Biomedical subjects

D J Li

Publications and source records attributed to D J Li.

At least 37 records · Page 2Linked to original sources

PubMed1998

The prognostic significance of troponin I and troponin T.

OBJECTIVES: To determine and compare the prognostic abilities of early, single-sample measurements of cardiac troponin I (cTn-I), cardiac troponin T (cTn-T), and creatine kinase-MB (CK-MB) among ED patients with possible myocardial ischemia. METHODS: Prospective collection of clinical and serologic data using an identity-unlinked technique from patients with possible myocardial ischemia at 2 urban EDs. Outcome data concerning the occurrence of adverse events (AEs) during the 14 days after enrollment were used to calculate and compare the relative risks (RRs) and predictive values (with 95% confidence intervals) of the 3 markers for predicting AEs. RESULTS: Among the 401 study patients, 105 AEs occurred in 67 patients. cTn-I, cTn-T, and CK-MB were all significantly predictive of AEs, with RRs of 3.87 (2.39, 6.26), 3.03 (1.92, 4.79), and 6.45 (4.74, 8.77), respectively. For prediction of AEs, sensitivity for each of the 3 markers was low (cTn-I = 15.38, cTn-T = 24.62, CK-MB = 15.38), while specificity was high (cTn-I = 97.62, cTn-T = 93.15, CK-MB = 99.70). No significant difference in predictive ability was found between cTn-I and cTn-T. However, a positive CK-MB result was a stronger predictor of AEs than either cTn-I (p = 0.01) or cTn-T (p = 0.001). CONCLUSIONS: No significant difference in predictive abilities was found between cTn-I and cTn-T. However, routine testing for both CK-MB and either of the troponins may optimize early identification of high-risk patients so they may be targeted for a higher level of care and consideration of more aggressive therapies.

Adult↗

PubMed1998

A subcutaneous tissue reaction in the early stage to a synthetic auditory ossicle (Bioceram) in rats.

The discs of synthetic auditory ossicle (Bioceram), which are composed of aluminium oxide (Al2O3), were implanted subcutaneously in the interscapular region of 16 rats. The implanted specimens were removed at 1, 3, 7 and 14 days after implantation. The decalcified 6 microns thick sections were stained with H.E. and cell types around the implants were counted microscopically. We found that an acute inflammatory reaction occurred at one day, in which macrophages and neutrophiles predominated, and almost disappeared at about 7 days after implantation. Fibrosis began to be observed at 3 days. During this early stage, foreign body giant cells were found in only one specimen at 3 days. These findings, in comparison with those in the controls, showed that the chemical irritation of Bioceram to the subcutaneous tissue is slight, although the physical and/or chemical irritation of Bioceram lasts continuously and induces fibrosis around the bioimplant. The results so far suggest that Bioceram seems to be a satisfactorily biocompatible material, at least within the extent of 2 weeks.

Aluminum Oxide↗

PubMed1997

Long-term observation of subcutaneous tissue reaction to synthetic auditory ossicle (Apaceram) in rats.

The present study evaluates histological characteristics of the soft tissue response to long-term implantation of Apaceram discs composed of dense hydroxyapatite in rats. Discs were implanted into the subcutaneous tissue of 76 rats for six to 20 months. Decalcified histological sections stained with haematoxylin and eosin (H & E) and Mallory's azan were examined. Different cell types surrounding implants were counted. The greatest proportion of macrophages was found at six months (13.5 per cent). This proportion gradually decreased to four per cent at 20 months. Small numbers of lymphocytes and foreign body giant cells were observed in every group, but neither neutrophils nor osteogenesis were observed in any specimens. Results of the present study and previous related studies indicate that despite reappearance of a small number of macrophages six months after implantation, Apaceram is useful for reconstructive surgery.

Animals↗

PubMed1997

[Treatment of integrated traditional and Western medicine in recurrent spontaneous abortion of immune abnormality type].

UNLABELLED: Immune abnormality type of recurrent spontaneous abortion (RSA) is an important etiological type, major findings of that are the abnormal increases in auto and/or allo-antibodies of anti-zona pellucida, antiphospholipid and anti-ABO blood group. In the present study, to assess the clinical values of integrated traditional and Western medicine and its therapeutic mechanisms in treating immune abnormality type of RSA. METHODS: Aborters were treated by Zhibai Dihuang Pills for anti-zona pellucida antibodies, and clear evil Heat, remove Dampness, replenish blood and activate circulation by Chinese medicinal herbs recipe for anti-phospholipid and anti-ABO group antibodies. RESULTS: After they had been treated by these recipe, 92.3% of them became pregnant with normal delivery. It was found in dynamic investigation that level of the antibodies turned to decrease gradually during the treatment, and that of anti-phospholipid and anti-ABO group antibodies increased again at beginning of pregnancy and then decreased gradually with continuing pregnancy. CONCLUSION: Chinese herbs recipe could be used to treat RSA of the immune abnormality type by way of decreasing the elevated levels of auto and/or allo-antibodies.

ABO Blood-Group System↗

PubMed1997

[Effects of propafenone on electrophysiologic changes caused by alteration of left ventricular afterload in anesthetized rabbits].

AIM: To study effects of propafenone (Pro) on ventricular electrophysiologic changes caused by alteration of left ventricular afterload of rabbit heart. METHODS: Before and after i.v. Pro 3 mg.kg-1, changing afterload of left ventricle (LV), occurrence of ventricular arrhythmia, left ventricular diastolic thresholds (VDT), relative refractory period (RRP), effective refractory period (ERP), dispersion of refractory period, and ventricular fibrillation threshold (VFT) were recorded. RESULTS: Increasing afterload of LV increased temporal dispersion of RRP and ERP [from 11 +/- 4 and 6 +/- 3 ms to 18 +/- 8 and 13 +/- 8 ms (+delta P = 8.4 +/- 2.9 kPa) individually (P < 0.05)] and decreased VFT [from 5.5 +/- 1.0 V to 3.9 +/- 0.9 V (P < 0.01)]; Ventricular arrhythmia was seen in all rabbits. But reducing left ventricular afterload did not alter the electrophysiologic parameters in LV and did not induce ventricular arrhythmia. Pro i.v. prolonged RRP and ERP, increased VDT and VFT (P < 0.01); Increasing or decreasing left ventricular afterload did not cause much alteration of ventricular electrophysiologic parameters (P > 0.05). CONCLUSION: Pro inhibited increase of dispersion of refractory period and decrease of VFT caused by increase of left ventricular afterload and has an effect of anti-ventricular arrhythmia.

Animals↗

PubMed1996

Comparison of cardiac troponin I and lactate dehydrogenase isoenzymes for the late diagnosis of myocardial injury.

Cardiac troponin I (cTnI) is a highly specific marker that is elevated in the blood for several days following myocardial infarction. The lactate dehydrogenase (LD) isoenzyme 1 to isoenzyme 2 ratio (LD1/LD2) is the established marker for the late diagnosis of myocardial infarction. In this study, the sensitivity of cardiac troponin I (cTnI) and LD1/LD2 were compared as late markers of myocardial injury over a 5-day period in 36 patients admitted with a diagnosis of myocardial infarction to the coronary care unit. Over this period, the sensitivity of cTnI was significantly greater than that of LD1/LD2 (P < .05). The concurrent elevation of both cardiac markers of the five day period range from 53.1% to 79.4%. However, this low concordance was largely due to an LD1/LD2 < 1 in the presence of an increased cTnI. The average discordance over the 5-day period was 29.5%. Because cardiac troponin I (cTnI) has greater sensitivity than lactate dehydrogenase isoenzymes for delayed diagnosis of myocardial injury and is a more cost-effective test, the authors recommend it as a test of choice in this setting.

Adult↗

PubMed1995

[Treatment of immunological infertility with Chinese medicinal herbs of ziyin jianghuo].

According to the microcosmic Syndrome Differentiation, immunological infertility is recognised as Kidney Yin Deficiency-Hyperactivity of Fire Syndrome. Zhibai Dihuang Pills, a recipe of Chinese medicinal herbs, was used to treat the infertile couples with antisperm and/or antizona pellucida antibodies in their blood serum. It was found that after the treatment, the antibodies were converted to negativeness in 81.3% of immunological infertile couples. All 8 cases of successful pregnancy occurred in 1-9 months after antibodies negative conversion and the negative status was maintained throughout the course of pregnancy.

Autoantibodies↗

PubMed1994

Human tumor extracellular pH as a function of blood glucose concentration.

PURPOSE: Mammalian cells are sensitized to hyperthermia when the extracellular pH (pHe) is acutely reduced to < pH 7.0-7.2. However, cells chronically adapted to low pHe may not demonstrate such sensitivity. Although much of the extracellular environment of human tumors is at lower than normal physiological pH, it may be necessary to acutely acidify tumors to cause a change in the therapeutic response to hyperthermia. The purpose of this study was to reduce extracellular pH in human tumors by elevation of blood glucose. METHODS AND MATERIALS: The change in tumor pHe was measured as a function of the change in blood glucose concentration after oral administration of 100 g glucose in 25 fasting, nondiabetic patients. pHe was determined by needle microelectrodes, and blood glucose determined by "Chemstrips" and a glucometer. In some patients blood glucose concentration rose with time after ingestion to a peak change of 50-100 mg/dL between 30-70 min and then began to decrease. In another group of patients glucose concentration increased by 100-200 mg/dL over 30-90 min and remained elevated as if the patients in this group were Type II diabetics. RESULTS: In 14 transient hyperglycemic patients (56%), as blood glucose increased tumor pHe decreased by a mean of -0.17 +/- 0.04 pH units (p < or = 0.0001, range of -0.41-(+)0.07). By contrast in eight persistent hyperglycemic patients, tumor pHe remained unchanged or actually increased an average of 0.03 +/- 0.04 pH units (range of -0.15-(-)0.14). Normal tissue pHe in five patients was unchanged by hyperglycemia, pHe = 7.33 +/- 0.03. Among all patients, 52% exhibited a pHe decrease > or = 0.1 pH unit, and 24% exhibited a pHe decrease > or = 0.2 pH unit. In five transient hyperglycemic patients whose preglucose tumor pHe was between 6.90 and 7.22, the average decrease in pHe induced by hyperglycemia was 0.25 +/- 0.05 pH unit. A linear relationship was observed between the change of pHe and the maximum change in blood glucose such that the greatest decrease in tumor pHe occurred when the glucose change was minimal. The slope was 0.0017 +/- 0.0005 pH units/mg/dL glucose (p < or = 0.005). The linear relationship included both tumors in transient hyperglycemic patients and in persistent hyperglycemia patients. CONCLUSION: Since patients who exhibited the lowest change in blood glucose exhibited the greatest decrease in tumor pHe, it may be that cells in these patients were better able to transport glucose intracellularly which in tumor cells would permit a more rapid production of lactic acid from aerobic and/or anaerobic glycolysis. These data may be helpful in predicting the response of individual patients to oral hyperglycemia as a clinical thermosensitizer.

Blood Glucose↗

PubMed1994

Bone scintigraphy of hip prostheses. Can analysis of patterns of abnormality improve accuracy?

The patterns of abnormality (both site and intensity of uptake) on bone scintigraphy in 76 total hip replacements were studied and graded to determine whether specific patterns of abnormality were associated with greater accuracy in deciding the need for revision surgery. Patients were divided into three groups: 1) 45 hips were considered to have required surgery, 2) in 15 hips surgery was retrospectively considered unnecessary, and 3) 16 prostheses were painless. There was a trend for fewer abnormal sites and a lower intensity of abnormality from group 1 to group 3. By considering patterns of uptake, the specificity of bone scintigraphy could be improved from 65% to 95%, but at the expense of lower sensitivity, falling from 90% to 75%. The most accurate criteria for determining the need for revision surgery (sensitivity 88%, specificity 85%) were increased uptake at the tip or a total scintigraphy score of greater than 3.

Hip↗

PubMed1994

Scintigraphic appearances in patients with pulmonary infection and lung scintigrams of intermediate or low probability for pulmonary embolism.

Out of 294 patients with lung scintigrams of low or intermediate probability for pulmonary embolism, the appearances in 54 patients with a final diagnosis of pulmonary infection were reviewed. The most common finding was a matched defect in ventilation and perfusion occurring in 40 patients (76%). Regional reverse mismatch occurred in 13 patients (24%) and both appearances were found in one patient (2%). Reverse mismatch was also present in a further seven patients, four of whom had bronchial obstruction. Although occurring less frequently than matched defects, 81% of regional reverse mismatched defects were because of chest infection. The presence of regional reverse mismatch in patients investigated for pulmonary embolism suggests the alternative diagnosis of chest infection.

Adult↗

PubMed1994

Bone marrow scintigraphy in small cell carcinoma of the lung.

A comparative study of bone marrow scintigraphy using 99Tcm-nanocolloid, conventional bone scintigraphy and bone marrow biopsy were performed in 35 patients with histologically proven small cell carcinoma of the lung to determine whether bone marrow scintigraphy has a role in the early detection of bone marrow metastases. The sensitivity, specificity and accuracy for detection of metastases were 100, 92 and 94%, respectively, in bone marrow scintigraphy, 91, 88 and 89%, respectively, in bone scintigraphy, and 50, 100 and 86%, respectively in bone marrow biopsy. This study confirmed that bone marrow scintigraphy is a useful technique for the detection of early metastases. Bone marrow scintigraphy is also suggested as the first choice examination in clinical practice for diagnosis of metastases in small cell carcinoma of the lung.

Adult↗

PubMed1994

Stabilization and multidose use of exametazime for cerebral perfusion studies.

The efficient use of exametazime for cerebral blood flow imaging is restricted by the short useful life of the reconstituted kit due to the instability of the primary complex. It is therefore recommended that 99Tcm-exametazime be used within half an hour after preparation allowing only a single patient dose to be prepared from one vial of exametazime. The shelf-life of 'cold' reconstituted exametazime has been extended by means of stannous enhancement. Freshly prepared stannous fluoride solution, 0.8 ml (5.4 micrograms SnF2), was mixed with 0.5 ml (42 micrograms) exametazime solution followed by the addition of up to 1500 MBq pertechnetate. The radiochemical purity of the chelate was 91% (S.D. 3.6%, n = 3). The rate of conversion of the primary complex (kc = 0.012 +/- 0.011 h-1) was considerably slower than the rate of degradation obtained using the recommended method of preparation (kc = 0.17 +/- 0.02 h-1). Radiochemical purity levels greater than 80% were maintained for up to 2.5 h after preparation and the level of free pertechnetate did not exceed 7%. There was only a slight deterioration of the cold reconstituted exametazime on storage of 0.3 +/- 0.1% per day. However, exametazime reconstituted up to 3 weeks previously produced more than 80% purity. The mean radiochemical purity obtained in 22 studies was 90% with a range of 81-98%. Clinical validation was performed in a blinded study of 38 patients using single photon emission computed tomography (SPECT). There was no significant difference between the images obtained using the tin enhancement method of preparation and the manufacturer's method (chi 2 = 3.62, P = 0.16).(ABSTRACT TRUNCATED AT 250 WORDS)

Drug Stability↗

PubMed1994

Can 99Tcm HMPAO leucocyte scintigraphy distinguish between Crohn's disease and ulcerative colitis?

This paper has retrospectively analysed the ability of 99Tcm HMPAO leucocyte scintigraphy to distinguish Crohn's disease from ulcerative colitis. The diagnostic criteria were established by reviewing 99Tcm HMPAO leucocyte scintigrams in 123 patients with histologically proven Crohn's disease (83) or ulcerative colitis (40). Uptake in the right iliac fossa with or without other segments of colon, irregular bowel uptake, small bowel uptake or colonic activity with rectal sparing were all strongly suggestive of Crohn's disease. Left sided colitis was found to indicate ulcerative colitis. Total colitis occurred in both ulcerative colitis and Crohn's disease. The criteria were later tested in an additional 62 patients with excellent results (accuracy 98%). In 63 patients in whom the results of barium radiology were also available, the accuracy of scintigraphy was higher (93% and 83%, respectively). We conclude that 99Tcm HMPAO leucocyte scintigraphy can accurately distinguish between Crohn's disease and ulcerative colitis in a large proportion of cases and appears to be more reliable than conventional radiology.

Barium Sulfate↗

PubMed1994

[Effects of amiodarone on ventricular refractory period caused by subthreshold electric stimulation].

Effects of amiodarone (Ami) 25 mg.kg-1 iv on ventricular refractory period caused by subthreshold single or train stimulations were studied in rabbits. Before Ami i.v., the refractory period was prolonged by S1-St (P < 0.05, P < 0.01) and by Ss (St) which was intercalated to S1-S2 interval [S1-Ss (St)-S2 methods]. After Ami iv, the refractory period was shortened by S1-St (50 ms, 330 Hz, 6 V) (P < 0.01) and minimal inhibitory voltage of Ss was higher than that of pre-medication in different Ss-S2 intervals (20, 25 ms). These results suggested Ami may change the mode of terminating tachycardia by electric stimulation.

Amiodarone↗

PubMed1994

[Seasonal changes of lactate dehydrogenase isozymes and blood glucose concentration in nyctus noctula and Rana Nigromaculata].

The blood sugar concentration and the lactate dehydrogenase (LDH) isozymes in serum, brain and skeletal muscle of Nyctus noctula during hibernation and of Rana Nigromaculata during dormancy and activity period were compared by using method of polyacrylanide gel electrophoresis. Both LDH isozymes and blood glucose concentration showed obvious seasonal changes. In contrast to animals during activity period, animals in hibernation and dormancy period lacked LDH1, while LDH5 and blood glucose concentration increased significantly (P < 0.001). Also seasonal variations of LDH isozymes and blood glucose concentration were found to be different between animal group in hibernation and animal group in dormancy. The above results indicated that seasonal changes of LDH isozymes and blood glucose concentration not only adapted to the level of energy metabolism but also showed difference between physiological status-during hibernation and during dormancy.

Animals↗

PubMed1993

Computer-derived regions of interest for the determination of renal parenchymal transit time.

Renal parenchymal transit time measurements are used in the diagnosis of obstructive nephropathy but parenchymal regions are usually drawn by hand with or without the aid of a functional image. This paper describes three computerized methods for derivation of parenchymal regions from a mean time functional image and compares them with the manual method by processing renogram data from 82 normal, 19 obstructed and 11 dilated nonobstructed kidneys using all four techniques. Receiver-operator characteristic analysis demonstrated the computer methods to be superior to manually drawn regions. The optimum computer method had a sensitivity of 95% and specificity 95% for distinguishing obstructed kidneys from dilated nonobstructed kidneys. The computer method could be readily incorporated into routine renogram analysis programs.

Electronic Data Processing↗

PubMed1993

Multidose use of exametazine for leukocyte labelling: a new approach using tin enhancement.

Reconstituted exametazime is inherently unstable due to the rapid oxidation of the small amount (7.6 micrograms) of stannous chloride present in the kit. A novel approach has been used to improve the shelf-life of reconstituted exametazime based on the premise that tin lost through oxidation should be replaced by further amounts of tin. Freshly prepared stannous solution, 0.1 ml (0.66 microgram Sn2+), was mixed with 0.3 ml (25 micrograms) exametazime solution followed by 400-500 MBq pertechnetate. Mixed leukocytes from 50 ml of patients' blood were labelled with 99Tcm-exametazime which had been prepared by the tin enhancement. One hundred and fourteen patients were investigated. The median labelling efficiency was 72%, range 30-96%. The exametazime had been reconstituted up to 5 months previously. Because of the small volumes of the exametazime solution used, up to 15 doses for leukocyte labelling could be prepared from one vial.

Butanones↗

PubMed1993

Early-stage development of auditory center: an experimental study of auditory evoked electrophysiologic recordings from fetal and newborn guinea pigs.

Five guinea pig fetuses at 8 weeks' gestation (term is 9 weeks) were tested for auditory brain stem response (ABR) generated by earphones placed outside the maternal abdomen. The results obtained from these fetuses were compared with the ABRs in 10 term newborn guinea pigs on the 1st and 20th day after delivery. The ABRs indicated a decreasing peak latency over wave III with increasing age. The interpeak latency to wave III-V decreased markedly, with very little change in wave I-III. The results suggested rapid maturation of the upper brain stem and midbrain during late gestation and in newborns. They also exhibited an increasing peak latency of ABRs from both fetuses and newborns with decreasing stimulus intensity.

Animals↗