Protective effects of N-acetylcysteine on the peroxidative changes of rat lungs exposed to inhalation of thinners

OBJECTIVE: Long-term inhalation of thinners may cause damage, both to the lungs and to other organ systems. It causes cellular damage via formation of reactive oxygen species. The lung is protected from oxidative stress by the glutathione (GSH) antioxidant system which can be augmented by the thiol drug, N-acetylcysteine (NAC). This study investigated the protective effect of NAC on peroxidative changes in rat lungs exposed to inhalation of thinners for 8 weeks. METHODOLOGY: Seventy-two male Wistar albino rats were used and divided into two groups: one group inhaled only thinners (TI), while the other inhaled TI plus NAC. Rats in the TI and TI + NAC groups were divided into four subgroups (each consisting of eight rats) according to the duration of exposure to TI: 2, 4, 6 and 8 weeks. A control group (n = 7) of rats inhaled neither TI nor NAC. Malondialdehyde (MDA) and GSH levels, and superoxide dismutase (SOD) activities were determined in the lung tissues. Histopathological findings were evaluated as acute and chronic changes in the alveoli and interstitium in the TI and TI + NAC groups and compared with those in the control group. RESULTS: While tissue MDA levels in the groups inhaling TI for 4, 6 and 8 weeks were significantly higher than those in the control groups (P < 0.01, P < 0.01, P < 0.0001, respectively), GSH levels were significantly lower (P < 0.05, P < 0.01, P < 0.01, respectively). Tissue SOD activities in the groups inhaling TI for 6 and 8 weeks were significantly lower than those in the control group (P < 0.05, P < 0.01, respectively). In the TI group, MDA levels were significantly increased (P < 0.01) with increasing duration of inhalation (from the second week through to the eighth week), while GSH levels and SOD activities were significantly decreased (P < 0.01, P < 0.01). Tissue MDA levels were significantly lower in the TI + NAC groups across all inhalation periods, when compared with the TI groups (P < 0.01, P < 0.0001, P < 0.0001, P < 0.0001, respectively). Tissue GSH levels in the TI + NAC groups were significantly higher than those of the TI groups (respective values: P < 0.05, P < 0.01, P < 0.01, P < 0.0001). Tissue SOD activities in the TI + NAC groups were significantly higher than those of the TI groups (respective values: P < 0.05, P < 0.0001, P < 0.05, P < 0.0001). Pathological examinations with light microscopy did not show any beneficial effect of NAC application in terms of deferring or alleviating the negative effects of TI. CONCLUSIONS: Thinners are agents that cause imbalance between oxidants and antioxidants produced by aerobic cellular systems. This imbalance between oxidant and antioxidant systems is decreased by the effect of NAC. However, ultrastructural studies may be needed to substantiate this evidence morphologically, as light microscopy was inconclusive.     

Microalbuminuria is associated with the severity of coronary artery disease independently of other cardiovascular risk factors

The potential early predictive value of microalbuminuria (MA) in the estimation of atherosclerosis and the relation between the degree of urinary albumin excretion and the extent of coronary artery disease (CAD) were investigated. Patients (n = 159) with stable angina pectoris and angiographically significant stenosis in at least 1 of the major coronary arteries were included. Microalbuminuria was measured by immunoturbidimetry. The extent of coronary artery stenosis was graded using the Gensini score. The Gensini score was significantly greater in patients who had MA. Also, the Gensini increased by 0.15 units with 1 unit increase in MA. In the groups who had diabetes mellitus and hypertension, there was no correlation between MA and Gensini score. The results of the present study suggest that MA is associated with the severity of CAD independent of other cardiovascular risk factors.     

The association between homocysteine (hcy) and serum natural antioxidants in elderly bone mineral densitometry (BMD)

Previous studies showed oxidative stress had an important impact on osteoclastic and osteoblastic functions. Oxidative stress or low levels of antioxidants are supposed to reduce BMD and cause osteoporosis. hcy, gamma glutamyltransferase (GGT), uric acid, albumin and total bilirubin are simple laboratory parameters that are related with oxidative stress. In this study we compare the serum hcy and antioxidant levels in patients with osteoporosis, osteopenia and control subjects. A total of 2190 elderly persons (1348 patients with osteoporosis, 643 patients with osteopenia and 199 control subjects) who were referred to the outpatient clinic of the Department of Internal Medicine, Division of Geriatric Medicine at Hacettepe University Hospital for comprehensive geriatric assessment were included in this cross-sectional study. Mean age of subjects were 72.30±6.34 in osteoporosis group, 71.92±6.90 in osteopenia and 71.86±5.88 in control group (p: 0.260). Multivariate regression analysis revealed that hypertension (HT) (OR: 0.675, 95% CI: 0.534-0.854, p: 0.001), diabetes mellitus (DM) (OR: 1.669, 95% CI: 1.301-2.142, p: <0.001), age (OR: 1.025, 95% CI: 1.006-1.044, p: 0.009), male gender (OR: 0.451, 95% CI: 0.358-0.569, p<0.001), uric acid (OR: 0.893, 95% CI: 0.837-0.952, p: 0.001), hcy (OR: 1.042, 95% CI: 1.023-1.061, p<0.001), albumin (OR: 0.521, 95% CI: 0.376-0.724, p<0.001), GGT (OR: 1.010, 95% CI: 1.003-1.017, p: 0.003), creatinine (OR: 0.630, 95% CI: 0.459-0.864, p: 0.004) were independent variables predicting the occurrence of osteoporosis. This study shows there is an imbalance between natural antioxidative and oxidative markers in patients with osteoporosis. Higher serum uric acid and albumin levels are associated with a lower prevalence of osteoporosis whereas higher hcy and GGT levels are associated lower BMD and higher osteoporosis prevalence.     

Assessment of Endothelial Function in Alzheimer's Disease: Is Alzheimer's Disease a Vascular Disease?

OBJECTIVES: To compare endothelial function of people with Alzheimer's disease (AD) with that of people without. DESIGN: Case-control study. SETTING: Geriatric medicine outpatient clinic of a university hospital. PARTICIPANTS: Twenty-five patients with AD who were free of vascular risk factors and 24 healthy elderly controls were enrolled. Exclusion criteria were diabetes mellitus, hypertension, dyslipidemia, evident stroke, smoking, documented coronary artery disease, history of myocardial infarction, heart failure, acute or chronic infection, malignancy, peripheral artery disease, renal disease, rheumatologic diseases, alcohol abuse, and certain drugs that may affect endothelial function. Both groups underwent comprehensive geriatric assessment and neuropsychiatric assessment. MEASUREMENTS: Endothelial function was evaluated according to flow-mediated dilation (FMD) from the brachial artery. RESULTS: Mean age +/- standard deviation was 78 +/- 5.9 in the group with AD (11 female and 14 male) and 72.1 +/- 5.8 in the control group (9 female and 11 male). Multiple linear regression analysis revealed that FMD was significantly lower in patients with AD (median 3.45, range 0-7) than controls (median 8.41, range 1-14) (P < .001), independent of age. It was also found that FMD values were inversely correlated with the stage of the disease as determined according to the Clinical Dementia Rating scale (r=-0.603, P < .001). CONCLUSION: Endothelial function is impaired in patients with AD. Endothelial function was worse in patients with severe AD. These findings provide evidence that vascular factors have a role in the pathogenesis of AD.     

Perinatal trauma with and without loss experiences

Objective: The present study explored differences in mental health between women who experienced a trauma which involved a loss of fetal or infant life compared to women whose trauma did not involve a loss (difficult childbirth). Method: The sample consisted of 144 women (mean age = 31.13) from the UK, USA/Canada, Europe, Australia/New Zealand, who had experienced either stillbirth, neonatal loss, ectopic pregnancy, or traumatic birth with a living infant in the last 4 years. Results: The trauma without loss group reported significantly higher mental health problems than the trauma with loss group (F (1,117) = 4.807, p = .03). This difference was observed in the subtypes of OCD, panic, PTSD and GAD but not for major depression, agoraphobia and social phobia. However, once previous mental health diagnoses were taken into account, differences between trauma groups in terms of mental health scores disappeared, with the exception of PTSD symptoms. Trauma groups also differed in terms of perceived emotional support from significant others. Conclusion: The findings illustrate the need for a change in the focus of support for women’s birth experiences and highlighted previous mental health problems as a risk factor for mental health problems during the perinatal period.     

Susceptibilities of Mycobacterium tuberculosis to isoniazid and rifampin on blood agar

In this study, blood agar was used instead of 7H10 agar for the susceptibility testing of 34 clinical isolates of Mycobacterium tuberculosis to isoniazid (INH) and rifampin (RIF) in accordance with the NCCLS. The BACTEC 460 TB system (Becton Dickinson, Sparks, Md.) was used as a "gold standard." Results for both media were in agreement for RIF and INH at 100 and 94.1%, respectively. For INH, the specificity, sensitivity, positive predictive value, and negative predictive value were found to be 71.4, 100, 93.1, and 100%, respectively, while these values were 100% for RIF. In addition, the results of the susceptibility test performed with blood agar were obtained on day 14 of incubation. In conclusion, results were obtained much earlier with blood agar (2 weeks) than with 7H10 agar (3 weeks), and the results of this study suggest that blood agar may be used as an alternative medium for the susceptibility testing of M. tuberculosis to INH and RIF.