A simple and inexpensive device for collecting urine samples from rats

Many studies require collection of metabolic wastes from laboratory animals, and oftentimes it is important that feces and urine be collected separately. The authors describe an easily assembled and inexpensive device that can be used to collect urine samples from rats without any invasive operations. The device affords reasonable separation of feces and urine.     

Effects of<Emphasis Type="Italic">Nigella sativa</Emphasis> and human parathyroid hormone on bone mass and strength in diabetic rats

Osteoporosis is a major complication in patients with diabetes mellitus (DM), particularly in those with insulin dependency. Recently, many therapeutic effects ofNigella sativa L. (NS) extracts have been exhibited such as anti-inflammatory, antitumor, and antidiabetic with clinical and experimental studies. Mechanical strength in the femur and vertebrae increases with human parathyroid hormone (hPTH) treatment. The aim of the present study was to test the hypothesis that combined treatment with NS and hPTH is more effective than treatment with NS or hPTH alone in improving bone mass, connectivity, and biomechanical behavior using the finite element method (FEM) in insulin-dependent diabetic rats. In the mechanical analysis, five rat bones (control, diabetic diabetic NS treated, diabetic hPTH treated, and diabetic NS + hPTH treated) have been studied for bending analysis using the finite element analysis program ANSYS. Combined treatment of NS and hPTH was more effective on bone histomorphometry and mechanical strength than treatment with NS or hPTH alone for streptozotocin-induced diabetic osteopenia, which notably decreased bone volume.     

Cell bank characterization and fermentation optimization for production of recombinant heavy chain C-terminal fragment of botulinum neurotoxin serotype E (rBoNTE(H(c)): antigen E) by Pichia pastoris

A process was developed for production of a candidate vaccine antigen, recombinant C-terminal heavy chain fragment of the botulinum neurotoxin serotype E, rBoNTE(H(c)) in Pichia pastoris. P. pastoris strain GS115 was transformed with the rBoNTE(H(c)) gene inserted into pHILD4 Escherichia coli-P. pastoris shuttle plasmid. The clone was characterized for genetic stability, copy number, and BoNTE(H(c)) sequence. Expression of rBoNTE(H(c)) from the Mut(+) HIS4 clone was confirmed in the shake-flask, prior to developing a fed-batch fermentation process at 5 and 19 L scale. The fermentation process consists of a glycerol growth phase in batch and fed-batch mode using a defined medium followed by a glycerol/methanol transition phase for adaptation to growth on methanol and a methanol induction phase resulting in the production of rBoNTE(H(c)). Specific growth rate, ratio of growth to induction phase, and time of induction were critical for optimal rBoNTE(H(c)) production and minimal proteolytic degradation. A computer-controlled exponential growth model was used for process automation and off-gas analysis was used for process monitoring. The optimized process had an induction time of 9 h on methanol and produced up to 3 mg of rBoNTE(H(c)) per gram wet cell mass as determined by HPLC and Western blot analysis.     

Salicylic acid induced changes on some physiological parameters symptomatic for oxidative stress and mineral nutrition in maize (Zea mays L.) grown under salinity

It has been proposed that salicylic acid (SA) acts as an endogenous signal molecule responsible for inducing abiotic stress tolerance in plants. The effect of varying salicylic acid (SA) supply (0, 0.1, 0.5 and 1.0mM) on growth, mineral uptake, membrane permeability, lipid peroxidation, H(2)O(2) concentration, UV-absorbing substances, chlorophyll and carotenoid concentrations of NaCl (40 mM) stressed maize (Zea mays L.) was investigated. Exogenously applied SA increased plant growth significantly both in saline and non-saline conditions. As a consequence of salinity stress, lipid peroxidation, measured in terms of malondialdehyde (MDA) content and membrane permeability was decreased by SA. UV-absorbing substances (UVAS) and H(2)O(2) concentration were increased by increasing levels of SA. SA also strongly inhibited Na(+) and Cl(-) accumulation, but stimulated N, Mg, Fe, Mn and Cu concentrations of salt stressed maize plants. These results suggest that SA could be used as a potential growth regulator to improve plant salinity stress resistance.     

Persistence of hyperbaric oxygen-induced oxidative effects after exposure in rat brain cortex tissue

Hyperbaric oxygen (HBO) causes oxidative stress in several organs and tissues. Due to its high rate of blood flow and oxygen consumption, the brain is one of the most sensitive organs to this effect. Many studies have reported oxidative effects of HBO, but there is no comprehensive data about how long this effect persists. The aim of this study was to elucidate the duration of HBO-induced oxidative/antioxidant action. Male Sprague-Dawley rats were divided into 5 groups. Except for the controls, the animals were subjected to 100% oxygen for 2 h at 3 atm and differed from each other by the time to dissection after exposure that began at 30, 60, 90, or 120 min. Thiobarbituric acid-reactive substances (TBARS), as well as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity was determined in brain cortex tissue. Additionally, nitrite-nitrate (NO(x)) concentrations were measured. All measured parameters were found to be significantly increased 30 min after exposure. SOD and GSH-Px levels persisted at significantly high levels for 60 min. In conclusion, the oxidative effect of HBO was shown to persist only for 1 h. Further studies should be performed to elucidate the possible molecular interactions during this period.     

Comparative evaluation of hepatotoxic and nephrotoxic effects of aroclors 1221 and 1254 in female rats

Polychlorinated biphenyls (PCBs) are persistent environmental pollutants. This study compared effects of two PCB mixtures, Aroclors 1221 (A1221) and 1254 (A1254) on serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), urea, creatinine and uric acid in female rats. Histopathological changes in the liver and kidney were also examined. A group of adult Wistar rats served as controls. Groups II and III were subcutaneously injected with A1221 and A1254 at 10 mg/kg every other day for 6 weeks. At the end of this period, all animals were decapitated and blood samples were collected. Serum urea, creatinine, uric acid, ALT, AST and ALP levels were determined. Liver and kidney were collected for histopathological examination. They were fixed in formaldehyde and processed for light microscopy. Both A1221 and 1254 significantly elevated serum ALT (p < 0.05) and AST (p < 0.01) levels compared to the control group. Serum ALP values were significantly increased by A1221 (p < 0.05), but they were unaffected in the A1254 group. Treatment with both A1221 and A1254 significantly increased serum levels of urea (p < 0.05), creatinine (p < 0.01) and uric acid (except in the A1221 group; p < 0.005). Distinct histopathological changes including renal corpuscular atrophy, peritubular vascular congestion and dilated cortical tubules, sinusoidal dilatation, congestion and mononuclear cell infiltration were observed. These findings suggest that PCBs may cause nephrotoxicity and hepatotoxicity in female rats.     

The effect of aminoguanidine against cholestatic liver injury in rats

We investigated the protective role of aminoguanidine (AG) in rat liver injury induced by chronic biliary obstruction. Secondary biliary cirrhosis was induced by bile duct ligation for 14 days. Swiss albino rats were divided into three groups: Common bile duct ligated (CBDL) rats; Group A, CBDL rats treated with AG as Group B and simple laparotomy group known as the Sham group; Group C. Group B received 200 mg/kg of AG intraperitoneally daily throughout 14 days. The present data showed decreased gama glutamyl transferase (GGT), aspartate aminotransferase (AST), bilirubin and alanine aminotransferase (ALT) levels in the AG treated rats, when compared with CBDL rats (p < 0.05). In the AG treated rats, tissue levels of malondialdehyde (MDA) were significantly lower than that in CBDL rats (p < 0.001). Although the levels of glutathione (GSH) in AG treated rats were higher and myeloperoxidase (MPO) were lower than that in CBDL rats, the difference was not statistically significant (p > 0.05). The levels of interleukin-1alpha (IL-1alpha) and tumor necrosis factor-alpha (TNF-alpha) were significantly lower and although the levels of interleukin-6 (IL-6) were lower in AG treated rats than that in CBDL rats, the difference was not statistically significant. Administration of AG in the rats with biliary obstruction resulted in inhibition of ductular proliferation and portal inflammation. The present study demonstrates that intraperitoneal administration of AG in CBDL rats maintains antioxidant defenses, reduces liver oxidative and cytokine damage and ductular proliferation and portal inflammation. This effect of AG may be useful in the preservation of liver injury in cholestasis.     

Univalent binding of the Cry1Ab toxin of Bacillus thuringiensis to a conserved structural motif in the cadherin receptor BT-R1

The Cry1Ab toxin produced by Bacillus thuringiensis (Bt) exerts insecticidal action upon binding to BT-R1, a cadherin receptor localized in the midgut epithelium of the tobacco hornworm Manduca sexta [Dorsch, J. A., Candas, M., Griko, N. B., Maaty, W. S., Midboe, E. G., Vadlamudi, R. K., and Bulla, L. A., Jr. (2002) Cry1A toxins of Bacillus thuringiensis bind specifically to a region adjacent to the membrane-proximal extracellular domain of BT-R1 in Manduca sexta: involvement of a cadherin in the entomopathogenicity of Bacillus thuringiensis, Insect Biochem. Mol. Biol. 32, 1025-1036]. BT-R1 represents a family of invertebrate cadherins whose ectodomains (ECs) are composed of multiple cadherin repeats (EC1 through EC12). In the present work, we determined the Cry1Ab toxin binding site in BT-R1 in the context of cadherin structural determinants. Our studies revealed a conserved structural motif for toxin binding that includes two distinct regions within the N- and C-termini of EC12. These regions are characterized by unique sequence signatures that mark the toxin-binding function in BT-R1 as well as in homologous lepidopteran cadherins. Structure modeling of EC12 discloses the conserved motif as a single broad interface that holds the N- and C-termini in close proximity. Binding of toxin to BT-R1, which is univalent, and the subsequent downstream molecular events responsible for cell death depend on the conserved motif in EC12.