Influence of environmental hypertonicity on the induction of ureogenesis and amino acid metabolism in air-breathing walking catfish (Clarias batrachus, Bloch).

Effect of environmental hypertonicity, due to exposure to 300 mM mannitol solution for 7 days, on the induction of ureogenesis and also on amino acid metabolism was studied in the air-breathing walking catfish, C. batrachus, which is already known to have the capacity to face the problem of osmolarity stress in addition to other environmental stresses in its natural habitats. Exposure to hypertonic mannitol solution led to reduction of ammonia excretion rate by about 2-fold with a concomitant increase of urea-N excretion rate by about 2-fold. This was accompanied by significant increase in the levels of both ammonia and urea in different tissues and also in plasma. Further, the environmental hypertonicity also led to significant accumulation of different non-essential free amino acids (FAAs) and to some extent the essential FAAs, thereby causing a total increase of non-essential FAA pool by 2-3-fold and essential FAA pool by 1.5-2.0-fold in most of the tissues studied including the plasma. The activities of three ornithine-urea cycle (OUC) enzymes such as carbamoyl phosphate synthetase, argininosuccinate synthetase and argininosuccinate lyase in liver and kidney tissues, and four key amino acid metabolism-related enzymes such as glutamine synthetase, glutamate dehydrogenase (reductive amination), alanine aminotransaminase and aspartate aminotransaminase were also significantly up-regulated in different tissues of the fish while exposing to hypertonic environment. Thus, more accumulation and excretion of urea-N observed during hypertonic exposure were probably associated with the induction of ureogenesis through the induced OUC, and the increase of amino acid pool was probably mainly associated with the up-regulation of amino acid synthesizing machineries in this catfish in hypertonic environment. These might have helped the walking catfish in defending the osmotic stress and to acclimatize better under hypertonic environment, which is very much uncommon among freshwater teleosts.

Effect of Wnt/β-catenin and NF-κB signaling pathways on mucus secretion with hypertonicity in 16HBE cells

This study aimed at identifying the molecular mechanisms and effects of hypertonicity on mucin5AC (MUC5AC) expression in airway epithelial cells for which immortalized human bronchial epithelial (16HBE) cells were cultured in 600 mOsm/L hypertonic medium for different times in vitro. Proteins of MUC5AC and β-catenin, Cyclin D1, NF-κB p65 were detected by enzyme linked immunosorbent assay (ELISA), reverse transcription (RT)-PCR and western blotting assays. After transfection of β-catenin siRNA in 16HBE cells, the levels of β-catenin, Cyclin D1, NF-κB p65 and MUC5AC protein were detected. Results showed that the levels of mRNAs and proteins of target genes increased significantly after the exposure to hypertonic conditions and the expression content increased in a time-dependent manner. Furthermore, transfection with β-catenin siRNA attenuated the expression of these genes. These results suggested that the Wnt/β-catenin and NF-κB signaling pathways played essential roles in inducing the MUC5AC hypersecretion in 16HBE cells in response to hypertonicity.

Reactive oxygen species regulate context-dependent inhibition of NFAT5 target genes

The activation of nuclear factor of activated T cells 5 (NFAT5), a well-known osmoprotective factor, can be induced by isotonic stimuli, such as activated Toll-like receptors (TLRs). It is unclear, however, how NFAT5 discriminates between isotonic and hypertonic stimuli. In this study we identified a novel context-dependent suppression of NFAT5 target gene expression in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS) or a high salt (NaCl) concentration. Although LPS and NaCl both used NFAT5 as a core transcription factor, these stimuli mutually inhibited distinct sets of NFAT5 targets within the cells. Although reactive oxygen species (ROS) are essential for this inhibition, the source of ROS differed depending on the context: mitochondria for high salt and xanthine oxidase for TLRs. Specifically, the high salt-induced suppression of interleukin-6 (IL-6) production was mediated through the ROS-induced inhibition of NFAT5 binding to the IL-6 promoter. The context-dependent inhibition of NFAT5 target gene expression was also confirmed in mouse spleen and kidney tissues that were cotreated with LPS and high salt. Taken together, our data suggest that ROS function as molecular sensors to discriminate between TLR ligation and osmotic stimuli in RAW 264.7 macrophages, directing NFAT5 activity toward proinflammatory or hypertonic responses in a context-dependent manner.

Adolescent Idiopathic Scoliosis: A 71 Cases Study Ascertaining that Straightening Is Possible, and a New Etiological Hypothesis

STUDY DESIGN: Seventy-one children (23 boys and 48 girls, aged 6 to 18 year-old) with adolescent idiopathic scoliosis (AIS) between 11degrees and 62degrees, without braces, have been treated manually, only at the level of the neck. PURPOSE: To ascertain that non-surgical straightening of AIS is possible (without brace). OVERVIEW OF LITERATURE: So far no disease modifying treatment for AIS existed. Braces can only slow down worsening (and this can only be achieved if they are worn 23 hours a day). Surgery is not without important risks. METHODS: All patients have been treated exclusively with a manual therapy called Brachy-Myotherapy. This method treats spasmed (contractured) muscles by placing them in a shortening position according to a specific protocol. RESULTS: An average straightening of 8degrees of AIS was observed, with a maximum of 25degrees. 94% of cases improved, 67 out of 71. The worst prognosis was, the better results. The more advanced AIS was, the better the results. CONCLUSIONS: A simple and reliable treatment of AIS is possible. AIS seems to be a compensation mechanism of the body, with the aim of keeping the ears, and thus the labyrinths, at a horizontal level for correct equilibrium. When lasting post-traumatic neck muscle contractures causing a permanent side-bending of the skull have been treated, this compensation mechanism becomes irrelevant and scoliosis tends to subside.

Application of Botulinum toxin Type A: An arsenal in dentistry.

An extremely effective way of preventing damage to and enhancing treatment of dental hard tissues and restorations would be to ''de-programme'' the muscles responsible for excessive destructive forces and other gnathological-related diseases. The new paradigm is the intramuscular injection of Botulinum toxin type A (BOTOX) into the affected muscles. It is a natural protein produced by anaerobic bacterium, Clostridium botulinum. The toxin inhibits the release of acetylcholine (ACH), a neurotransmitter responsible for the activation of muscle contraction and glandular secretion, and its administration results in reduction of tone in the injected muscle. There are seven distinct serotypes of Botulinum toxin, viz., A, B, C, D, E, F, and G, which differ in their potency, duration of action, and cellular target sites. This paper describes the different applications of BOTOX in dentistry.

Hypertonic saline and reduced peroxynitrite formation in experimental pancreatitis

OBJECTIVES: In this study, we tested the hypothesis that hypertonic saline exerts anti-inflammatory effects by modulating hepatic oxidative stress in pancreatitis. INTRODUCTION: The incidence of hepatic injury is related to severe pancreatitis, and hypertonic saline reduces pancreatic injury and mortality in pancreatitis. METHODS: Wistar rats were divided into four groups: control (not subjected to treatment), untreated pancreatitis (NT, pancreatitis induced by a retrograde transduodenal infusion of 2.5 percent sodium taurocholate into the pancreatic duct with no further treatment administered), pancreatitis with normal saline (NS, pancreatitis induced as described above and followed by resuscitation with 0.9 percent NaCl), and pancreatitis with hypertonic saline (HS, pancreatitis induced as described above and followed by resuscitation with 7.5 percent NaCl). At 4, 12, and 24 h after pancreatitis induction, liver levels of inducible nitric oxide synthase (iNOS), heat-shock protein 70, nitrotyrosine (formation of peroxynitrite), nitrite/nitrate production, lipid peroxidation, and alanine aminotransferase (ALT) release were determined. RESULTS: Twelve hours after pancreatitis induction, animals in the HS group presented significantly lower iNOS expression (P<0.01 vs. NS), nitrite/nitrate levels (P<0.01 vs. NS), lipid peroxidation (P<0.05 vs. NT), and ALT release (P<0.01 vs. NS). Twenty-four hours after pancreatitis induction, nitrotyrosine expression was significantly lower in the HS group than in the NS group (P<0.05). DISCUSSION: The protective effect of hypertonic saline was related to the establishment of a superoxide-NO balance that was unfavorable to nitrotyrosine formation. CONCLUSIONS: Hypertonic saline decreases hepatic oxidative stress and thereby minimizes liver damage in pancreatitis.

Botulinum Toxin A Treatment for Patients with Periorbital Spasm after Facial Nerve Paresis

PURPOSE: To evaluate clinical features of periorbital spasm and facial asymmetry in the patients who recovered poorly from Bell's palsy and facial trauma and to investigate the effect of Botulinum toxin A as a treatment for periorbital spasm and facial asymmetry. METHODS: Between November 2001 and January 2010, Botulinum toxin injection was performed in 17 patients who had blepharospasm and facial asymmetry following poor recovery from facial palsy. The past history, trauma history, clinical manifestation of blepharospasm, Botulinum toxin A injection dose, injection site, frequency of injection, and duration of effect was evaluated. Data was analyzed using the Mann-Whitney U test, SPSS 12.0. RESULTS: The mean number of injections was 2.7 +/- 2.4 times and the mean dose per injection unit was 12.2 +/- 1.2 units. The Botulinum toxin effect lasted 6.9 +/- 5.5 months in Bell's palsy patients, and 8.0 +/- 4.2 months in trauma patients. There was no significant difference between the 2 groups. Most patients reported improvement of periorbital spasm and facial asymmetry. After treatment, 1 patient complained of epiphora and 1 patient complained of ptosis; conservative treatment was performed for these patients. CONCLUSIONS: Blepharospasm can be treated and a cosmetic improvement in facial symmetry can be achieved by Botulinum toxin A injection in the patients who recover poorly from facial palsy.

Urine Concentration and the Adaptation of Renal Medullary Cells to Hypertonicity

Hypertonicity(hypernatremia) of extracellular fluid causes water movement out of cells, while hypotonicity(hyponatremia) causes water movement into cells, resulting in cellular shrinkage or cellular swelling, respectively. In most part of the body, the osmolality of extracellular fluid is maintained within narrow range(285-295 mOsm/kgH2O) and some deviations from this range are not problematic in most tissue of the body except brain. On the other hand, the osmolality in the human renal medulla fluctuates between 50 and 1,200 mOsm/kgH2O in the process of urine dilution and concentration. The adaptation of renal medullary cells to the wide fluctuations in extracellular tonicity is crucial for the cell survival. This review will summarize the mechanisms of urine concentration and the adaptation of renal medullary cells to the hypertonicity, which is mediated by TonEBP transcription factor and its target gene products(UT- A1 urea transporter etc.).

Alternative Isoforms of TonEBP with Variable N-termini are Expressed in Mammalian Cells

Hypertonicity imposes a great deal of stress to cells since it causes rise in cellular ionic strength, which can be reduced by the accumulation of compatible osmolytes. TonEBP plays a central role in the cellular accumulation of compatible osmolytes via transcriptional stimulation of membrane transporters and aldose reductase. Alternatively spliced forms of TonEBP mRNA have previously been reported and two of them showed different transcriptional activity. In the present study, isoform-specific antibodies were produced to confirm the translation of the spliced mRNA to protein. TonEBP was immunoprecipitated by using anti-TonEBP antibody and then immunoblotted using anti-TonEBP or isoform specific antibodies to find out the expression profile of TonEBP isoforms in basal or stimulated condition. From these results, we conclude that all TonEBP isoforms are expressed in mammalian cells and their expression patterns are not same in every cells.

Physiology and Pathophysiology of Transcellular Shift of Potassium Balance

Plasma potassium level is maintained within a narrow normal range through a transcellular shift between intracellular and extracellular space, and through renal excretion. Internal potassium balance via transcellular shift is affected by several hormones and physiologic conditions. Catecholamine through beta2-adrenergic receptor stimulates cellular uptake of potassium and defends against increments in plasma potassium concentration. Insulin promotes cellular potassium uptake in muscle, liver and adipose tissues. Changes of acid-base status affects internal potassium balance as well as renal potassium excretion. Other physiologic and pathophysiologic conditions such as exercise or tissue damage also have acute effects on the distribution of potassium. Although a lot of medications are the causes of hyperkalemia, drugs that alter internal potassium balance would appear to be uncommon. Understanding the physiology of potassium distribution is important to evaluate and manage the patients with potassium disturbances including hypokalemia or hyperkalemia.

The Abundance and Nuclear Distribution of TonEBP in Response to Changes of Tonicity in Hyperglycemic Cells / 대한내분비학회지

BACKGROUND: TonEBP (Tonicity-responsive enhancer binding protein) regulates the transcription of tonicity responsive genes, such as sodium-myo-inositol and the sodium- chloride-betaine co- transporters (SMIT & BGT1), heat shock protein 70 (HSP70) and aldose reductase (AR). To characterize the signals that activate TonEBP in hyperglycemic human retinal pigment epithelial (hRPE) cells, the abundance and nuclear distribution of TonEBP were studied in response to changes of tonicity in culture media. METHODS: After the cultures reached confluence, the hRPE cells were exposed for 3 days to 25 mM glucose and 100 mM NaCl, both with and without 20 M tolrestat. The expressions of AR, SMIT and HSP 70 were determined by northern blot, and the abundances of TonEBP by western blot. The nuclear distributions of TonEBP were observed by fluorescence microscopy, after immuno staining. RESULTS: The AR and SMIT mRNA levels in hyperglycemic and hypertonic media were decreased compared to those in hypertonic media alone. These decreased AR and SMIT mRNA expressions were also observed to be significantly prevented in those cells incubated with tolrestat. Stimulation of TonEBP in hypertonic medium occurs due to a combination of an increased abundance of TonEBP and an increased distribution into the nucleus from the cytoplasm. However, the expressions and nuclear distributions of TonEBP in hyperglycemic and hypertonic media were not different from those in hypertonic media alone. CONCLUSION: The expressions of AR and SMIT genes that may influence the development of diabetic complication were down-regulated by the intracellular accumulation of sorbitol in sustained hyperglycemia. TonEBP does not play a key role in the hypertonicity-induced transcriptional regulation of AR and SMIT in hyperglycemic cells, due to the intracellular accumulation of sorbitol and depletion of myo-inositol