Oral [13C]bicarbonate measurement of CO2 stores and dynamics in children and adults

During exercise, less additional CO2 is stored per kilogram body weight in children than in adults, suggesting that children have a smaller capacity to store metabolically produced CO2. To examine this, tracer doses of [13C]bicarbonate were administered orally to 10 children (8-12 yr) and 12 adults (25-40 yr) at rest. Washout of 13CO2 in breath was analyzed to estimate recovery of tracer, mean residence time (MRT), and size of CO2 stores. CO2 production (VCO2) was also measured breath by breath using gas exchange techniques. Recovery did not differ significantly between children [73 +/- 13% (SD)] and adults (71 +/- 9%). MRT was shorter in children (42 +/- 7 min) compared with adults (66 +/- 15 min, P less than 0.001). VCO2 per kilogram was higher in the children (5.4 +/- 0.9 ml.min-1.kg-1) compared with adults (3.1 +/- 0.5, P less than 0.0001). Tracer estimate of CO2 production was correlated to VCO2 (r = 0.86, P less than 0.0001) and when corrected for mean recovery accurately predicted the VCO2 to within 3 +/- 14%. There was no difference in the estimate of resting CO2 stores between children (222 +/- 52 ml CO2/kg) and adults (203 +/- 42 ml CO2/kg). We conclude that orally administered [13C]bicarbonate can be used to assess CO2 transport dynamics. The data do not support the hypothesis of lower CO2 stores under resting conditions in children.     

The alteration of PLCζ protein expression in unexplained infertile and asthenoteratozoospermic patients: A potential effect on sperm fertilization ability

Failed oocyte activation has been observed in unexplained infertile (UI) and asthenoteratozoospermic (AT) men. The deficiency of phospholipase C‐zeta (PLCζ) could be a possible reason for such failures and has not been studied yet. We investigated the expression and localization of PLCζ protein in the sperms of patients with UI and AT conditions. The relationships between PLCζ‐related parameters with male age, sperm characteristics, DNA integrity, and cellular maturity were assessed. Semen samples were collected from fertile (n = 40), UI (n = 40), and AT (n = 40) men. Subsequently, semen analysis, DNA fragmentation, hyaluronic acid‐binding ability, and PLCζ level along with its distribution were evaluated using computer‐assisted sperm analyzer, sperm chromatin structure assay (SCSA), hyaluronic acid‐binding assay (HBA), western blot analysis and immunofluorescence microscopy, respectively. Unlike SCSA, the values of HBA, and PLCζ expression were significantly reduced in UI and AT patients compared to fertile men, whereas no significant differences were observed among the experimental groups in terms of PLCζ localization patterns. The regression analysis also showed that HBA is the only variable associated with PLCζ levels. Furthermore, the correlation of male age with PLCζ localization in postacrosomal, equatorial, and acrosomal+postacrosomal+equatorial (A+PA+E) patterns, as well as the relation of normal morphology, with the (A+PA+E) pattern, remained in the regression model. Our findings indicated that reduced PLCζ level along with the increased DNA fragmentation and impaired maturation may be possible etiologies of decreased fertilization in the studied subjects.     

Synthesis and antibacterial activity of some new derivatives of pyrazole

In this study, we report the synthesis and antibacterial activity of a new series of 5-amido-1-(2,4-dinitrophenyl)-1H-4-pyrazolecarbonitriles. Our results show that all compounds exhibit antimicrobial activities against methicillin susceptible Staphylococcus aureus and methicillin resistant S. aureus with MIC values of 25.1 and 91.0 μM.     

SAR comparative studies on pyrimido[4,5-b][1,4] benzothiazine derivatives as 15-lipoxygenase inhibitors, using ab initio calculations

The enzyme inhibitory activity of a new group of 2-substituted pyrimido[4,5-b][1,4]benzothiazines on soybean 15-lipoxygenase (15-LO) was evaluated and compared with those of their 4-methyl analogs using ab initio calculations. The results of these studies showed that the lack of 4-methyl substituent in the pyrimido[4,5-b][1,4] benzothiazine molecules greatly reduces their 15-LO inhibitory activities.     

Design and synthesis of pyrimido[4,5-b][1,4]benzothiazine derivatives, as potent 15-lipoxygenase inhibitors

A group of 2-substituted pyrimido[4,5-b][1,4]benzothiazines were designed, synthesized, and evaluated as potential inhibitors of 15-lipoxygenase (15-LO). Compounds 4d and 4e showed the best IC50 of 15-LO inhibition (IC50=18 and 34 microM, respectively). All compounds were docked into 15-LO. As a result the sulfur atom was oriented toward the iron atom of the active site of 15-LO. We suggest the interaction of the iron atom is essential for the activity of the inhibitors.     

Benzothiazole thiourea derivatives as anticancer agents: Design,synthesis, and biological screening

In a systematic effort to identify a potent anticancer agent, we synthesized benzothiazole thiourea derivatives and examined their cytotoxic activity against five different human and animal cancer cell lines. Benzothiazolylthiocarbamides have been prepared in excellent yields by reaction of substituted 2-amino benzothiazoles with carbon disulfide and dimethyl sulfate followed by their ammonolysis. Cytotoxicity of the four compounds were screened for antitumor activity against human breast cancer cells (MCF-7), human cervix epithelial carcinoma (HeLa), human colon cancer cell line (HT-29), human leukemia cell line (K-562), and mouse neuroblastoma cell line (Neuro-2a) using cisplatin as a reference by MTT assay. Our results presented herein provide experimental evidence that benzothiazolylthiocarbamides induce apoptosis in cancer cell lines. According to flow cytometry results, treatment of HT-29 cells with 1-(6-ethoxy-1,3-benzothiazol- 2-yl)thiourea produced a large population of apoptotic cell (79.45%), which was 1.2-fold higher than that produced by cisplatin (65.28%) at the same concentration.     

Remote Paraparesis due to a Traumatic Extradural Arachnoid Cyst Developing 2 Years after Brachial Plexus Root Avulsion Injury: Case Report and Review of the Literature

Traumatic extradural arachnoid cyst is a rare entity. However, late appearance of paraparesis due to formation of an extradural arachnoid cyst as a sequel of brachial plexus injury is extremely rare and the literature regarding this issue is scarce revealing only 11 cases. Herein, we report a patient with delayed progressive spastic paraparesis appearing after a multilevel brachial plexus root avulsion injury where imaging revealed formation of a large traumatic extradural arachnoid cyst at the cervicothoracic region. Furthermore, to propose that a high-energy trauma might simultaneously result in delayed formation of an extradural arachnoid cyst. However, preganglionic root avulsion injury with pseudomeningocele formation in association with extradural arachnoid cyst is not reported previously. A case of a 36-year-old man with spastic paraparesis developing 2 years after a multilevel brachial plexus root avulsion injury is presented. Root avulsion had immediately resulted in complete paralysis of the left upper limb that had not ameliorated. Imaging studies of the cervicothoracic region disclosed left-sided multilevel pseudomeningoceles and a large extradural arachnoid cyst extending from C5 to T2. After appropriate en bloc laminotomy, the cyst was excised and the causative dural tear was closed. Subsequently, three large defects of pseudomeningoceles were obliterated with artificial dural patch for the prevention of cord herniation. This was followed with laminoplasty of the corresponding levels after dural closure. The postoperative course was uneventful and paraparesis recovered steadily within 2 months. Paraparesis even years after brachial plexus injury should be regarded as a serious event that deserves extensive imaging survey for the possibility of the formation of an extradural arachnoid cyst. Careful review of the literature disclosed that the current case is the 12th case that an extradural arachnoid cyst has developed after brachial plexus injury and the first example that the pathogenic factor that might be implicated in occurrence of this rare association could be clarified with review of the MRI features. Actually, the presence of posttraumatic pseudomeningoceles in association with an arachnoid cyst in the current case is in favor of the belief that only preganglionic root injuries that are in close proximity to the spinal canal had been the cause dural tear with remote formation of extradural arachnoid cyst.     

Fluoride in Iranian Drinking Water Resources: a Systematic Review,Meta-analysis and Non-carcinogenic Risk Assessment

Biological Trace Element Research - A systematic review, meta-analysis, and non-carcinogenic risk considering fluoride content of drinking water resources of 31 provinces of Iran among some...     

Optimized immobilization of endoglucanase Cel9A onto glutaraldehyde activated chitosan nanoparticles by response surface methodology: The study of kinetic behaviors

Immobilization of enzyme onto nanoparticles such as chitosan can have biotechnological importance. In this study, chitosan nanoparticles (ChNPs) were prepared by Ionic gelation method and Endoglucanase Cel9A from Alicyclobacillus acidocaldariius (AaCel9A) immobilized on the nanoparticles. The FTIR results showed that the enzymes were immobilized on the ChNPs. The dynamic light scattering and scanning electron microscope (SEM) results illustrated that the AaCel9A-ChNPs approximately had 40 nm diameters. For optimizing enzyme immobilization, response surface methodology was employed using different variables (pH, enzyme immobilization time, and enzyme to ChNPs ratio [E/Cs]). The results showed that the high immobilization efficiency was achieved in pH 7, E/Cs of 0.4 in 2.63 hr. The enzyme activity results showed that, immobilization increased optimum pH for activity (from 6.5 to 7.5) and the enzyme K_m (from 3.703 to 12.195 [mg/ml]), which make it suitable to use in some industries such as detergents.