[The effect of natural mineral bicarbonate sodium-calcium water «Tib-1¼ on the antioxidant status of rats with adjuvant rheumatoid arthritis]. / Vliyanie prirodnoi mineral'noi gidrokarbonatnoi natrievo-kal'tsievoi vody «Tib-1¼ na antioksidantnyi status krys s ad"yuvantnym revmatoidnym artritom.

The combination of traditional basic pharmacotherapy for rheumatoid arthritis (RA) and physiotherapeutic methods can reduce the activity of the disease and accelerate the onset of remission, and therefore the development of new non-drug methods for the treatment of RA is relevant. PURPOSE OF THE STUDY: Study of the effect of natural mineral water « Tib-1¼ on the lipid peroxidation system in an experiment with a model adjuvant-induced RA in rats. MATERIAL AND METHODS: The object of the study were Wistar rats, divided into three groups: negative control (solvents), positive control (model of adjuvant-induced RA by subcutaneous injection of complete Freund's adjuvant) and experimental (correction of RA with mineral water « Tib-1¼, diluted in a ratio of 1:3 during the first 2 weeks from the moment the model was formed in the ad libitum mode). On the 3rd and 7th weeks in the blood of the animals were determined: the total number of leukocytes, the content of hydroperoxides according to Gavrilov, the level of malondialdehyde (MDA), catalase activity. Pathological changes in the hip and knee joints were recorded using radiography. RESULTS: The inflammatory process in the positive control group by the 3rd week was characterized by an increase in the number of leukocytes by 66% (p<0.01) and was accompanied by an increase in MDA by 60% (p<0.001). By the 7th week, despite a relative increase in catalase activity (16%), the MDA level continued to be elevated compared to the negative control by 67% (p<0.001). Against the background of exposure to mineral water, inflammation decreased (the number of leukocytes in the "model/experiment" groups turned out to be reduced by 41%; p<0.01) and an increase in compensatory-adaptive reactions in the form of catalase activation was noted (by 8%; p<0.01), which was accompanied by a persistent (weeks 3 and 7) decrease in MDA output (by 20%; p<0.01). Using the method of radiation diagnostics, positive changes in the articular apparatus of experimental animals were revealed, consisting in the relief of signs of subchondral sclerosis of the bone heads, which were noted for animals of the model group. CONCLUSION: The use of natural mineral water «Tib-1¼ helps to reduce the acute inflammatory response during the formation of adjuvant-induced RA in Wistar rats, initiates the normalization of the balance of pro- and antioxidant processes in the body, and minimizes the intensity of degenerative-inflammatory joint lesions.

Effect of Del Nido cardioplegia on ventricular arrhythmias after cardiovascular surgery.

BACKGROUND: Del Nido cardioplegia (DNC) has been proven safe and effective in pediatric patients. However, the use of DNC in adult undergoing cardiovascular surgery lacks support with substantial evidence. This study aimed to evaluate the efficacy of DNC as a cardioplegia of prophylaxis to ventricular arrhythmias associated to cardiovascular surgery in adult patients. METHODS: This study recruited nine hundred fifty-four patients who underwent cardiopulmonary bypass surgeries in Nanjing Hospital affiliated to Nanjing Medical University between January 2019 and December 2019. Among 954 patients, 324 patients were treated with DNC (DNC group), and 630 patients were treated with St. Thomas cardioplegia (STH group). The incidence of postoperative arrhythmia as well as other cardiovascular events relavant to the surgery were investigated in both groups. RESULTS: In DNC group, the incidence of postoperative ventricular arrhythmias was lower (12.4% vs. 17.4%, P = 0.040), and the length of ICU stay was shorter (1.97 ± 1.49 vs. 2.26 ± 1.46, P = 0.004). Multivariate logistic regression demonstrated that the use of DNC helped to reduce the incidence of postoperative ventricular arrhythmias (adjusted odds ratio 0.475, 95% CI 0.266-0.825, P = 0.010). The propensity score-based analysis and subgroup analysis indicated that DNC has the same protecting effects towards myocardial in all kinds of cardiopulmonary bypass surgeries. CONCLUSIONS: Del Nido cardioplegia may potentially reduce the incidence of postoperative ventricular arrhythmias, shorten the length of ICU stay and improve the overall outcome of the patients undergoing cardiovascular surgery.

Half Saline-Bicarbonate Solution as Intraoperative Fluid Replacement Therapy Leads to Less Acidosis and Better Early Renal Function During Deceased-Donor Transplant.

OBJECTIVES: Normal saline is the most common crystalloid solution that is used in renal transplant surgery. In this study, our aim was to determine the effects of a combination of half saline and bicarbonate versus normal saline as a routine solution. MATERIALS AND METHODS: For this double-blind random-ized clinical trial, we enrolled 100 adult patients undergoing kidney transplant. Patients were divided into 2 groups: those who received normal saline and those who received half saline and bicarbonate infusion as fluid replacement therapy during renal transplant. All patients received about 40 mL/kg of crystalloids during surgery. Serial creatinine con-centrations (primary outcomes) were compared between groups at 1, 2, 3, and 7 days after surgery. Urine output (secondary outcome) was compared between groups at recovery and at 6 and 24 hours after surgery. In addition, base excess, chloride, and sodium levels were measured before and 6 hours after surgery. Each liter of half saline-bircarbonate, which is relatively isoosmotic to human plasma, was composed of 70 mEq bicarbonate, 77 mEq chloride, and 147 mEq sodium. RESULTS: Patients who received half saline-bicarbonate had significantly lower postoperative creatinine levels at all time points than patients who received normal saline (P = .019). Serum chloride and sodium levels (P = .001) were significantly higher and base excess (P = .007) was significantly lower in the normal saline group at 6 hours after transplant. At all time points, urine output levels were significantly higher in the half saline-bicarbonate group (P = .001). CONCLUSIONS: The use of half saline-bicarbonate was associated with better early graft function compared with normal saline in the first 7 days after transplant.

Cambios estructurales de la superficie dental erosionada pre y post tratamiento con bicarbonato de arginina y monofluorofosfato de sodio: estudio piloto / Structural changes of the eroded tooth surface before and after treatment with arginine bicarbonate and sodium monofluorophosphate: pilot study

La erosión dental se define como la pérdida patológica, crónica e indolora de los tejidos dentales, por la acción química de ácidos no producidos por la microflora bacteriana bucal. Los estadíos más avanzados pueden generar diferentes niveles de desgaste y producir hipersensibilidad destinaria. Objetivo: evaluar y describir los cambios estructurales de la superficie dental erosionada pre y post tratamiento con bicarbonato de arginina y monofluorofosfato de sodio, observados mediante microscopia electrónica de barrido (MEB). Materiales y Métodos: Se realizó un estudio piloto de tipo descriptivo, transversal y cuasi-experimental. Se seleccionó una muestra de cuatro pacientes, previo consentimiento informado; de manera aleatoria se le asignó el tratamiento luego de la primera cirugía, grupo 1 (bicarbonato de arginina) y grupo 2 (monofluorofosfato de sodio). Las exodoncias se realizaron en dos tiempos (tiempo 0 y post-tratamiento) para obtener los especímenes y ser evaluados con MEB. Resultados: Tras la evaluación realizada por MEB se observó que los segmentos de esmalte dental diagnosticados clínicamente con grado 1 de erosión, ya presentaban exposición de algunos túbulos dentinarios en la superficie evaluada. Luego de 14 días de tratamiento, se observó que ambas cremas dentales fueron capaces de sellar la entrada de los canalículos dentinarios; sin embargo, la crema dental con bicarbonato de arginina, formó una estructura mineralizada que se depositó sobre la superficie dental. Conclusión: ambos tratamientos fueron capaces de producir cambios estructurales en la superficie dental erosionada sellando la entrada de los túbulos dentinarios(AU)

Dental erosion is defined as the pathological, chronic and painless loss of dental tissues due to the chemical action of acids not produced by the oral bacterial microflora. The more advanced stages can generate different levels of wear and produce dentine hypersensitivity. Objective: to evaluate and describe the structural changes of the eroded dental surface before and after treatment with arginine bicarbonate and sodium monofluorophosphate, observed by scanning electron microscopy (SEM). Materials and Methods: A pilot study of descriptive, transversal and quasi-experimental type was carried out. A sample of four patients was selected, with prior informed consent; Randomly, he was assigned to the treatment after the first surgery, group 1 (arginine bicarbonate) and group 2 (sodium monofluorophosphate). Extractions were performed in two stages (time 0 and post-treatment) to obtain the specimens and be evaluated with SEM. Results: After the evaluation made by SEM, it was observed that dental enamel segments clinically diagnosed with erosion grade 1, already had exposure of some dentinal tubules in the evaluated surface. After 14 days of treatment, it was observed that both dental creams were able to seal the entrance of the dentinal canaliculi; however, the toothpaste with arginine bicarbonate, formed a mineralized structure that was deposited on the tooth surface. Conclusion: both treatments were able to produce structural changes in the eroded dental surface sealing the entrance of the dentinal tubules(AU)

Normokalemic nondepolarizing long-acting blood cardioplegia.

Objective Blood cardioplegia, the gold-standard cardioprotective strategy, requires frequent dosing, resulting in hyperkalemia-induced myocardial edema. The aim of our study was to compare the efficacy and safety of a long-acting blood-based cardioplegia with physiological potassium levels versus the well-established cold blood St. Thomas' Hospital no. 1 cardioplegia solution in multivalve surgeries. Methods One hundred patients undergoing simultaneous elective aortic and mitral valve replacement ± tricuspid valve repair were randomized in two groups. In group 1, adenosine 12 mg was given via the aortic root after crossclamping, followed by a single dose of long-acting solution at 14℃ (30 mLckg-1); in group 2, an initial 30 mLckg-1 of St. Thomas' cardioplegia at 14℃ was administered, followed by 15 mLckg-1 every 20 min. Duration of cardiopulmonary bypass, inotropic score, arrhythmias, ventilation time, and the levels of interleukin-6, creatinine kinase-MB, and troponin I were compared. Results Mean cardiopulmonary bypass and crossclamp times were 134.04 ± 36.12 vs. 154.34 ± 34.26 ( p = 0.004) and 110.37 ± 24.80 vs. 132.48 ± 31.68 min ( p = 0.002), respectively, in the long-acting and St. Thomas' groups. Cardiac index, creatinine kinase-MB and troponin I levels were comparable. Interleukin-6 levels post-bypass were 61.72 ± 15.33 and 75.44 ± 31.78 pgcmL-1 ( p = 0.007) in the long-acting and St. Thomas' cardioplegia groups, respectively. Conclusions Single-dose long-acting cardioplegia gives a cardioprotective effect comparable to repeated doses of the well-established St. Thomas' Hospital no. 1 cold blood cardioplegia.

Bicarbonate versus lactate solutions for acute peritoneal dialysis.

BACKGROUND: The high mortality rate among critically ill patients with acute kidney injury (AKI) remains an unsolved problem in intensive care medicine, despite the use of renal replacement therapy (RRT). Increasing evidence from clinical studies in adults and children suggests that the new peritoneal dialysis (PD) fluids may allow for better long-term preservation of peritoneal morphology and function. Formation of glucose degradation products (GDPs) can be reduced and even avoided with the use of newer "biocompatible" solutions. However, it is still unclear if there are any differences in using conventional (lactate) solutions compared with low GDP (bicarbonate) solutions for acute PD. OBJECTIVES: To look at the benefits and harms of bicarbonate versus lactate solutions in acute PD. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1966), EMBASE (from 1980), Latin American and Caribbean Health Sciences Literature Database LILACS (from 1982), and reference lists of articles.Date of last search: 6 May 2014. SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing bicarbonate to lactate solution for acute PD. DATA COLLECTION AND ANALYSIS: Two authors independently assess the methodological quality of studies. One author abstracted data onto a standard form, and a second author checked data extraction. We used the random-effects model and expressed the results as relative risk (RR) for dichotomous outcomes and mean difference (MD) for continuous outcomes with 95% confidence intervals (CI). MAIN RESULTS: We included one study (20 patients) in this review. In shock patients, bicarbonate did not differ from lactate with respect to mortality (RR 0.50, 95% CI 0.06 to 3.91); however there were significant differences in blood lactate (MD -1.60 mmol/L, 95% CI -2.04 to -1.16), serum bicarbonate (MD 5.00 mmol/L, 95% CI 3.26 to 6.74) and blood pH (MD 0.12, 95% CI 0.06 to 0.18). In non-shock patients there was a significance difference in blood lactate (MD -0.60 mmol/L, 95% CI -0.85 to -0.35) but not in serum bicarbonate (MD 1.10 mmol/L, 95% CI -0.27 to 2.47) or blood pH (MD -0.02, 95% CI -0.02 to -0.06). Other outcomes could not be analysed because of the limited data available. AUTHORS' CONCLUSIONS: There is no strong evidence that any clinical advantage for patients requiring acute PD for AKI when comparing conventional (lactate) with low GDP dialysis solutions (bicarbonate).

Initial large-dose administration of modified St. Thomas' solution.

BACKGROUND: We introduced an initial large dose of modified St. Thomas' Hospital cardioplegic solution with the aim of providing both myocardial protection as well as a smooth intraoperative process. METHODS: In 90 cases of isolated aortic valve replacement, we used the modified technique of cardioplegia in 45 (group S) and conventional administration of glucose-insulin-potassium solution in 45 (group G). The patients were selected at random. In group S, we added 4 mEq of potassium to the original St. Thomas' Hospital solution and administered 30 mL·kg(-1) as an initial dose. The temperature was decreased to 2. RESULTS: The mean of reperfusion time after declamping in group S was significantly shorter (16.7 ± 6.4 vs. 21.5 ± 10.0 min; p = 0.007). The average of postoperative maximum creatine kinase-MB was significantly lower in group S (25.6 ± 9.5 vs. 40.6 ± 37.2 IU·L(-1); p = 0.014). On multivariate analysis, use of the modified cardioplegia and aortic crossclamp time were significantly associated with creatine kinase-MB level and reperfusion time after declamping. CONCLUSIONS: This modified technique was an acceptable option that provided a bloodless operative field and avoided multiple cardioplegic administrations.

Bicarbonate therapy in severely acidotic trauma patients increases mortality.

BACKGROUND: Normally, end-tidal CO(2) is within 2 mm Hg of arterial PO(2) (PaCO(2)). However, if dead space in the lungs increases owing to shock with poor lung perfusion, the arterial-end tidal PCO(2) difference [P(a-ET)CO(2)] increases. We have found that in severely injured patients, P(a-ET)CO(2) of less than 10 mm Hg is associated with survival and P(a-ET)CO(2) of greater than 16 mm Hg is usually fatal. Our initial studies suggested that intravenously administered bicarbonate increases P(a-ET)CO(2). METHODS: This retrospective therapeutic study evaluated the effects of intravenously administered bicarbonate in a cohort of 225 severely acidotic (arterial pH ≤ 7.10) trauma patients who underwent emergency surgery from 1989 through 2011. Patients were divided into groups: early deaths (<48 hours), deaths in the operating room, deaths within 48 hours, and survivors. Winter's formula was defined as PaCO(2) = (HCO(3)) (1.5) + 8 ± 4. RESULTS: Of the 225 patients, the mean (SD) initial arterial pH was 6.92 (0.16) with HCO(3) of 11.0 (3.5) mEq/L. According to the Winter's formula, PaCO(2) should have been 24 (4) mm Hg but actually was 50 (14) mm Hg. In 73 patients, the effect of an average of two to eight vials of bicarbonate increased HCO(3) from 10.5 (3.1) mEq/L to 16.8 (4.0) mEq/L. In addition, PaCO(2) increased from 44 (9) mm Hg to 51 (11) mm Hg and end-tidal CO(2) stayed relatively constant (26 [6] to 25 [5]). This resulted in a increase in P(a-ET)CO(2) from 17 (9) mm Hg to 24 (13) mm Hg, affecting survival. In the final values after resuscitation, the P(a-ET)CO(2) in the 75 patients who survived was 10 (6) mm Hg, while the 103 patients who died in the operating room or within 48 hours of surgery had a P(a-ET)CO(2) of 23 (10) mm Hg (p < 0.001). CONCLUSION: In severely acidotic, critically injured patients, reducing the PaCO(2) to less than 40 mm Hg and decreasing the P(a-ET)CO(2) to 10 (6) mm Hg should be attempted, using as little HCO(3) therapy as possible. Bicarbonate should be given only if severe acidosis persists despite resuscitation and if PaCO(2) levels near those which are appropriate can be obtained. LEVEL OF EVIDENCE: Therapeutic study, level IV.

Combined St. Thomas and histidine-tryptophan-ketoglutarat solutions for myocardial preservation in heart transplantation patients.

BACKGROUND: To establish quicker cardiac arrest and less myocardial distension injury during heart procurement, we combined St. Thomas and histidine-tryptophan-ketoglutarate (HTK) solutions for donor heart preservation since June 2008. METHODS: From June 2008 to March 2010, we enrolled 31 heart transplantation (HT) patients in this study. During heart procurement we initially infused 1,000 mL cold St Thomas cardioplegic solution to achieve cardiac arrest. After procurement, a further 2,000 mL of cold HTK solution was infused at low perfusion pressure. Another 1,000 mL cold HTK solution was perfused before donor heart implantation. We examined donor age, recipient preoperative characteristics, ischemia time, hospital stay, postoperative graft function, major cardiac events, and transplant vasculopathy (TCAD). RESULTS: Twenty-two patients (71.0%) presented with dilated cardiomyopathy and 7 (23.3%) with ischemia cardiomyopathy. There were 23 (76.7%) male donors, and the mean donor age was 38.4 ± 13.8 years. Six patients underwent a redo sternotomy, 1 patient needed a third-do sternotomy, and 1 a seventh sternotomy (third HT) for repeated endocarditis and graft failure. The average ischemia time was 224.9 ± 71.0 minutes and the postoperative hospital stay was 57.7 ± 47.7 days. The surgical mortality (3.2%) was not accompanied by hospital or follow-up mortality. Patient left ventricular ejection fraction postoperative was 59.6 ± 2.3% with good functional status. Major cardiac events occurred in 8 patients (26.7%) without major complications. There were two subjects with TCAD but normal graft function. The correlation between ischemia time and hospital stay was insignificant (r = 0.21; P = .26). CONCLUSIONS: Donor heart preservation combining St Thomas cardioplegic arest and low-pressure perfusion with HTK solution seemed to be safe with. short-term survival similar to other approaches.

Testing the biocompatibility of a glutathione-containing intra-ocular irrigation solution by using an isolated perfused bovine retina organ culture model - an alternative to animal testing.

The effects of a glutathione-containing intra-ocular irrigation solution, BSS Plus©, on retinal function and on the survival of ganglion cells in whole-mount retinal explants were studied. Evidence is provided that the perfused ex vivo bovine retina can serve as an alternative to in vivo animal testing. Isolated bovine retinas were prepared and perfused with an oxygen-saturated standard irrigation solution, and an electroretinogram was recorded to assess retinal function. After stable b-waves were detected, the isolated retinas were perfused with BSS Plus for 45 minutes. To investigate the effects of BSS Plus on photoreceptor function, 1mM aspartate was added to the irrigation solution in order to obtain a-waves, and the ERG trace was monitored for 75 minutes. For histological analysis, isolated whole retinal mounts were stored for 24 hours at 4°C, in the dark. The percentages of cell death in the retinal ganglion cell layer and in the outer and inner nuclear layers were estimated by using an ethidium homodimer-1 stain and the TUNEL assay. General swelling of the retina was examined with high-resolution optical coherence tomography. During perfusion with BSS Plus, no significant changes in a-wave and b-wave amplitudes were recorded. Retinas stored for 24 hours in BSS Plus showed a statistically significant smaller percentage (52.6%, standard deviation [SD] = 16.1%) of cell death in the retinal ganglion cell layer compared to the control group (69.6%, SD = 3.9, p = 0.0031). BSS Plus did not seem to affect short-term retinal function, and had a beneficial effect on the survival of retinal ganglion cells. This method for analysing the isolated perfused retina represents a valuable alternative for testing substances for their retinal biocompatibility and toxicity.

Predicting the safety and efficacy of buffer therapy to raise tumour pHe: an integrative modelling study.

BACKGROUND: Clinical positron emission tomography imaging has demonstrated the vast majority of human cancers exhibit significantly increased glucose metabolism when compared with adjacent normal tissue, resulting in an acidic tumour microenvironment. Recent studies demonstrated reducing this acidity through systemic buffers significantly inhibits development and growth of metastases in mouse xenografts. METHODS: We apply and extend a previously developed mathematical model of blood and tumour buffering to examine the impact of oral administration of bicarbonate buffer in mice, and the potential impact in humans. We recapitulate the experimentally observed tumour pHe effect of buffer therapy, testing a model prediction in vivo in mice. We parameterise the model to humans to determine the translational safety and efficacy, and predict patient subgroups who could have enhanced treatment response, and the most promising combination or alternative buffer therapies. RESULTS: The model predicts a previously unseen potentially dangerous elevation in blood pHe resulting from bicarbonate therapy in mice, which is confirmed by our in vivo experiments. Simulations predict limited efficacy of bicarbonate, especially in humans with more aggressive cancers. We predict buffer therapy would be most effectual: in elderly patients or individuals with renal impairments; in combination with proton production inhibitors (such as dichloroacetate), renal glomular filtration rate inhibitors (such as non-steroidal anti-inflammatory drugs and angiotensin-converting enzyme inhibitors), or with an alternative buffer reagent possessing an optimal pK of 7.1-7.2. CONCLUSION: Our mathematical model confirms bicarbonate acts as an effective agent to raise tumour pHe, but potentially induces metabolic alkalosis at the high doses necessary for tumour pHe normalisation. We predict use in elderly patients or in combination with proton production inhibitors or buffers with a pK of 7.1-7.2 is most promising.

Adjuvants to local anaesthesia in ophthalmic surgery.

This article reviews the use of adjuvants to local anaesthesia for ophthalmic regional anaesthesia. Hyaluronidase, bicarbonate, epinephrine, muscle relaxants, opiates and clonidine have all been described singly and in combination for use as an adjuvant to ophthalmic regional anaesthesia. The article focuses on the efficacy of the adjuvants with regard to improving akinesia, analgesia, speed of onset and reducing block failure. A description of the pharmacological action of each adjuvant is given followed by a review of randomised control trials, dosage and notable papers on the subject. There is no effective consensus between anaesthetists or surgeons on the use of adjuvants to local anaesthesia and it so is the purpose of this review to draw attention to the wealth of current data and allow an informed decision on the choices available.

Medications that affect calcium.

OBJECTIVE: To review medications that can affect serum calcium concentrations. METHODS: The literature was reviewed for articles pertaining to medications that affect calcium concentrations. RESULTS: The serum calcium concentration is tightly regulated because of the importance of this mineral in diffuse cellular processes. Many medications have been reported to cause changes in serum calcium levels by influencing intestinal calcium absorption, renal calcium resorption, and bone remodeling or through altering parathyroid or 1,25-dihydroxyvitamin D-mediated regulation. Some medications are used specifically to alter serum calcium as a therapeutic intervention. With others, the calcium disturbances are viewed as a side effect of the treatment. CONCLUSION: It is important to be aware of the influence that medications can have on serum calcium levels when evaluating patients with disorders of calcium homeostasis.

Bicarbonate versus lactate solutions for acute peritoneal dialysis.

BACKGROUND: The high mortality rate among critically ill patients with acute kidney injury (AKI) remains an unsolved problem in intensive care medicine, despite the use of renal replacement therapy (RRT). Increasing evidence from clinical studies in adults and children suggests that the new peritoneal dialysis (PD) fluids may allow for better long-term preservation of peritoneal morphology and function. Formation of glucose degradation products (GDPs) can be reduced and even avoided with the use of newer "biocompatible" solutions. However, it is still unclear if there are any differences in using conventional (lactate) solutions compared with low GDP (bicarbonate) solutions for acute PD. OBJECTIVES: To look at the benefits and harms of bicarbonate versus lactate solutions in acute PD. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1966), EMBASE (from 1980), Latin American and Caribbean Health Sciences Literature Database LILACS (from 1982), and reference lists of articles. SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing bicarbonate to lactate solution for acute PD. DATA COLLECTION AND ANALYSIS: Two authors independently assess the methodological quality of studies. One author abstracted data onto a standard form, and a second author checked data extraction. We used the random-effects model and expressed the results as relative risk (RR) for dichotomous outcomes and mean difference (MD) for continuous outcomes with 95% confidence intervals (CI). MAIN RESULTS: We included one study (20 patients) in this review. In shock patients, bicarbonate did not differ from lactate with respect to mortality (RR 0.50, 95% CI 0.06 to 3.91); however there were significant differences in blood lactate (MD -1.60 mmol/L, 95% CI -2.04 to -1.16), serum bicarbonate (MD 5.00 mmol/L, 95% CI 3.26 to 6.74) and blood pH (MD 0.12, 95% CI 0.06 to 0.18). In non-shock patients there was a significance difference in blood lactate (MD -0.60 mmol/L, 95% CI -0.85 to -0.35) but not in serum bicarbonate (MD 1.10 mmol/L, 95% CI -0.27 to 2.47) or blood pH (MD -0.02, 95% CI -0.02 to -0.06). Other outcomes could not be analysed because of the limited data available. AUTHORS' CONCLUSIONS: There is no strong evidence that any clinical advantage for patients requiring acute PD for AKI when comparing conventional (lactate) with low GDP dialysis solutions (bicarbonate).

Mechanoenergetic function and troponin T release following cardioplegic arrest induced by St Thomas' and histidine-tryptophan-ketoglutarate cardioplegia--an experimental comparative study in pigs.

The study compares the single dose histidine-tryptophan-ketoglutarate (HTK) cardioplegia to the repeatedly delivered St Thomas' Hospital Solution (STHS) with respect to preservation of left ventricular mechanoenergetics and leakage of troponin T in a porcine experimental model. Fourteen pigs were randomized to a single infusion of 30 ml/kg HTK cardioplegia (n=7) or 500 ml STHS (n=7) followed by 200 ml after 20 and 40 min. After 1 h of aortic cross-clamping on cardiopulmonary bypass (CPB), the pigs were weaned and the hearts reperfused for 4 h. Stroke work (SW) was determined by a conductance catheter in the left ventricle. Myocardial oxygen consumption (MvO(2)) was measured as a function of coronary blood flow and arterial-to-coronary sinus oxygen saturation difference. Troponin T was sampled from the coronary sinus. The slope of the SW-MvO(2) relationship increased by 1.09 (+/-0.53) in the HTK group compared with 0.33 (+/-0.70) in the STHS group following ischemia and 4 h of reperfusion (P=0.04). Troponin T was significantly higher in the HTK group compared with the STHS group (P=0.04). Repeatedly delivered STHS gives better preservation of postischemic mechanoenergetic function and lower troponin T release compared with single dose HTK cardioplegia, indicating improved cardioprotection with STHS.

Effect of bicarbonate on fluoride reactivity with enamel / Efeito do bicarbonato na reatividade do fluoreto com esmalte

Purpose: Bicarbonate (HCO-3) is an alkaline and buffering substance found in dentifrices, which could improve the anti-caries effect of fluoride (F). However, HCO-3 could reduce the formation of calcium fluoride-like (CaF2), the most important product of F reactivity with enamel, whose formation is higher in low pH. The aim of this in vitro study was to evaluate if HCO-3 interferes with the reactivity of F with human enamel. Methods: Five dentifrice formulations were evaluated: placebo of F and HCO-3 (pH 7.0); HCO-3 (pH 9.0); F (pH 7.0); F (pH 9.0) and F+HCO-3 (pH 9.0). F dentifrices contained NaF and all dentifrices were silica-based. The concentrations of total F (TF), CaF2 and firmly bound F (FA, fluorapatite-like) formed in enamel after 1-min reaction with dentifrice slurries (1:3) were determined. Results: The formation of TF, CaF2 and FA was reduced in 22.1 %, 47.9 % and 4.8 %, respectively, by the presence of HCO-3 in the dentifrice formulation. Conclusion: This in vitro data suggest that addition of HCO-3 to a dentifrice may interfere with the reactivity of F with enamel, reducing mainly the concentration of CaF2 formed.

Objetivo: O bicarbonato (HCO-3 ) é uma substância alcalina e tamponante encontrada em dentifrícios, que poderia melhorar o efeito anticárie do fluoreto (F). No entanto, HCO-3 poderia reduzir a formação de fluoreto de cálcio (CaF2), o mais importante produto da reatividade do F com esmalte, cuja formação é maior em baixo pH. O objetivo deste estudo foi avaliar in vitro se o HCO-3 interfere na reatividade do F com o esmalte humano. Metodologia: Cinco formulações de dentifrícios foram avaliadas: placebo de F e HCO-3(pH 7,0); HCO-3 (pH 9,0); F (pH 7,0); F (pH 9,0) e F+HCO-3 (pH 9,0). Os dentifrícios fluoretados continham NaF e todos continham sílica como abrasivo. As concentrações de F total (FT), CaF2 e F firmemente ligado (FA, tipo flúorapatita) formadas no esmalte após 1 minuto de reação com as suspensões dos dentifrícios (1:3) foram determinadas. Resultados: A formação de FT, CaF2 e FA foram reduzidas em 22,1 %; 47,9 % e 4,8 %, respectivamente, pela presença de HCO-3 na formulação do dentifrício. Conclusão: Os resultados in vitro sugerem que a adição de HCO-3 a um dentifrício pode interferir com a reatividade do F com o esmalte, principalmente reduzindo a concentração de CaF2 formado no esmalte.

Bicarbonate dialysis, unlike acetate-free biofiltration, triggers mediators of inflammation and apoptosis in endothelial and smooth muscle cells.

BACKGROUND: We previously demonstrated that bicarbonate dialysis solutions incubated with endothelial cells (EC) enhance nitric oxide synthase (NOS). We then investigated whether blood circulated in simulated dialysis circuits triggers inflammatory and apoptotic mediators in vessel wall cells, aiming to compare the effects of bicarbonate hemodialysis (BHD) and acetate-free biofiltration (AFB). METHODS: Blood units from 22 healthy donors were dialyzed on AN69 with BHD in 11 sessions and AFB in another 11 sessions. Each dialysate remained endotoxin-free during the 60 min of dialysis. Blood samples having been re-circulated for 15 and 60 min were incubated with EC and smooth muscle cells (SMC), which were then investigated for NOS activity (3H citrulline production from 3H arginine), mRNAs transcription of the inducible isoforms of NOS (iNOS) and cyclooxygenase (COX-2) and the pro-apoptotic p53 protein. To investigate cell-cell interactions, in an-other series of 16 simulated dialyses, lympho-monocytes from blood circulated in either BHD or AFB were incubated with EC co-cultured in transwell devices with SMC. NOS activity was measured in EC and SMC. RESULTS: In comparison to AFB, blood circulated in BHD induced a significantly greater enhancement of NOS activity in EC, SMC and mRNAs transcription of pro-inflammatory iNOS, COX-2 and pro-apoptotic p53 (for each BHD data series p < 0.01 to p < 0.0001 vs. AFB). Lympho-monocytes from blood circulated in BHD but not in AFB, triggered the final SMC activation. CONCLUSIONS: Ex vivo AFB is less effective than BHD in activating vessel wall cells to synthesis/release of pro-inflammatory and pro-apoptotic mediators.

Accidental acute metabolic acidosis due to inappropriate selection of bicarbonate concentrate.

Haemodialysis using a bicarbonate concentrate (bicarbonate dialysis) is the treatment modality of choice for correction of metabolic acidosis in chronic renal failure. However, improper ratios of acid and bicarbonate concentrates in dialysis fluid can result in an iatrogenically induced metabolic acidosis. The following report presents a case of acute metabolic acidosis, which resulted from the accidental use of an inappropriate bicarbonate concentrate for haemodialysis treatment. Awareness of the problem and a rapid examination of the dialysis fluid in patients who unexpectedly deteriorate rather than improve with haemodialysis may help in averting potentially severe complications due to errors in the concentrate selection. Conductivity cell devises are not suitable for the control of the acid-base composition of the dialysis fluid (dialysate), therefore, monitoring of the dialysate pH in addition to conductivity should become part of the equipment in haemodialysis machines.

Etiology of pancreatic cancer, with a hypothesis concerning the role of N-nitroso compounds and excess gastric acidity.

In the United States, pancreatic cancer is the fourth most frequent cause of cancer death in males as well as females, after lung, prostate or breast, and colorectal cancer. Each year, approximately 30 000 Americans are diagnosed with pancreatic cancer and about the same number die of it. Germline mutations in a few genes including p16 and BRCA2 have been implicated in a small fraction of cases, as has chronic pancreatitis. The one established risk factor for pancreatic cancer is cigarette smoking: current smokers have two to three times the risk of nonsmokers. Studies of dietary factors have not been entirely consistent but do suggest associations of higher risk with consumption of smoked or processed meats or with animal foods in general and lower risk with consumption of fruits and vegetables. Colonization by Helicobacter pylori appears to increase risk, and a history of diabetes mellitus may also increase risk. The purpose of this epidemiologic review is to consider the possibility that risk of pancreatic cancer is increased by factors associated with pancreatic N-nitrosamine or N-nitrosamide exposures and with chronic excess gastric or duodenal acidity. Host genetic variation in inflammatory cytokine mechanisms may also be involved in this process. Many features of the evidence bearing on the pathophysiology of pancreatic cancer appear to support connections with N-nitroso compounds and with gastric acidity.