Enhanced sensitivity to oxidant-induced micronucleus frequency in elderly individuals is not associated with glutathione S-transferase M1 (GSTM1) null genotype in lymphocytes

BACKGROUND: A large number of studies have demonstrated that various kinds of DNA damage accumulate during aging and that oxidative stress possibly contributes to this process. Glutathione S-transferase M1 (GSTM1) can prevent their possible effects on DNA via detoxification of reactive substances that induced oxidative stress. OBJECTIVE: To investigate the relationship between GSTM1 polymorphism and DNA sensitivity to oxidative stress with age, we used micronucleus (MN) frequency as a marker of DNA damage in lymphocytes from young and elderly subjects. Methods: This study was performed in 30 young (age range 20-36 years) and 30 elderly (age range 66-87 years) healthy individuals who were chosen on the basis of their GSTM1 genotype (15 GSTM1 null and 15 GSTM1 positive for each group). Lymphocytes were cultured after Ficoll isolation and treated for 48 h with a 30-muM dose of cumene hydroperoxide (CumOOH), a dose that does not decrease cell viability. RESULTS: There was no significant difference in the MN frequency observed in control cultures from young and elderly individuals. However, the MN frequency in CumOOH-treated cultures was significantly higher in the elderly group than the young group (p < 0.001). No association was found between the GSTM1 phenotype and CumOOH-induced MN frequency. CONCLUSIONS: The results suggest that lymphocytes of elderly individuals are more susceptible to in vitro MN induction by CumOOH. However, this difference in susceptibility is not explained by the lack of GSTM1.     

Induction of apoptosis and inhibition of growth of human hepatoma HepG2 cells by heparin

BACKGROUND/AIMS: Apoptotic and anti-proliferative effects of heparin on a number of cancers have been described. There have been no studies analyzing the effect of heparin on human hepatoma cells. The aim of this study was to investigate the effect of heparin on human hepatoma cell line, HepG2. METHODOLOGY: HepG2 cell line was cultured with different concentrations of heparin. Colony count, viability assay, percentage of the apoptosis and proliferative index were assessed at the end of the 7th day. Trypan blue was used to assess viability. Apoptosis and proliferative indexes were assessed by flow-cytometry. RESULTS: Hepatoma cells were arrested at the G0/G1 phase with heparin incubation and proliferative indexes decreased significantly in 20, 40 and 80 U/mL of heparin concentrations in comparison with the control (36 +/- 1%, 30 +/- 5% and 29 +/- 8% vs. 44 +/- 1%, p < 0.01). Flow cytometry revealed a statistically significant increase in apoptosis in groups incubated with 40 and 80 U/mL of heparin in comparison with the control (39 +/- 26% and 58 +/- 18% vs. 0.83 +/- 1.3%, p < 0.01). Colony counts per well and viable cells per microL decreased significantly in 80 U/mL of heparin. CONCLUSIONS: Heparin leads to a significant anti-proliferative and an apoptotic effect on human hepatoma cells in vitro.     

A Chryseobacterium meningosepticum outbreak observed in 3 clusters involving both neonatal and non-neonatal pediatric patients

Three clusters of Chryseobacterium meningosepticum infections in a tertiary health center in July 2006 and January 2007 involving 8 newborns and 5 older children were investigated. The index patient was from the neonatal intensive care unit, and the older patients were from other pediatric wards. Cultures were obtained from the environment and from health care workers' hands as part of an outbreak investigation. C meningosepticum was isolated from hand cultures obtained from a senior resident and from environmental cultures obtained from powdered infant formula, an electrical button, a computer keyboard, phone, a doorknob, and an Ambu bag. Antibiogram typing and enterobacterial repetitive intergenic consensus sequence polymerase chain reaction indicated that all of the isolates were epidemiologically related. Nine patients improved on antimicrobial treatment, and 4 premature infants died after the infection. C meningosepticum is a well-known etiologic agent for nosocomial infections involving newborns and immunocompromised patients. Wet and dry environmental surfaces and equipment may act as a source or play a role in disseminating the microorganism. Outbreaks may be controlled with strong emphasis on infection control measures.     

In vivo effect of losartan on platelet aggregation in patients with hypertension

The angiotensin II receptor, losartan, has been found to inhibit platelet aggregability to some extent in in vitro experiments. There have been conflicting results about the in vivo effects of losartan. We sought to clarify the in vivo effect of losartan on platelet aggregation. Forty patients with grade I essential hypertension were treated with losartan for 3 weeks. Platelet aggregation tests with adenosine diphosphate (ADP) and ristocetin were analyzed and compared before and at the end of the study. Losartan effectively decreased systolic (SBP) and diastolic (DBP) blood pressure. Mean SBP before and after treatment was 159.6 ± 12.8 and 149.2 ± 17.3mmHg, respectively. Mean DBP decreased from 93.7 ± 8.2 to 87.7 ± 10.3mmHg after treatment. The results of the platelet aggregation tests with ADP and ristocetin were not significantly different when both rate and amplitude of maximal aggregation were included. Peak platelet aggregation with ADP regarding the lowest light transmission in the aggregometer was 59.8% ± 24.3% before and 58.3% ± 18.1% after the treatment. The same variables with ristocetin were 66.8% ± 21.6% and 60.8% ± 23.3%, respectively. In vivo effects of losartan on platelet aggregation with ADP and ristocetin were insignificant.     

Impedance cardiographic monitoring during pericardiocentesis: comparison with echocardiography

OBJECTIVE: Thoracic impedance cardiography (TIC) is a noninvasive method which has proved to be useful in monitoring the haemodynamic status of the patients. In this study, we evaluated the TIC findings in patients with pericardial effusion and cardiac tamponade. METHODS AND RESULTS: The study consisted of patients with pericardial effusion with (group A) or without (group B) cardiac tamponade (CT). The stroke volume, cardiac output and ejection fraction was measured by both echocardiography and TIC. The measurements were done at baseline in both groups and following pericardiocentesis in group A. The variables were compared by linear regression analysis, paired sample's t test and chi-square test. The study included 32 patients. Group A consisted of 16 patients and group B of 14 patients. Two patients were excluded from comparisons because of insufficient quality of the echocardiographic examination. There were no significant differences between group A and B with regard to demographic features. Both echocardiographic and TIC measurements at baseline revealed decreased cardiac output, EDV and SV in group A and EF was not different. Linear regression analysis revealed that echocardiography and TIC were in significant correlation with regard to cardiac output, enddiastolic volume, stroke volume (p < 0.01) but not ejection fraction (p = 0.8910). The correlation was also present after pericardiocentesis. CONCLUSIONS: TIC can be safely used in patients with pericardial effusion. It provides suggestive data for the diagnosis of CT and can be used as a means of monitoring the results of the pericardiocentesis.     

Pinealectomy exaggerates and melatonin treatment suppresses neuroma formation of transected sciatic nerve in rats: gross morphological, histological and stereological analysis

At present, an intensive effort for prevention of neuroma formation following peripheral nerve section continues. It has been recently suggested that surgical pinealectomy (Px) induces elevation of the collagen content in the granulation tissue of a wound, while melatonin application after Px suppresses elevation of the collagen accumulation in the tissue. The aim of the present study was to assess whether melatonin had the ability to suppress collagen production and neuroma formation following peripheral nerve transection. A total of 40 male rats (four groups of 10) were left intact (intact controls) or sham operated (sham group), were Px, or were Px and given melatonin (Px + melatonin group). All animals underwent a surgical intervention consisting of right sciatic nerve neurectomy. After 4 wk, the animals were killed following intracardiac perfusion. Gross morphology of neuroma formation in the proximal nerve segment was examined and proximal neuroma evaluated. Macroscopic and microscopic findings revealed that Px caused a proliferation of connective tissue and large neuroma formation at the proximal ends of transected nerves. Stereological analysis showed that there was a statistically significant reduction in connective tissue content of the same region in Px animals treated with melatonin (P < 0.005). The results achieved in a rodent model of sciatic nerve neuroma formation showed that there was a positive correlation between macroscopic and microscopic observations, and that melatonin enhanced axonal regeneration presumably due to its inhibitory effect on neuroma formation.     

Prevalence and significance of MEFV gene mutations in patients with gouty arthritis

Gouty arthritis is a chronic erosive autoinflammatory disease. Pyrin has anti-inflammatory effects in the regulation of inflammasome and is encoded by the MEFV gene. The relationship between different rheumatic diseases and the MEFV gene mutations was demonstrated. The aim of this study was to determine the frequency of MEFV gene mutations in patients with gouty arthritis and identify a possible correlation with disease phenotype. Ninety-three patients with gouty arthritis and 102 healthy controls, compatible with age, gender and ethnicity, were included in the study. MEFV gene mutations were investigated by PCR method. Out of 93 patients with gouty arthritis, 36 (38.7 %) showed MEFV gene mutations carriage, whereas 20.6 % in healthy control group. Distribution of mutations identified in patients with gouty arthritis was as; R202Q in 18 (19.3 %), E148Q in 5 (5.4 %), K695R in 4 (4.3 %), M680I in 2 (2.1 %), V726A in 2 (2.1 %), P369S in 2 (2.1 %), R408Q in 2 (2.1 %), M694 V in 1 (1.1 %), respectively. Three patients were identified with compound heterozygosity. Distribution of MEFV gene mutations carriage in healthy controls was; E148Q in 11 (10.7 %), M694 V in 2 (1.9 %), M694I in 1 (0.9 %), M680I in 2 (1.9 %), V726A in 1 (0.9 %), A744S in 1 (0.9 %), K695R in 2 (1.9 %), and P369S in 1 (0.9 %) patients, respectively. Higher MEFV gene mutations carrier frequency was observed in patients with gouty arthritis, compared with the control group (p = 0.009). Heterozygous R202Q was the most common mutation detected in patients with gouty arthritis, while heterozygous E148Q in healthy control group. Statistically significant difference was not detected between clinical findings of gouty arthritis and the MEFV gene mutations (p > 0.05). We determined higher prevalence of MEFV gene mutations in patients with gouty arthritis compared with the healthy control group. The most frequently detected mutation was heterozygous R202Q, whereas E148Q in healthy controls. High carriage rates of MEFV gene mutations in gouty arthritis suggest that it may play an important role in the pathogenesis of the disease and predisposition to the disease.