The application of a 4D-printed chitosan-based stem cell carrier for the repair of corneal alkali burns.

BACKGROUND: Corneal alkali burns can lead to ulceration, perforation, and even corneal blindness due to epithelial defects and extensive cell necrosis, resulting in poor healing outcomes. Previous studies have found that chitosan-based in situ hydrogel loaded with limbal epithelium stem cells (LESCs) has a certain reparative effect on corneal alkali burns. However, the inconsistent pore sizes of the carriers and low cell loading rates have resulted in suboptimal repair outcomes. In this study, 4D bioprinting technology was used to prepare a chitosan-based thermosensitive gel carrier (4D-CTH) with uniform pore size and adjustable shape to improve the transfer capacity of LESCs. METHODS: Prepare solutions of chitosan acetate, carboxymethyl chitosan, and ß-glycerophosphate sodium at specific concentrations, and mix them in certain proportions to create a pore-size uniform scaffold using 4D bioprinting technology. Extract and culture rat LESCs (rLESCs) in vitro, perform immunofluorescence experiments to observe the positivity rate of deltaNp63 cells for cell identification. Conduct a series of experiments to validate the cell compatibility of 4D-CTH, including CCK-8 assay to assess cell toxicity, scratch assay to evaluate the effect of 4D-CTH on rLESCs migration, and Calcein-AM/PI cell staining experiment to examine the impact of 4D-CTH on rLESCs proliferation and morphology. Establish a severe alkali burn model in rat corneas, transplant rLESCs onto the injured cornea using 4D-CTH, periodically observe corneal opacity and neovascularization using a slit lamp, and evaluate epithelial healing by fluorescein sodium staining. Assess the therapeutic effect 4D-CTH-loaded rLESCs on corneal alkali burn through histological evaluation of corneal tissue paraffin sections stained with hematoxylin and eosin, as well as immunofluorescence staining of frozen sections. RESULTS: Using the 4D-CTH, rLESCs were transferred to the alkali burn wounds of rats. Compared with the traditional treatment group (chitosan in situ hydrogel encapsulating rLESCs), the 4D-CTH-rLESC group had significantly higher repair efficiency of corneal injury, such as lower corneal opacity score (1.2 ± 0.4472 vs 0.4 ± 0.5477, p < 0.05) and neovascularization score (5.5 ± 1.118 vs 2.6 ± 0.9618, p < 0.01), and significantly higher corneal epithelial wound healing rate (72.09 ± 3.568% vs 86.60 ± 5.004%, p < 0.01). CONCLUSION: In summary, the corneas of the 4D-CTH-rLESC treatment group were similar to the normal corneas and had a complete corneal structure. These findings suggested that LESCs encapsulated by 4D-CTH significantly accelerated corneal wound healing after alkali burn and can be considered as a rapid and effective method for treating epithelial defects.

Oral Sodium Bicarbonate and Bone Turnover in CKD: A Secondary Analysis of the BASE Pilot Trial.

SIGNIFICANCE STATEMENT: In CKD, metabolic acidosis is commonly treated with alkali in the hope that it will improve bone health. In a post hoc analysis of the Bicarbonate Administration to Stabilize eGFR Pilot Trial, we investigated whether sodium bicarbonate affects serum levels of bone turnover markers and other hormones related to bone health in individuals with CKD who have normal to slightly reduced total CO2 (20-28 mEq/L). Sodium bicarbonate increased serum levels of α-klotho but had no significant effect on other bone health markers, including intact fibroblast growth factor-23 (iFGF-23), intact parathyroid hormone (iPTH), and bone-specific alkaline phosphatase (B-SAP). Further study is needed to determine the effect of bicarbonate administration on clinical aspects of bone health. BACKGROUND: Treatment with alkali has been hypothesized to improve bone health in CKD by mitigating adverse effects of acid on bone mineral. We investigated the effect of treatment with sodium bicarbonate on bone turnover markers and other factors related to bone metabolism in CKD. METHODS: This is a post hoc analysis of the Bicarbonate Administration to Stabilize eGFR Pilot Trial in which 194 individuals with CKD and serum total CO2 20-28 mEq/L were randomly assigned to placebo or one of two doses of sodium bicarbonate (0.5 or 0.8 mEq/kg lean body weight per day) for 28 weeks. The following serum measurements were performed at baseline, week 12, and week 28: B-SAP, c-telopeptide, procollagen type I intact N-terminal propeptide, iPTH, iFGF-23, soluble klotho, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and tartrate-resistant acid phosphatase 5b. The difference (sodium bicarbonate versus placebo) in mean change of each bone biomarker from baseline was determined using linear mixed models. RESULTS: One hundred sixty-eight participants submitted samples for post hoc investigations. Mean eGFR was 37±10 ml/min per 1.73 m2 and mean total CO2 was 24±3 mEq/L at baseline. Sodium bicarbonate induced a dose-dependent increase in soluble klotho levels compared with placebo. There was no significant effect of treatment with either dose of sodium bicarbonate on any of the other bone biomarkers, including iFGF-23, iPTH, and B-SAP. Effects on bone biomarkers were similar in those with baseline serum total CO2 <24 mEq/L compared with those with total CO2 ≥24 mEq/L. CONCLUSIONS: In this pilot trial of individuals with CKD and total CO2 20-28 mEq/L, sodium bicarbonate treatment increased serum klotho levels but did not affect other bone health markers over 28 weeks. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: ClinicalTrials.gov, NCT02521181.

Comparison of Class-Specific Side Effects Across Preventative Pharmacologic Therapies for Kidney Stone Disease.

INTRODUCTION: Clinical guidelines recommend monitoring for metabolic derangements while on preventive pharmacologic therapy for kidney stone disease. The study objective was to compare the frequency of side effects among patients receiving alkali citrate, thiazides, and allopurinol. METHODS: Using claims data from working-age adults with kidney stone disease (2008-2019), we identified those with a new prescription for alkali citrate, thiazide, or allopurinol within 12 months after their index stone-related diagnosis or procedure. We fit multivariable logistic regression models, adjusting for cohort characteristics like comorbid illness and medication adherence, to estimate 2-year measured frequencies of claims-based outcomes of acute kidney injury, falls/hip fracture, gastritis, abnormal liver function tests/hepatitis, hypercalcemia, hyperglycemia/diabetes, hyperkalemia, hypokalemia, hyponatremia, and hypotension. RESULTS: Our cohort consisted of 1776 (34%), 2767 (53%), and 677 (13%) patients prescribed alkali citrate, thiazides, or allopurinol, respectively. Comparing unadjusted rates of incident diagnoses, thiazides compared to alkali citrate and allopurinol were associated with the highest rates of hypercalcemia (2.3% vs 1.5% and 1.0%, respectively, P = .04), hypokalemia (6% vs 3% and 2%, respectively, P < .01), and hyperglycemia/diabetes (17% vs 11% and 16%, respectively, P < .01). No other differences with the other outcomes were significant. In adjusted analyses, compared to alkali citrate, thiazides were associated with a higher odds of hypokalemia (OR=2.01, 95% CI 1.44-2.81) and hyperglycemia/diabetes (OR=1.52, 95% CI 1.26-1.83), while allopurinol was associated with a higher odds of hyperglycemia/diabetes (OR=1.34, 95% CI 1.02-1.75). CONCLUSIONS: These data provide evidence to support clinical guidelines that recommend periodic serum testing to assess for adverse effects from preventive pharmacologic therapy.

Subconjunctival Administration of Mesenchymal Stem Cells Alleviates Ocular Inflammation in a Murine Model of Corneal Alkali Burn.

Corneal alkali burns cause extensive damage not only to the cornea but also to the intraocular tissues. As an anti-inflammatory therapy, subconjunctival administration of mesenchymal stem cells (MSCs) for corneal protection after corneal alkali burn has been explored. Little evidence demonstrates the potential of subconjunctival MSCs delivery in protecting the post-burn intraocular tissues. This study aimed to evaluate the therapeutic efficacy of subconjunctival injection of human placental (hP)-MSCs in protecting against ocular destruction after the burn. hP-MSCs were subconjunctivally administered to C57/BL mice after corneal alkali burn. Western blot of iNOS and CD206 was performed to determine the M1 and M2 macrophage infiltration in the cornea. Infiltration of inflammatory cells in the anterior uvea and retina was analyzed by flow cytometry. The TUNEL assay or Western blot of Bax and Bcl2 was used to evaluate the anti-apoptotic effects of MSCs. MSCs could effectively facilitate cornea repair by suppressing inflammatory cytokines IL-1ß, MCP-1, and MMP9, and polarizing CD206 positive M2 macrophages. Anterior uveal and retinal inflammatory cytokines expression and inflammatory cell infiltration were inhibited in the MSC-treated group. Reduced TUNEL positive staining and Bax/Bcl2 ratio indicated the anti-apoptosis of MSCs. MSC-conditioned medium promoted human corneal epithelial cell proliferation and regulated LPS-stimulated inflammation in RAW 264.7 macrophages, confirming the trophic and immunoregulatory effects of MSCs. Our findings demonstrate that subconjunctival administration of MSCs exerted anti-inflammatory and anti-apoptotic effects in the cornea, anterior uvea, and retina after corneal alkali burn. This strategy may provide a new direction for preventing post-event complications after corneal alkali burn.

The mechanisms of alkali therapy in targeting renal diseases.

Chronic kidney disease (CKD) is characterized by progressive reduction in kidney function and treatments aiming at stabilizing or slowing its progression may avoid or delay the necessity of kidney replacement therapy and the increased mortality associated with reduced kidney function. Metabolic acidosis, and less severe stages of the acid stress continuum, are common consequences of CKD and some interventional studies support that its correction slows the progression to end-stage kidney disease. This correction can be achieved with mineral alkali in the form of bicarbonate or citrate salts, ingestion of diets with fewer acid-producing food components or more base-producing food components, or a pharmacological approach. In this mini-review article, we summarize the potential mechanisms involved in the beneficial effects of alkali therapy. We also discuss the perspectives in the field and challenges that must be overcome to advance our understanding of such mechanisms.

A Liraglutide Injection Superimposing a Starvation Acidosis: a Case Report.

Background: Metabolic acidosis is defined by reduced serum bicarbonate level; this reduction can be from the addition of acid, reduced acid excretion, or loss of alkali. Starvation acidosis is one of the differential diagnoses of high anion gap metabolic acidosis (HAGMA). Objective: We report a rare case presentation of HAGMA associated with Liraglutide and low carbohydrates diet. Case presentation: A 27-year-old female patient presented to the Emergency Department (ED) with a complaint of nausea and vomiting for two days. She was following a strict low carbohydrate diet for three months to reduce her weight as her body mass index (BMI) was 30 kg/m3. Her bedside investigations were significant for HAGMA. The patient was seen by the endocrine service and was admitted as a case of starvation ketoacidosis (SKA) vs. euglycemic diabetic ketoacidosis (DKA). The patient was treated with D10W 250 cc/hr with insulin infusion, her the anion gap was closed after 5 hours. She was discharged home as SKA secondary to diet with the possibility of drug superimposing the starvation state. She was given a follow-up clinic regularly to monitor her clinical status. Conclusion: This case highlights the possibility of a HAGMA as a rare complication of a low carbohydrate diet with the possibility of Liraglutide injection attribution in developing such critical complication. Further studies are needed to evaluate the safety of a low carbohydrate diet and the effect of Liraglutide injection on these patients following this diet.

New mechanisms for the kidney-protective effect of alkali in chronic kidney disease.

Worldwide, more than one in ten adults are estimated to have chronic kidney disease (CKD). As CKD progresses, both the cost of treatment and associated risk of morbidity and mortality increase exponentially. As such, there is a great need for therapies that effectively slow CKD progression. Evidence from several small clinical trials indicates that alkali therapy may slow the rate of CKD progression. The biological mechanisms underlying this protective effect, however, remain unknown. In their recently published manuscript, Pastor Arroyo et al. (Clin Sci (Lond) (2022) 136(8): https://doi.org/10.1042/CS20220095) demonstrate that the alkali sodium bicarbonate protects against loss of renal function in a crystal nephropathy model in mice. Using unbiased approaches in both mice and human tissue, the authors go on to identify two novel mechanisms that may underly this protection. The first pathway is through promoting pathways of cell metabolism, which they speculate helps the remaining functional nephrons adapt to the greater metabolic needs required to maintain kidney filtration. The second pathway is by restoration of α-Klotho levels, which may limit the expression of adhesion molecules in the injured kidney. This, the authors speculate, may prevent inflammation from driving the functional decline of the kidney. Identifying these novel pathways represents an important step forward harnessing the potential benefits of alkali therapy in CKD.

Comparison of Empiric Preventative Pharmacologic Therapies on Stone Recurrence Among Patients with Kidney Stone Disease.

OBJECTIVE: To compare the frequency of stone-related events among patients receiving thiazides, alkali citrate, and allopurinol without prior 24 h urine testing.  It is unknown whether 1 preventative pharmacological therapy (PPT) medication class is more beneficial for reducing kidney stone recurrence when prescribed empirically. MATERIALS AND METHODS: Using medical claims data from working-age adults with kidney stone disease diagnoses (2008-2018), we identified those prescribed thiazides, alkali citrate, or allopurinol. We excluded those who received 24 h urine testing prior to initiating PPT and those with less than 3 years of follow-up. We fit multivariable regression models to estimate the association between the occurrence of a stone-related event (emergency department visit, hospitalization, or surgery for stones) and PPT medication class. RESULTS: Our cohort consisted of 1834 (60%), 654 (21%), and 558 (18%) patients empirically prescribed thiazides, alkali citrate, or allopurinol, respectively. After controlling for patient factors including medication adherence and concomitant conditions that increase recurrence risk, the adjusted rate of any stone event was lowest for the thiazide group (14.8%) compared to alkali citrate (20.4%) or allopurinol (20.4%) (each P < .001). Thiazides, compared to allopurinol, were associated with 32% lower odds of a subsequent stone event by 3 years (OR 0.68, 95% CI 0.53-0.88). No such association was observed when comparing alkali citrate to allopurinol (OR 1.00, 95% CI 0.75-1.34). CONCLUSION: Empiric PPT with thiazides is associated with significantly lower odds of subsequent stone-related events. When 24 h urine testing is unavailable, thiazides may be preferred over alkali citrate or allopurinol for empiric PPT.

Pycnogenol a promising remedy for diabetic keratopathy in experimentally induced corneal alkali burns in diabetic rats.

AIM: This study aimed to investigate the efficiency of topically applied pycnogenol (PYC) in healing the standardized alkaline corneal ulcer in diabetic and normal rats. MATERIALS AND METHODS: The corneal alkali-burn injury (CA-I) model was unilaterally developed in Wistar rats by filter paper saturated with 0.01 M of NaOH and touching the eyes for 45 s. Rats were divided into four groups: Normal control (NC), normal PYC (NPYC), diabetic control (DC), and diabetic PYC (DPYC). Both NPYC and DPYC groups were daily treated with PY eye drops three times, whereas NC and DC ones were treated with ordinary saline for six successive days. RESULTS: The wound healing of corneal epithelial was improved in the NPYC group compared to the NC group. Meanwhile, it was significantly improved (P < 0.05) in the DPYC group than in the DC group. Histological examination revealed that corneal re-epithelialization was more accomplished in the DPYC group than in the DC group. In addition, the inflammatory cells were augmented in the DC group more than those in the DPYC one. CONCLUSION: The findings obtained revealed the efficiency of PYC for enhancing the corneal re-epithelialization and reducing the inflammatory reaction post alkali burn in rats, and thus it could be beneficially valuable as a treatment for the diabetic keratopathy.

Alkali therapy protects renal function, suppresses inflammation, and improves cellular metabolism in kidney disease.

Chronic kidney disease (CKD) affects approximately 10-13% of the population worldwide and halting its progression is a major clinical challenge. Metabolic acidosis is both a consequence and a possible driver of CKD progression. Alkali therapy counteracts these effects in CKD patients, but underlying mechanisms remain incompletely understood. Here we show that bicarbonate supplementation protected renal function in a murine CKD model induced by an oxalate-rich diet. Alkali therapy had no effect on the aldosterone-endothelin axis but promoted levels of the anti-aging protein klotho; moreover, it suppressed adhesion molecules required for immune cell invasion along with reducing T-helper cell and inflammatory monocyte invasion. Comparing transcriptomes from the murine crystallopathy model and from human biopsies of kidney transplant recipients (KTRs) suffering from acidosis with or without alkali therapy unveils parallel transcriptome responses mainly associated with lipid metabolism and oxidoreductase activity. Our data reveal novel pathways associated with acidosis in kidney disease and sensitive to alkali therapy and identifies potential targets through which alkali therapy may act on CKD and that may be amenable for more targeted therapies.

Cordycepin prevents the esophageal stricture formation in the alkali-burn rat model by exerting anti-inflammatory and antifibrotic effects.

PURPOSE: To investigate the efficacy of cordycepin, an adenosine analogue, on prevention of esophageal damage and stricture formation due to esophageal caustic burns in rat model comparing with prednisolone. METHODS: Caustic esophageal burn was introduced by 37.5% of NaOH to distal esophagus. Thirty-two Wistar albino rats were divided in four groups: sham rats undergone laparotomy, treated with 0.9% NaCl; control rats injured with NaOH without cordycepin treatment; cordycepin group injured with NaOH, treated with 20 mg/kg cordycepin; prednisolone group injured with NaOH, treated with 1 mg/kg prednisolone for 28 days. Efficacy was assessed by histopathological and immunohistochemical analysis of esophageal tissues. RESULTS: Cordycepin treatment significantly decreased inflammation, granulation tissue and fibrous tissue formation and prevented formation of esophageal strictures shown by histopathological damage score and stenosis indexes compared to control group (p < 0.01). These effects are relatively more substantial than prednisolone, probably based on attenuation of elevation of proinflammatory cytokines hypoxia-inducible factor 1-alpha (HIF-1?), tumor necrosis factor alpha (TNF-?), proliferative and fibrotic factor fibroblast growth factor 2 (FGF2) and angiogenic factor vascular endothelial growth factor A (VEGFA) (p < 0.05). CONCLUSIONS: The findings suggest that cordycepin has a complex multifactorial healing process in alkali-burned tissue, more successful than prednisolone in preventing the formation of esophageal strictures and may be used as a therapeutic agent in the acute phase of esophageal alkali-burn.

Malignancy-induced lactic acidosis in adult lymphoma.

Malignancy-induced lactic acidosis (MILA), a rare paraneoplastic phenomenon, is mostly described with hematologic malignancies (lymphomas and leukemias) but has also been reported with solid tumors. It is a subset of type B lactic acidosis being mediated without evidence of tissue hypoperfusion. Lymphoma-induced lactic acidosis is often considered an oncologic emergency and is associated with an increased risk of mortality and poor prognosis. It has a complex pathophysiology centered in the "Warburg effect," i.e., the programming of cancer cells to depend on aerobic glycolysis for promotion of their proliferation and anabolic growth. The treatment of lymphoma-induced lactic acidosis is focused on prompt administration of chemotherapy. The role of alkali therapy in this setting is controversial and has limited proven benefit with a potential for worsening the lactic acidosis. If alkali therapy is used in the presence of severe acidemia to optimize cardiovascular status, it should be administered judiciously.

Cordycepin prevents the esophageal stricture formation in the alkali-burn rat model by exerting anti-inflammatory and antifibrotic effects

ABSTRACT Purpose To investigate the efficacy of cordycepin, an adenosine analogue, on prevention of esophageal damage and stricture formation due to esophageal caustic burns in rat model comparing with prednisolone. Methods Caustic esophageal burn was introduced by 37.5% of NaOH to distal esophagus. Thirty-two Wistar albino rats were divided in four groups: sham rats undergone laparotomy, treated with 0.9% NaCl; control rats injured with NaOH without cordycepin treatment; cordycepin group injured with NaOH, treated with 20 mg/kg cordycepin; prednisolone group injured with NaOH, treated with 1 mg/kg prednisolone for 28 days. Efficacy was assessed by histopathological and immunohistochemical analysis of esophageal tissues. Results Cordycepin treatment significantly decreased inflammation, granulation tissue and fibrous tissue formation and prevented formation of esophageal strictures shown by histopathological damage score and stenosis indexes compared to control group (p < 0.01). These effects are relatively more substantial than prednisolone, probably based on attenuation of elevation of proinflammatory cytokines hypoxia-inducible factor 1-alpha (HIF-1?), tumor necrosis factor alpha (TNF-?), proliferative and fibrotic factor fibroblast growth factor 2 (FGF2) and angiogenic factor vascular endothelial growth factor A (VEGFA) (p < 0.05). Conclusions The findings suggest that cordycepin has a complex multifactorial healing process in alkali-burned tissue, more successful than prednisolone in preventing the formation of esophageal strictures and may be used as a therapeutic agent in the acute phase of esophageal alkali-burn.

Alkali supplementation as a therapeutic in chronic kidney disease: what mediates protection?

Sodium bicarbonate (NaHCO3) has been recognized as a possible therapy to target chronic kidney disease (CKD) progression. Several small clinical trials have demonstrated that supplementation with NaHCO3 or other alkalizing agents slows renal functional decline in patients with CKD. While the benefits of NaHCO3 treatment have been thought to result from restoring pH homeostasis, a number of studies have now indicated that NaHCO3 or other alkalis may provide benefit regardless of the presence of metabolic acidosis. These data have raised questions as to how NaHCO3 protects the kidneys. To date, the physiological mechanism(s) that mediates the reported protective effect of NaHCO3 in CKD remain unclear. In this review, we first examine the evidence from clinical trials in support of a beneficial effect of NaHCO3 and other alkali in slowing kidney disease progression and their relationship to acid-base status. Then, we discuss the physiological pathways that have been proposed to underlie these renoprotective effects and highlight strengths and weaknesses in the data supporting each pathway. Finally, we discuss how answering key questions regarding the physiological mechanism(s) mediating the beneficial actions of NaHCO3 therapy in CKD is likely to be important in the design of future clinical trials. We conclude that basic research in animal models is likely to be critical in identifying the physiological mechanisms underlying the benefits of NaHCO3 treatment in CKD. Gaining an understanding of these pathways may lead to the improved implementation of NaHCO3 as a therapy in CKD and perhaps other disease states.

Alkali Therapy for Respiratory Acidosis: A Medical Controversy.

Alkali therapy for certain organic acidoses remains a topic of ongoing controversy, but little attention has been given to a related medical controversy, namely the prescription of alkali for respiratory acidosis. We first describe the determinants of carbon dioxide retention in the 2 types of respiratory failure; hypercapnic respiratory failure and hypoxemic respiratory failure with coexisting hypercapnia. We then highlight the deleterious consequences of severe acidemia for several organ systems, particularly the cardiovascular and central nervous systems. We argue that alkali therapy is not indicated for respiratory acidosis as a simple acid-base disturbance. Notwithstanding, we recommend prescription of alkali for severe acidemia caused by mixed acidosis (ie, combined respiratory and metabolic acidosis) or permissive hypercapnia. We examine the utility of alkali therapy in various clinical scenarios incorporating respiratory acidosis. We conclude that controlled studies will be required to test the impact of alkali therapy on clinical outcomes of these clinical settings. Such studies should also examine the optimal mode of administering alkali (amount, rate, and tonicity) and the blood pH to be targeted. The development of new buffers should be explored, especially systems that do not generate carbon dioxide or even consume it.

Alkali delivery in chronic hemodialysis: Would more acetate be helpful?

The dialysate alkali used in hemodialysis to replace low body alkali levels in end stage renal disease (ESRD) patients has changed over time from bicarbonate to acetate and finally back to bicarbonate with a small addition of acetate. The ideal way to replace alkali in dialysis patients remains uncertain. Elsewhere in this issue of the journal, Sargent and Gennari, who have contributed greatly to our understanding of dialysis and acid-base kinetics, suggest that decreasing the currently used concentration of bicarbonate while increasing concentration of acetate in the dialysate may be a much more physiological approach to alkali delivery during hemodialysis. These recommendations are based on results from a series of hemodialysis simulations using mathematical theoretical methods, with the assumption that acetate metabolism will be sufficiently delayed with the higher acetate dialysate and reduce the rate of correction of metabolic acidosis during dialysis. Although valuable in calling attention to the issues surrounding alkali repletion during hemodialysis, these postulations should be tested in clinical trials. We believe, however, that the available evidence suggests that the rate of gain of bicarbonate during dialysis with the higher acetate dialysate would not be slower and that the replacement of some dialysate bicarbonate with acetate will not alter alkali accretion or intradialytic pH.

A novel treatment of hyperinsulinemic hypoglycemia induced by insulin antibodies with alkali administration: a case report.

BACKGROUND: Insulin autoimmune syndrome is a rare cause of hyperinsulinemic hypoglycemia characterized by autoantibodies to human insulin without previous insulin use. We report a case of a patient with hyperinsulinemic hypoglycemia possibly caused by insulin antibodies induced by insulin analogs and a novel therapeutic measure for this condition. CASE PRESENTATION: An 84-year-old Japanese man with a 28-year history of type 2 diabetes and chronic kidney disease, treated with biphasic insulin aspart 30, experienced persistent early morning hypoglycemia with daytime hyperglycemia. Despite discontinuation of biphasic insulin aspart 30, the condition persisted even after the patient ate small, frequent meals. Sodium bicarbonate was administered to correct the chronic metabolic acidosis, which then rectified the early morning glucose level. CONCLUSIONS: We believe this to be the first published case of a therapeutic approach to the treatment of hyperinsulinemic hypoglycemia associated with insulin antibodies that factors in blood pH and the correction of acidosis using sodium bicarbonate, which physicians could consider.

Preservation of kidney function in kidney transplant recipients by alkali therapy (Preserve-Transplant Study): rationale and study protocol.

BACKGROUND: Graft survival after kidney transplantation has significantly improved within the last decades but there is a substantial number of patients with declining transplant function and graft loss. Over the past years several studies have shown that metabolic acidosis plays an important role in the progression of Chronic Kidney Disease (CKD) and that alkalinizing therapies significantly delayed progression of CKD. Importantly, metabolic acidosis is highly prevalent in renal transplant patients and a recent retrospective study has shown that metabolic acidosis is associated with increased risk of graft loss and patient death in kidney transplant recipients. However, no prospective trial has been initiated yet to test the role of alkali treatment on renal allograft function. METHODS: The Preserve-Transplant Study is an investigator-initiated, prospective, patient-blinded, multi-center, randomized, controlled phase-IV trial with two parallel-groups comparing sodium bicarbonate to placebo. The primary objective is to test if alkali treatment will preserve kidney graft function and diminish the progression of CKD in renal transplant patients by assesing the change in eGFR over 2 years from baseline. Additionally we want to investigate the underlying pathomechanisms of nephrotoxicity of metabolic acidosis. DISCUSSION: This study has the potential to provide evidence that alkali treatment may slow or reduce the progression towards graft failure and significantly decrease the rate of end stage renal disease (ESRD), thus prolonging long-term graft survival. The implementation of alkali therapy into the drug regimen of kidney transplant recipients would have a favorable risk-benefit ratio since alkali supplements are routinely used in CKD patients and represent a well-tolerated, safe and cost-effective treatment. TRIAL REGISTRATION: ClinicalTrials.gov NCT03102996 . Trial registration was completed on April 6, 2017.

Acid Balance, Dietary Acid Load, and Bone Effects-A Controversial Subject.

Modern Western diets, with higher contents of animal compared to fruits and vegetable products, have a greater content of acid precursors vs. base precursors, which results in a net acid load to the body. To prevent inexorable accumulation of acid in the body and progressively increasing degrees of metabolic acidosis, the body has multiple systems to buffer and titrate acid, including bone which contains large quantities of alkaline salts of calcium. Both in vitro and in vivo studies in animals and humans suggest that bone base helps neutralize part of the dietary net acid load. This raises the question of whether decades of eating a high acid diet might contribute to the loss of bone mass in osteoporosis. If this idea is true, then additional alkali ingestion in the form of net base-producing foods or alkalinizing salts could potentially prevent this acid-related loss of bone. Presently, data exists that support both the proponents as well as the opponents of this hypothesis. Recent literature reviews have tended to support either one side or the other. Assuming that the data cited by both sides is correct, we suggest a way to reconcile the discordant findings. This overview will first discuss dietary acids and bases and the idea of changes in acid balance with increasing age, then review the evidence for and against the usefulness of alkali therapy as a treatment for osteoporosis, and finally suggest a way of reconciling these two opposing points of view.