Nitric oxide: a novel inducer for enhancement of microbial lipase production

The purpose of this study was to elucidate whether exogenous nitric oxide (NO) has a potential beneficial effect on lipase production capacity of some microorganisms. Sodium nitroprusside (SNP) was used as an exogenous NO donor in production medium. In comparison with the control (0 nM SNP), SNP concentrations from 10 to 100 nM induced lipase production in mesophilic bacterium Bacillus subtilis and cold-adapted yeast Yarrowia lipolytica. Especially, the maximum lipase activities for Y. lipolytica (81.2 U/L) and B. subtilis (74.5 U/L) were attained at 30 and 50 nM SNP concentrations, respectively. When compared to the control, the optimal SNP concentrations resulted in about 5.14 and 2.27-fold increases in lipase activities of B. subtilis and Y. lipolytica, respectively. Besides, it was found that the optimal SNP concentrations provided shorter incubation periods for lipase production. Conversely, no significant positive effect of exogenous NO on lipase production was determined for thermophilic bacterium Geobacillus stearothermophilus. This study showed for the first time that exogenous NO could be used as an inducer in the production of microbial lipases.     

Accumulation of aluminum in rat brain: does it lead to behavioral and electrophysiological changes?

The present study was undertaken to examine possible aluminum (Al) accumulation in the brain of rats and to investigate whether subchronic exposure to the metal leads to behavioral and neurophysiological changes in both treated and control groups. Each of the groups consisted of 10 animals. Aluminum chloride (AlCl₃) at a low (50 mg/kg/d) or high (200 mg/kg/d) dose was applied to male Wistar rats by gavage for 8 wk. Al-free water by gavage was given to the control group throughout the experiment. Behavioral effects were evaluated by open-field (OF) motor activity and by acoustic startle response (ASR). Electrophysiological examination was done by recording spontaneous activity and sensory-evoked potentials from the visual, somatosensory, as well as auditory cortex. The Al content of each whole brain was determined by electrothermal atomic absorption spectrophotometry. Subchronic Al exposure slightly caused some changes in the evoked potentials and electrocorticograms and in the OF and ASR performance, but these results were not statistically significant. The brain Al levels of the control and the low and high dose of Al-exposed groups were measured as 0.717±0.208 μg/g (wet weight), 0.963±0.491 μg/g (wet weight) and 1.816±1.157 μg/g (wet weight), respectively.     

Takayasu's arteritis is associated with HLA-B*52, but not with HLA-B*51, in Turkey

Introduction

HLA-B*51 and HLA-B*52 are two close human leukocyte antigen (HLA) allele groups with minor amino acid differences. However, they are associated with two different vasculitides (HLA-B*51 in Behçet's disease and HLA-B*52 in Takayasu's arteritis (TAK)) and with major clinical and immunological differences. In this study, we aimed to screen a large cohort of TAK patients from Turkey for the presence of HLA-B*51 and HLA-B*52 as susceptibility and severity factors.

Methods

TAK patients (n = 330) followed at a total of 15 centers were included in the study. The mean age of the patients was 37.8 years, and 86% were women. DNA samples from the patients and healthy controls (HC; n = 210) were isolated, and the presence of HLA-B*51 or HLA-B*52 was screened for by using PCR with sequence-specific primers.

Results

We found a significant association of HLA-B*52 with TAK (20.9% vs HC = 6.7%, P = 0.000, OR = 3.7, 95% CI = 2.02 to 6.77). The distribution of HLA-B*51 did not differ between TAK patients and HCs (22.7% vs 24.8%, OR = 0.9, 95% CI = 0.60 to 1.34). The presence of HLA-B*52 decreased in late-onset patients (> 40 years of age; 12.0%, P = 0.024, OR = 0.43, 95% CI = 0.20 to 0.91). Patients with angiographic type I disease with limited aortic involvement also had a lower presence of HLA-B*52 compared to those with all other disease subtypes (13.1% vs 26%, P = 0.005, OR = 0.43, 95% CI = 0.23 to 0.78).

Conclusions

In this study, the previously reported association of TAK with HLA-B*52 in other populations was confirmed in patients from Turkey. The functional relevance of HLA-B*52 in TAK pathogenesis needs to be explored further.     

Tool addition strategies for flexible manufacturing systems

The allocation of tools to machines determines potential part routes in flexible manufacturing systems. Given production requirements and a minimum feasible set of tools, the decision of how to fill vacant slots in tool magazines to maximize routing flexibility is shown to be a minimum cost network flow problem for the cases when routing flexibility is a function of the average workload per tool aggregated over tool types, or of the number of possible routes through the system. A linear programming model is then used to plan a set of routes for each part type so as to minimize either the material handling requirement or the maximum workload on any machine. The impact of these tool addition strategies on the material handling and workload equalization is investigated and computational results presented. The advantage of the overall approach is computational simplicity at each step and the ability to react to dynamic changes.     

Development of a protease activity assay using heat-sensitive Tus-GFP fusion protein substrates

Proteases are implicated in various diseases and several have been identified as potential drug targets or biomarkers. As a result, protease activity assays that can be performed in high throughput are essential for the screening of inhibitors in drug discovery programs. Here we describe the development of a simple, general method for the characterization of protease activity and its use for inhibitor screening. GFP was genetically fused to a comparatively unstable Tus protein through an interdomain linker containing a specially designed protease site, which can be proteolyzed. When this Tus–GFP fusion protein substrate is proteolyzed it releases GFP, which remains in solution after a short heat denaturation and centrifugation step used to eliminate uncleaved Tus–GFP. Thus, the increase in GFP fluorescence is directly proportional to protease activity. We validated the protease activity assay with three different proteases, i.e., trypsin, caspase 3, and neutrophil elastase, and demonstrated that it can be used to determine protease activity and the effect of inhibitors with small sample volumes in just a few simple steps using a fluorescence plate reader.     

Effects of 3-aminobenzamide on unilateral testicular ischemia-reperfusion injury: what is the role of PARP inhibition?

The therapeutic effects of poly(adenosine diphosphate-ribose) polymerase inhibition by 3-aminobenzamide (3-AB) were investigated in testicular ischemia-reperfusion (I/R) injury, using sperm analysis and histopathological and biochemical examinations, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities and reduced glutathione (GSH) levels. Male rats were divided into 3 groups: sham (n = 12), I/R (n = 12), and I/R with 3-AB (I/R-3-AB) (n = 12). The left testicular artery was occluded for 1 h, followed by 24 h (for biochemical and histopathological examinations) and 30 days (for sperm analysis) of reperfusion. 3-AB treatment intraperitoneally 10 min prior to and 1 h after reperfusion increased the I/R-induced decrease in sperm motility in both testes and reduced the increased abnormal sperm rates in the ipsilateral testis. However, 3-AB treatment failed to prevent the I/R-induced decrease in sperm concentration in both testes. SOD and CAT activities did not change in any group. GSH-Px activity and GSH levels were increased by I/R. 3-AB treatment reversed the I/R-induced increase in GSH-Px activity, similar to the level in sham rats, but did not alter GSH levels. 3-AB treatment significantly increased the I/R-induced decrease in histopathologic score. In conclusion, 3-AB treatment has potential biochemical and histopathological benefits beyond improving sperm quality and may have the potential to decrease damage from testicular torsion.     

Co-infection of Giardia intestinalis and Cyclospora cayetanensis in an immunocompetent patient with prolonged diarrhea: case report

Cyclospora cayetanensis is an agent of emerging infectious disease, and a recognized cause of diarrhea in some patients. Also, the flagellated protozoan, Giardia intestinalis, induces a diarrheal illness of the small intestine. Cases of cyclosporiasis are frequently missed, primarily due to the fact that the parasite can be quite difficult to detect in human fecal samples, despite an increasing amount of data regarding this parasite. On the other hand, G. intestinalis can be readily recognized via the microscopic visualization of its trophozoite or cyst forms in stained preparations or unstained wet mounts. In this report, we describe an uncommon case of co-infection with G. intestinalis and C. cayetanensis in an immunocompetent patient with prolonged diarrhea, living in a non-tropical region of Turkey.