جستجوی مقالات مرتبط با کلیدواژه « آدنوزین دآمیناز » در نشریات گروه « پزشکی »

The main problem with using stents in the treatment of coronary artery atherosclerotic stenosis in percutaneous coronary intervention (PCI) is In-stent restenosis (ISR). In this study, we investigated the possible role of the G22A variant of the Adenosine Deaminase gene (ADA) in the development of ISR. In this study, 91 patients who underwent PCI were divided into two groups: the case with ISR (n=40) and control without ISR after 6 months from stenting (n=51). The case and control groups were matched in terms of age and sex matching. The genotypes of the G22A variant in the samples were examined by the molecular method of PCR-RFLP and electrophoresis and the results were statistically analyzed by using t-test. The results of this study show that the frequency of allele A of variant G22A in (+ ISR) group is higher than (- ISR). However, there is no significant relationship between the distribution of allele and genotype frequency of this variant with the incidence of ISR (p>0.05).

Tuberculosis is still considered as one of the major health-care problems in our country and affects annually population of 10 to 20 million TB patients. The aim of this study was to evaluate the diagnostic value of cerebrospinal fluid adenosine deaminase enzyme in tuberculosis meningitis. A total of 67 patients were included in the study based on CSF criteria that were suspected to cause saline meningitis. When performing LP, a 2-cc of CSF fluid was taken to measure the level of ADA fluid in the CSF. The level of ADA liquid CSF was measured using kinetic spectrophotometry. Highest ADA values in patients with TB meningitis (25.57 ± 19.63 IU/L) and the lowest ADA values in neuro-brucellosis meningitis (2.50 ± 0.57 IU/L). The amount of Cutoff Point was ADA in detecting TB meningitis with a sensitivity of 81.1% and specificity of 76.5%, equal to 9.68 IU ‏. ADA levels of cerebrospinal fluid in cases of TB meningitis, compared to non-TB meningitis, with a high sensitivity and specificity increase and is a simple and inexpensive diagnostic procedure, along with other diagnostic methods for the rapid diagnosis of TB meningitis.

Recurrent spontaneous abortion (RSA) is defined by two or more consecutive miscarriages before 20 weeks of gestation. Adenosine deaminase (ADA) is an enzyme of purine salvage pathway and has two important isoenzymes ADA1 and ADA2. The adenosine deaminase G22A polymorphism (ADA*2) increases the level of adenosine. Adenosine may play a protective role against recurrent spontaneous abortions, since it regulates blood flow into the uterus and placenta. In consideration of the effect of decreased enzymatic activity of adenosine deaminase G22A polymorphism on adenosine levels we evaluated the protective effect of ADA*2 allele against recurrent spontaneous abortions in north-west of Iran. A total of 100 women were recruited to form two groups. First one, with a history of recurrent spontaneous abortions (N=50), and the second one, without a history of abortions (N=50). Genomic DNA was extracted from peripheral blood with a commercial kit and PCR-RFLP analysis was used to identify the G22A genetic polymorphism. Fisher's exact test and odds ratio values were used to compare the proportions of adenosine deaminase genotypes and alleles between women with and without a history of recurrent spontaneous abortion (p<0.05). The frequency of homozygotes (AA) was 2% in control group, whereas no homozygote (AA) was found in the case group. The frequency of heterozygotes (AG) was 20% in control group and 8% in the case group (p<0.05). The frequency of homozygotes (GG) was 78% in control group and 92% in the case group (p<0. 05). A significant increase in the frequency of AG genotype in controls (p=0.014, OR=0.348) relative to women with the history of RSA demonstrates the protective effect of AG genotype in controls. The data suggest that women carrying the G22A polymorphism (ADA*2 allele) and AG genotype which is associated with the lower enzymatic activity are better protected against recurrent spontaneous abortions.

Measurement of adenosine deaminase and its isoenzymes in serum has been used for diagnosis and differentiation of intracellular infections and malignancies of immune cells. The aim of this study was to compare ADA levels and its isoenzymes in HIV positive patients and HIV positive patients co-infected with hepatitis B and C and healthy individuals، as a quick and low-cost diagnostic biochemical marker. This historical cohort study included 97 HIV positive IDU patients. After obtaining blood samples، serum was separated and examined for hepatitis B and C. We used Guisti method for measurment of ADA activity and EHNA inhibitor for the activity of its isoenzymes. Data analysis was performed by SPSS 16 (SPSS Inc.، Chicago). Our results showed that there was a high prevalence of HBV and HCV in HIV positive IV drug users. We found that total ADA activity in the patients groups was significantly higher than control group. Also HIV-HCV group showed a higher activity of this enzyme in comparison to HIV positive groups. Significant differences were found in regard to ADA2 isoenzymes among the four groups (P<0. 05). But ADA1 activity showed no significant difference. CD4+ counts were lower in HIV-HCV and HIV-HBV patients than HIV positive patients. ADA activity was considerably increased in HIV positive patients co-infected with either HBV or HCV. According to the results of this study and because of its low cost and simplicity to perform، in addition to other markers، measurement of ADA activity in serum is a sensitive biological marker for assessment of intracellular infections، particularly hepatitis in HIV positive patients.

Adenosine deaminase (ADA) is a marker of T cell activation. ADA catalyzes the deamination of adenosine and modulates the bioactivity of insulin. The aim of this study was to investigate a possible relationship between ADA activity and various clinical and metabolic parameters, including fasting plasma sugar (FBS) and glycated hemoglobin (HBA1c), in gestational diabetes (GDM).

Fasting ADA activity, FBS, HBA1c, serum insulin level, and blood lipids were measured in 70 GDM patients and in 70 non-diabetic pregnant subjects. Insulin resistance was measured using a homeostasis model of assessment-insulin resistance (HOMA-IR).

ADA activity was increased in the GDM patients compared with that in the non-diabetic pregnant subjects (mean ± standard error, 13.9 ± 7.1 U/L vs. 9.6 ± 3.8 U/L; p value <0.0001). ADA activity was correlated with FBS (r=0.277, p value =0.001) and HbA1c (r=0.344, p value <0.0001). HOMA-IR was higher in the GDM patients than that in the non-diabetic pregnant subjects; however, no correlation was observed between ADA activity and HOMA-IR.

Our results show that ADA activity, as a marker of T cell activation, is increased in GDM. Serum levels of ADA activity are positively correlated with glycemic control.

Adenosine has been considered as a fine-tuner of the neurotransmitters in the nerve system. Adaptive changes in the brain adenosine system occur in some patho-physiological situations such as chronic exposure to morphine. In this study, the adaptive changes in the adenosine deaminase activity as a key enzyme in the adenosine metabolism that converts adenosine to inosine and ammonia, irreversibly, due to morphine dependence and tolerance to anti-nociceptive effects of sodium-salicylate were investigated. Morphine dependence was induced by morphine administration in tap water (0.4mg/ml for 24 days). Tolerance to sodium-salicylate was induced by 6 i.p. injection (1 injection/day) of sodium-salicylate. Tolerance to antinociceptive effects of sodium-salicylate was measured by tail flick (TF) and hot plate (HP) tests. Right hippocampus was dissected, homogenized at phosphate buffer, centrifuged and then the supernatant fraction was isolated. Protein content of the samples was measured by the Bradford method. Hippocampus adenosine deaminase activity was measured by a calorimetric method of enzyme assay which is based on the direct measurement of the produced ammonia from excessive adenosine degradation by adenosine deaminase. Daily injection of Sodium-salicylate produced antinociception in early days by latency increase rather than saline injection (P<0.0001) but in the following days this antinociceptive effect progressively decreased so at the day 5 and 6 following injection it was similar to saline (P>0.05). Injection of morphine (5mg/Kg) at the day 7 showed more increase in the latency of saline injected rather than sadium-salicylate injected (P<0.001). Adenosine deaminase activity was significantly higher in sucrose administrated rather than chronic morhine administrated (P<0.05) and in saline injected rather than sodium-salicylate injected (P<0.05). Single injection of sodium-salicylate and its control shows the same activity. There was no significant difference in enzyme activity of morphine dependent with sadium-salicylate tolerance (P>0.05). This decline in the adenosine deaminase activity may be related with adaptation in brain adenosine system subsequent of dependent to morphine or tolerance to sodium-salicylate.

Adenosine deaminase (ADA) is a purine catabolic enzyme that removes amino group of adenosine or 2' deoxyadenosine irreversibly. ADA enhances immune system and also intervenes the inflammation process. In this study, the effect of ibuprofen as an anti- inflammatory drug has been studied on the ADA activity in the physiologic and pathologic temperatures.

ADA was assessed in the presence of 3 different doses of ibuprofen at 37oC and 42oC via spectrometry in 265 nm.

Ibuprofen at high and low doses had an activation effect on the ADA activity at 37oC and moderated the sensitivity of enzyme activity to its substrate. It also decreased the anti-inflammatory effect of adenosine via decrease of its concentration and had a positive effect on immune system as well. The activation of the enzyme by Ibuprofen was decreased at 42oC and also Ibuprofen moderated the effect of temperature on dependency of enzyme activity to its substrate. Ibuprofen effects on immune system and anti-inflammatory effects of adenosine decreased at 42oC.

Ibuprofen is a putative activator for adenosine deaminase and administration of this drug could be useful for immune deficiency. Since there is no activator for ADA so far, this drug is important. Ibuprofen decreases anti-inflammatory effect of adenosine. In-vivo studies would be needed.

Global initiative for Chronic Obstructive Pulmonary Disease (Gold) has defined COPD as a disease characterized by airflow limitation that is not fully reversible. COPD is a subset of obstructive lung diseases which also includes cystic fibrosis, bronchitis and asthma. Adenosine deaminase (ADA, E.C.3.5.4.4) converts adenosine to inosine. ADA has two isoenzymes; ADA1 and ADA2. In COPD patients the serum level of ADA increases which can be regarded as a result of reduction in ADA activity. In this study we evaluated the level of ADA and its isoenzymes in COPD patients and healthy subjects. Martial and This was a case control study. ADA activity in 30 COPD patients with age range of 20-60 years whose disease had been confirmed by a pulmonologist in Ekbatan Hospital, was compared to the activity of the same enzyme in 60 healthy subjects consisting of 30 non smoker and 30 smoker subjects as control groups. Data were introduced into SPSS version.13 software and analyzed by Kruskall-Wallis and two-way ANOVA tests. ADA activity in the COPD and smoker control groups was significantly lower than that of non smoker group (18.99±7 and 22.99±6.7 U/L, respectively). Regarding ADA2 serum level, the difference between patient group and non smoker control group was significant (P<0.05). Activity of ADA1 isoenzyme in the study groups did not show any significant differences. In general ADA activity was decreased in COPD patients. Decreased ADA activity together with increased adenosine level may play an important role in producing pulmonary damage in COPD patients

Diagnosis of tuberculosis pleurisies is difficult because of its nonspecific clinical presentation and insufficient traditional diagnostic methods. We investigated the use of adenosine deaminase (ADA) activity in tuberculosis pleurisies. A number of 85 patients were analyzed with exudative pleural effusions. Using the ROC curve, we determined the optimal cutoff for TB pleurisy. A number of 58 exudative samples were nontuberculous (non-TB) and 27 were tuberculosis (TB). There was statistically significant difference (p<0.0001) between the means of pleural fluid ADA levels among the TB and non-TB populations. The prevalence of TB pleurisy in the studied population was 31%. Using the cutoff point equal to 35 for diagnosing TB effusions the sensitivity and specificity 70.3% and 91.3%, respectively. The positive predictive value (PPV) was 79.1% and the negative predictive value (NPV) was 86.8%. A pleural fluid ADA value <19 IU/L suggests that a tuberculosis effusion is highly unlikely. Pleural fluid total ADA assay is a sensitive and specific test suitable for rapid diagnosis of TB pleurisy.

Adenosine deaminase is an enzyme which catalyses adenosine to Inosine. The determination of adenosine deaminase in body fluids is important for the diagnosis of tuberculosis. There are contradictory reports about the diagnostic value of serum adenosine deaminase in pulmonary tuberculosis. This study was set up to investigate the diagnostic value of serum adenosine deaminase and its isoenzymes activities on pulmonary tuberculosis. In this descriptive study, blood samples were obtained from 26pulmonary tuberculosis patients (group 1), 17 suspected tuberculosis with negative in both smear and culture tests (group 2), and 67 healthy subjects (group 3). Total ADA and ADA2 determination was carried out by kinetic method and EHNA Inhibitor, respectively. ADA and ADA2 activities are as follow: 19.35±5.04, 13.35±5.34 (group 1) 17.24±6.20, 11.47±3.92 (group 2) and 13.96±4.25, 7.36±2.91(group 3). The mean differences of ADA and ADA2 activity between group 1 and 2 with group 3 was meaningful. The sensitivity and specificity for ADA and ADA2 tests were (26.9%, 94 %) and (50%, 97 %) respectively. The PPV for ADA and ADA2 were 63.6% and 86.7% and the NPV were 76.8% and 83.3%, respectively. This study indicated that the assessment of these enzymes in serum to some extend can be a useful method for differentiation of healthy subjects from respiratory disease, but these tests do not have enough sensitivity to assist in the diagnoses of tuberculosis patients from other respiratory diseases.

Pleural effusion is seen in the background of many diseases, two major groups of which are tuberculosis and malignancies. At present pleural biopsy helps us differentiate these two causes from each other, but it is not only an invasive method but also an expensive one. For this reason, investigators are in search of simple and less invasive methods to diagnose the cause of pleural effusion. One of the new methods is measuring adenosine deaminase activity in pleural fluid. This method has been practiced worldwide and has come up with various results. The main objective of this study is to measure adenosine deaminase levels in pleural fluids of patients and compare them with the histopathological results, and if the outcomes are meaningful, this method can be recommended for clinically confusing cases. Patients & This descriptive analytical cross-sectional study was performed on sixty patients who were hospitalized in the infectious and internal wards on suspicion of tuberculosis or malignancy. First, pleural fluid was aspirated to measure the ADA level(cutoff point 35u/lit). Then biopsy was done and the results were compared with each other. The data was analyzed using SPSS 10 software and Chi-square test. Compared to biopsy, the sensitivity and specificity of ADA for the diagnosis of tuberculosis were 68.4% and 92.6% and for malignancies were 91.3% and 37.8% respectively. In comparison to biopsy, the positive predictive value of ADA to diagnose tuberculosis and malignancies was 81.2% and 47.8% respectively, and the negative predictive value of ADA for the diagnosis of TB and malignancies was 86.36% and 87.5% respectively. Based on the obtained data, raised levels of ADA in pleural effusion(over 35u/l) suggest tuberculosis with a more than 90% probability. Although low levels of ADA(below 35u/l) have great sensitivity for the diagnosis of malignancies, as the specificity of ADA level is 37.8%, it does not necessarily propound malignancy.