The effect of nasal douching by hypertonic 2.3 per cent sea water with algae extracts on the concentration of epidermal growth factor, transforming growth factor-α and interleukin-8 in nasal secretions of patients with nasal polyposis following endoscopic surgical treatment

OBJECTIVE

To investigate epidermal growth factor, transforming growth factor-α and interleukin-8 production in nasal mucosa irrigated with hypertonic 2.3 per cent solution with algae extracts, in comparison to 0.9 per cent NaCl during the first two weeks after surgery for nasal polyposis, in relation to symptoms and local findings.

METHODS

This prospective study included 20 nasal polyposis patients postoperatively irrigated with hypertonic solution and 20 nasal polyposis patients postoperatively irrigated with isotonic solution. We evaluated nasal symptom score, endoscopic score and mediator levels in nasal secretions before and after irrigation.

RESULTS

Following treatment, nasal symptom score and endoscopic score were significantly lower in the hypertonic solution group (p = 0.023; p < 0.001, respectively). The increase in the epidermal growth factor and the decrease in the transforming growth factor-α and interleukin-8 concentration were higher in the hypertonic group (p < 0.001 for all mediators).

CONCLUSION

Irrigation with a hypertonic solution was found to be more effective than an isotonic solution in nasal mucosa reparation.

Estimation of negative membrane tension in lipid bilayers and its effect on antimicrobial peptide magainin 2-induced pore formation

Positive membrane tension in the stretched plasma membrane of cells and in the stretched lipid bilayer of vesicles has been well analyzed quantitatively, whereas there is limited quantitative information on negative membrane tension in compressed plasma membranes and lipid bilayers. Here, we examined negative membrane tension quantitatively. First, we developed a theory to describe negative membrane tension by analyzing the free energy of lipid bilayers to obtain a theoretical equation for negative membrane tension. This allowed us to obtain an equation describing the negative membrane tension (σosm) for giant unilamellar vesicles (GUVs) in hypertonic solutions due to negative osmotic pressure (Π). Then, we experimentally estimated the negative membrane tension for GUVs in hypertonic solutions by measuring the rate constant (kr) of rupture of the GUVs induced by the constant tension (σex) due to an external force as a function of σex. We found that larger σex values were required to induce the rupture of GUVs under negative Π compared with GUVs in isotonic solution and quantitatively determined the negative membrane tension induced by Π (σosm) by the difference between these σex values. At small negative Π, the experimental values of negative σosm agree with their theoretical values within experimental error, but as negative Π increases, the deviation increases. Negative tension increased the stability of GUVs because higher tensions were required for GUV rupture, and the rate constant of antimicrobial peptide magainin 2-induced pore formation decreased.

Influence of Na+ disorder on cytoplasmic conductivity and cellular electromagnetic (EM) energy absorption of human erythrocytes (PONE-D-21-36089)

Cytoplasmic conductivity of human erythrocytes may be significantly disturbed by the composition of the external suspending media. Effects of external NaCl on cytoplasmic conductivity of human erythrocyte (Human Red Blood Cells, HRBC) were investigated in a simple NaCl system. Using thermodynamic theory cytoplasmic conductivities could be calculated from internal [K+], [Na+], [Cl-] and [HCO3-]. Effect of cell volume and cell water changes were introduced and allowed for using the Debye-Hückel-Onsager relation and Walden's rule of viscosity. Cell volume and cell water change of HRBCs were measured in suspending isotonic solutions with conductivities from 0.50 S m-1 up to hypertonic solutions of conductivity of 2.02 S m-1 at selected temperatures of 25°C (standard benchmark temperature) and 37°C (physiological temperature). In isotonic solutions, cytoplasmic conductivity of human erythrocyte decreases with rise in the external media ionic concentration and vice versa for hypertonic solutions. The HRBC is capable of rapidly regulating its volume (and shape) over quite a wide range of osmolality. Specific Absorption Rate (SAR, 900 MHz) values (W kg-1) of electromagnetic radiation are below safe limits at non-physiological 25°C but above legal limits at 37°C [National Council on Radiation Protection and Measurements, NCRP]. However, at 37°C under both hypertonic [Na+] and isotonic but low [Na+], SAR increases further beyond legal limits.

Efficacy and safety of a hypertonic nasal wash solution containing sea algae extracts in patients that underwent surgical correction of a deviated nasal septum and radiofrequency turbinate volume reduction

OBJECTIVE

The objective of this study was to evaluate efficacy and safety of a Hypertonic Seawater Solution (2.3% NaCl) containing brown and blue-green Algae (HSS-A) in comparison to Isotonic Saline Solution (ISS) regarding the improvement of nasal breathing in patients that have undergone surgical correction of a deviated nasal septum and radiofrequency turbinate volume reduction.

PATIENTS AND METHODS

A total of 101 individuals were enrolled in the study (HSS-A: 57; ISS: 44). Nasal breathing was evaluated using a Peak Nasal Inspiratory Flow (PNIF) measurement device at four timepoints: prior to surgical intervention (up to 30 days pre-surgery) and at the 2nd, 10th and 20th postoperative days. On the 20th postoperative day, patients also answered a Nasal Surgical Questionnaire (NSQ) evaluating breathing ability and overall satisfaction from the use of both nasal sprays.

RESULTS

No significant differences were observed in PNIF measurements between groups at different points. On the 20th postoperative day, NSQ analysis showed that ISS-treated patients had more frequently moderate nasal bleeding compared to the HSS-A group (85.7% vs. 14.3%, p=0.038). No other statistically significant differences were observed between groups. When NSQ parameters were evaluated in a binary mode, a trend for reduced crusting scores was seen in the HSS-A group (15.9% vs. 35.5% in ISS, p=0.053). No safety concerns were reported throughout the study.

CONCLUSIONS

In patients that have undergone surgical correction of a deviated nasal septum and radiofrequency turbinate volume reduction, PNIF values did not differ significantly in patients receiving HSS-A and ISS solutions. Nasal bleeding was more frequent in ISS patients versus HSS-A. Overall, both solutions provided symptomatic relief and use satisfaction in the absence of side effects.

Stability of benzylpenicillin for continuous intravenous infusions: An isotonic formulation for therapeutic use and a low-dose formulation for clinical trial

INTRODUCTION

The objectives of this study were to develop a stability-indicating high performance liquid chromatography (HPLC) assay for benzylpenicillin (BPC) in pharmaceutical fluids, and to investigate the stability of (i) isotonic citrate-buffered BPC solutions at the clinically relevant concentration of 30 mg/mL, and (ii) low concentration citrate-buffered BPC intravenous infusions (5-30 μg/mL).

METHODS

The stability of isotonic BPC solutions containing 3.4 or 7.2 mg/mL sodium citrate was compared against contemporary hypertonic solutions. The HPLC assay was shown to be stability-indicating following acidic, alkali, oxidative and elevated temperature stress testing.

RESULTS

After 7 d storage at 4 °C and 24 h at 35 °C, the concentrations of isotonic BPC 30 mg/mL solutions containing 3.4 and 7.2 mg/mL sodium citrate were 96% and 95% respectively, compared to day 0. After 3 d at 4 °C and 24 h at room temperature (22 °C), the concentrations of isotonic BPC solutions with 3.4 and 7.2 mg/mL sodium citrate were 99% and 96% respectively, compared to day 0. These data were comparable to the hypertonic solutions and meet pharmacopeial stability requirements. Low concentration BPC infusions showed 0.5% and 2.5% degradation after 24 h storage at 22 °C and 35 °C, respectively.

CONCLUSIONS

The isotonic BPC 30 mg/mL formulation is simple to prepare and may offer clinical benefits in settings where hypertonic solutions are problematic. This study provides assurance that high- and low-dose isotonic BPC infusions are stable at room temperature and our findings may be applicable to in vitro studies of BPC.

Sodium Fate after Sodium Bicarbonate Infusion: Influence of Altered Acid-Base Status

BACKGROUND

We have previously investigated the fate of administered bicarbonate infused as a hypertonic solution in animals with each of the 4 chronic acid-base disorders. Those studies did not address the fate of sodium, the coadministered cation.

METHODS

We examined baseline total body water (TBW), Na+ space, HCO3- space, and urinary sodium and bicarbonate excretion after acute hypertonic NaHCO3 infusion (1-N solution, 5 mmol/kg body weight) in dogs with each of the 4 chronic acid-base disorders. Observations were made at 30, 60, and 90 min postinfusion. Retained sodium that remains osmotically active distributes in an apparent space that approximates TBW. Na+ space that exceeds TBW uncovers nonosmotic sodium storage.

RESULTS

Na+ space approximated TBW at all times in normal and hyperbicarbonatemic animals (metabolic alkalosis and respiratory acidosis), but exceeded TBW by ~30% in hypobicarbonatemic animals (metabolic acidosis and respiratory alkalosis). Such osmotic inactivation was detected at 30 min and remained stable. The pooled data revealed that Na+ space corrected for TBW was independent of the initial blood pH but correlated with initial extracellular bicarbonate concentration (y = -0.01x + 1.4, p= 0.002). The fate of administered sodium and bicarbonate (internal distribution and urinary excretion) was closely linked.

CONCLUSIONS

This study demonstrates that hypobicarbonatemic animals have a Na+ space that exceeds TBW after an acute infusion of hypertonic NaHCO3 indicating osmotic inactivation of a fraction of retained sodium. In addition to an expanded Na+ space, these animals have a larger HCO3- space compared with hyperbicarbonatemic animals. Both phenomena appear to reflect the wider range of titration of nonbicarbonate buffers (Δ pH) occurring during NaHCO3- loading whenever initial [HCO3-]e is low. The data indicate that the fate of administered bicarbonate drives the internal distribution and the external disposal of sodium, the co-administered cation, and is responsible for the early, but non-progressive, osmotic inactivation of a fraction of the retained sodium.

Osmotic and Nonosmotic Sodium Storage during Acute Hypertonic Sodium Loading

BACKGROUND

The Edelman equation has long guided the expected response of plasma [Na+] to changes in sodium, potassium, and water balance, but recent short-term studies challenged its validity. Plasma [Na+] following hypertonic NaCl infusion in individuals on low-sodium diet fell short of the Edelman predictions supposedly because sodium restriction caused progressive osmotic inactivation of 50% of retained sodium. Here, we examine the validity of this challenge.

METHODS

We evaluated baseline total body water (TBW) and Na+ space following acute hypertonic NaHCO3 infusion in dogs with variable sodium and potassium stores, including normal stores, moderate depletion (chronic HCl feeding), or severe depletion (diuretics and dietary NaCl deprivation).

RESULTS

TBW (percentage body weight) averaged 65.9 in normals, 62.6 in HCl-induced metabolic acidosis and moderate sodium and potassium depletion, and 57.6 in diuretic-induced metabolic alkalosis and severe sodium and potassium depletion (p < 0.02). Na+ space (percentage body weight) at 30, 60, and 90 min postinfusion averaged 61.1, 59.8, and 56.1, respectively, in normals (p = 0.49); 70.0, 74.4, and 72.1, respectively, in acidotic animals (p = 0.21); and 56.4, 55.1, and 54.2, respectively, in alkalotic animals (p = 0.41). Absence of progressive expansion of Na+ space in each group disproves progressive osmotic inactivation of retained sodium. Na+ space at each time point was not significantly different from baseline TBW in normal and alkalotic animals indicating that retained sodium remained osmotically active in its entirety. However, Na+ space in acidotic animals at all times exceeded by ∼16% baseline TBW (p < 0.01) signifying an early, but nonprogressive, osmotic inactivation of retained sodium, which we link to baseline bone-sodium depletion incurred during acid buffering.

CONCLUSIONS

Our investigation affirms the validity of the Edelman construct in normal dogs and dogs with variable sodium and potassium depletion and, consequently, refutes the recent observations in human volunteers subjected to dietary NaCl restriction.

Sphingosine kinase and sphingosine-1-phosphate regulate epithelial cell architecture by the modulation of de novo sphingolipid synthesis

Sphingolipids regulate several aspects of cell behavior and it has been demonstrated that cells adjust their sphingolipid metabolism in response to metabolic needs. Particularly, sphingosine-1-phosphate (S1P), a final product of sphingolipid metabolism, is a potent bioactive lipid involved in the regulation of various cellular processes, including cell proliferation, cell migration, actin cytoskeletal reorganization and cell adhesion. In previous work in rat renal papillae, we showed that sphingosine kinase (SK) expression and S1P levels are developmentally regulated and control de novo sphingolipid synthesis. The aim of the present study was to evaluate the participation of SK/S1P pathway in the triggering of cell differentiation by external hypertonicity. We found that hypertonicity evoked a sharp decrease in SK expression, thus activating the de novo sphingolipid synthesis pathway. Furthermore, the inhibition of SK activity evoked a relaxation of cell-cell adherens junction (AJ) with accumulation of the AJ complex (E-cadherin/β-catenin/α-catenin) in the Golgi complex, preventing the acquisition of the differentiated cell phenotype. This phenotype alteration was a consequence of a sphingolipid misbalance with an increase in ceramide levels. Moreover, we found that SNAI1 and SNAI2 were located in the cell nucleus with impairment of cell differentiation induced by SK inhibition, a fact that is considered a biochemical marker of epithelial to mesenchymal transition. So, we suggest that the expression and activity of SK1, but not SK2, act as a control system, allowing epithelial cells to synchronize the various branches of sphingolipid metabolism for an adequate cell differentiation program.

Cap-independent protein synthesis is enhanced by betaine under hypertonic conditions

Protein synthesis is one of the main cellular functions inhibited during hypertonic challenge. The subsequent accumulation of the compatible osmolyte betaine during the later adaptive response allows not only recovery of translation but also its stimulation. In this paper, we show that betaine modulates translation by enhancing the formation of cap-independent 48 S pre-initiation complexes, leaving cap-dependent 48 S pre-initiation complexes basically unchanged. In the presence of betaine, CrPV IRES- and sodium-dependent neutral amino acid transporter-2 (SNAT2) 5'-UTR-driven translation is 2- and 1.5-fold stimulated in MCF7 cells, respectively. Thus, betaine could provide an advantage in translation of messengers coding for proteins implicated in the response of cells to different stressors, which are often recognized by ribosomal 40 S subunit through simplified cap-independent mechanisms.

[THE ROLE OF HYDROGEN SULFIDE IN VOLUME-DEPENDENT MECHANISMS OF REGULATION OF VASCULAR SMOOTH MUSCLE CELLS CONTRACTILE ACTIVITY]

The hydrogen sulfide (H2S) influence on the contractile activity of vascular smooth muscle cells (SMC) was studied on endothelium-denuded aortic ring segments of male Wistar rats with method of mechanography. Contractions of SMS were induced by incubation in high potassium solution as well as in hyper-, hypo- and isosmotic solutions. 5-100 LM of H2S donor--sodium hydrosulfide (NaHS) increased mechanical tension of SMC precontracted with high potassium solution that was abolished by bumetanide--the inhibitor of Na+, K+, 2Cl(-) -cotransporter (NKCC), but 100-1000 microM of NaHS relaxed SMS. NaHS (10 microM) increased the amplitude of hyper- and isosmotic contraction, but not of hyposmotic contraction. NaHS (ImM) decreased the amplitude of hyper-, iso-, and hyposmotic contractions. The direct measurements of NKCC activity with radionuclide method showed an increase in NKCC activity under the action of 5-100 microM of NaHS. These findings suggest that low concentrations of H2S participate in the NKCC activation. This mechanism underlines constrictive action of H2S on smooth muscle cells.

[Application of hyperosmotic iso-oncotic solutions for prolonged veno-venous haemofiltration in patients with gramm negative sepsis]

Dynamics of circulation and elimination of low and medium molecular weight substances and lipopolysaccharides of Gramm negative bacteria were studied during prolonged veno-venous haemofiltration in patients with Gramm negative sepsis. Positive effect of HyperHAES solution for endotoxicosis compensation has been defined in the study. HyperHAES can be used repeatedly during prolonged veno-venous haemofiltration.

Effects of short- and long-duration hypothyroidism on hypothalamic-pituitary-adrenal axis function in rats: in vitro and in situ studies

The purpose of this study is to assess the effects of hypothyroidism on the hypothalamic-pituitary-adrenal (HPA) axis; the functional integrity of each component of the HPA axis was examined in short-term and long-term hypothyroidism. Neuropeptide synthesis, release, and content were evaluated in vitro both in the hypothalamus and anterior pituitary, and corticosterone release was assessed in primary adrenal cell cultures at 7 (short-term) and 60 days (long-term hypothyroidism) after thyroidectomy in male rats. Hypothyroid rats showed adrenal insufficiency in several parameters, which were associated with the duration of hypothyroidism. Cerebrospinal (CSF) ACTH was decreased in all hypothyroid animals, while CSF corticosterone levels were significantly decreased only in long-term hypothyroidism. Long-term hypothyroid animals showed decreased corticotropin-releasing hormone (CRH) mRNA expression in the hypothalamic paraventricular nucleus under both basal and stress conditions, decreased CRH release from hypothalamic organ cultures after KCL and arginine vasopressin stimulation, as well as an increased number of anterior pituitary CRH receptors. In contrast, short-term hypothyroid rats showed changes in anterior pituitary function with an increased responsiveness to CRH that was associated with an increase in CRH receptors. Although both short- and long-term hypothyroidism was associated with significant decreases in adrenal weights, only long-term hypothyroid rats showed changes in adrenal function with a significant decrease of ACTH-induced corticosterone release from cultured adrenal cells. The data suggest that long-term hypothyroidism is associated with adrenal insufficiency with abnormalities in all three components of the HPA axis. Short-term hypothyroidism, on the other hand, is associated with increased pituitary corticotroph responsiveness to CRH.

Not all collectivisms are equal: opposing preferences for ideal affect between East Asians and Mexicans

Previous research has revealed differences in how people value and pursue positive affect in individualistic and collectivistic cultural contexts. Whereas Euro-Americans place greater value on high activation positive affect (HAP; e.g., excitement, enthusiasm, elation) than do Asian Americans and Hong Kong Chinese, the opposite is true for low activation positive affect (LAP; e.g., calmness, serenity, tranquility). Although the form of collectivism present in East Asia dictates that individuals control and subdue their emotional expressions so as to maintain harmonious relationships, the opposite norm emerges in Mexico and other Latin American countries, in that the cultural script of simpatía promotes harmony through the open and vibrant expression of positive emotion. Across two studies, we found that Mexicans display a pattern of HAP/LAP preference different from those from East Asian collectivistic cultures, endorsing HAP over LAP.

Differentiation between Candida albicans and Candida dubliniensis using hypertonic Sabouraud broth and tobacco agar

INTRODUCTION

Opportunistic fungal infections in immunocompromised hosts are caused by Candida species, and the majority of such infections are due to Candida albicans. However, the emerging pathogen Candida dubliniensis demonstrates several phenotypic characteristics in common with C. albicans, such as production of germ tubes and chlamydospores, calling attention to the development of stable resistance to fluconazole in vitro. The aim of this study was to evaluate the performance of biochemistry identification in the differentiating between C. albicans and C. dubliniensis, by phenotyping of yeast identified as C. albicans.

METHODS

Seventy-nine isolates identified as C. albicans by the API system ID 32C were grown on Sabouraud dextrose agar at 30°C for 24-48h and then inoculated on hypertonic Sabouraud broth and tobacco agar.

RESULTS

Our results showed that 17 (21.5%) isolates were growth-inhibited on hypertonic Sabouraud broth, a phenotypic trait inconsistent with C. albicans in this medium. However, the results observed on tobacco agar showed that only 9 (11.4%) of the growth-inhibited isolates produced characteristic colonies of C. dubliniensis (rough colonies, yellowish-brown with abundant fragments of hyphae and chlamydospores).

CONCLUSIONS

The results suggest that this method is a simple tool for screening C. albicans and non-albicans yeast and for verification of automated identification.

Factors influencing the action of glycine on Escherichia coli in nutrient broth and in hypertonic medium

The effect of various glycine concentrations in nutrient broth and in a hypertonic nutrient medium against E. coli at various temperatures has been examined. Optimum spheroplast formation was found to occur in bacteria which were in the logarithmic growth phase. Glycine has no action on the viability of non-growing bacteria.

Effect of chlorhexidine diacetate on “protoplasts” and spheroplasts of Escherichia coli, protoplasts of Bacillus megaterium and the Gram staining reaction of Staphylococcus aureus

Chlorhexidine prevents the transformation of Bacillus megaterium cells to protoplasts by lysozyme, of E. coli cells to spheroplasts by penicillin and causes lysis of “protoplasts” and spheroplasts of E. coli stabilised in hypertonic sucrose solution. Transformation of Staphylococcus aureus cells to the Gram-negative condition occurred in contact with 10 to 800 μg/ml of chlorhexidine and 10, 50 and 100 μg/ml of cetyltrimethylammonium bromide but higher concentrations of the latter prevented this change. Results indicate that chlorhexidine damages the permeability barrier of bacterial cells.

[Continuous low volume infusion of hydroxyethyl starch as an option of water balance correction in patients with gestosis]

The method of long-term continuous low-volume infusion of hydroxyethyl starch (low-flow low volume correction HES) is administrated for correction of fluid balance disorders. The method is aimed to improve the outcomes in preeclamsia patients with multiple organ dysfunction and failure, as the most severe manifestation of system inflammatory response syndrome. After 4 days of the intensive care with application of the developed method in patients with preeclamsia the total body water level is decreased to the normal physiological level, the oedemas are significantly reduced or ceased, the haemodynamics stabilizes, which leads to the reduce of neurologic symptoms. The suggested method of low-flow low volume correction HES, in dose of 15 ml/kg/day is a significant addition to the existing methods of homeostasis and preeclampsia correction.

Electrophysiological effects of osmotic cell shrinkage in rat pancreatic β-cells

Electrical and secretory activity in the pancreatic β-cell can be elicited by hypotonic cell swelling, due largely to activation of a volume-regulated anion channel (VRAC) leading to depolarisation and electrical activity. However, β-cell responses to cell shrinkage are less well characterised. The present study has examined the effects of osmotic cell shrinkage on rat pancreatic β-cells. Electrical activity and whole-cell current were studied in isolated β-cells using the perforated patch and conventional whole-cell recording techniques. Insulin release was measured using intact islets by radioimmunoassay. Exposure to a 33% hypertonic bath solution resulted in an initial depolarisation and a period of electrical activity. In several cases, this depolarisation was transient and was followed by a hyperpolarisation. A similar pattern was observed with insulin release. In voltage-clamp experiments, osmotic shrinkage resulted in activation of a non-selective cation channel (NSCC) sensitive to inhibition by flufenamic acid and Gd3+. It is suggested that activation of this NSCC is responsible for the depolarisation evoked by hypertonic media. The secondary hyperpolarisation is likely to be the result of inhibition of VRAC activity. These opposing ionic effects could underlie the biphasic effect on insulin release following exposure to hypertonic media.

[Case of hyperkalemia after the administration of hypertonic mannitol during craniotomy]

We report a case of severe hyperkalemia which developed following administration of mannitol during craniotomy. The blood potassium levels rose from 4.8 mEq x l(-1) to 6.7 mEq x l(-1) 30 minutes after the infusion of mannitol 300 ml during the operation for brain tumor. Since the patient did not develop metabolic acidosis, the hyperkalemia was probably caused by a rise in plasma osmotic pressure resulting from mannitol infusion. The risk factors for hyperkalemia have not yet been determined, and it is necessary to monitor carefully the electrocardiogram and electrolyte levels during the infusion of mannitol.

Influences of hypertonic and hypovolemic treatments on vasopressin response in propylthiouracil (PTU) induced hypothyroid rat and effect on supplementation with L-thyroxine

This study was performed to investigate the effects of L-thyroxine treatment on plasma vasopressin (AVP) levels in rats with hypothyroidism induced by propylthiouracil (PTU). Animals were separated into three groups each having 6 rats: control, PTU, PTU+L-thyroxine groups. Then, the groups were further divided into 3 sub-groups including 6 rats (a; basal, b; hypertonic stimulated and c; hypovolemic stimulated). At the end of the experiments all rats were decapitated in order to obtain plasma samples for analysis in terms of Hct, osmolality, TT 3 , TT 4 and vasopressin. Haematocrit (Hct) levels were the highest in hypovolemic stimulated sub-group (P < 0.001). Osmolality levels were higher in hypertonic stimulated sub-groups (P < 0.001). Total T 3 and T 4 values were the lowest in the PTU group and the highest in the L-thyroxine treated group (P < 0.001). Plasma AVP levels were reduced by hypothyroidism. However, L-thyroxine treatment after the hypothyroidism prevented this reduction (P < 0.001). Vasopressin responses to basal, hypovolemic and hypertonic stimulations were the lowest in the PTU group (P < 0.001). The results of the present study show that basal and stimulated plasma vasopressin levels are reduced in PTU-induced hypothyroidism. However, L-thyroxine treatment following hypothyroidism prevents this reduction.

Isotonic and hypertonic crystalloid solutions in the critically ill

Disorders of fluid and electrolyte balance in the critically ill are volume-related, compositional, or both. Targeting 'normal' values for plasma volume, osmolality and electrolytes might not be optimal in conditions as diverse as intracranial trauma/haemorrhage, hepatic encephalopathy, abdominal hypertension, or major surgery, because a hyperosmolar state seems to favourably affect tissue (brain and intestinal) oedema formation. However, adequately powered studies regarding the impact of hypertonic saline on outcome are lacking. Isotonic crystalloids are the cornerstone of resuscitation and must be balanced against natural or artificial colloids and vasopressors. Crystalloid resuscitation is superior to vasopressors in shock associated with blunt trauma, and is at least not inferior to colloids in septic shock. Traditional rules of thumb indicating the need for three to four times the amount of crystalloids for the plasma volume to be replaced are probably erroneous and might have contributed to association of overly aggressive crystalloid resuscitation with poor outcome.

Lung transplantation in pulmonary fibrosis: challenging early outcomes counterbalanced by surprisingly good outcomes beyond 15 years

Interstitial lung disease (ILD) has been reported to have a poor outcome following lung transplantation due to difficulties getting ill recipients to transplantation and challenging early postoperative outcomes. To assess long-term outcomes for this cohort, we performed a retrospective 18-year chart review of all ILD lung transplant recipients. ILD single (SLT) and bilateral sequential lung transplantations (BSLT) were compared with all other lung transplant patients and International Society for Heart and Lung Transplantation (ISHLT) Registry data over the same time period. Of 585 lung transplantations, 90 (15%) were ILD (53 SLT, 37 BSLT); 67 (74%) were idiopathic pulmonary fibrosis (IPF), 9 (10%) were sarcoidosis, 9 (10%) were lymphangioleiomyomatosis, and 5 (6%) had other indications. Mean age was 52 years (range, 34-69 years). Actuarial survival at 1, 5, 10, 15, and 18 years compared favorably to all other lung transplantations performed (77% vs 83%, 51% vs 50%, 42% vs 26%, 28% vs 17%, and 28% vs 8%, respectively). IPF actuarial survival at 1, 5, and 10 years appeared superior to ISHLT Registry data (76% vs 72%, 50% vs 44%, and 34% vs 20%, respectively). There was equivocal survival between SLT and BSLT at 1, 5, and 10 years (78% vs 68%, 49% vs 50%, and 29% vs 50%, respectively). Our ILD figures compared favorably to lung transplantation for other diseases and international standards, while survival from SLT was as successful as BSLT both in the short and the longer term. Consideration should be given to utilizing SLT to maximize the allocation of donor lungs and to decrease waiting list mortality associated with IPF.

Changes in osmolality modulate voltage-gated sodium channels in trigeminal ganglion neurons

Voltage-gated sodium channels (VGSCs) are important channels which participate in many physiological functions. Whether VGSCs can be modulated by changes in osmolality in trigeminal ganglion (TG) neurons remains unknown. In this study, by using whole-cell patch clamp techniques, we tested the effects of hypo- and hypertonicity on VGSCs in cultured TG neurons. Our data show that tetrodotoxin-resistant sodium current (TTX-R current) was inhibited in the presence of hypo- and hypertonic solutions. In hypertonic solutions both voltage-dependent activation and inactivation curves shifted to the hyperpolarizing direction, while in hypotonic solutions only inactivation curve shifted to the hyperpolarizing direction. Transient Receptor Potential Vanilloid 4 (TRPV4) receptor activator mimicked the inhibition of TTX-R current by hypotonicity and the inhibition by hypotonicity was markedly attenuated by TRPV4 receptor blocker and in TRPV4(-/-) mice TG neurons. We also demonstrate that the inhibition of PKA selectively attenuated hypotonicity-induced inhibition, whereas antagonism of PLC and PI3K selectively attenuated hypertonicity-induced inhibition. We conclude that although hypo- and hypertonicity have similar effect on VGSCs, receptor and intracellular signaling pathways are different for hypo- versus hypertonicity-induced inhibition of TTX-R current.

Eosinophilic airway inflammation in chronic obstructive pulmonary disease and asthma

Eosinophilic airway inflammation is regarded as a typical feature of asthma, while in chronic obstructive pulmonary disease (COPD) neutrophils seem predominant inflammatory airway cells. The aim of the present study was to compare the cellular components of airway inflammation in patients with newly diagnosed mild or moderate COPD and asthma. Seventeen patients with COPD (M/F 10/7, aged 57 +/-11 yr) and 22 patients with asthma (M/F 12/10, aged 36 +/-14 yr) were enrolled into the study. None of the patients has been treated with steroids for at least 3 months. All patients underwent clinical examination, laboratory examinations, skin-prick tests, pulmonary function tests, methacholine challenge test, and sputum induction with the total and differential cell count assessments. We found increased number of eosinophils in both study groups. However, there were no significant differences in the cellular composition of induced sputum between the asthma and COPD patients. We conclude that eosinophils are important inflammatory cells not only in asthma, but also in COPD.

Abnormal protoplasmic patterns and death in slightly hypertonic solutions

Some interesting properties of protoplasm are revealed when slightly hypertonic solutions of sugars or of electrolytes are applied to Nitella. The chloroplasts contract and the space between them increases and forms a characteristic pattern consisting of clear areas extending lengthwise along the cell and tapering off at both ends. The development of these areas is irreversible from the start. If the cell is returned to water after plasmolysis begins these areas continue to enlarge in much the same fashion as when no change is made in the external solution. The cell soon dies whether returned to water or left in the plasmolyzing solution. Similar results are obtained with other sugars, with NaCl, CaCl₂, and sea water. Similar reactions are also brought about by strong ingoing or outgoing currents of water. This suggests that mechanical action may be chiefly responsible for the result and this idea is in harmony with other facts. It seems possible that the retraction of the protoplasm from the cellulose wall may disturb the delicate non-aqueous film which covers the outer surface of the protoplasm and thus produce injury. Such an effect might take place even without visible retraction if the injury occurred in protoplasmic projections extending into the cellulose wall. A study of this behavior may throw light on the nature of the protoplasmic surface and on the properties of protoplasmic gels as well as on the process of death. An understanding of the mechanism involved may help to explain the action of hypertonic solutions in other cases as, for example, in the artificial parthenogenesis of marine eggs.

Hypertonicity-induced cation channels rescue cells from staurosporine-elicited apoptosis

Cell shrinkage is one of the earliest events during apoptosis. Cell shrinkage also occurs upon hypertonic stress, and previous work has shown that hypertonicity-induced cation channels (HICCs) underlie a highly efficient mechanism of recovery from cell shrinkage, called the regulatory volume increase (RVI), in many cell types. Here, the effects of HICC activation on staurosporine-induced apoptotic volume decrease (AVD) and apoptosis were studied in HeLa cells by means of electronic cell sizing and whole-cell patch-clamp recording. It was found that hypertonic stress reduces staurosporine-induced AVD and cell death (associated with caspase-3/7 activation and DNA fragmentation), and that this effect was actually due to activation of the HICC. On the other hand, staurosporine was found to significantly reduce osmotic HICC activation. It is concluded that AVD and RVI reflect two fundamentally distinct functional modes in terms of the activity and role of the HICC, in a shrunken cell. Our results also demonstrate, for the first time, the ability of the HICC to rescue cells from the process of programmed cell death.

Skin decontamination of glyphosate from human skin in vitro

This study compared three model decontaminant solutions (tap water, isotonic saline, and hypertonic saline) for their ability to remove a model herbicide (glyphosate) from an in vitro human skin model. Human cadaver skin was dosed (approximately 375microg) of [14C]-glyphosate on 3cm2 per skin. After each exposure time (1, 3, and 30min post-dosing, respectively), the surface skin was washed three times (4ml per time) with each solution. After washing, the skin was stripped twice with tape discs. Lastly, the wash solutions, strippings, receptor fluid, and remainder of skin were liquid scintillation analyzer counted to determine the amount of glyphosate. There were no statistical differences among these groups at any time points. The total mass balance recovery at three time exposure points was between 94.8% and 102.4%. The wash off rates (glyphosate in wash solutions) at three different exposure times is 79-101.2%. Thus the three tested decontaminants possess similar effectiveness in removing glyphosate from skin. This in vitro model is not only economic and rapid, but also provides quantitative data that may aid screening for optimal decontaminants.

Cotransport systems in the brush border membrane of the human placenta

The cotransport systems present in the brush border membrane of the human placental syncytiotrophoblast are reviewed. Attention is focused on the systems that are powered by the electrochemical gradient of Na+ (for example, for neutral amino acids but not for glucose), and on recently described systems in which K+ flux is coupled to C1- flux or to that for Na+ and C1-. These systems are similar to those found in other tissues and may be significant for net trans-placental transport and its control, as well as for the regulation of placental trophoblast volume.

[Results of alginate and hypertonic solution in wound healing of head and neck cancers]

INTRODUCTION

In head and neck cancers, complications such as pharyngostoma, orostoma, or fistula can present following surgery or surgery after irradiation.

OBJECTIVE

To report the results of the association of two sea-derived products (Sinomarin and Algosteril) compared to normal saline for the management of healing.

MATERIAL AND METHODS

This is retrospective study (1998-2000). Thirty patients were included in group 1 (Sinomarin-Algosteril) and 17 patients in group 2 (normal saline). The average age was respectively 60 and 56.2. Patients in both groups presented with advanced head and neck carcinoma (T3-T4) and healing complications.

RESULTS

The delay of healing was respectively of 33.53 and 72.94 days. Results were statistically significant (Student T-test P < 0.05).

CONCLUSION

Our results show the efficiency (p < 0.05) of the Sinomarin Algosteril association in head and neck cancer healing complications.

Respuestas cardiovasculares al NaCl hipertónico inyectado en la región anteroventral del tercer ventrículo de ratas con hipertensión e insulinorresistencia inducidas por fructosa

INTRODUCTION AND OBJECTIVES

To investigate the hemodynamic sympathetic response evoked by NaCI microinjection into the third ventricle anteroventral brain area (AV3V) in rats long-term fed with high fructose diet.

METHODS

Twelve male rats received 60% fructose enriched diet for 6 months. Control rats (n=12) received regular diet.

RESULTS

Fructose diet increased (P< .01) body weight; plasma glucose, triglycerides; cholesterol, insulin; systolic (SBP) and diastolic blood pressure (DBP). Basal heart rate (HR) did not change. AV3V microinjection of 2 microL of hypertonic 1.5 M NaCI in fructose fed rats increased SBP 44.64(3.6) mm Hg, DBP 19.9(2.4) mm Hg and HR 66.2(8.4) beats/min over basal values (P< .01). In control rats, smaller responses were observed, SBP increased 28.33(3.10) mm Hg, DBP 13.0(1.9) mm Hg and HR 23.0(5.0) beats/min over basal values (P< .01).

CONCLUSIONS

Long-term fructose diet in rats induces cardiovascular hyperactivity of AV3V neurons to sodium chloride, and is associated to hypertension and insulin-resistance.

Signalling events employed in the hypertonic activation of cation channels in HeLa cells

In the present study, the signalling network behind the hypertonic activation of cation channels in HeLa cells was analysed by use of various inhibitors. Channel activation was monitored in whole-cell patch-clamp recordings, whereas the role of the channel in cell volume regulation was determined by electronic cell sizing. It is found that channel activation and volume control probably employs tyrosine kinases, G-proteins, PLC, PKC and p38MAP kinase, and that the process appears to depend on an intact actin skeleton. In contrast, RhoA, PI 3-kinase, ERK 1/2, JNK 1/2 as well as the exocytotic insertion of channels into the plasma membrane are likely not part of the signalling machinery.

MEK/ERK signaling controls osmoregulation of nucleus pulposus cells of the intervertebral disc by transactivation of TonEBP/OREBP

Earlier studies have shown that intervertebral disc cells express TonEBP, a transcription factor that permits adaptation to osmotic stress and regulates aggrecan gene expression. However, the mechanism of hyperosmotic activation of TonEBP in disc cells is not known. Results of this study show that hypertonic activation of ERK signaling regulates transactivation activity of TonEBP, modulating its function.

INTRODUCTION

In an earlier report, we showed that tonicity enhancer binding protein (TonEBP) positively regulates aggrecan gene expression in disc cells, thereby autoregulating its osmotic environment. Although these studies indicated that the cells of the nucleus pulposus were optimally adapted to a hyperosmotic state, the mechanism by which the cells transduce the osmotic stress was not delineated. The primary goal of this study was to test the hypothesis that, in a hyperosmotic medium, the extracellular signal-regulated kinase (ERK) signaling pathway regulated TonEBP activity.

MATERIALS AND METHODS

Nucleus pulposus cells were maintained in isotonic or hypertonic media, and MAPK activation and TonEBP expression were analyzed. To study the role of MAPK in regulation of TonEBP function, gel shift and luciferase reporter assays were performed. ERK expression in cells was modulated by using expression plasmids or siRNA, and transactivation domain (TAD)-TonEBP activity was studied.

RESULTS

We found that hypertonicity resulted in phosphorylation and activation of ERK1/2 proteins and concomitant activation of C terminus TAD activity of ELK-1, a downstream transcription factor. In hypertonic media, treatment with ERK and p38 inhibitors resulted in downregulation of TonE promoter activity of TauT and HSP-70 and decreased binding of TonEBP to TonE motif. Similarly, forced expression of DN-ERK and DN-p38 in nucleus pulposus cells suppressed TauT and HSP-70 reporter gene activity. Finally, we noted that ERK was needed for transactivation of TonEBP. Expression of DN-ERK significantly suppressed, whereas, WT-ERK and CA-MEK1 enhanced, TAD activity of TonEBP. Experiments performed with HeLa cells indicated that the ERK signaling pathway also served a major role in regulating the osmotic response in nondiscal cells.

CONCLUSIONS

Together, these studies showed that adaptation of the nucleus pulposus cells to their hyperosmotic milieu is dependent on activation of the ERK and p38- MAPK pathways acting through TonEBP and its target genes.

Comparison of HTK and hypertonic citrate to intraarterial cooling in human non-heart-beating kidney donors

Intraarterial cooling (IAC) of non-heart-beating donors (NHBD) for renal donation requires a cheap, low-viscosity solution. HTK contains a high hydrogen ion buffer level that theoretically should reduce the observable acidosis associated with ongoing anaerobic metabolism. A retrospective comparison of all retrieved NHBD kidneys as well as of viability on the Organ Recovery Systems Lifeporter machine perfusion circuit was performed with respect to the preservation solution HTK or Marshall's HOC. Forty-two NHBD kidneys (19 HTK and 23 HOC) were machine perfused between February 2004 and May 2005. Most of the HTK kidneys were obtained from uncontrolled donors (12 vs 5; Fisher exact test, P = .01). As a consequence, the glutathione-s-transferase viability assay (411 vs 292 IU/L, P = .12) and the lactate concentrations (2.33 vs 1.94 mmol/L, P = .13) were higher among the HTK cohort. There was evidence of greater buffering capacity in HTK, since the lactate:hydrogen ion ratios were consistently lower during the first 2 perfusion hours (1 hour P = .03, 2 hour P = .02). A linear regression analysis confirmed that this was related to the IAC solution (ANCOVA, P < .001). All controlled donor kidneys passed viability testing and were transplanted. In contrast, 83% (10/12) of the uncontrolled donor kidneys preserved with HTK passed the viability test and were transplanted, compared with only 20% (1/5) of the HOC-treated comparators (Fisher exact test, P = .03). It may be concluded that the postulated advantages of improved pH buffering with HTK appear to have clinical relevance.

Using hyperosmolar stress to measure biologic and stress-activated protein kinase responses in preimplantation embryos

We used hyperosmolar stress to test blastocysts for their biologic and enzymatic responses to culture stress. Embryos mount dose- and time-dependent responses to hyperosmolar stress. Biological responses included slowed cavitation and cell accumulation and increased apoptosis at increasing doses. These responses were preceded by stress-activated protein kinase (SAPK) phosphorylation and nuclear translocation consistent with its causal role. For cavitation and new cell cycle initiation, 200 mM sorbitol caused stasis. Above 200 mM, sorbitol was ultimately lethal and below 200 mM, its embryos had milder effects. Phosphorylated SAPK was induced rapidly in embryos at 0.5 h in a dose-dependent manner from 0 to 600 mM sorbitol. Higher hyperosmolarity caused a biphasic peak of phosphorylated SAPK, but there was no return to baseline through 3 h. At 24 h, a dose-dependent response persisted that was linear from 0 to 200 mM sorbitol. Hyperosmolar stress rapidly induced, within 0.5 h, phosphorylated, nuclear c-Jun and decreased phosphorylated, nuclear c-Myc in a SAPK-dependent manner. The data suggest that SAPK is induced and functions on down-stream effector molecules in a temporal and quantitative manner consistent with its function in the embryonic homeostatic response to stress. The remarkable resistance of embryos to high concentrations of sorbitol suggests that part of its homeostatic response is different from that of somatic cells.

Regulation of Cytochrome P450 2E1 under Hypertonic Environment through TonEBP in Human Hepatocytes

Whereas the liver as well as the other organs are continually exposed to the change of osmotic status, it has never been investigated whether activities and gene expressions of drug-metabolizing enzymes, including cytochromes P450, are dependent on osmotic change in the liver. In the present study, we determined that CYP2E1 is induced under hypertonic environments at a transcriptional level in human primary hepatocytes, as assessed by cDNA microarray and real time-reverse transcription-polymerase chain reaction analyses. Both a protein level and the catalytic activity of CYP2E1 were consistently increased in response to hypertonic conditions. In promoter-reporter assay, it was demonstrated that -586 to -566 in the CYP2E1 5'-flanking region was necessary for 2E1 promoter activation by hypertonic stimulation. It is noteworthy that tonicity-response element (TonE) consensus sequence was found at -578 to -568 in human CYP2E1 5'-flanking region, and electrophoretic mobility shift assay demonstrated the interaction of TonE binding protein (TonEBP) with TonE motif of CYP2E1 promoter. Furthermore, cotransfection of a CYP2E1 promoter construct with wild-type TonEBP expression vector enhanced promoter activity under both isotonic and hypertonic conditions, whereas dominant-negative TonEBP suppressed an induction of CYP2E1 promoter activity. These results indicate that the level of CYP2E1 is induced by hypertonic condition via TonEBP transactivation. The present study suggests that osmotic status may influence individual responses to the substrate of CYP2E1.

Osmosensitive gene expression of taurine transporter and cyclin C in embryonic fibroblast cells

Hypertonic conditions induce osmoregulatory activity. Molecular mechanism, however, remains to be further elucidated concerning the osmosensitive balancing activity. Using a differential display protocol, the genes of taurine transporter (TauT) and cyclin C were identified as candidate responding to the hypertonicity. When a quantitative PCR analysis was performed on the total RNA from KBEF cell treated under hypertonic conditions, the gene expressions of TauT and cyclin C were greatly increased. In terms of protein, the level of TauT expression increased up to 3.2-fold in response to the hypertonic treatment. Similarly to TauT, cyclin C protein also increased 2.4-fold compared to the control treatments. Under taurine-rich extracellular conditions, however, the level of TauT expression increased as little as 1.8-fold by hypertonicity treatment. Cyclin C expression was also lowered compared with low-taurine hypertonic treatment. Cysteine dioxygenase was shown to be highly responsive to the hypertonic treatment. Taken together, these results strongly indicate that the gene expressions of TauT and cyclin C are cooperatively regulated under hypotonic conditions.

The transcript levels of two plant mitochondrial uncoupling protein (pUCP)-related genes are not affected by hyperosmotic stress in durum wheat seedlings showing an increased level of pUCP activity

Etiolated early seedlings of durum wheat submitted to moderate and severe salt (NaCl) and osmotic (mannitol) stress showed no relevant increase of both transcript levels of two plant uncoupling protein (pUCP)-related genes and maximal pUCP activity in purified mitochondria (which estimates protein level); contrarily, pUCP functioning due to endogenous free fatty acids strongly increased. These results show that pUCP activation under hyperosmotic stress may be due to modulation of pUCP reaction rather than to an increased protein synthesis. Finally, a properly developed method, based on a single membrane potential measurement, to evaluate both pUCP maximal activity and functioning, is reported.

Effect of Preservation Solution on Graft Viability in Single-Lung Transplantation From Heart-Beating Donors in Pigs

BACKGROUND

Low-potassium-dextran preservation solution Perfadex (PER) may provide better outcome of transplanted lungs than high-potassium Euro-Collins (EC) solution. However, there are no comparative studies of the recipient inflammatory response to the graft.

PURPOSE

The purpose of this study was to compare EC versus PER as preservation solutions with respect to the functional performance and inflammatory response in single-lung transplantation from heart-beating donors in pigs.

MATERIALS AND METHODS

The donor left lung flushed with the corresponding cold preservation solution was stored at 3 degrees C for 3 hours. We assessed hemodynamic values and pulmonary function in the recipient over a 2-hour reperfusion period calculated as percent of basal values, and expressed as mean of the reperfusion period. Interleukin-8 (IL-8) concentration in the donor was estimated in bronchoalveolar lavage fluid 2 hours after recipient reperfusion. Biopsies of the donor right lung and the transplanted lung were obtained to measure myeloperoxidase (MPO) activity. IL-8 and MPO values were expressed as percent of the donor value. We evaluated the wet/dry pulmonary weight ratio (W/D), polymorphonuclear neutrophil count (PMN), and a score of histological damage in the transplanted graft.

RESULTS

Pulmonary function evaluated by % static: 66.6 +/- 6.8 (EC), 82.3 +/- 10.2 (PER), and dynamic: 74.0 +/- 7.3 (EC), 89.3 +/- 7.7 (PER) compliances, as well as % IL-8: 562.5 +/- 168.6 (EC), 232.3 +/- 148.7 (PER), % MPO: 485.9 +/- 194.9 (EC), 140.8 +/- 21.1 (PER), W/D: 9.9 +/- 3.1 (EC), 6.8 +/- 1.4 (PER), PMN 13.5 +/- 6.8 (EC), 5.5 +/- 3.3 (PER) and the histological damage score: 3.0 +/- 1.5 (EC), 0.7 +/- 0.4 (PER) showed significant differences between the EC and the PER (P < .01).

CONCLUSIONS

PER affords good lung preservation with early graft function and modest evidences of inflammation, lung injury, and edema compared with the EC perfused lung.

Hypertonicity induced apoptosis in HL-60 cells in the presence of intracellular potassium

Cell shrinkage is a hallmark of apoptosis. Potassium efflux, which is involved in cell shrinkage, has been previously described as an essential event of apoptosis. This study was designed to address the importance of potassium efflux in hypertonicity (450 mOsm and 600 mOsm) induced apoptosis. We initiated apoptosis in HL-60 cells in hypertonic medium consisting of either high concentrations of NaCl, mannitol or KCl. Apoptotic activity was evaluated based on the DNA content of the cells, annexin-V staining and calcium content. Apoptosis was initiated in hypertonic conditions consisting of high intracellular K(+). We demonstrate that apoptosis can occur in the presence of high intracellular potassium contrary to previous predictions.

Enhanced suicidal death of erythrocytes from gene-targeted mice lacking the Cl-/HCO(3)(-) exchanger AE1

Genetic defects of anion exchanger 1 (AE1) may lead to spherocytic erythrocyte morphology, severe hemolytic anemia, and/or cation leak. In normal erythrocytes, osmotic shock, Cl(-) removal, and energy depletion activate Ca(2+)-permeable cation channels with Ca(2+)-induced suicidal erythrocyte death, i.e., surface exposure of phosphatidylserine, cell shrinkage, and membrane blebbing, all features typical for apoptosis of nucleated cells. The present experiments explored whether AE1 deficiency favors suicidal erythrocyte death. Peripheral blood erythrocyte numbers were significantly smaller in gene-targeted mice lacking AE1 (AE1(-/-) mice) than in their wild-type littermates (AE1(+/+) mice) despite increased percentages of reticulocytes (AE1(-/-): 49%, AE1(+/+): 2%), an indicator of enhanced erythropoiesis. Annexin binding, reflecting phosphatidylserine exposure, was significantly larger in AE1(-/-)erythrocytes/reticulocytes ( approximately 10%) than in AE1(+/+) erythrocytes ( approximately 1%). Osmotic shock (addition of 400 mM sucrose), Cl(-) removal (replacement with gluconate), or energy depletion (removal of glucose) led to significantly stronger annexin binding in AE1(-/-) erythrocytes/reticulocytes than in AE1(+/+) erythrocytes. The increase of annexin binding following exposure to the Ca(2+) ionophore ionomycin (1 muM) was, however, similar in AE1(-/-) and in AE1(+/+) erythrocytes. Fluo3 fluorescence revealed markedly increased cytosolic Ca(2+) permeability in AE1(-/-) erythrocytes/reticulocytes. Clearance of carboxyfluorescein diacetate succinimidyl ester-labeled erythrocytes/reticulocytes from circulating blood was more rapid in AE1(-/-) mice than in AE1(+/+) mice and was accelerated by ionomycin treatment in both genotypes. In conclusion, lack of AE1 is associated with enhanced Ca(2+) entry and subsequent scrambling of cell membrane phospholipids.

Shrinkage insensitivity of NKCC1 in myosin II-depleted cytoplasts from Ehrlich ascites tumor cells

Protein phosphorylation/dephosphorylation and cytoskeletal reorganization regulate the Na(+)-K(+)-2Cl(-) cotransporter (NKCC1) during osmotic shrinkage; however, the mechanisms involved are unclear. We show that in cytoplasts, plasma membrane vesicles detached from Ehrlich ascites tumor cells (EATC) by cytochalasin treatment, NKCC1 activity evaluated as bumetanide-sensitive (86)Rb influx was increased compared with the basal level in intact cells yet could not be further increased by osmotic shrinkage. Accordingly, cytoplasts exhibited no regulatory volume increase after shrinkage. In cytoplasts, cortical F-actin organization was disrupted, and myosin II, which in shrunken EATC translocates to the cortical region, was absent. Moreover, NKCC1 activity was essentially insensitive to the myosin light chain kinase (MLCK) inhibitor ML-7, a potent blocker of shrinkage-induced NKCC1 activity in intact EATC. Cytoplast NKCC1 activity was potentiated by the Ser/Thr protein phosphatase inhibitor calyculin A, partially inhibited by the protein kinase A inhibitor H89, and blocked by the broad protein kinase inhibitor staurosporine. Cytoplasts exhibited increased protein levels of NKCC1, Ste20-related proline- and alanine-rich kinase (SPAK), and oxidative stress response kinase 1, yet they lacked the shrinkage-induced plasma membrane translocation of SPAK observed in intact cells. The basal phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) was increased in cytoplasts compared with intact cells, yet in contrast to the substantial activation in shrunken intact cells, p38 MAPK could not be further activated by shrinkage of the cytoplasts. Together these findings indicate that shrinkage activation of NKCC1 in EATC is dependent on the cortical F-actin network, myosin II, and MLCK.

PERCEIVED INTENSITY AND PLEASANTNESS OF SUCROSE TASTE IN MALE ALCOHOLICS

AIMS

The aim of the present study was to evaluate a possible relationship between taste responses to sweet solutions and alcoholic status.

METHODS

The rated intensity and pleasantness of sucrose taste was compared in male alcoholics (n = 45) and non-alcoholic controls (n = 33).

RESULTS

The rated intensity, but not pleasantness, of water taste (0% sucrose) was higher in the alcoholics. The two groups did not differ with respect to the rated intensity or pleasantness of sucrose solutions (1-30%). The proportion of sweet-likers, i.e. subjects rating 30% sucrose as most pleasant, was similar in both groups (the controls: 57.6%, the alcoholics: 62.2%). A subgroup of alcoholics with a paternal history of alcoholism (n = 22) rated the highest sucrose concentration as more pleasant compared to alcoholics without alcoholic fathers. The proportion of sweet-likers among the alcoholics with a paternal history of alcoholism (77.3%) was significantly higher than that found in the alcoholics without a familial history of alcoholism (47.8%).

CONCLUSIONS

The present results suggest the following: (i) alcohol dependence is not associated with any major alterations in taste responses to sucrose solutions, (ii) sweet liking is a phenotypic marker of male alcoholics with a paternal history of alcoholism.

Release of prostaglandin D2 and leukotriene C4 in response to hyperosmolar stimulation of mast cells

BACKGROUND

Mannitol-induced bronchoconstriction in subjects with exercise-induced asthma is associated with increased urinary excretion of 9alpha, 11beta-PGF(2), a metabolite of prostaglandin D(2) (PGD(2)) serving as a mast cell marker. It has however been questioned whether or not human mast cells release PGD(2) and leukotriene C(4) (LTC(4)) after osmotic challenge with mannitol in vitro.

METHODS

Cord blood-derived human mast cells were stimulated osmotically, immunologically or with a combination of both. Supernatants were analysed for PGD(2), LTC(4) and histamine contents with enzyme immunoassays.

RESULTS

Significant release of de novo synthesized eicosanoids, predominantly PGD(2) [12 (8.8, 14) pmol/10(6)cells; median (25th, 75th percentile) but also LTC(4) (0.1 (0.08, 0.15) pmol/10(6) cells] were found in mast cells in vitro in response to 0.7 M mannitol stimulation. A massive release of histamine [70 (5.3)% of total; mean (SEM)] was also found. There were no correlations between the levels of released mediators after mannitol stimulation. In contrast, there was a correlation between release of PGD(2) and LTC(4), following immunological stimulation.

CONCLUSION

The findings support that hyperosmolar challenge activates mast cells, but different than antigen stimulation.

Early outcomes comparing Perfadex, Euro-Collins, and Papworth solutions in lung transplantation

BACKGROUND

Despite improved surgical techniques and medical management, primary graft dysfunction (PGD) remains a major cause of early morbidity and mortality after lung transplantation. Different types of lung preservation solutions have been developed and applied to clinical use; however, the relative clinical efficacy of these solutions to prevent PGD remains controversial. This study aimed to investigate the effect of the three solutions most commonly used (Perfadex [Vitrolife, Göteborg, Sweden], Papworth, and Euro-Collins [Baxter Healthcare, Old Toongabbie NSW, Australia]) on posttransplant outcomes.

METHODS

Early outcomes from 157 consecutive lung transplants (113 bilateral and 44 single) performed at The Alfred Hospital were compared across three preservation solutions.

RESULTS

Posttransplant oxygenation (p = 0.57), pulmonary vascular resistance (p = 0.34), intubation hours (p = 0.66), intensive care unit days (p = 0.34), severe PGD (grade 3) (p = 0.70), 30-day mortality (p = 0.87), and 3-month % predicted forced expiratory volume in 1 second (p = 0.58) were not statistically different; however, Perfadex trended toward superiority among the three solutions. After adjustment of donor, recipient, and operative factors in multivariate analysis, Perfadex was significantly associated with the prevention of moderate to severe PGD (grade 2 to 3) at 48 hours posttransplant (odds ratio = 0.26 [0.10 to 0.72], p < 0.01) compared with Papworth (odds ratio = 0.75 [0.32 to 1.75], p = 0.51) and Euro-Collins (reference) solutions.

CONCLUSIONS

Although any advantageous effects of Perfadex on early posttransplant outcomes were generally subtle and statistically nonsignificant, Perfadex prevented moderate to severe PGD. Switching preservation solution from Euro-Collins (or Papworth) to Perfadex would appear to usefully contribute to a strategy to reduce PGD in lung transplantation.