Comprehensive biophysical and functional study of ziv-aflibercept: characterization and forced degradation.

Aflibercept (AFL) is an Fc fusion protein used in the treatment of colorectal cancers and different ophthalmological diseases. There are two medicines in which AFL is the active substance: Zaltrap and Eylea, referred as ziv-AFL and AFL respectively. No proper accelerated degradation studies were published on either AFL or ziv-AFL. These studies are essential during research, development and manufacturing stages. Here, we characterized ziv-AFL and submitted it to different stress conditions: light, 60 °C, freeze-thaw cycles, changes in pH, high hypertonic solution and strong denaturing conditions. We used an array of techniques to detect aggregation (SE-HPLC/DAD and DLS), changes in secondary structure (Far-UV circular dichroism), changes in conformation or tertiary structure (Intrinsic tryptophan fluorescence) and alterations in functionality (ELISA). Results indicate that aggregation is common degradation pathway. Two different types of aggregates were detected: dimers and high molecular weight aggregates attributed to ß-amyloid-like structures. Secondary structure was maintained in most of the stress tests, while conformation was altered by almost all the tests except for the freeze-thaw cycles. Functionality, evaluated by its immunochemical reaction with VEGF, was found to be stable but with decrease when exposed to light and with likely partial inactivation of the drug when pH was altered.

Role of Hypoxia in Renal Failure Caused by Nephrotoxins and Hypertonic Solutions.

Hypoxia plays a role in the pathogenesis of acute kidney injury under diverse clinical settings, including nephrotoxicity. Although some nephrotoxins exert direct renal parenchymal injury, likely with consequent altered oxygenation, others primarily reduce renal parenchymal oxygenation, leading to hypoxic tubular damage. As outlined in this review, nephrotoxin-related renal hypoxia may result from an altered renal oxygen supply (cyclosporine), enhanced oxygen consumption for tubular transport (agents inducing osmotic diuresis), or their combination (nonsteroidal anti-inflammatory drugs, radiocontrast agents, and others). Most agents causing hypoxic renal injury further supress physiologic low medullary Po2, in which a limited regional blood supply barely matches the intense regional tubular transport and oxygen consumption. The medullary tubular transport and blood supply are finely matched, securing oxygen sufficiency. Predisposition to hypoxia-mediated nephrotoxicity by medical conditions, such as chronic kidney disease or diabetes, may be explained by malfunctioning of control systems that normally maintain medullary oxygenation. However, this propensity may be diminished by hypoxia-mediated adaptive responses governed by hypoxia-inducible factors. Recent reports have suggested that inhibitors of sodium-glucose cotransporters and the administration of hypertonic saline may be added to the growing list of common therapeutic interventions that intensify medullary hypoxia, and potentially could lead to hypoxic acute kidney injury.

Life-Threatening Mannitol-Induced Hyperkalemia in Neurosurgical Patients.

BACKGROUND: Mannitol is the most commonly used intraoperative hypertonic solution in patients undergoing craniotomy. However, its use has been reported to be associated with hyperkalemia, which can occasionally be life threatening. CASE DESCRIPTION AND LITERATURE REVIEW: In this report, we discuss the case of a patient who had intraoperative cardiac arrest secondary to mannitol-induced hyperkalemia during a craniotomy for tumor resection. In addition, we provide a comprehensive review of the literature concerning similar cases previously reported, as well as a discussion of the pathophysiology of mannitol-induced hyperkalemia. Review of the literature suggests that patients prone to this phenomenon are young and healthy individuals with normal preoperative and postoperative cardiopulmonary and renal functions. The literature also suggests that the total dose of mannitol, as well as its rate of infusion, may play a role in the development of this phenomenon. CONCLUSIONS: Knowledge of the existence of mannitol-induced hyperkalemia is paramount for the neurosurgeon and the anesthesiologist, because early treatment with insulin and calcium can quickly restore normal cardiac rhythm and prevent intraoperative death.

[Is physiological saline really physiological? Hyponatreamia treatment--small deviations from the rules of appropriate therapy create serious complications and side effects]. / Czy sól fizjologiczna jest fizjologiczna? Leczenie hiponatremii--male odstepstwa od regul prawidlowego leczenia powoduja powazne powiklania i objawy uboczne.

Physiological saline can hardly be treated as physiological as it contains qualitatively and quantitatively different amounts of electrolytes. In particular, it contains 50% more chlorine ions than serum. Physiological saline can cause metabolic acidosis and in diabetic patients hyperchloremic acidosis. In comparison with Ringer solution and plasma-lyte, physiological saline is causing higher number of untoward effects and mortality associated with surgery. Ringer solution should be used in the situations requiring expansion of extracellular fluid. Physiological saline is a solution of choice in hypochloremic alkalosis in the case of brain injuries quite unfavourable is unnecessary rapid correction with physiological saline which can lead to serious sequelae in form of brain oedema and central extrapontine myelinolysis (osmotic demyelinisation) and permanent brain lesions. The hyponatremia's treatment depends on severity of symptoms, neurological deficit motivates immediate 4-6 mmol/l infusion, but further correction should be prolonged to 24-hrs; cautious correction corresponds to 8-mmol/l for 24 hrs. The modern treatment encompasses the introduction of vasopressin receptors antagonist--vaptans.

Prehospital Resuscitation of Traumatic Hemorrhagic Shock with Hypertonic Solutions Worsens Hypocoagulation and Hyperfibrinolysis.

Impaired hemostasis frequently occurs after traumatic shock and resuscitation. The prehospital fluid administered can exacerbate subsequent bleeding and coagulopathy. Hypertonic solutions are recommended as first-line treatment of traumatic shock; however, their effects on coagulation are unclear. This study explores the impact of resuscitation with various hypertonic solutions on early coagulopathy after trauma. We conducted a prospective observational subgroup analysis of large clinical trial on out-of-hospital single-bolus (250 mL) hypertonic fluid resuscitation of hemorrhagic shock trauma patients (systolic blood pressure, ≤70 mmHg). Patients received 7.5% NaCl (HS), 7.5% NaCl/6% Dextran 70 (HSD), or 0.9% NaCl (normal saline [NS]) in the prehospital setting. Thirty-four patients were included: 9 HS, 8 HSD, 17 NS. Treatment with HS/HSD led to higher admission systolic blood pressure, sodium, chloride, and osmolarity, whereas lactate, base deficit, fluid requirement, and hemoglobin levels were similar in all groups. The HSD-resuscitated patients had higher admission international normalized ratio values and more hypocoagulable patients, 62% (vs. 55% HS, 47% NS; P < 0.05). Prothrombotic tissue factor was elevated in shock treated with NS but depressed in both HS and HSD groups. Fibrinolytic tissue plasminogen activator and anti-fibrinolytic plasminogen activator inhibitor type 1 were increased by shock but not thrombin-activatable fibrinolysis inhibitor. The HSD patients had the worst imbalance between procoagulation/anticoagulation and profibrinolysis/antifibrinolysis, resulting in more hypocoagulability and hyperfibrinolysis. We concluded that resuscitation with hypertonic solutions, particularly HSD, worsens hypocoagulability and hyperfibrinolysis after hemorrhagic shock in trauma through imbalances in both procoagulants and anticoagulants and both profibrinolytic and antifibrinolytic activities.

Mannitol versus hypertonic saline for brain relaxation in patients undergoing craniotomy.

BACKGROUND: Patients with brain tumour usually suffer from increased pressure in the skull due to swelling of brain tissue. A swollen brain renders surgical removal of the brain tumour difficult. To ease surgical tumour removal, measures are taken to reduce brain swelling, often referred to as brain relaxation. Brain relaxation can be achieved with intravenous fluids such as mannitol or hypertonic saline. This review was conducted to find out which of the two fluids may have a greater impact on brain relaxation. OBJECTIVES: The objective of this review was to compare the effects of mannitol versus those of hypertonic saline on intraoperative brain relaxation in patients undergoing craniotomy. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 10), MEDLINE via Ovid SP (1966 to October 2013) and EMBASE via Ovid SP (1980 to October 2013). We also searched specific websites, such as www.indmed.nic.in, www.cochrane-sadcct.org and www.Clinicaltrials.gov. SELECTION CRITERIA: We included randomized controlled trials (RCTs) that compared the use of hypertonic saline versus mannitol for brain relaxation. We also included studies in which any other method used for intraoperative brain relaxation was compared with mannitol or hypertonic saline. Primary outcomes were longest follow-up mortality, Glasgow Outcome Scale score at three months and any adverse events related to mannitol or hypertonic saline. Secondary outcomes were intraoperative brain relaxation, intensive care unit (ICU) stay, hospital stay and quality of life. DATA COLLECTION AND ANALYSIS: We used standardized methods for conducting a systematic review, as described by the Cochrane Handbook for Systematic Reviews of Interventions. Two review authors independently extracted details of trial methodology and outcome data from reports of all trials considered eligible for inclusion. All analyses were made on an intention-to-treat basis. We used a fixed-effect model when no evidence was found of significant heterogeneity between studies, and a random-effects model when heterogeneity was likely. MAIN RESULTS: We included six RCTs with 527 participants. Only one RCT was judged to be at low risk of bias. The remaining five RCTs were at unclear or high risk of bias. No trial mentioned the primary outcomes of longest follow-up mortality, Glasgow Outcome Scale score at three months or any adverse events related to mannitol or hypertonic saline. Three trials mentioned the secondary outcomes of intraoperative brain relaxation, hospital stay and ICU stay; quality of life was not reported in any of the trials. Brain relaxation was inadequate in 42 of 197 participants in the hypertonic saline group and in 68 of 190 participants in the mannitol group. The risk ratio for brain bulge or tense brain in the hypertonic saline group was 0.60 (95% confidence interval (CI) 0.44 to 0.83, low-quality evidence). One trial reported ICU and hospital stay. The mean (standard deviation (SD)) duration of ICU stay in the mannitol and hypertonic saline groups was 1.28 (0.5) and 1.25 (0.5) days (P value 0.64), respectively; the mean (SD) duration of hospital stay in the mannitol and hypertonic saline groups was 5.7 (0.7) and 5.7 (0.8) days (P value 1.00), respectively AUTHORS' CONCLUSIONS: From the limited data available on the use of mannitol and hypertonic saline for brain relaxation during craniotomy, it is suggested that hypertonic saline significantly reduces the risk of tense brain during craniotomy. A single trial suggests that ICU stay and hospital stay are comparable with the use of mannitol or hypertonic saline. However, focus on other related important issues such as long-term mortality, long-term outcome, adverse events and quality of life is needed.

Hyperkalemia by Euro-Collins solution in anesthesia for renal transplantation: a case report.

OBJECTIVE: To describe anesthesia for renal transplantation that progressed to a sharp potassium increase after kidney reperfusion with Euro-Collins' solution in the operative field. We will also report on diagnosis and treatment used. CONCLUSION: The use of infusion solutions in the surgical field requires careful monitoring, such as electrocardiography, measurement of serum potassium, and availability of calcium gluconate, insulin, and albuterol for immediate use. The replacement of Euro-Collins' solution for saline solution immediately before the implant may be a useful option in patients with high levels of potassium.

[Severe allergic reaction due to a rectal enema]. / Réaction allergique sévère suite à un lavement.

Allergic drug reactions must always be considered when prescribing treatment, even in frequent pediatric problems such as acute abdominal pain due to constipation. We describe an original case of anaphylactic shock due to the administration of hypertonic rectal enema in a child. A 9-year-old child admitted to the emergency department for an acute complaint of abdominal pain related to constipation received an administration of a hypertonic rectal enema to allow the passage of stools. Afterwards, the child presented a life-threatening episode, requiring emergency treatment with transfer to the pediatric intensive care unit, suggesting an anaphylactic shock. The absence of any other drug or food intake, the chronology of events, and favorable outcome after treatment led to the diagnosis of a probable allergy to methylparaben, sodium parahydroxybenzoate, present as the excipient in the rectal enema. Anaphylactic shock is a serious allergic reaction, setting in rapidly, which may lead to fatal outcome. Most reactions to parabens reported concern, almost exclusively, the cutaneous application of paraben-containing topical preparations. The present observation underscores the original and undescribed risk of an allergic general reaction following the rectal administration of parabens. The indications of any prescription must be carefully observed and potential drug contraindications, considering the patient's history of allergy, should be sought.

Hiperpotassemia pela solução Euro-Collins na anestesia para transplante renal: relato de caso / Hyperkalemia by Euro-Collins solution in anesthesia for renal transplantation: a case report / Hiperpotasemia por la solución de Euro-Collins en la anestesia para transplante renal: relato de caso

OBJETIVOS: Descrever uma anestesia para transplante renal que se complicou com a elevação brusca de potássio, pela reperfusão do rim com solução Euro-Collins no campo operatório. Também será relatado o diagnóstico e o tratamento empregados nessa complicação. CONCLUSÃO: O uso de soluções de perfusão no campo cirúrgico requer cuidados na monitoração, como eletrocardioscopia e dosagem de potássio sérico, e disponibilidade para uso imediato de gluconato de cálcio, insulina e salbutamol. A substituição da solução Euro-Collins por soro fisiológico imediatamente antes do implante pode ser uma opção útil em pacientes com níveis de potássio sabidamente elevados.

OBJECTIVE: To describe anesthesia for renal transplantation that progressed to a sharp potassium increase after kidney reperfusion with Euro-Collins' solution in the operative field. We will also report on diagnosis and treatment used. CONCLUSION: The use of infusion solutions in the surgical field requires careful monitoring, such as electrocardiography, measurement of serum potassium, and availability of calcium gluconate, insulin, and albuterol for immediate use. The replacement of Euro-Collins' solution for saline solution immediately before the implant may be a useful option in patients with high levels of potassium.

OBJETIVOS: Describir una anestesia para transplante renal que se complicó con la elevación brusca de potasio por la reperfusión del riñón con solución de Euro-Collins en el campo operatorio. También será relatado el diagnóstico y el tratamiento usados en esa complicación. CONCLUSIONES: El uso de soluciones de perfusión en el campo quirúrgico requiere cuidados en el monitoreo, como la electrocardioscopia, la dosificación de potasio sérico y la disponibilidad para el uso inmediato del gluconato de calcio, insulina y salbutamol. El reemplazo de la solución de Euro-Collins por suero fisiológico inmediatamente antes del implante, puede ser una opción útil en los pacientes con niveles de potasio consabidamente elevados.

Early utilization of hypertonic peritoneal dialysate and subsequent risks of non-traumatic amputation among peritoneal dialysis patients: a nationwide retrospective longitudinal study.

BACKGROUND: The hemodialysis (HD) population has a particularly high incidence of amputation, which is likely associated with decreased tissue oxygenation during HD. However, information about the risk factors leading to amputation in peritoneal dialysis (PD) patients is limited. Here, we have investigated the association between the use of hypertonic peritoneal dialysate (HPD) and subsequent amputation in PD patients. METHODS: Based on the data from the Taiwan National Health Insurance research database, this observational cohort study enrolled 203 PD patients who had received HPD early during treatment and had not undergone amputation and 296 PD controls who had not undergone amputation. Subjects were followed through until the end of 2009 and the event rates of new non-traumatic amputation were compared between groups. RESULTS: The incidence of amputation was 3 times higher for the HPD cohort than for the comparison cohort (23.68 vs. 8.01 per 1000 person-years). The hazard ratio (HR) for this group, estimated using a multivariable Cox model, was 2.48 (95% confidence interval [CI] = 1.06-5.79). The HR for patients with both diabetes and early adoption of HPD increased to 44.34 (95% CI = 5.51-357.03), compared to non-HPD non-diabetic PD controls. CONCLUSION: Early utilization of HPD in PD patients is associated with increasing risk of amputation; this risk considerably increases for those with concomitant diabetes.

Osmotherapy in brain edema: a questionable therapy.

Despite the fact that it has been used since the 1960s in diseases associated with brain edema and has been investigated in >150 publications on head injury, very little has been published on the outcome of osmotherapy. We can only speculate whether osmotherapy improves outcome, has no effect on outcome, or leads to worse outcome. Here we describe the action and potentially beneficial and adverse effects of the 2 most commonly used osmotic solutions, mannitol and hypertonic saline, and present some critical aspects of their use. There is a well-documented transient intracranial pressure (ICP)-reducing effect of osmotherapy, but an adverse rebound increase in ICP after its withdrawal has been discussed extensively in the literature and is an expected pathophysiological phenomenon. From side effects related to renal and pulmonary failure, electrolyte disturbances, and a rebound increase in ICP, osmotherapy can be negative for outcome, which may explain why we lack scientific support for its use. These drawbacks, and the fact that the most recent Cochrane meta-analyses of osmotherapy in brain edema and stroke could not find any beneficial effects on outcome, make routine use of osmotherapy in brain edema doubtful. Nevertheless, the use of osmotherapy as a temporary measure may be justified to acutely prevent brain stem compression until other measures, such as evacuation of space-occupying lesions or decompressive craniotomy, can be performed. This article is the Con part in a Pro-Con debate in the present journal on the general routine use of osmotherapy in brain edema.

A successful combined treatment with dermal substitutes and products of regenerative medicine in a patient affected by extravasation injury from hypertonic solution.

In neonatal intensive care units, extravasation is one of the most common injuries occurring in infants as a complication of infusion therapy. These very preterm infants have immature skin which is easily damaged. They often require a longer duration of intravenous therapy, and obtaining intravenous access can be difficult. An invasive treatment should be avoided, whenever possible, particularly for very immature infants. In our Special Operative Unit for ulcers and difficult-to-heal wounds, University of Rome, we successfully treated a premature neonate, who experienced extravasation of hypertonic fluid, using dermal substitutes and products of regenerative medicine.

Out-of-hospital hypertonic resuscitation after traumatic hypovolemic shock: a randomized, placebo controlled trial.

OBJECTIVE: To determine whether out-of-hospital administration of hypertonic fluids would improve survival after severe injury with hemorrhagic shock. BACKGROUND: Hypertonic fluids have potential benefit in the resuscitation of severely injured patients because of rapid restoration of tissue perfusion, with a smaller volume, and modulation of the inflammatory response, to reduce subsequent organ injury. METHODS: Multicenter, randomized, blinded clinical trial, May 2006 to August 2008, 114 emergency medical services agencies in North America within the Resuscitation Outcomes Consortium. INCLUSION CRITERIA: injured patients, age ≥ 15 years with hypovolemic shock (systolic blood pressure ≤ 70 mm Hg or systolic blood pressure 71-90 mm Hg with heart rate ≥ 108 beats per minute). Initial resuscitation fluid, 250 mL of either 7.5% saline per 6% dextran 70 (hypertonic saline/dextran, HSD), 7.5% saline (hypertonic saline, HS), or 0.9% saline (normal saline, NS) administered by out-of-hospital providers. Primary outcome was 28-day survival. On the recommendation of the data and safety monitoring board, the study was stopped early (23% of proposed sample size) for futility and potential safety concern. RESULTS: : A total of 853 treated patients were enrolled, among whom 62% were with blunt trauma, 38% with penetrating. There was no difference in 28-day survival-HSD: 74.5% (0.1; 95% confidence interval [CI], -7.5 to 7.8); HS: 73.0% (-1.4; 95% CI, -8.7-6.0); and NS: 74.4%, P = 0.91. There was a higher mortality for the postrandomization subgroup of patients who did not receive blood transfusions in the first 24 hours, who received hypertonic fluids compared to NS [28-day mortality-HSD: 10% (5.2; 95% CI, 0.4-10.1); HS: 12.2% (7.4; 95% CI, 2.5-12.2); and NS: 4.8%, P < 0.01]. CONCLUSION: Among injured patients with hypovolemic shock, initial resuscitation fluid treatment with either HS or HSD compared with NS, did not result in superior 28-day survival. However, interpretation of these findings is limited by the early stopping of the trial. CLINICAL TRIAL REGISTRATION: Clinical Trials.gov, NCT00316017.

Flow-through peritoneal dialysis in neonatal enema-induced hyperphosphatemia.

Fleet enemas are hypertonic solutions with an osmotic action and a high concentration of phosphate. When retained in the human body they have a great toxic potential, causing severe hydro-electrolyte disorders in children, especially in newborns. We report the case of a previously healthy 8-day-old newborn who needed neonatal intensive care treatment after the inadvertent administration of an osmotically active hypertonic phosphate enema. Taking into account that phosphate removal by peritoneal dialysis (PD) strongly depends on total dialysate turnover, we chose continuous flow PD (CFPD) as the treatment option, with a successful outcome. Clinical experience with this dialytic modality is limited to a few case reports in pediatric and adult patients. To the best of our knowledge, we report here the first description of CFPD in the setting of acute phosphate nephropathy in the neonatal period. The modality of PD described here has potential as an alternative management option as it is a highly efficient, methodologically simple, and low-cost method without any need for sophisticated equipment. Physicians and parents should be aware of the adverse effects of a hypertonic phosphate enema and should never use these medications in infants and newborns.

Rescue of postcompaction-stage mouse embryo development from hypertonicity by amino acid transporter substrates that may function as organic osmolytes.

Early preimplantation embryos are sensitive to external osmolarity and use novel mechanisms to accumulate organic osmolytes and thus control their cell volumes and maintain viability. However, these mechanisms are restricted to the cleavage stages of development, and it was unknown whether postcompaction embryos use organic osmolytes. Mouse embryos developing from the 8-cell stage formed blastocoel cavities in vitro at osmolarities up to 360 mOsM. Above this range, several putative organic osmolytes (alanine, glutamine, glycine, and beta-alanine) rescued blastocyst development, but several effective osmoprotectants in cleavage-stage embryos (such as betaine and proline) did not. At physiological osmolarities, each of these compounds resulted in significantly larger blastocysts. This was not due to increased cell numbers, which were unaffected in blastocysts by osmolarity in the range where blastocyst size was rescued by potential organic osmolytes, although cell number was decreased at higher osmolarities and was rescued by each osmolyte. The effective osmolytes were accumulated intracellularly by embryos developing in vitro from the 8-cell stage to blastocysts. However, unlike conventional organic osmolytes in somatic cells or those in cleavage-stage embryos, their intracellular concentrations were not increased with increasing external osmolarity. With the exception of beta-alanine, which is taken up via the beta-amino acid transport system, the effective osmolytes were transported by the B(0,+) system, which becomes highly active in blastocysts. The intracellular accumulation of these osmolytes in postcompaction embryos thus appears to support optimal development and blastocyst expansion at physiological osmolarities and may contribute to the embryo's ability to withstand stress.

Genome-wide RNAi screen and in vivo protein aggregation reporters identify degradation of damaged proteins as an essential hypertonic stress response.

The damaging effects of hypertonic stress on cellular proteins are poorly defined, and almost nothing is known about the pathways that detect and repair hypertonicity-induced protein damage. To begin addressing these problems, we screened approximately 19,000 Caenorhabditis elegans genes by RNA interference (RNAi) feeding and identified 40 that are essential for survival during acute hypertonic stress. Half (20 of 40) of these genes encode proteins that function to detect, transport, and degrade damaged proteins, including components of the ubiquitin-proteasome system, endosomal sorting complexes, and lysosomes. High-molecular-weight ubiquitin conjugates increase during hypertonic stress, suggesting a global change in the ubiquitinylation state of endogenous proteins. Using a polyglutamine-containing fluorescent reporter, we demonstrate that cell shrinkage induces rapid protein aggregation in vivo and that many of the genes that are essential for survival during hypertonic stress function to prevent accumulation of aggregated proteins. High levels of urea, a strong protein denaturant, do not cause aggregation, suggesting that factors such as macromolecular crowding also contribute to protein aggregate formation during cell shrinkage. Acclimation of C. elegans to mild hypertonicity dramatically increases the osmotic threshold for protein aggregation, demonstrating that protein aggregation-inhibiting pathways are activated by osmotic stress. Our studies demonstrate that hypertonic stress induces protein damage in vivo and that detection and degradation of damaged proteins are essential mechanisms for survival under hypertonic conditions.

Fatal iatrogenic hyperphosphatemia.

Hypertonic sodium phosphate enemas are available for relief of constipation. They are widely used as colorectal laxatives because of their efficacy and because most patients tolerate the preparation well. Nevertheless, their use has been associated with decreases in intravascular volume as well as measurable changes in serum phosphorus and calcium levels. Usually these effects are transient and cause no ill effects. Severe toxicity may occur when the osmotically active hypertonic phosphate enema is retained or when it is administered to a patient with a decreased glomerular filtration rate. We report an elderly patient with previously normal renal function who developed severe hyperphosphatemia, hypocalcemia, and cardiac arrest after the administration of hypertonic sodium phosphate enemas for the treatment of an ileus. We review the patient characteristics that increase the risk of adverse effects from hypertonic sodium phosphate enemas and emphasize the danger that moderate dehydration poses when considering the use of these cathartics.