Oxidant/antioxidant parameters and their relationship with medical treatment in multiple myeloma

Multiple myeloma (MM) is a neoplastic disorder characterized by monoclonal multiplying of plasma cells. Although radiation, environmental factors, viruses and other factors have been suggested as potential causes of the disease, the aetiopathogenesis of MM is still obscure. This clinical study was designed to investigate the role of reactive oxygen species (ROS) in the aetiopathogenesis of the disease and the possible relationships between treatment and ROS production. For this purpose, erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities as well as plasma nitric oxide (NO) and malondialdehyde (MDA) levels were measured in 14 MM patients newly diagnosed at stage III. The relationship between the above-mentioned parameters and vincristine-adriamycin-dexamethasone (VAD) therapy were also investigated in the same patients. All the enzyme activities and the parameters of oxidative stress were found to be significantly reduced after VAD therapy. These findings suggest that ROS may be involved in the aetiopathogenesis of MM. Further investigations with a larger cohort of MM patients are needed to provide definitive data about the role of ROS in MM and the alternative therapeutic approaches to MM.     

Prevalence of enterotoxigenic Bacteroides fragilis in patients with diarrhea: a controlled study

In this age matched controlled study performed in Malatya, a city in east region of Turkey, enterotoxigenic Bacteroides fragilis (ETBF) was investigated in stool specimens obtained from children and adults with and without diarrhea. A nested polymerase chain reaction (PCR) method was used to detect the enterotoxin gene of B. fragilis in a total of 418 stool samples, including 221 samples from 117 children (aged 0-16 years) and 104 adults (aged >16 years) with diarrhea, and 197 samples from 102 children and 95 adults as control group that was the same age group with those having diarrhea. ETBF was detected in 13 of 117 diarrheal children (11.1%) and 8 of 102 control children (7.8%) (P>0.05). In children aged 1-5 years, the rate of ETBF was significantly higher in patients than in controls (25% versus 9.5%, respectively; P<0.05). On the other hand ETBF was detected similar rates (2.2% and 2.4%, respectively) in children younger than 1 year in both patients and controls. ETBF positivity was not significantly difference between patient and control groups who were older than 5 years of age and adults. The frequency of ETBF in the controls was slightly higher in older persons than in younger ones; however, it was not significant. The rate of ETBF as the only enteropathogen in the patients with ETBF was significantly higher than in controls with ETBF (88% versus 39%, respectively; P<0.02). We found that in east region of Turkey, the prevalence of ETBF was higher in the childhood diarrhea, particularly in aged 1-5. As the only enteropathogen, ETBF may play an important role in diarrheal diseases. Persons after 6 years old can be carrier for ETBF regardless diarrhea.     

Levels of malondialdehyde and superoxide dismutase in subclinical hyperthyroidism

We aimed to determine whether patients with subclinical hyperthyroidism (SH) are subject to oxidative stress. Twenty-two women and 8 men having endogenous subclinical hyperthyroidism for a duration of at least 6 months, and 21 women and 9 men healthy controls were included in this study. We measured the level of plasma malondialdehyde, as one of the lipid peroxidation markers, and the activity of erythrocyte superoxide dismutase, which is an antioxidant enzyme. The activity of erythrocyte superoxide dismutase and plasma malondialdehyde levels were found to be significantly higher in subjects with subclinical hyperthyroidism than the control group (P < .01). The results of this study suggest that oxidative stress and antioxidative response could be increased in patients having subclinical hyperthyroidism.     

Mouse sperm desiccated and stored in trehalose medium without freezing

Mouse sperm with and without trehalose were desiccated under nitrogen gas and stored at 4 degrees C and 22 degrees C. After rehydration, sperm were injected into oocytes using intracytoplasmic sperm injection and embryonic development was followed. Sperm were dried for 5.0, 6.25, or 7.5 min, stored at 22 degrees C for 1 wk with and without trehalose. The percentages of blastocysts that developed from sperm with trehalose were 51%, 31%, and 20%, respectively, which was significantly higher than sperm without trehalose (10%, 3%, and 5%, respectively). Desiccation and storage in medium with trehalose significantly increased sperm developmental potential compared to medium without trehalose. Sperm dried for 5 min produced more blastocysts than sperm dried for 6.25 or 7.5 min. When sperm were dried in trehalose for 5 min and stored for 1 wk, 2 wk, 1 mo, or 3 mo at 4 degrees C, the percentages of blastocysts were 73%, 84%, 63%, and 39%; whereas those stored at 22 degrees C for 1 wk, 2 wk, or 1 mo were significantly lower (53%, 17%, and 6%, respectively). Embryos from sperm partially desiccated in trehalose for 5 min and stored at 4 degrees C for 1 or 3 mo were transferred to 10 pseudopregnant recipients. Implantation rates were 81% and 48%; live fetuses were 26% and 5%, respectively. One of the recipients delivered three live fetuses. The results show that trehalose has a significant beneficial effect in preserving the developmental potential of mouse sperm following partial desiccation and storage at temperatures above freezing.     

Effects of some drugs on the activity of glucose 6-phosphate dehydrogenase from rainbow trout (Oncorhynchus mykiss) erythrocytes in vitro

Inhibitory effects of some drugs on glucose 6-phosphate dehydrogenase from the erythrocytes of rainbow trout (Oncorhynchus mykiss Walbaum, 1792) were investigated. The enzyme was purified 2488-fold in a yield of 76.8% using ammonium sulfate precipitation and 2',5'-ADP Sepharose 4B affinity gel at 4 degrees C. The drugs pental sodium, MgSO4, vancomycin, metamizol, marcaine, and prilocaine all exhibited inhibitory effects on the enzyme. While MgSO4 (K(i) = 12.119 mM), vancomycin (K(i) = 1.466 mM) and metamizol (K(i) = 0.392 mM) showed competitive inhibition, pental sodium (K(i) = 0.748 mM) and marcaine (K(i) = 0.0446 mM) displayed noncompetitive inhibition.     

Coronary artery bypass surgery in high-risk patients

Background

In high-risk coronary artery bypass patients; off-pump versus on-pump surgical strategies still remain a matter of debate, regarding which method results in a lower incidence of perioperative mortality and morbidity. We describe our experience in the treatment of high-risk coronary artery patients and compare patients assigned to on-pump and off-pump surgery.

Methods

From March 2002 to July 2004, 86 patients with EuroSCOREs > 5 underwent myocardial revascularization with or without cardiopulmonary bypass. Patients were assigned to off-pump surgery (40) or on-pump surgery (46) based on coronary anatomy coupled with the likelihood of achieving complete revascularization.

Results

Those patients undergoing off-pump surgery had significantly poorer left ventricular function than those undergoing on-pump surgery (28.6 ± 5.8% vs. 40.5 ± 7.4%, respectively, p < 0.05) and also had higher Euroscore values (7.26 ± 1.4 vs. 12.1 ± 1.8, respectively, p < 0.05). Differences between the two groups were nonsignificant with regard to number of grafts per patient, mean duration of surgery, anesthesia and operating room time, length of stay intensive care unit (ICU) and rate of postoperative atrial fibrillation

Conclusion

Utilization of off-pump coronary artery bypass graft (CABG) does not confer significant clinical advantages in all high-risk patients. This review suggest that off-pump coronary revascularization may represent an alternative approach for treatment of patients with Euroscore ≥ 10 and left ventricular function ≤ 30%.     

Maximization of production of secreted recombinant proteins in Pichia pastoris fed-batch fermentation

Pontryagin's Maximum Principle has been applied for optimization of secreted proteins from Pichia pastoris fed-batch fermentation. The objective of this work is to maximize the total accumulated product per unit operation time under different given conditions and system constraints. To obtain optimal solutions, an automated curve-fitting software, Table Curve 2D, was employed to construct the necessary mathematical models and solve the complicated functions. In the solution processes, the end of the glycerol batch phase was defined as the initial state of the system, the end of the methanol fed-batch phase as the final state, the cell mass produced along with product accumulated as state variables, and the specific growth rate (mu) as the control variable. Initially, a relationship between the specific production rate (rho) and mu was established. Then, according to Pontryagin's Maximum Principle, the admissible range of mu and its trajectories for the optimal operations were determined. Four representative cases with different combinations of the operation time along with the initial and final states were evaluated. A close correlation was obtained between the predicted values of the model equation with the experimental results from the Pichia pastoris fed-batch fermentations producing secreted alpha-galactosidase. The approaches proposed here greatly simplify the computational processes and validate the optimization strategy as a generalized approach to maximize the yield from fed-batch fermentations.     

The improvement of sensitivity in lead and cadmium determinations using flame atomic absorption spectrometry

Various designs of quartz tubes of the slotted tube atom trap were examined to improve the sensitivity of flame atomic absorption spectrophotometry. The studied designs include the diameter length and the length of the upper slot of quartz tubes. Tubes having a diameter of 5 and 6 mm and an upper slot length of 2.3 cm produce the best sensitivity—as high as 6- and 10-fold enhancement for lead (Pb) and cadmium (Cd), respectively. The limits of quantitation were found to be 35 and 4 ng ml⁻¹ for Pb and Cd, respectively, by the optimized method. The achieved technique was applied to determine the concentrations of Pb and Cd in cancerous (malign) and noncancerous (adenoma) human thyroid tissues.