injury and pulmonary was demonstrated. The dogs in TG were treated with injection of shenmai zhusheye, ketoprofen, anisodamine, sodium aesculin, hydrocortisone succinate, vitamin C and E, penicillin, amikacin, oxygen inhalation and airway suctioning after injury. The results showed that the increase in extravascular lung water volume, lung edema shadow in x-ray films, elevation of lung vascular resistance, carbonemia, hypoxemia, respiratory alkalosis, metabolic acidosis, dyspnea, dry and moist rales of the lungs, reduction of tidal volume, etc, were markedly improved in TG as compared with that of CG. It indicated that the pulmonary edema and lung dysfunction was markedly ameliorated in TG. The mortality was 19.1% in TG, which was significant lower than that of CG which was 47.6%.

Animals↗
PubMed1991

Changes of length of elastic fibers in rabbit lungs after smoke inhalation injury.

Pulmonary morphometry was determined in rabbit lungs after smoke inhalation. Twenty-four hours after injury, changes of the total lung volume (TLV) and the total length of all parenchymal elastic fibers (LT) were measured. Concomitant changes in arterial blood gas levels and pathomorphology of lung tissues were also studied. It was found that alveolar walls were broken and became thinner, and that alveoli were dilated. TLV was markedly increased and LT was markedly decreased as compared to normal lungs (P less than 0.05). These findings suggest that proteinases, especially elastase, released from phagocytes may play an important role in acute lung injury after smoke inhalation.

Animals↗
PubMed1987

Blood gas studies in dogs with severe steam inhalation injury.

The dynamic changes in blood gases in 34 dogs suffering severe steam inhalation injury were studied during the first 14 days post-burn to determine the effects of inhalation injury on lung function. Nineteen dogs received only severe steam inhalation injury, while 15 other dogs received both 30 per cent total body surface area (TBSA) deep burns and steam inhalation injury. The results showed marked reductions of PaO2, PaCO2, AB, SBE, T-CO2, SB, BBp, pHNR and SatO2 (P less than 0.05 approximately 0.01), whereas the P(A-a)O2 increased (P less than 0.05 approximately 0.01) within week 1 post-burn in both groups. These data suggest that the injured animals were suffering from hypoxaemia and respiratory alkalosis induced by disturbance of the gas-exchange function of the lungs. There was also metabolic acidosis, which was closely related to high fever, excessive catabolism, and particularly to hypoxaemia in week 1 post-burn. If the animals survived through the critical period (1-7 days post-burn), most of the abnormal gas parameters then gradually returned to the pre-burn levels. It is clear, therefore, that blood gas monitoring in patients with inhalation injury is not only of diagnostic importance but also of prognostic value.

Acidosis, Respiratory↗
PubMed1983

Effect of intravenous infusion on development of pulmonary oedema after inhalation injury.

Last year, after a systematic search of pathological and patho-physiological changes of inhalation injury in dogs, we recorded severe pulmonary oedema as early as 2 h postburn (the earliest monitoring time designed in experiment) on dogs inflicted with both body surface and severe respiratory burns without any fluid replacement during the whole course of experiment. In an analysis of cases admitted into our burn centre in the past ten years, we also found that there was no definite relationship between the incidence and severity of pulmonary oedema occurring in severe burn patients and the amount of fluid infused in the early burn phase. These facts led us to the following experiment designed to study the effect of intravenous infusion on development of pulmonary oedema after severe burns complicated with inhalation injuries.

Animals↗