BACKGROUND: ADA is an enzyme found in most cells, and is involved in purine metabolism, but its chief role concerns the proliferation and differentiation of lymphocytes, especially T-lymphocytes. For that reason ADA has been looked on as a marker of cell-mediate immunity, which is th key mechanism of the tuberculous pleural effusion. Thus, the pleural fluid ADA activity is increased in the tuberculous pleural effusion.Age associated immune deline is characterized by decreases in both B and T-lymphocyte function and the former may be largely a result of the latter. Therefore, the epleural fluid ADA activity would be lower in old rather than in young, patients with tuberculous pleural effusion. We studied the relationship between age, and pleural fluid ADA activity, in patients with tuberculous pleural effusion. METHODS: In the 46 patients with tuberculous pleural effusion enroll in this study, the pleural fluid ADA activities were measured by means of an automated kinetic method. RESULTS: The mean age of the patients was 53.0+/-22.0 years, with a male to female ratio of 30 : 16. The patients were divided into two groups, young patients, regarded as <65 and old regarded as >or=65 years with 28 and 18 patients, respectively. The pleural fluid ADA activity in both groups show significant differences : 99.4+/- 22.6 IU/L(young patients) Vs. 75.8+/-30.9 IU/L(old patients)(p<0.05), but a negative correlation with age (r=-0.311, p<0.05). CONCLUSION: Although pleural fluid ADA activity was not adequately increase, tuberculous pleural effusion, in older patients, would have to be considered clinically suspicious tuberculous pleural effusion.
Adenosine Deaminase* ; Adenosine* ; Female ; Humans ; Lymphocytes ; Male ; Metabolism ; Pleural Effusion* ; T-Lymphocytes

BACKGROUND: ADA is an enzyme found in most cells, and is involved in purine metabolism, but its chief role concerns the proliferation and differentiation of lymphocytes, especially T-lymphocytes. For that reason ADA has been looked on as a marker of cell-mediate immunity, which is th key mechanism of the tuberculous pleural effusion. Thus, the pleural fluid ADA activity is increased in the tuberculous pleural effusion.Age associated immune deline is characterized by decreases in both B and T-lymphocyte function and the former may be largely a result of the latter. Therefore, the epleural fluid ADA activity would be lower in old rather than in young, patients with tuberculous pleural effusion. We studied the relationship between age, and pleural fluid ADA activity, in patients with tuberculous pleural effusion. METHODS: In the 46 patients with tuberculous pleural effusion enroll in this study, the pleural fluid ADA activities were measured by means of an automated kinetic method. RESULTS: The mean age of the patients was 53.0+/-22.0 years, with a male to female ratio of 30 : 16. The patients were divided into two groups, young patients, regarded as <65 and old regarded as >or=65 years with 28 and 18 patients, respectively. The pleural fluid ADA activity in both groups show significant differences : 99.4+/- 22.6 IU/L(young patients) Vs. 75.8+/-30.9 IU/L(old patients)(p<0.05), but a negative correlation with age (r=-0.311, p<0.05). CONCLUSION: Although pleural fluid ADA activity was not adequately increase, tuberculous pleural effusion, in older patients, would have to be considered clinically suspicious tuberculous pleural effusion.
Adenosine Deaminase* ; Adenosine* ; Female ; Humans ; Lymphocytes ; Male ; Metabolism ; Pleural Effusion* ; T-Lymphocytes

OBJECTIVETo observe the electroacupuncture (EA) pretreatment at Baihui (GV20) on the concentration of adenosine deaminase (ADA) and adenosine, and to evaluate its effects on the neurologic function score and the infarction volume after middle cerebral artery occlusion (MCAO) ischemia/reperfusion (I/R), thus exploring its mechanisms for relieving the ischemia/reperfusion injury.

METHODSTotally 54 male SD rats were randomly divided into 3 groups, the sham-EA group, the EA group, and the control group, 18 in each group. Rats in the control group were not intervened after anesthesia. Rats in the EA group were needled at Baihui (GV20) for 30 min. Rats in the sham-EA group received the same procedure as those performed in the EA group without electricity connected. The changes of adenosine and ADA contents were detected at 30, 60, and 120 min after EA respectively. The I/R model was established. Totally 48 male SD rats were randomly divided into 6 groups, i.e., the model group (Group A), the EA group (Group B), the EA +8-Cyclopentyl-1,3-dipropylxanthine (DPCPX) group (Group C), the EA + DMSO group (Group D), the Deoxycoformycin (Deo) group (Group E), and the normal saline group (Group F). Rats in Group B, C, and D received EA for 30 min before modeling. Rats in Group C and D were peritoneally injected with DPCPX (1 mg/kg) and DMSO (1 mL/kg) at 30 min before EA. The neurologic function score was evaluated and the infarct volumes were detected after 24-h reperfusion.

RESULTSCompared with the sham-EA group, there was no statistical difference in the contents of the adenosine or ADA in the control group at each time point (P > 0.05). Compared with the control group at the same time point, the content of ADA significantly decreased at 60 min in the EA group [(315.0 +/- 22.9 U/L), P < 0.05], and restored to the normal level at 120 min after EA. The content of adenosine increased in the EA group at 120 min [(20.4 +/- 2.2) ng/microL, P < 0.05]. Compared with the model group, the neurologic function score decreased (P < 0.05) and the infarct volumes were obviously reduced (P < 0.01) in Group B, D and E. There was no statistical difference in the neurologic function score or the infarct volumes in other groups, when compared with the model group (P > 0.05)

CONCLUSIONEA at Baihui (GV20) showed protective effects on the cerebral I/R rats, which might be achieved through lowering the ADA concentration and elevating the adenosine content, and further activating adenosine A1 receptor.

Adenosine Deaminase ; metabolism ; Animals ; Brain Ischemia ; metabolism ; Electroacupuncture ; Male ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; metabolism

Leprosy is an infectious diseases caused by Mycobacterium leprae. It is considered to be manifested in person with an impaired. immune system and is divided into two polar forms; the first being tuberculoid leprosy(TL) with nearly norrnal cell-mediated immunity(CMI) and the second heing lepromatous leprosy(LL) with deficient CMI. Adenosine deaminase(ADA) is an enzyme concerned with intermediary purine metabolism, which is known to be deficient in case of immunological dysfunction. To find out if there is any ADA deficiency in leprosy, the ADA activities in the lymphocytes of leprosy patients were compared with those of normal ones. The ADA activities in lymphocytes of normal subjects, TL patients and. LL patients were as follows; ID. 36-I-l. 90 units/10cells, 6. 35+0. 86units/10'cells and 4. 58+0. 52units/IO'cells respectively. The ADA activities in lymphocytes were revealed to be significantly different between normal subjects and LL patients(p<0. 01) and also between normal subjects and TL patients(p<0. 05). The lowered ADA activities in lymphocytes of leprosy patients, particularly in lepromatous leprosy, suggests a similar role in ADA for immunological response as demonstrated in severe combined immunodeficiency diseases.
Adenosine Deaminase* ; Adenosine* ; Communicable Diseases ; Humans ; Immune System ; Leprosy* ; Leprosy, Lepromatous ; Lymphocytes* ; Metabolism ; Mycobacterium leprae ; Severe Combined Immunodeficiency

Adenosine deaminase (ADA), an enzyme essential for the differentiation of lymphoid cells, has been used for monitoring diseases with altered immunity. The purpose of this study was to investigate the changes in serum ADA activity throughout normal pregnancy. We measured the catalytic values of serum ADA from 202 normal pregnant women using a commercial kit. Subjects were divided into four groups according to the gestational age in weeks (Gwks) (Group I: 5-9 Gwks [n=58]; Group II: 15-20 Gwks [n= 63]; Group III: 24-30 Gwks [n=34]; Group IV: 30-39 Gwks [n=47]). The serum ADA levels for the Groups I, II, III, and IV were as follows: 20.1+/-6.9 IU/L, 20.0+/-7.6 IU/L, 37.9+/-19.9 IU/L, and 24.5+/-8.6 IU/L, respectively. The serum ADA activity of group III was significantly higher than the other groups (p<0.05). However, there was no significant correlation between the Gwks and the serum ADA activity. Furthermore, other parameters, such as maternal age (p=0.29), gestational age at delivery (p=0.07), delivery mode (p=0.39), and birth weight (p=0.59) had no correlation with ADA activity. Reference values of serum ADA in normal pregnancy may provide important database for making clinical decisions in pregnancies complicated by conditions where cellular immunity has been altered.
Adenosine/metabolism ; Adenosine Deaminase/*blood/*metabolism ; Adult ; Analysis of Variance ; Birth Weight ; Female ; Gestational Age ; Humans ; Infant, Newborn ; Inosine/metabolism ; Logistic Models ; Maternal Age ; Pregnancy ; Substrate Specificity

RNA editing, especially A-to-I RNA editing, is a common post-transcriptional modification in mammals. Adenosine deaminase acting on RNA (ADAR) is a key protein for A-to-I editing, which converts the adenosine group of a double-stranded RNA to creatinine group by deaminating it, resulting in a change of nucleotide sequence. There are 3 types of ADARs (ADAR1, ADAR2, ADAR3) that have been found in recent years. The abnormalities of ADARs are closely related to many human diseases such as viral infections, metabolic diseases, nervous system diseases, and tumors.
Adenosine ; metabolism ; Adenosine Deaminase ; physiology ; Base Sequence ; Creatinine ; metabolism ; Deamination ; Disease ; etiology ; Humans ; RNA Editing ; physiology ; RNA, Double-Stranded ; RNA-Binding Proteins ; physiology

BACKGROUNDPrevious studies reported interleukin-27 (IL-27), interferon-γ (IFN-γ), or adenosine deaminase (ADA) alone plays a helpful role in diagnosing tuberculous pleural effusion (TPE). The present study aims at comparing the diagnostic accuracy of pleural IL-27, IFN-γ, and ADA, and investigate the diagnostic accuracy of the combination of IL-27, IFN-γ, or/and ADA for differentiating TPE from pleural effusions with the other etiologies.

METHODSThe concentrations of IL-27, IFN-γ and ADA were simultaneously determined in pleural fluids and sera from 40 patients with TPE; 26 with malignant pleural effusion, seven with infectious pleural effusion, and eight with transudative pleural effusion by enzyme linked immunosorbent assay and colorimetric method. The corresponding biochemical indexs were also simultaneously determined.

RESULTSThe concentrations of pleural IL-27 and IFN-γ in the tuberculous group were significantly higher than those in the malignant, infectious, and transudative groups. The concentrations of ADA in TPE were significantly higher than those in MPE or transudative effusions, while much lower than those in infectious effusions. Among these three biomarkers, IL-27 was the most effective for TPE diagnosis, with the cut off value of 900.8 ng/L. IL-27 had a high sensitivity of 95% and specificity of 97.6% for differential diagnosis of TPE from non-TPEs. Combinations of IL-27, IFN-γ and ADA measurements further increased the sensitivity or specificity up to 100%.

CONCLUSIONSCompared to non-TPEs, IL-27, IFN-γ and ADA all simultaneously increased in TPE; and among these three rapid detection methods, IL-27 appeared to be the best for distinguishing tuberculous from non-TPEs, especially from MPE. Combinations of the three markers (IL-27, IFN-γ and ADA) yielded the highest sensitivity and specificity. These findings suggest that the applications of a new biomarker, IL-27, alone or with IFN-γ and ADA, may contribute to more efficient diagnosis strategies in the management of tuberculous pleurisy.

Adenosine Deaminase ; blood ; metabolism ; Aged ; Female ; Humans ; Interferon-gamma ; blood ; metabolism ; Interleukin-27 ; blood ; metabolism ; Male ; Middle Aged ; Pleural Effusion ; blood ; metabolism ; Tuberculosis, Pleural ; blood ; diagnosis ; metabolism

Adenosine Deaminase ; metabolism ; Adult ; Aged ; Female ; Humans ; Interferon-gamma ; analysis ; Interleukin-12 ; analysis ; Isoenzymes ; metabolism ; Male ; Middle Aged ; Pleural Effusion ; chemistry ; Tuberculosis, Pleural ; diagnosis ; metabolism

The assessment of the adenosine deaminase activity (ADA) in the pleural effusion is used for the diagnosis of tuberculous pleural effusion (TPE). To examine whether the procedure can be applied to immunocompromised patients, we analyzed the ADA activity in the pleural fluid of renal transplant recipients. We studied 23 renal transplant patients with TPE (21 men and 2 women; the mean age, 33 years). They were treated at the Yonsei University Hospital between January 1985 and December 2001. Patients with granuloma in the pleural biopsy specimen or positive for Mycobacterium tuberculosis in the pleural fluid culture were recruited. The ADA activity in the pleural effusion of 23 renal transplant patients with TPE was compared with 23 immunocompetent patients with TPE. The mean ADA activity was 69.5 +/- 4.6 in renal transplant patients and 65.0 +/- 4.9 U/L in immunocompetent patients. Applying the 40 U/L cut-off point, the positivity of ADA was 91.3% in renal transplant patients, and 86.9% in immunocompetent patients. We thus concluded that the measurement of ADA in the pleural fluid is a useful means in the diagnosis of TPE in renal transplant patients.
Adenosine Deaminase/*metabolism ; Adult ; Female ; Humans ; Immunocompromised Host ; *Kidney Transplantation ; Male ; Pleural Effusion/*diagnosis/*enzymology/microbiology ; Tuberculosis, Pleural/*diagnosis/immunology/metabolism

OBJECTIVETo study some factors (temperature, time, anticoagulate, reagent, apparatus) which influence the detection of serum enzyme.

METHODSSerums obtained from same patient are determined in different conditions. Compare the statistical difference among each group.

RESULTSThe anticoagulant-heparinize Li influence the determination of ADA and CH50. If serums were sent in room temperature for 24 hours, the results will be different. Using regents from different factories will receive different results.

CONCLUSIONDifferent conditions and reagents will influence results. To obtain correct data, we must institute and perform standard regulation.

Adenosine Deaminase ; metabolism ; Blood Specimen Collection ; Complement Hemolytic Activity Assay ; Complement System Proteins ; metabolism ; Equipment and Supplies ; Hepatitis ; blood ; enzymology ; Humans ; Indicators and Reagents ; Male ; Serum ; enzymology ; Specimen Handling ; Temperature