Biomedical subjects

S Wan

Publications and source records attributed to S Wan.

At least 73 records · Page 4Linked to original sources

PubMed1997

Cytokine responses to cardiopulmonary bypass: lessons learned from cardiac transplantation.

BACKGROUND: A growing body of evidence relates the release during cardiopulmonary bypass (CPB) of proinflammatory cytokines, such as tumor necrosis factor-alpha, interleukin (IL)-6, and IL-8, to the postoperative systemic inflammatory response syndrome. Antiinflammatory cytokines, such as IL-10, however, may also play an important role in limiting these complications. METHODS: The English-language literature was reviewed. Emphasis was placed on cytokine responses during clinical CPB for cardiac operations and, in particular, for heart and heart-lung transplantation. RESULTS: The recent data indicate that (1) although cytokine release can be triggered by many factors during CPB, ischemia-reperfusion may play the most important role; (2) the levels of tumor necrosis factor-alpha, IL-6, and IL-8 are correlated with the duration of cardiac ischemia and the myocardium is a major source of these three cytokines during CPB; (3) IL-10 levels are correlated with the duration of CPB and the liver is a major source of IL-10 during CPB; and (4) steroid pretreatment is an effective intervention to inhibit the release of proinflammatory cytokines and enhance IL-10 production. CONCLUSIONS: The improved knowledge of cytokine responses to CPB may help to develop interventions aimed at reducing postoperative morbidity and mortality.

Adrenal Cortex Hormones↗

PubMed1997

Thrombus formation on a calcific and severely stenotic bicuspid aortic valve.

We report on a case of thrombus formation on a native bicuspid aortic valve, which was found during an elective operation for aortic valve replacement. Although no apparent predisposing cause of thrombosis could be ascertained, severe calcific stenosis of the bicuspid valve and cardiac catheterization may have played a role. The patient is in excellent condition 9 months after the operation.

Aged↗

PubMed1997

Inflammatory response to cardiopulmonary bypass: mechanisms involved and possible therapeutic strategies.

BACKGROUND: Recent study of the inflammatory reactions occurring during and after cardiopulmonary bypass (CPB) has improved our understanding of the involvement of the inflammatory cascade in perioperative injury. However, the exact mechanisms of this complex response remain to be fully determined. METHODS: Literature on the inflammatory response to CPB was reviewed to define current knowledge on the possible pathways and mediators involved, and to discuss recent developments of therapeutic interventions aimed at attenuating the inflammatory response to CPB. RESULTS: CPB has been shown to induce complement activation, endotoxin release, leukocyte activation, the expression of adhesion molecules, and the release of many inflammatory mediators including oxygen-free radicals, arachidonic acid metabolites, cytokines, platelet-activating factor, nitric oxide, and endothelins. Therapies aimed at interfering with the inflammatory response include the administration of pharmacologic agents such as corticosteroids, aprotinin, and antioxidants, as well as modification of techniques and equipment by the use of heparin-coated CPB circuits, intraoperative leukocyte depletion, and ultrafiltration. CONCLUSIONS: Improved understanding of the inflammatory reactions to CPB can lead to improved patient outcome by enabling the development of novel therapies aimed at limiting this response.

Adrenal Cortex Hormones↗

PubMed1997

[A study on the action of tang niao kang decoction].

Experiments have verified that Tang Niao Karg (a preparation from Chinese medicinal herbs) taken orally does not decrease the blood sugar of empty stomach in mice, but markedly helps lower high levels of blood sugar and lipid induced by epinephrine and glucose in mice. For rat models of diabetes induced by 4-o-pyrincidine Tang Niao Kang can significantly lower the content of blood sugar, raise the insulin level of blood serum, and enhance the tolerance to sugar.

Animals↗

PubMed1997

[Studies on expansion ex vivo of murine bone marrow cells and its hematopoietic reconstitution capacity].

OBJECTIVE: To investigate the effects of stem cell factor (SCF) in combination with interleukin-1 (IL-1) or/and interleukin-3 (IL-3) on ex vivo expansion of 5FU treated bone marrow cells and hematopoietic recovery in lethally irradiated mice transplanted with the expanded cells. METHODS: 5FU treated bone marrow cells (d3-5FU-BMC) were cultured in a cytokines-containing medium, and the net increments of CFU-GM and high proliferative potential colony forming cell (HPP-CFC) were evaluated. RESULTS: CFU-GM increased by 33.7 +/- 18.1- or 18.1 +/- 6.3- fold, and HPP-CFC by 17.8 +/- 10.5- or 12.7 +/- 9.1- fold, respectively, in cultures containing SCF with IL- or IL-3, as compared with that in control; while SCF alone had little effect. Compared with fresh d3-5FU-BMC, transplantation of the expanded bone marrow cells accelerated the recovery of recipients' peripheral blood cell counts by 1 approximately 3 days and increased the survival rate of the transplanted animals (d3-5FU-BMC group 50% vs expansion group 8U approximately 100%). CONCLUSION: SCF in combination with IL-1 or IL-3 synergetically ex vivo expands hematopoietic cells. Transplantation of the expanded bone marrow cells accelerates the recipient's hematopoietic reconstitution.

Animals↗

PubMed1997

Patient education in the management of diabetes mellitus.

AIM: A patient education programme in the management of diabetes mellitus (DM) was piloted in a government polyclinic. This study aimed to evaluate the effectiveness of the education programme in improving knowledge of DM and skills in self-care in order to achieve long term control of DM. METHOD: The study was carried out on an intervention group of 183 diabetic patients who completed the education programme and a control group of 95 diabetic patients who attended the clinic during the period of the study. The patients were assessed on their knowledge of diabetes and their practice for good control of the disease (dietary practice, compliance, home monitoring) through a questionnaire. Long term control was assessed by their glycosylated haemoglobin levels. The education programme comprised individual counselling using a diabetes education guide, talks, videoshows and food displays. RESULTS: The intervention group showed a significant and greater improvement in the knowledge of the disease and self-care and in the dietary practice (taking more unpolished rice/high fibre food, reducing calories intake and cutting down oily/fatty food) when compared to the control group. Compliance with medication and the mean HbA1c levels were also improved in the intervention group. CONCLUSION: In this study the educational intervention was observed to have improved the diabetic patients' knowledge of the disease and self-care and the long term control of the disease. Patient education is thus an important component in the management of diabetes mellitus.

Adult↗

PubMed1996

Steroid administration in heart and heart-lung transplantation: is the timing adequate?

BACKGROUND: The release of cytokines after cardiopulmonary bypass may play an important role in postoperative morbidity. The release of proinflammatory cytokines, such as tumor necrosis factor alpha, interleukin (IL)-6 and IL-8, is even greater in patients undergoing heart transplantation (HTx) than coronary artery grafting. We tested the hypothesis that in HTx patients the earlier administration of steroids, before rather than after cardiopulmonary bypass as usual, can reduce the inflammatory response. METHODS: In 20 consecutive patients who underwent HTx or heart-lung transplantation (HLTx), plasma levels of tumor necrosis factor alpha, IL-6, IL-8, and anti-inflammatory cytokine IL-10 were measured before heparin administration, at aortic cross-clamping and declamping, and 0.5, 1, 1.5, 2, 4, 12, and 24 hours after aortic declamping. In 10 patients (group I, 6 HTx and 4 HLTx), 500 mg of methylprednisolone was first given as usual at 1.5 hours after aortic declamping (at the end of cardiopulmonary bypass). In the next 10 patients (group II, 6 HTx and 4 HLTx), the first doses of methylprednisolone were given 1 hour before operation. In both groups, 125 mg of methylprednisolone were given every 8 hours thereafter during the first postoperative day. RESULTS: The ischemic time and cardiopulmonary bypass time were similar in the two groups (166 +/- 16 minutes versus 157 +/- 13 minutes, and 192 +/- 21 minutes versus 186 +/- 20 minutes, respectively, mean +/- standard error of the mean). At 30 minutes after aortic declamping and throughout the next 4 hours, tumor necrosis factor alpha levels were significantly lower in group II than in group I (all p < 0.03). Interleukin-8 values 1 hour after declamping were also lower in group II than in group I (49 +/- 15 pg/mL versus 130 +/- 38 pg/mL, p < 0.02). Interleukin-10 levels were significantly higher in group II than in group I from 30 minutes after declamping through 2 hours after (all p < 0.03). Interleukin-6 levels were similar in the two groups. CONCLUSIONS: Earlier steroid administration in the immunosuppressive protocol for HTx or HLTx may be preferable to reduce the inflammatory response to cardiopulmonary bypass, as reflected by a lower production of tumor necrosis factor alpha and IL-8, and a greater release of IL-10.

Adult↗

PubMed1996

Myocardium is a major source of proinflammatory cytokines in patients undergoing cardiopulmonary bypass.

Proinflammatory cytokines, such as tumor necrosis factor-alpha, interleukin-6, and interleukin-8, and anti unflammatory cytokines, such as interleukin-10, may play an important role in patient responses to cardiopulmonary bypass. We sought to define whether the myocardium and the lungs serve as important sources of these cytokines under conditions of cardiopulmonary bypass. Ten patients (age 64 +/- 3 years, mean +/- standard error of the mean) undergoing elective coronary artery bypass grafting were monitored with an arterial catheter, a coronary sinus catheter, and pulmonary artery catheter. Plasma levels of tumor necrosis factor-alpha, interleukin-6, interleukin-8, and interleukin-10 were measured simultaneously in peripheral arterial blood, coronary sinus blood, and mixed venous blood before heparin administration, 1 minute before aortic crossclamping, 5 minutes after aortic declamping, and at 0.5, 1, 1.5 and 2 hours after aortic declamping. The durations of cardiopulmonary bypass and aortic crossclamping were 114 +/- 9 and 64 +/- 5 minutes, respectively. Levels of tumor necrosis factor-alpha and interleukin-6 were significantly higher in coronary sinus blood than in arterial blood after aortic declamping. Tumor necrosis factor-alpha and interleukin-6 levels were also higher in mixed venous blood than in arterial blood within 1 hour after declamping. There were no significant differences among the three sampling sites with respect to interleukin-8 and interleukin-10 levels. In one patient who had postoperative myocardial infarction, however, interleukin-8 levels were three times as high as in coronary sinus blood than in arterial blood. These data indicate that the myocardium is a major source of tumor necrosis factor-alpha and interleukin-6 in patients undergoing cardiopulmonary bypass. The lungs may consume rather than release proinflammatory cytokines in the early phase of reperfusion. The source under these conditions of the antünflammatory cytokine interleukin-10 remains to be determined.

Aged↗

PubMed1996

Human cytokine responses to cardiac transplantation and coronary artery bypass grafting.

Cardiac surgery with cardiopulmonary bypass triggers an inflammatory response involving proinflammatory cytokines such as tumor necrosis factor-alpha, interleukin-6, and interleukin-8. To elucidate the pathophysiology of this cytokine response, we explored the possible differences in cytokine responses between patients undergoing heart transplantation and those undergoing coronary artery bypass grafting. Plasma levels of tumor necrosis factor-alpha, interleukin-6, interleukin-8, and interleukin-10 were measured in eight patients undergoing heart transplantation (mean age 44 years) and eight patients undergoing coronary artery bypass grafting (mean age 61 years). Duration of cardiopulmonary bypass and ischemic time were both longer in the heart transplantation group than in the coronary artery bypass grafting group (133 +/- 26 min vs 100 +/- 31 min, p < 0.05, and 130 +/- 47 min vs 58 +/- 21 min, p < 0.005, respectively). Samples were collected before heparin administration, at aortic crossclamping and declamping, and at 0.5, 1, 1.5, 2, 4, 12, and 24 hours after declamping. Tumor necrosis factor-alpha levels were significantly higher 30 minutes after aortic declamping in the heart transplantation group than in the coronary artery bypass grafting group (68 +/- 30 vs 18 +/- 5 pg/ml, p < 0.05). Interleukin-6 and interleukin-8 levels were also significantly higher 90 minutes after declamping in patients undergoing heart transplantation than in those undergoing coronary artery bypass grafting (310 +/- 63 vs 169 +/- 24 pg/ml, p < 0.05, and 73 +/- 17 vs 24 +/- 5 pg/ml, p < 0.01, respectively). Furthermore, interleukin-6 and interleukin-8 values 90 minutes after declamping were significantly correlated with the ischemic time (r = 0.72 and r = 0.82, respectively, both p < 0.05). Interleukin-10 levels in both groups rose to reach a peak value of around 115 pg/ml 1 hour after declamping. Patients undergoing heart transplantation exhibited a second peak of tumor necrosis factor-alpha, interleukin-8, and interleukin-10 levels 12 hours after declamping, probably related to the administration of rabbit antihuman thymocyte immunoglobulin (Thymoglobuline) 3 hours after declamping. Interleukin-6 levels decreased more significantly 12 and 24 hours after declamping in patients undergoing heart transplantation, probably related to methylprednisolone therapy. In conclusion, cardiopulmonary bypass is associated with the production of both proinflammatory and antiinflammatory cytokines. The production of proinflammatory cytokines in patients undergoing heart transplantation is higher than that in patients undergoing coronary artery bypass grafting, and this increase could be related to the longer duration of ischemia in the former group. The later course of cytokine levels after heart transplantation may be further influenced by immunosuppressive therapy.

Adolescent↗

PubMed1996

Cardiac tamponade due to spontaneous rupture of right coronary artery aneurysm.

A case of acute cardiac tamponade caused by spontaneous rupture of a right coronary artery aneurysm is reported. The aneurysm, which was present distally, was ligated during operation. Postoperative angiography suggested the aneurysm was congenital. The patient is doing well 5 months after operation.

Aneurysm, Ruptured↗

PubMed1996

[Clinical observation on effect of yiqi huoxue decoction over the left ventricular diastolic dysfunction].

The left ventricular diastolic function, grade of heart function and degree of Heart-Qi Deficiency of 52 aged patients with left ventricular diastolic dysfunction (LVDD) were measured by means of Doppler echocardiography and left ventricular impedance cardiography before and after treatment with Buqi Qiangxin decoction (BQQXD), a recipe of TCM for reinforcing Qi and promoting blood circulation. The data were compared with that of control group (15 cases) treated with verapamil. Results showed that 92.3% of the LVDD patients were associated with Heart-Qi Deficiency and 69.2% were complicated with blood stasis. After treated with BQQXD, the grade of heart function was elevated in 82.6%, the degree of Heart-Qi Deficiency was improved in 89.6% of the patients. The parameters reflecting the left ventricular diastolic function were all improved in different degree (P < 0.05-0.01), but the parameters reflecting left ventricular compliance were changed insignificantly (P > 0.05). It indicated that besides controlling on the etiological factors, the mechanism of BQQXD in treating left ventricular dysfunction might be related with its calcium antagonistic effect.

Aged↗

PubMed1995

[Epidemiological investigation of Campylobacter Jejuni infection in children].

Epidemiological studies on campylobacter jejuni infection in children were carried out in Chengdu during December 1987 to October 1989. Detection rate of campylobacter in 1,092 children with diarrhea was 11.36%, with the highest in children aged 1-2 and the lowest in babies within six months. Campylobacter jejuni could be detected in young children with acute diarrhea all the year round, with a higher detection rate in the spring and summer and lower in the autumn and winter. Campylobacter jejuni could be detected in 5.09% of healthy children, with a significant difference between kindergartens due to their living conditions. Use of spectrum of drug-resistance and plasmid analysis in children of nurseries and kindergartens to study campylobacter infection suggested campylobacter jejuni infection in children could be caused by a lot of distant-associated strains with genetic homogeneity.

Age Factors↗

PubMed1995

[Chemical constituents of Stellera chamaejasme L].

Twelve compounds were isolated from the roots of Stellera chamaejasma. Five of them were elucidated by spectroscopic and chemical methods as 3', 14-dimethyl-4', 11-dimethoxy-5, 7-dihydroxybenzoflavanone (10), daphnetin (1), umbelliferone (2), daucosterol (5) and beta-sitosterol (3). Compound 10 is new. Compounds 1, 2, 5, 10 were isolated for the first time from S. chamaejasme.

Benzoflavones↗

PubMed1995

[Guinea pigs infected by bacterial dust aerosol of Bacillus tuberculosis].

There still is controversy over whether Bacillus tuberculosis could be spread by dust. For the purpose to illustrate the possible contagious route, guinea pigs were exposed to bacterial dust aerosol which was generated by mixing Bacillus tuberculosis H37Rv with dried dust. The percentage of the size of particles, diameter < 4 microns, was 5.1%. The density of bacteria in the dust aerosol was 386.7 cfu/L and the mass medium diameter (MMD) was 1.9 microns. On the 70 days after exposure, in the 3 minutes exposed group, positive reaction to OT test (1:20) was 2/7, culture of Bacillus tuberculosis was positive from lungs and spleen was 1/7, in the 18 minutes exposed group, 5/8 were positive for OT test, the positive culture found from lungs was 2/8 and from spleen 1/8. These results showed that Bacillus tuberculosis could be spread by bacterial aerosol.

Aerosols↗

PubMed1994

[Percutaneous intra-aortic balloon pumping in cardiogenic shock].

Eleven patients with cardiogenic shock underwent percutaneous intra-aortic balloon pumping (PIABP). Six (55%) survived and 5 (45%) died. Seven patients were referred to the hospital after acute myocardial infarction and 4 of them survived after the therapy in conjunction with thrombolysis or percutaneous transluminal coronary. In another four patients receiving postcardiotomy, half survived without complication. We believe that PIABP can make early revascularization safe by combating reperfusion injury.

Adult↗

PubMed1992

Intra-articular osteoid osteoma.

Osteoid osteomas located within the capsule of a joint are uncommon and present challenging diagnostic difficulties. Twelve patients with an intra-articular osteoid osteoma were studied retrospectively to determine the spectrum of clinical and radiological findings. The features differ significantly from the well known classical hallmarks of the extra-articular lesion. The symptoms are non-specific with pain similar to other common joint disorders and the response to salicylate less precise. On plain radiography intra-articular lesions are difficult to identify, lacking the florid periosteal new bone and intense perifocal sclerotic reaction. A detectable focal lesion is commonly absent with considerable delay between the onset of symptoms and radiological detection of the tumour nidus. Bone scintigraphy and computed tomography (CT) are essential for an accurate and early diagnosis. These imaging techniques reveal abnormalities in bone and cartilage growth, new bone formation and sclerosis distant from the tumour on either side of the joint, and disruption of the articular surface. Radiological follow up after surgery shows that these changes can be reversible, especially when the diagnosis is made early.

Adolescent↗

PubMed1986

The acute haemodynamic effects of nicardipine in patients with chronic left ventricular failure.

Nicardipine is a new slow channel calcium blocker. It has been shown to be effective in the treatment of hypertension and angina pectoris. Nine patients with mild to moderate left ventricular failure were given intravenous infusions of nicardipine and the haemodynamic effects measured. In patients receiving 20 mg of nicardipine, mean cardiac index rose to a peak 1.81 X min-1 X m-2 (64%) above the preinfusion level, stroke volume index rose by 12 ml X m-2 (35%) and heart rate rose by 16 beats X min-1 (20%). There was a significant fall in systemic vascular resistance of 50% manifested by a reduction of 22 mm Hg in systolic blood pressure (18%) and 18 mm Hg in diastolic blood pressure (22%). Pulmonary vascular resistance fell by 45%. Mean pulmonary artery pressure and capillary wedge pressure did not change significantly. This study suggests that concomitant mild to moderate left ventricular failure is not a contra-indication to nicardipine therapy in patients with angina.

Adult↗

PubMed1984

Amylase excretion after exercise.

Increase in amylase excretion in the urine in response to 8 days of aerobic running is delayed until after the athletes have rested for 24-48 h. In contrast, the amylase creatinine ratio is increased immediately after intense short-term exercise. The mechanism for these differences is unknown, but the timing of the amylase excretion pattern after long- and short-term exercise is similar to the urinary amylase after continuous and single bolus intravenous glucagon.

Amylases↗