Search

Ilmenite ore fine and coke breeze as reduced material were briquetted with different amounts of organic materials such as molasses or pitch were studied in this investigation. The produced briquettes at reasonable condition were reduced in nitrogen atmosphere at temperature range 800 - 1100oC to determine the factors controlling the reduction and to determine the controlling mechanism. Also ilmenite ore fine with coke breeze were reduced at the same temperature range in nitrogen atmosphere without briquetting process, for the sake of comparison.

Background: Device-associated infections (DAIs) are a significant cause of morbidity following living donor liver transplantation (LDLT). We aimed to assess the impact of bundled care on reducing rates of device-associated infections., Methods: We performed a before-and-after comparative study at a liver transplantation facility over a three-year period, spanning from January 2016 to December 2018. The study included a total of 57 patients who underwent LDLT. We investigated the implementation of a care bundle, which consists of multiple evidence-based procedures that are consistently performed as a unified unit. We divided our study into three phases and implemented a bundled care approach in the second phase. Rates of pneumonia related to ventilators [VAP], bloodstream infections associated with central line [CLABSI], and urinary tract infections associated with catheters [CAUTI] were assessed throughout the study period. Bacterial identification and antibiotic susceptibility testing were performed using the automated Vitek-2 system. The comparison between different phases was assessed using the chi-square test or the Fisher exact test for qualitative values and the Kruskal-Wallis H test for quantitative values with non-normal distribution., Results: In the baseline phase, the VAP rates were 73.5, the CAUTI rates were 47.2, and the CLABSI rates were 7.4 per one thousand device days (PDD). During the bundle care phase, the rates decreased to 33.3, 18.18, and 4.78. In the follow-up phase, the rates further decreased to 35.7%, 16.8%, and 2.7% PDD. The prevalence of Klebsiella pneumonia (37.5%) and Methicillin resistance Staph aureus (37.5%) in VAP were noted. The primary causative agent of CAUTI was Candida albicans, accounting for 33.3% of cases, whereas Coagulase-negative Staph was the predominant organism responsible for CLABSI, with a prevalence of 40%., Conclusion: This study demonstrates the effectiveness of utilizing the care bundle approach to reduce DAI in LDLT, especially in low socioeconomic countries with limited resources. By implementing a comprehensive set of evidence-based interventions, healthcare systems can effectively reduce the burden of DAI, enhance infection prevention strategies and improve patient outcomes in resource-constrained settings., (© 2024. The Author(s).)

Invasive candidiasis (IC) represents a growing concern worldwide, with a considerable increase in non-albicans Candida (NAC) species. The study's primary goal was to determine if species identification by semi-nested PCR (sn-PCR) with primers for the five most prevalent Candida species is sufficient to deal with the current trends of Candida infections in cancer patients. Over one year, Candida isolates were collected from samples of patients with hematological and solid organ tumors in a single center. Species of Candida were identified by chromagar and multiplex sn-PCR using specific primers for Candida albicans, Candida tropicalis, Candida glabrata, Candida krusei, and the Candida parapsilosis complex. Most Candida infection episodes are caused by NAC species (70.5% of 105 isolates). Rare species (14 isolates) accounted for 13.3% of isolates and were not identified by sn-PCR using the five most common Candida species primers. More than half of these rare species caused candidemia in cancer patients (57.1%; p = 0.011). The risk factor for candidiasis was recent surgeries (p = 0.020) in adults and chemotherapy in pediatric patients (p = 0.006). Prolonged hospitalization and genitourinary tract cancer were significantly associated with invasive infections (p = 0.005 and 0.049, respectively). Recent surgery was a significant risk factor associated with C. parapsilosis and C. glabrata infections (P = 0.038 and 0.003, respectively), while C. tropicalis was significantly more common in patients with hematological malignancies (P = 0.012). Techniques with a broader identification spectrum than the major five Candida species are crucial for the optimal management of cancer patients., (© 2023. The Author(s).)

Candidemia is a life-threatening invasive fungal infection in immunocompromised patients. The widespread use of azoles and the shift toward non-albicans Candida (NAC) species remarkably increase azole resistance in developing countries. We aimed to study candidemia trends and associated risk factors in oncology patients since they vary geographically, and rapid and appropriate treatment improves outcomes. Vitek 2 was used to identify the Candida species, and the E-test determined their susceptibility to azoles. Candida was the cause of 3.1% (n = 53/1701) of bloodstream infections (BSIs) during a 1-year study. Candida tropicalis was the most predominant species among the 30 candidemia episodes studied (36.7%), followed by C. albicans (33.3%). However, C. krusei, C. guilliermondii, C. pelliculosa, C. parapsilosis, C. famata, and C. inconspicua accounted for 30.0% of the isolates. An increased risk of NAC BSI was significantly associated with chemotherapy and leucopenia (P = 0.036 and 0.016, respectively). However, the multivariable analysis revealed that leucopenia was the only independent risk factor (P = 0.048). Fluconazole and voriconazole resistance were 58.3% and 16.7%, with NAC species showing higher resistance rates than C. albicans. Both fluconazole and voriconazole minimum inhibitory concentration (MIC) median values were higher in NAC than in C. albicans, but only voriconazole was significantly higher (0.220 versus 0.048 μg/ml, P = 0.047). In conclusion, the increased prevalence of NAC BSIs and incredibly high fluconazole resistance rates in cancer patients emphasize the necessity of antifungal stewardship to preserve voriconazole effectiveness, continued surveillance of candidemia, and future studies into azole resistance molecular mechanisms., (© 2023. The Author(s).)

Purpose: Antimicrobial resistance is a major concern that we are facing nowadays. This is due to antibiotic misuse and bacteria developing resistance to the commonly used antibiotics. This may lead to increased mortality and consumption of country resources. Implementation of an antimicrobial stewardship program [ASP] can limit the use of unnecessary antibiotics and subsequently decrease the infection rates with better patient outcome. We aimed to control antibiotic misuse, reduce infection rate, decrease drug costs, and reduce length of hospital stay in the ICU., Methods: We conducted a prospective study on the surgical neonatal ICU [SNICU] over a period of 6 months divided into pre-implementation phase, followed by an ASP phase, in which we applied the antibiotic guidelines approved by the ASP committee. Data were collected in the two phases and analyzed for demographics, compliance with guidelines, prescribed antibiotics, lab investigations, surgical site infection [SSI], length of stay and patient outcome., Results: Compliance to the guidelines was encountered in 86% and SSI rate decreased to 20%. Days of Therapy (DOT) per 1000 patient days showed a significant decrease in Ampicillin Sulbactam by 296 (p = 0.024), Imipenem by 220.34 (p = 0.024) and Vancomycin by 287.34 (p = 0.048). Drug cost showed a 1185.97 EGP decrease in the ASP period compared to the pre-implementation period (p = 0.714). Average LOS decreased in the ASP period by a mean difference of 2.5 (p = 0.027)., Conclusion: ASP implementation can control antibiotic misuse, decrease the medical care expenses and improve patient outcome., Type of Study: Clinical research paper., Level of Evidence: Level one., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Selective MSCs differentiation protocol into pancreatic beta cells was conducted in the present study using exendin-4 and TGF-beta. Differentiated and undifferentiated MSCs were assessed in experimental type I diabetes in rats. Ninety female white albino rats were included in the study and divided equally (n=15/group) into 6 groups: healthy control, healthy control rats received acellular tissue culture medium, diabetic rats, diabetic rats received acellular tissue culture medium, diabetic rats received undifferentiated MSCs and diabetic rats received differentiated MSCs. Therapeutic efficacy of undifferentiated versus differentiated MSCs was evaluated via assessment of quantitative gene expressions of insulin1, insulin 2, Smad-2, Smad-3, PDX-1, PAX-4, neuroD . Blood glucose and insulin hormone levels were also assessed. Results showed that quantitative gene expressions of all studied genes showed significant decrease in diabetic rat groups. Use of undifferentiated and differentiated MSCs led to a significant elevation of expression levels of all genes with more superior effect with differentiated MSCs except smad-2 gene. As regards insulin hormone levels, use of either undifferentiated or differentiated MSCs led to a significant elevation of its levels with more therapeutic effect with differentiated MSCs. Blood glucose levels were significantly decreased with both undifferentiated and differentiated MSCs in comparison to diabetic groups but its levels were normalized 2 months after injection of differentiated MSCs. In conclusion, use of undifferentiated or differentiated MSCs exhibited significant therapeutic potentials in experimental type I diabetes in rats with more significant therapeutic effect with the use of differentiated MSCs.

A series of 3-(2,4-dichlorophenyl)-N-alkyl-N-fluoroalkyl-2,5-dimethylpyrazolo[1,5-a]pyrimidin-7-amines were synthesized and evaluated as potential positron emission tomography (PET) tracers for the corticotropin-releasing factor type-1 (CRF1) receptor. Compounds 27, 28, 29, and 30 all displayed high binding affinity (⩽1.2 nM) to the CRF1 receptor when assessed by in vitro competition binding assays at 23 °C, whereas a decrease in affinity (⩾10-fold) was observed with compound 26. The logP7.4 values of [(18)F]26-[(18)F]29 were in the range of ∼2.2-2.8 and microPET evaluation of [(18)F]26-[(18)F]29 in an anesthetized male cynomolgus monkey demonstrated brain penetrance, but specific binding was not sufficient enough to differentiate regions of high CRF1 receptor density from regions of low CRF1 receptor density. Radioactivity uptake in the skull, and sphenoid bone and/or sphenoid sinus during studies with [(18)F]28, [(18)F]28-d8, and [(18)F]29 was attributed to a combination of [(18)F]fluoride generated by metabolic defluorination of the radiotracer and binding of intact radiotracer to CRF1 receptors expressed on mast cells in the bone marrow. Uptake of [(18)F]26 and [(18)F]27 in the skull and sphenoid region was rapid but then steadily washed out which suggests that this behavior was the result of binding to CRF1 receptors expressed on mast cells in the bone marrow with no contribution from [(18)F]fluoride., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Although many components of the genetic pathways that provide positional information during embryogenesis have been identified, it remains unclear how these signals are integrated to specify discrete tissue territories. Here, we investigate the molecular mechanisms underlying the formation of one of the hindbrain segments, rhombomere (r) 3, specified by the expression of the gene krox20. Dissecting krox20 transcriptional regulation has identified several input pathways: Hox paralogous 1 (PG1) factors, which both directly activate krox20 and indirectly repress it via Nlz factors, and the molecular components of an Fgf-dependent effector pathway. These different inputs are channelled through a single initiator enhancer element to shape krox20 initial transcriptional response: Hox PG1 and Nlz factors define the anterior-posterior extent of the enhancer's domain of activity, whereas Fgf signalling modulates the magnitude of activity in a spatially uniform manner. Final positioning of r3 boundaries requires interpretation of this initial pattern by a krox20 positive-feedback loop, orchestrated by another enhancer. Overall, this study shows how positional information provided by different patterning mechanisms is integrated through a gene regulatory network involving two cis-acting elements operating on the same gene, thus offering a comprehensive view of the delimitation of a territory., (© 2015. Published by The Company of Biologists Ltd.)

Background: Stem cell therapy holds a great promise for the repair of injured tissues and organs, including the kidney. We studied the effect of mesenchymal stem cells (MSC) on experimental diabetic nephropathy (DN) in rats and the possible paracrine signals that mediate their action., Materials and Methods: Rats were divided into controls, DN rats, DN rats receiving MSCs. MSCs were given in a dose of (106cells) by intravenous injection. After 4 weeks, 24 h urinary albumin, serum urea and creatinine concentrations, transforming growth factor β (TGF β), tumor necrosis factor α (TNFα), B-cell lymphoma 2 (bcl2) and Bax gene expression and vascular endothelial growth factor (VEGF) were assessed. Histopathology staining was performed., Results: MSC therapy significantly improved 24 h urinary albumin, serum urea and creatinine concentrations, increased angiogenic growth factor VEGF, and anti-apoptotic protein bcl2 while decreased the pro-inflammatory TNF-α, fibrogenic growth factor TGF β, and pro-apoptotic protein Bax. The histopathology examination showed patchy areas of minimal necrosis and degeneration in renal tubules.

Background: Hyperglycemia induces activation of the c-Jun N-terminal kinase (JNK) pathway, which suppresses insulin gene expression and reduces DNA binding of pancreatic and duodenal homeobox factor (PDX)-1. This study aims to investigate the effects of a novel curcumin derivative (NCD) on JNK signaling pathway on insulin synthesis and secretion in streptozotocin (STZ)-treated rat pancreatic islets in vitro., Methods: Isolated rat pancreatic islets were divided into five groups: untreated control group; group treated with NCD (10 μM); group exposed to STZ (5 mM); group treated with NCD (10 μM) and then exposed to STZ (5 mM); and group exposed to STZ (5 mM) and then treated with NCD (10 μM). The pancreatic islets from all groups were used for DNA fragmentation assays and quantitative assessments of the JNK, Pdx1, glucose transporter-2 (GLUT2), heme oxygenase (HO)-1, transcription factor 7-like 2 (TCF7L2), and glucagon-like peptide (GLP)-1 gene expression levels. The intracellular calcium, zinc, and the phosphorylated and total JNK protein levels were assessed. The insulin (secreted/total) and C-peptide levels were examined in islet culture medium., Results: NCD protected pancreatic islets against STZ-induced DNA damage, improved total insulin (P = 0.001), secreted insulin (P = 0.001), and C-peptide levels (P = 0.001), normalized mRNA expressions of insulin, Pdx1, and GLUT2 (P = 0.0001), and significantly elevated calcium and zinc levels (P = 0.0001). All effects were significant when islets were treated with NCD before STZ (P = 0.05). JNK gene overexpression and JNK protein levels induced by STZ were significantly inhibited after NCD treatment of islets ( P = 0.0001). NCD-treated islets showed significantly elevated gene expressions of HO-1, TCF7L2, and GLP-1 (P = 0.0001), and these upregulated gene expressions were more significantly elevated with NCD treatment before STZ than after STZ (P = 0.05)., Conclusions: NCD improved insulin synthesis and secretion in vitro in isolated pancreatic islets treated with STZ through inhibition of the JNK pathway, up-regulation of the gene expressions of HO-1, TCF7L2, and GLP-1 and enhancing effects on calcium and zinc levels.

Background: Several studies highlight curcumin's benefit as a hypoglycemic agent, however; a limited number of reports present the importance of curcumin in improvement of pancreatic islets in diabetes. The aim of the present study is to evaluate the antidiabetic effect of a novel curcumin derivative and its effect on pancreatic islet regeneration in type I diabetes-induced by STZ., Materials and Methods: Rats were divided into diabetic rats and diabetic rats treated orally with the novel curcumin derivative (NCD) for 40 days. Fasting blood samples were withdrawn periodically from all rats to estimate plasma glucose, insulin and C-peptide for 10 months. Histopathology was performed to allow the assessment of pancreatic islet morphology. Insulin and CD105 were detected immunohistochemically., Results: In diabetic rats, the plasma glucose, insulin and C-peptide levels remained within the diabetic range for about 4 months, after which a gradual decrease in glucose and increase in insulin and C-peptide was observed, which reached almost normal levels after 10 months. NCD treated diabetic rats showed significantly lowered plasma glucose and increased plasma insulin and C-peptide levels. This was followed by a further significant decrease in plasma glucose and increase in plasma insulin and C-peptide after two months from oral administration of the NCD. The plasma insulin and C-peptide continued to increase for ten months reaching levels significantly higher than the basal level. Histopathological examination of diabetic rat pancreas revealed absence of islets of Langerhans, minimal adipose tissue infiltration and localized lymphocytic infiltrates. However, after 6 months of induction of diabetes, rat pancreas showed the appearance of small well formed islets and positive insulin cells but no CD105 positive cells. NCD treated rats showed the appearance of primitive cell collections, large insulin positive cells and CD105 positive cells in the adipose tissue infiltrating the pancreatic tissues. This was followed by the gradual appearance of insulin positive cells in the islets while, CD 105 positive cells remained in the adipose tissue. After 5 and 10 months from the onset of diabetes, rat pancreas showed, well developed larger sized islets with disappearance of primitive cell collections and CD 105 positive cells. Also, insulin positive islets of variable size with disappearance of insulin positive cells in adipose tissue were detected., Conclusion: The NCD possesses antidiabetic actions and enhanced pancreatic islets regeneration.

Background: Curcumin exhibits anti-diabetic activities, induces heme-oxygenase-1 (HO-1) and is an inhibitor of transcriptional co-activator p300. A novel water soluble curcumin derivative (NCD) has been developed to overcome low invivo bioavailability of curcumin. We evaluated the effect of the NCD on signaling mechanisms involved in cardiomyocyte hypertrophy and studied whether its action is mediated via inducible HO-1., Materials and Methods: Rats were divided into controls, controls receiving NCD, diabetic, diabetic receiving NCD, diabetic receiving pure curcumin, diabetic receiving HO inhibitor, zinc protoporphyrin IX (ZnPP IX) and diabetic receiving NCD and ZnPP IX. NCD and curcumin were given orally. After 45 days, cardiac physiologic parameters, plasma glucose, insulin, glycated hemoglobin (GHb), HO-1 gene expression and HO activity in pancreas and cardiac tissues were assessed. Gene expression of p300, atrial natriuretic peptide (ANP) and myocyte enhancer factor 2 (MEF2A and MEF2C) were studied., Results: NCD and curcumin decreased plasma glucose, GHb and increased insulin levels significantly in diabetic rats. This action may be partially mediated by induction of HO-1 gene. HO-1 gene expression and HO activity were significantly increased in diabetic heart and pancreas. Diabetes upregulated the expression of ANP, MEF2A, MEF2C and p300. NCD and curcumin prevented diabetes-induced upregulation of these parameters and improved left ventricular function. The effect of the NCD was better than the same dose of curcumin.

Although feedback loops are essential in development, their molecular implementation and precise functions remain elusive. Using enhancer knockout in mice, we demonstrate that a direct, positive autoregulatory loop amplifies and maintains the expression of Krox20, a transcription factor governing vertebrate hindbrain segmentation. By combining quantitative data collected in the zebrafish with biophysical modelling that accounts for the intrinsic stochastic molecular dynamics, we dissect the loop at the molecular level. We find that it underpins a bistable switch that turns a transient input signal into cell fate commitment, as we observe in single cell analyses. The stochasticity of the activation process leads to a graded input-output response until saturation is reached. Consequently, the duration and strength of the input signal controls the size of the hindbrain segments by modulating the distribution between the two cell fates. Moreover, segment formation is buffered from severe variations in input level. Finally, the progressive extinction of Krox20 expression involves a destabilization of the loop by repressor molecules. These mechanisms are of general significance for cell type specification and tissue patterning.

Background: Diabetes mellitus type 1 is an autoimmune disorder caused by lymphocytic infiltration and beta cells destruction. Curcumin has been identified as a potent inducer of heme-oxygenase-1 (HO-1), a redoxsensitive inducible protein that provides protection against various forms of stress. A novel water soluble curcumin derivative (NCD) has been developed to overcome low in vivo bioavailability of curcumin. The aim of the present work is to evaluate the anti diabetic effects of the "NCD" and its effects on diabetes-induced ROS generation and lipid peroxidation in experimental type- 1 diabetes mellitus. We also examine whether the up regulation of HO-1 accompanied by increased HO activity mediates these antidiabetic and anti oxidant actions., Materials and Methods: Rats were divided into control group, control group receiving curcumin derivative, diabetic group, diabetic group receiving curcumin derivative and diabetic group receiving curcumin derivative and HO inhibitor ZnPP. Type-1 diabetes was induced by intraperitoneal injection of streptozotocin. Curcumin derivative was given orally for 45 days. At the planned sacrification time (after 45 days), fasting blood samples were withdrawn for estimation of plasma glucose, plasma insulin and lipid profile . Animals were sacrificed; pancreas, aorta and liver were excised for the heme oxygenase - 1 expression, activity and malondialdehyde estimation., Results: NCD supplementation to diabetic rats significantly lowered the plasma glucose by 27.5% and increased plasma insulin by 66.67%. On the other hand, the mean plasma glucose level in the control group showed no significant difference compared to the control group receiving the oral NCD whereas, NCD supplementation to the control rats significantly increased the plasma insulin by 47.13% compared to the control. NCD decreased total cholesterol, triglycerides, LDL cholesterol and increased HDL cholesterol levels. Also, it decreased lipid peroxides (malondialdehyde) in the pancreas, aorta and liver., Conclusion: The (NCD) by its small dose possesses antidiabetic actions and that heme oxygenase induction seems to play an important role in its anti-diabetic effects. NCD also improves the lipid profile and oxidative status directly, proved by decreasing lipid peroxides (malondialdehyde) in pancreas, liver & aorta. The new water soluble curcumin derivative still retains the essential potencies of natural curcumin.

Vertebrate hindbrain segmentation is an evolutionarily conserved process that involves a complex interplay of transcription factors and signalling pathways. Fibroblast growth factor (FGF) signalling plays a major role, notably by controlling the expression of the transcription factor Krox20 (Egr2), which is required for the formation and specification of two segmental units: rhombomeres (r) 3 and 5. Here, we explore the molecular mechanisms downstream of FGF signalling and the function of Sprouty 4 (Spry4), a negative-feedback regulator of this pathway, in zebrafish. We show that precise modulation of FGF signalling by Spry4 is required to determine the appropriate onset of krox20 transcription in r3 and r5 and, ultimately, rhombomere size in the r3-r5 region. FGF signalling acts by modulating the activity of krox20 initiator enhancer elements B and C; in r5, we show that this regulation is mediated by direct binding of the transcription factor MafB to element B. By contrast, FGF signalling does not control the krox20 autoregulatory element A, which is responsible for amplification and maintenance of krox20 expression. Therefore, early krox20 transcription sets the blueprint for r3-r5 patterning. This work illustrates the necessity for fine-tuning in a common and fundamental patterning process, based on a bistable cell-fate choice involving the coupling of an extracellular gradient with a positive-feedback loop. In this mode of patterning, precision and robustness can be achieved by the introduction of a negative-feedback loop, which, in the hindbrain, is mediated by Spry4.

Curcumin exerts a hypoglycemic action and induces heme-oxygenase-1 (HO-1). We evaluated the effect of curcumin on isolated islets of Langerhans and studied whether its action on insulin secretion is mediated by inducible HO-1. Islets were isolated from rats and divided into control islets, islets incubated in different curcumin concentrations, islets incubated in hemin, islets incubated in curcumin and HO inhibitor, stannous mesoporphyrin (SnMP), islets incubated in hemin and SnMP, islets incubated in SnMP only, and islets incubated in 16.7 mmol/L glucose. Heme-oxygenase activity, HO-1 expression, and insulin estimation was assessed. Insulin secretion, HO-1 gene expression and HO activity were significantly increased in islets incubated in curcumin, hemin, and glucose compared with controls. This increase in insulin secretion was significantly decreased by incubation of islets in SnMP. The action of curcumin on insulin secretion from the isolated islets may be, in part, mediated through increased HO-1 gene expression.

Introduction: Erectile response depends on nitric oxide (NO) generated by NO synthase (NOS) enzyme of the nerves and vascular endothelium in the cavernous tissue. NO activates soluble guanylate cyclase (sGC), leading to the production of cyclic guanosine monophosphate (cGMP). cGMP activates cGMP-dependent protein kinase that activates Ca(2+)/ATPase pump that activates Ca(2+)/K efflux pump extruding Ca(2+) across the plasma membrane with consequent smooth muscle cell relaxation. A role similar to that of NOS/NO signaling has been postulated for carbon monoxide (CO) produced in mammals from heme catabolism by heme oxygenase (HO) enzyme., Aim: To assess CO signaling pathway for erectile function by reviewing published studies., Methods: A systematic review of published studies on this affair based on Pubmed and Medical Subject Heading databases, with search for all concerned articles., Main Outcome Measures: Documentation of positive as well as negative criteria of CO/HO signaling focused on penile tissue., Results: The concept that HO-derived CO could play a role in mediating erectile function acting in synergism with, or as a potentiator for, NOS/NO signaling pathway is gaining momentum. CO/HO signaling pathway has been shown to partially mediate the actions of oral phosphodiesterase type 5 inhibitors. In addition, it was shown that the use of CO releasing molecules potentiated cavernous cGMP levels. However, increased CO production or release was reported to be associated, in some studies, with vasoconstriction., Conclusion: This review sheds a light on the significance of cavernous tissue CO signaling pathway that may pave the way for creation of therapeutic modalities based on this pathway.

The morphogenesis of the vertebrate hindbrain involves the generation of metameric units called rhombomeres (r), and Krox20 encodes a transcription factor that is expressed in r3 and r5 and plays a major role in this segmentation process. Our knowledge of the basis of Krox20 regulation in r3 is rather confusing, especially concerning the involvement of Hox factors. To investigate this issue, we studied one of the Krox20 hindbrain cis-regulatory sequences, element C, which is active in r3-r5 and which is the only initiator element in r3. We show that element C contains multiple binding sites for Meis and Hox/Pbx factors and that these proteins synergize to activate the enhancer. Mutation of these binding sites allowed us to establish that Krox20 is under the direct transcriptional control of both Meis (presumably Meis2) and Hox/Pbx factors in r3. Furthermore, our data indicate that element C functions according to multiple modes, in Meis-independent or -dependent manners and with different Hox proteins, in r3 and r5. Finally, we show that the Hoxb1 and Krox20 expression domains transiently overlap in prospective r3, and that Hoxb1 binds to element C in vivo, supporting a cell-autonomous involvement of Hox paralogous group 1 proteins in Krox20 regulation. Altogether, our data clarify the molecular mechanisms of an essential step in hindbrain patterning. We propose a model for the complex regulation of Krox20, involving a novel mode of initiation, positive and negative controls by Hox proteins, and multiple direct and indirect autoregulatory loops.

Introduction: Heme oxygenase (HO) enzyme catalyzes the rate limiting step in oxidative degradation of heme to biliverdin and carbon monoxide (CO). CO has been shown to share many properties with nitric oxide (NO), including activation of guanyl cyclase, signal transduction, and gene regulation., Aim: To assess the signaling pathways mediating cavernous tissues response to sildenafil citrate intake experimentally., Main Outcome Measures: In dissected cavernous tissues; detection of HO-1, HO-2 and nueronal nitric oxide synthase (nNOS) gene expressions by reverse transcriptase polymerase chain reaction (RT-PCR), HO enzyme activity assay, HO-1, HO-2 protein detection by Western blot, cyclic guanosine monophosphate (cGMP) tissue levels by enzyme linked immunosorbent assay (ELISA) and histopathology., Methods: Two hundred forty Sprague-Dawley rats divided into five equal groups were investigated: group (Gr) 1, controls received regular diet; Gr 2, received sildenafil citrate 4 mg/kg orally; Gr 3, received the same dose of sildenafil added to HO inducer, diferuloylmethane; Gr 4, received sildenafil added to HO inhibitor, zinc protoporphyrin, and Gr 5, received sildenafil kg orally by gastric tube. Gr 3 received the same dose of sildenafil added to HO inducer, added to nitric oxide synthase inhibitor, L-Nitroarginine methylester. Twelve rats from each group were sacrificed by cervical dislocation successively after 1/2, 1, 2, and 3 hours from the intake., Results: HO-2 gene expression was demonstrated in all groups. HO-1 was not expressed in controls, expressed in Gr 2, accentuated in Gr 3, and attenuated in Gr 4 and 5. These results were confirmed by Western blot. The nNOS was expressed in controls, increased in Gr 2 and 3, and decreased in Gr 4 and 5. HO enzyme activity and cGMP levels were significantly elevated in Gr 2, accentuated in Gr 3, and significantly decreased in Gr 4 and 5 compared to controls. Vasodilatations were observed in cavernous tissues of histopathologic sections of Gr 2 and increased in those of Gr 3., Conclusion: Sildenafil citrate actions may be mediated by up-regulation of HO-1 gene expression.

JVP domes are of a set of small grating surfaces recently introduced for cutaneous spatial resolution measurement. The gratings are placed on the skin and subjects are required to identify the orientation of grooves and bars. The finest grating whose orientations are discriminated reliably (75% correct) provides an estimate of the spatial resolution limit in the tested area. In the present study, we sought to determine the capacity of elderly subjects to resolve such grating stimuli in order to obtain normative data for this population. Thirty-two elderly individuals in good health (range: 60-88 years) were assessed for their ability to perceive grating orientation at the tip of the dominant index finger. Testing proceeded from the widest grating dome (3 mm) to the next (e.g., 2 mm), until the performance level dropped below 75% correct discrimination. The grating orientation task proved to be very difficult for most subjects and only a minority (14/32) was able to provide reliable reports of grating orientation even with presentation of the widest dome available (3 mm). Accordingly, individual grating resolution thresholds were often considerably higher (> 2.5 mm, n = 26) than values previously reported in young adults for the fingertip region (approximately 1 mm). These results suggest that the current set of grating domes may not be adequate for spatial acuity measurement at the fingertip of older adults. New larger grating dimensions should be added to the set presently available to improve their sensitivity for an older population.