Bailing Capsule combined with α-ketoacid tablets for stage 3 chronic kidney disease: Protocol of a double-blinded, randomized, controlled trial.

BACKGROUND: Chronic kidney disease (CKD) is a progressive and irreversible loss of kidney function. After stage 3, there will be increased risks of hypertension, heart failure, bone disease, anemia, gastrointestinal symptoms, and progression to end-stage kidney failure without proper intervention and treatment. Compound α-ketoacid tablets (KA) administration plays an important role in clinical CKD adjunctive therapy for patients with restricted protein intake. Bailing Capsule (BC), a commonly used Chinese patent medicine for renal diseases, could regulate human immune function, repair renal tubular epithelial cells, prevent renal tubular atrophy, and reduce kidney damage to improve renal function. In this study, we try to conduct a double-blinded, randomized, controlled trial to observe the efficacy and safety of BC combined with KA in treating patients with stage 3 CKD. METHODS: This is a double-blinded, randomized, controlled trial. Patients will be randomly divided into treatment group (BC and KT) and control group (BC-simulation and KT) in a 1:1 ratio according to random number table. The treatment course will be 8 weeks, and the changes of subjective symptoms, patient global assessment (PGA) scale, serum creatinine, cystatin C, and estimated glomerular filtration rate, all related adverse events, vital sign measurements, and physical examinations will be recorded. SPSS 21.0 will be used for data analysis. CONCLUSIONS: The results will show whether BC combined with KA could alleviate the symptoms of fatigue, anorexia, halitosis, nausea, itching, and edema, improve kidney function in patients with CKD at stage 3. TRIAL REGISTRATION: OSF Registration number: DOI 10.17605/OSF.IO/24AJ7.

Anti-inflammatory and antioxidant activity of essential amino acid α-ketoacid analogues against renal ischemia-reperfusion damage in Wistar rats. / Actividad antiinflamatoria y antioxidante de los α-cetoanálogos de aminoácidos esenciales en un modelo de daño por isquemia-reperfusión en ratas Wistar

INTRODUCTION: Essential amino acid α-keto acid analogs are used in the treatment of chronic kidney disease to delay the symptoms of uremia. However, it is unknown whether essential amino acid α-keto acid analogs affect the oxidative stress and the inflammation in acute renal injury such as those produced by ischemia-reperfusion. OBJECTIVE: To evaluate the effect of essential amino acid α-keto acid analogs on renal ischemia-reperfusion injury in Wistar rats. MATERIALS AND METHODS: Rats were divided into 11 groups (n=6/group): Two groups received physiological saline with or without ischemia-reperfusion injury (45 min/24 h), six groups received essential amino acid α-keto acid analogs (400, 800, or 1,200 mg/kg/24 h/7d) with or without ischemia-reperfusion injury (essential amino acid α-keto acid analogs + ischemia-reperfusion), and two groups received allopurinol (50 mg/kg/24 h/7d) with or without ischemia-reperfusion injury. Biochemical markers included creatinine and blood urea nitrogen (BUN), proinflammatory cytokines (IL-1ß, IL-6, and TNF-α), renal damage markers (cystatin C, KIM-1, and NGAL), and markers of oxidative stress such as malondialdehyde (MDA) and total antioxidant activity. RESULTS: The essential amino acid α-keto acid analog- and allopurinol-treated groups had lower levels of creatinine, BUN, renal damage markers, proinflammatory cytokines, and MDA than their corresponding ischemia-reperfusion groups. These changes were related to the essential amino acid α-keto acid analogs dosage. Total antioxidant activity was lower in essential amino acid α-keto acid analog- and allopurinol-treated groups than in the corresponding ischemia-reperfusion groups. CONCLUSIONS: This is a new report on the nephroprotective effects of essential amino acid α-keto acid analogs against ischemia-reperfusion injury. Essential amino acid α-keto acid analogs decreased the levels of biochemical markers, kidney injury markers, proinflammatory cytokines, and MDA while minimizing total antioxidant consumption.

Introducción. Los α-cetoanálogos de aminoácidos esenciales se utilizan en el tratamiento de la enfermedad renal crónica para retrasar los síntomas de la uremia. Sin embargo, se desconoce si los α-cetoanálogos de aminoácidos esenciales afectan el estrés oxidativo y la inflamación en la lesión renal aguda tal como en la producida por la isquemia-reperfusión. Objetivo. Evaluar el efecto de las α-cetoanálogos de aminoácidos esenciales sobre la lesión renal por isquemia-reperfusión en ratas Wistar. Materiales y métodos. Se emplearon 11 grupos de ratas (n=6): dos grupos recibieron solución salina fisiológica con lesión isquemia-reperfusión o sin ella (45 min/24 h), seis grupos recibieron α-cetoanálogos de aminoácidos esenciales (400, 800 o 1.200 mg/kg/24 h/7d) con lesión isquemia-reperfusión o sin ella (α-cetoanálogos de aminoácidos esenciales + isquemia-reperfusión), y dos grupos recibieron (50 mg/kg/24 h/7d) con lesión isquemia-reperfusión o sin ella. Los marcadores bioquímicos incluyeron creatinina y nitrógeno ureico en sangre (BUN), citocinas proinflamatorias (IL-1ß, IL-6 y TNF-α), marcadores de daño renal (cistatina C, KIM-1 y NGAL) y marcadores del estrés oxidativo como el malondialdehído (MDA) y la actividad antioxidante total. Resultados. Los grupos tratados con α-cetoanálogos de aminoácidos esenciales y alopurinol tuvieron niveles inferiores de creatinina, BUN, marcadores de daño renal, citocinas proinflamatorias, actividad antioxidante total y MDA que los grupos isquemia-reperfusión correspondientes. Estos cambios se asociaron con la dosis. La actividad antioxidante total fue menor en los grupos tratados con α-cetoanálogos de aminoácidos esenciales que en los grupos isquemia-reperfusión correspondientes. Conclusiones. Este es un nuevo informe de los efectos nefroprotectores de las α-cetoanálogos de aminoácidos esenciales contra la lesión isquemia-reperfusión. Los α-cetoanálogos de aminoácidos esenciales disminuyeron los niveles de los marcadores bioquímicos, de los de lesión renal, de las citocinas proinflamatorias y el MDA, a la vez que minimizaron el consumo total de antioxidantes.

Cationized liposomal keto-mycolic acids isolated from Mycobacterium bovis bacillus Calmette-Guérin induce antitumor immunity in a syngeneic murine bladder cancer model.

Intravesical therapy using Mycobacterium bovis bacillus Calmette-Guérin (BCG) is the most established cancer immunotherapy for bladder cancer. However, its underlying mechanisms are unknown. Mycolic acid (MA), the most abundant lipid of the BCG cell wall, is suspected to be one of the essential active components of this immunogenicity. Here, we developed cationic liposomes incorporating three subclasses (α, keto, and methoxy) of MA purified separately from BCG, using the dendron-bearing lipid D22. The cationic liposomes using D22 were efficiently taken up by the murine bladder cancer cell line MB49 in vitro, but the non-cationic liposomes were not. Lip-kMA, a cationic liposome containing keto-MA, presented strong antitumor activity in two murine syngeneic graft models using the murine bladder cancer cell lines MB49 and MBT-2 in comparison to both Lip-aMA and Lip-mMA, which contained α-MA and methoxy-MA, respectively. Interestingly, Lip-kMA(D12), which was made of D12 instead of D22, did not exhibit antitumor activity in the murine syngeneic graft model using MB49 cells, although it was successfully taken up by MB49 cells in vitro. Histologically, compared to the number of infiltrating CD4 lymphocytes, the number of CD8 lymphocytes was higher in the tumors treated with Lip-kMA. Antitumor effects of Lip-kMA were not observed in nude mice, whereas weak but significant effects were observed in beige mice with natural killer activity deficiency. Thus, a cationized liposome containing keto-MA derived from BCG induced in vivo antitumor immunity. These findings will provide new insights into lipid immunogenicity and the underlying mechanisms of BCG immunotherapy.

Safety and effectiveness of low-protein diet supplemented with ketoacids in diabetic patients with chronic kidney disease.

BACKGROUND: The impact of the low-protein diet on nutrition in CKD diabetics is uncertain. METHODS: The metabolic and nutritional effects of a low-protein (0.5-0.6 g/kg/d), normal-high energy (30-35 kcal/kg/d) diet supplemented with ketoacids (LPD-KA) were prospectively evaluated in CKD patients with (DM) and without (non-DM) diabetes mellitus. RESULTS: 197 patients on CKD stages 3-5 were enrolled. DM (n = 81) and non-DM (n = 116) were comparable for gender (Male 58 vs 55%), age (66 ± 9 vs 63 ± 18 years), renal function (eGFR 23 ± 13 vs 24 ± 13 mL/min). After 6-month, serum urea (DM: 131 ± 58 to 105 ± 49 mg/dl, p < 0.05; non-DM: 115 ± 52 to 88 ± 36, p < 0.05) and phosphate (DM: 4.5 ± 1.3 to 4.1 ± 1.2 mg/dl, p = 0.06; non-DM: 4.3 ± 1.0 to 3.7 ± 0.8, p < 0.05) declined. Fasting glucose decreased in DM (126 ± 52 to 103 ± 29 mg/dl, p < 0.05) without insulin dose increase. These effects were preserved after 3-year. Serum albumin did not change after 6 months (DM: 3.7 ± 0.6 to 3.8 ± 0.4 mg/dl; non-DM: 4.0 ± 0.6 to 4.0 ± 0.4) and in the long-term. Body weight (BW) declined after the diet start (DM: 68.9 ± 14.3 to 65.1 ± 12.1 kg, p < 0.05; non-DM: 66.6 ± 15.1 to 64.1 ± 15.1, p < 0.05) and was stable at 6 months and 3 years. Muscle strength at baseline was reduced in all patients and remained stable during the diet period. Changes of nutritional markers during the study were similar among groups and diabetes was not associated to any nutritional change at the multivariate analysis. As attain wasting, lower BMI (< 23 kg/m2) and albumin (< 3.8 g/dl) levels were present in 1/3 patients at start and along 3 years, cholesterol never dropped below the lower threshold (< 100 mg/dl) and poorer FM (< 10%) was less than 10% during the study in both groups. CONCLUSIONS: In diabetic CKD patients a low-protein diet supplemented with ketoacids improves uremia and diabetes, causes sudden decline of body weight which remains stable over time and has not a negative effect on wasting and muscle mass and fitness. In diabetic CKD patients the LPD-KA is safe and the nutritional impact is the same as in non-diabetics CKD.

Randomized controlled clinical trial of ketoanalogues supplementation in dogs with chronic kidney disease / Estudo clínico randomizado controlado da suplementação de cetoanálogos em cães com doença renal crônica

The objective was to verify the effectiveness of ketoanalogues in dogs with Chronic Kidney Disease (CKD) stage 3. Controlled randomized clinical trial was performed with twenty dogs with CKD stage 3. Animals were subjected to: Group 1 (control): conventional therapy (CT) for CKD; Group 2: CT and 60mg/kg, OA, q48h of keto-supplementa; Group 3, CT and 60mg/kg, OA, q24h of keto-supplementa; and Group 4, CT and 120mg/kg, OA, q12h of keto-supplementa. All dogs received canine renal diet. Animals were evaluated at the beginning of therapy and after 15 and 30 days. Complete blood count (CBC), serum urea, creatinine, phosphorus, calcium, potassium and sodium and urine protein/creatinine (UPC) ratio were analyzed. The use of ketoanalogues in dogs with CKD stage 3 during the period of 30 days showed no efficacy, in any of the studies dosages, to improve signs and symptoms of the disease, improve the values of CBC, reduce serum urea and creatinine, normalize electrolytes or reduce UPC. It is concluded that the use of ketoanalogues does not impact the clinical outcomes in dogs with CKD stage 3.(AU)

O objetivo foi de verificar a eficácia da suplementação com cetoanálogos em cães com Doença Renal Crônica (DRC) grau 3. Um ensaio clínico controlado e randomizado foi realizado com 20 cães com DRC grau 3. Os animais foram divididos em 4 grupos: grupo 1 (controle): terapia convencional (TC) para DRC; grupo 2: TC e 60mg/kg, VO, q48h de cetoanálogoa; grupo 3: TC e 60mg/kg, VO, q24h de cetoanálogoa; e grupo 4, TC e 120mg/kg, VO, q12h de cetoanálogoa. Todos os cães receberam ração renal para cães. Os animais foram avaliados no início da terapia e após 15 e 30 dias. Hemograma completo, ureia, creatinina, fósforo, cálcio, potássio e sódio séricos e a razão proteína creatinina (RPC) urinária foram analisados. Foi verificado que o uso dos cetoanálogos em cães com DRC grau 3 durante 30 dias não mostrou eficácia, em nenhuma das dosagens utilizadas, em melhorar os sinais clínicos e sintomatologia da doença, os valores do hemograma e ureia e creatinina séricos, normalizar eletrólitos e reduzir RPC. Concluiu-se que o uso de cetoanálogos não impacta na melhora de sintomatologia clínica em cães com CKD grau 3. Como esse parece ser o primeiro ensaio clínico sobre cetoanálogos em cães com CKD, mais estudos podem ser necessários com maior acompanhamento e maiores grupos.(AU)

Pregnancy, Proteinuria, Plant-Based Supplemented Diets and Focal Segmental Glomerulosclerosis: A Report on Three Cases and Critical Appraisal of the Literature.

Chronic kidney disease (CKD) is increasingly recognized in pregnant patients. Three characteristics are associated with a risk of preterm delivery or small for gestational age babies; kidney function reduction, hypertension, and proteinuria. In pregnancy, the anti-proteinuric agents (ACE-angiotensin converting enzyme-inhibitors or ARBS -angiotensin receptor blockers) have to be discontinued for their potential teratogenicity, and there is no validated approach to control proteinuria. Furthermore, proteinuria usually increases as an effect of therapeutic changes and pregnancy-induced hyperfiltration. Based on a favourable effect of low-protein diets on proteinuria and advanced CKD, our group developed a moderately protein-restricted vegan-vegetarian diet tsupplemented with ketoacids and aminoacids for pregnant patients. This report describes the results obtained in three pregnant patients with normal renal function, nephrotic or sub-nephrotic proteinuria, and biopsy proven diagnosis of focal segmental glomerulosclerosis, a renal lesion in which hyperfiltration is considered of pivotal importance (case 1: GFR (glomerular filtration rate): 103 mL/min; proteinuria 2.1 g/day; albumin 3.2 g/dL; case 2: GFR 86 mL/min, proteinuria 3.03 g/day, albumin 3.4 g/dL; case 3: GFR 142 mL/min, proteinuria 6.3 g/day, albumin 3.23 g/dL). The moderately restricted diet allowed a stabilisation of proteinuria in two cases and a decrease in one. No significant changes in serum creatinine and serum albumin were observed. The three babies were born at term (38 weeks + 3 days, female, weight 3180 g-62th centile; 38 weeks + 2 days, female, weight 3300 g-75th centile; male, 38 weeks + 1 day; 2770 g-8th centile), thus reassuring us of the safety of the diet. In summary, based on these three cases studies and a review of the literature, we suggest that a moderately protein-restricted, supplemented, plant-based diet might contribute to controlling proteinuria in pregnant CKD women with focal segmental glomerulosclerosis. However further studies are warranted to confirm the potential value of such a treatment strategy.

Diet as a system: an observational study investigating a multi-choice system of moderately restricted low-protein diets.

BACKGROUND: There is no single, gold-standard, low-protein diet (LPD) for CKD patients; the best compliance is probably obtained by personalization. This study tests the hypothesis that a multiple choice diet network allows patients to attain a good compliance level, and that, in an open-choice system, overall results are not dependent upon the specific diet, but upon the clinical characteristics of the patients. METHODS: Observational study: Three LPD options were offered to all patients with severe or rapidly progressive CKD: vegan diets supplemented with alpha-ketoacids and essential aminoacids; protein-free food in substitution of normal bread and pasta; other (traditional, vegan non supplemented and tailored). Dialysis-free follow-up and survival were analyzed by Kaplan Meier curves according to diet, comorbidity and age. Compliance and metabolic control were estimated in 147 subjects on diet at March 2015, with recent complete data, prescribed protein intake 0.6 g/Kg/day. Protein intake was assessed by Maroni Mitch formula. RESULTS: Four hundreds and forty nine patients followed a LPD in December, 2007- March, 2015 (90% moderately restricted LPDs, 0.6 g/Kg/day of protein, 10% at lower targets); age (median 70 (19-97)) and comorbidity (Charlson index: 7) characterized our population as being in line with the usual CKD European population. Median e-GFR at start of the diet was 20 mL/min, 33.2% of the patients were diabetics. Baseline data differ significantly across diets: protein-free schemas are preferred by older, high-comorbidity patients (median age 76 years, Charlson index 8, GFR 20.5 mL/min, Proteinuria: 0.3 g/day), supplemented vegan diets by younger patients with lower GFR and higher proteinuria (median age 65 years, Charlson index 6, GFR 18.9 mL/min; Proteinuria: 1.2 g/day); other diets are chosen by an intermediate population (median age 71 years, Charlson index 6; GFR 22.5 mL/min; Proteinuria: 0.9 g/day); (p <0.001 for age, Charlson index, proteinuria, GFR). Adherence was good, only 1.1% of the patients were lost to follow-up and protein intake was at target in most of the cases with no differences among LPDs (protein intake: 0.47 (0.26-0.86) g/Kg/day). After adjustment for confounders, and/or selection of similar populations, no difference in mortality or dialysis start was observed on the different LPDs. Below the threshold of e-GFR 15 mL/min, 50% of the patients remain dialysis free for at least two years. CONCLUSION: A multiple choice LPD system may allow reaching good adherence, without competition among diets, and with promising results in terms of dialysis-free follow-up. The advantages with respect to a non-customized approach deserve confirmation in further comparative studies or RCTs.

Very low protein diets supplemented with keto-analogues in ESRD predialysis patients and its effect on vascular stiffness and AVF Maturation.

BACKGROUND: Native arteriovenous fistula (AVF) is the most appropriate type of vascular access for chronic dialysis. Its patency rates depend on vascular wall characteristics. Ketoacid analogues of essential amino acids (KA/EAA) are prescribed in end-stage renal disease (ESRD) pre-dialysis patients to lower toxic metabolic products generation and improve nutritional status. We hypothesized that very-low protein diet (VLPD) supplemented with KA/EAA may influence arterial wall stiffness and affect AVF maturation rates and duration in pre-dialysis ESRD patients. METHODS: In a prospective, cohort, 3 years study we enrolled 67 consecutive non-diabetic early referral ESRD patients that underwent AVF creation in our hospital. Patients were divided in two groups based on their regimen 12 months prior to surgery: a VLPD supplemented with KA/EAA study group versus a low protein diet non-KA/EAA-supplemented control group. For each patient we performed serum analysis for the parameters of bone mineral disease, inflammation and nutritional status, one pulse wave velocity (PWV) measurement and one Doppler ultrasound (US) determination prior the surgery, followed by consequent Doppler US assessments at 4, 6, 8 and 12 weeks after it. Rates and duration of mature AVF achievement were noted. We used logistic regression to analyze the association between AVF maturation and KA/EAA administration, by comparing rates and durations between groups, unadjusted and adjusted for systolic blood pressure, C-reactive protein, PWV, phosphorus values. All parameters in the logistic model were transformed in binary variables. A p-value < α = 0.05 was considered significant; data were processed using SPSS 16 software and Excel. RESULTS: In the study group (n = 28, aged 57 ± 12.35, 13 females) we registered better serum phosphate (p = 0.022) and C-reactive protein control (p = 0.021), lower PWV (p = 0.007) and a higher percent of AVF creation success (33.3 % versus 17.8 %, p < 0.05). AVF maturation duration was lower in study group (5.91 versus 7.15 weeks, p < 0.001). CONCLUSIONS: VLPD supplemented with KA/EAA appear to improve the native AVF primary outcome, decreasing the initial vascular stiffness, possible by preserving vascular wall quality in CKD patients through a better serum phosphate levels control and the limitation of inflammatory response.

Low-protein diet supplemented with ketoacids reduces the severity of renal disease in 5/6 nephrectomized rats: a role for KLF15.

Dietary protein restriction is an important treatment for chronic kidney disease. Herein, we tested the effect of low-protein or low-protein plus ketoacids (KA) diet in a remnant kidney model. Rats with a remnant kidney were randomized to receive normal protein diet (22%), low-protein (6%) diet (LPD), or low-protein (5%) plus KA (1%) diet for 6 months. Protein restriction prevented proteinuria, decreased blood urea nitrogen levels, and renal lesions; however, the LPD retarded growth and decreased serum albumin levels. Supplementation with KA corrected these abnormalities and provided superior renal protection compared with protein restriction alone. The levels of Kruppel-like factor-15 (KLF15), a transcription factor shown to reduce cardiac fibrosis, were decreased in remnant kidneys. Protein restriction, which increased KLF15 levels in the normal kidney, partially recovered the levels of KLF15 in remnant kidney. The expression of KLF15 in mesangial cells was repressed by oxidative stress, transforming growth factor-ß, and tumor necrosis factor (TNF)-α. The suppressive effect of TNF-α on KLF15 expression was mediated by TNF receptor-1 and nuclear factor-κB. Overexpression of KLF15 in mesangial and HEK293 cells significantly decreased fibronectin and type IV collagen mRNA levels. Furthermore, KLF15 knockout mice developed glomerulosclerosis following uninephrectomy. Thus, KLF15 may be an antifibrotic factor in the kidney, and its decreased expression may contribute to the progression of kidney disease.

Acute supplementation with keto analogues and amino acids in rats during resistance exercise.

During exercise, ammonia levels are related to the appearance of both central and peripheral fatigue. Therefore, controlling the increase in ammonia levels is an important strategy in ameliorating the metabolic response to exercise and in improving athletic performance. Free amino acids can be used as substrates for ATP synthesis that produces ammonia as a side product. Keto analogues act in an opposite way, being used to synthesise amino acids whilst decreasing free ammonia in the blood. Adult male rats were divided into four groups based on receiving either keto analogues associated with amino acids (KAAA) or a placebo and resistance exercise or no exercise. There was an approximately 40% increase in ammonaemia due to KAAA supplementation in resting animals. Exercise increased ammonia levels twofold with respect to the control, with a smaller increase (about 20%) in ammonia levels due to exercise. Exercise itself causes a significant increase in blood urea levels (17%). However, KAAA reduced blood urea levels to 75% of the pre-exercise values. Blood urate levels increased 28% in the KAAA group, independent of exercise. Supplementation increased glucose levels by 10% compared with control animals. Exercise did not change glucose levels in either the control or supplemented groups. Exercise promoted a 57% increase in lactate levels in the control group. Supplementation promoted a twofold exercise-induced increase in blood lactate levels. The present results suggest that an acute supplementation of KAAA can decrease hyperammonaemia induced by exercise.

Effects of low-protein diet supplemented with ketoacids and erythropoietin in chronic renal failure: a long-term metabolic study.

Ketoacids (KA) and recombinant human erythropoietin (rHuEPO) may each, on their own, influence the metabolic status of patients with chronic renal failure (CRF). A long-term prospective randomized study was designed to monitor the metabolic and nutritional status and progression of CRF using three therapeutic protocols: (A) low-protein diet (LPD) with 0.6 g of protein and 35 kcal/kg/day, with recombinant human erythropoietin (rHuEPO) at a dose of 40 U kg/week and keto acids (KA) 100 mg/kg/day, (Group I), (B) LPD and rHuEPO (Group II), and (C) LPD only (Group III). A total of 105 patients (50M/55F), aged 26-78 years, CCr 22-36 ml/min, were monitored at the beginning, and at every 6 months for 3 years in the above three study groups. Group I comprised 35 patients, Group II 38 patients and Group III 32 patients. During follow-up, a significantly smaller decrease in GFR (CCr, Cin) and in I/SCr, and an increase in serum albumin, transferrin, leucine, body mass, index and HDL-cholesterol were found in Group I (all p < 0.01). In addition, significant decreases were also seen in proteinuria, renal fractional leucine excretion and serum triglycerides level (p < 0.01). Co-administration of LPD, rHuEPO and KA thus constitutes an effective alternative to conservative management of CRF, delaying in follow-up period progression of renal failure and correction of metabolic parameters.

Increased rates of duodenal mucosal protein synthesis in vivo in patients with untreated coelia disease.

BACKGROUND AND AIMS: A robust, reproducible method for the measurement of protein synthesis in the gastrointestinal mucosa was applied to investigate possible differences between the rate of duodenal mucosal protein synthesis in coeliac patients and normal control subjects. PATIENTS AND METHODS: Eight patients, means (SD) (51 (10) years, 57 (11) kg, 160 (6) cm) with newly diagnosed untreated coeliac disease and seven control subjects (48 (11) years, 71.5 (12) kg, 172 (10) cm) received primed, continuous, intragastric (IG) and intravenous (i.v.) infusions of L-[1-13C]leucine and L-[1-13C]valine after an overnight fast. Distal duodenal biopsy specimens were obtained at endoscopy performed after 240 minutes of infusion. Protein synthesis was calculated from protein labelling relative to intracellular free amino acid enrichment, after appropriate mass spectrometric measurements. RESULTS: Rates of duodenal protein synthesis were significantly greater in coeliac patients than in control subjects (i.v. tracer, coeliac v control, 3.58 (0.45) v 2.26 (0.22)%/h, p< 0.05; IG tracer, 6.25 (0.97) v 2.34 (0.52)%/h respectively, p < 0.01). The rates of mucosal protein synthesis calculated on the basis of the tracer infused via the intragastric route were higher in patients with coeliac disease than in control subjects. Tissue protein/DNA ratios were significantly reduced in coeliac patients (coeliac v control, 9.2 (1.6) mg/micrograms v 13.0 (2.2) mg/micrograms respectively, p < 0.05) suggesting smaller mucosal cell size in coeliac patients. CONCLUSIONS: Despite the villous atrophy and reduced cell size observed in coeliac disease, the rates of mucosal protein synthesis are considerably increased. These results suggest that a high rate of protein synthesis may be adaptive to a high rate of protein breakdown or mucosal cell loss in coeliac patients.

Protein synthesis in skeletal muscle of uremic patients: effect of low-protein diet and supplementation with ketoacids.

The purpose of this study was to investigate the modifications of muscle protein synthesis activity in uremic patients fed a low-protein diet and a low-protein diet supplemented with a keto acid-amino acid mixture. The protein synthesis activity was evaluated in vitro on isolated muscle ribosomes incubated in a cell-free medium with tritiated leucine. Simultaneously, nitrogen kinetics and amino acid patterns were examined. Protein synthesis activity is correlated with the protein content of the diet in uremic patients. The keto acid-amino acid supplementation enhances protein synthesis. Variations of protein synthesis can be correlated with the variations of nitrogen balance which implies a major role of protein synthesis activity in muscle protein metabolism. Variations in plasma levels of the essential amino acids, mainly leucine and valine, can be correlated with the variations of protein synthesis activity, and these amino acids seem therefore to be mediators of the dietary effects on protein synthesis in uremia.

Improvement of leucocytic Na+ K+ pump activity in uremic patients on low protein diet.

Leucocytic Na+ K+ pump activity was assessed in 20 patients with advanced renal failure. Na+ K(+)-ATPase activity was reduced when compared with the values obtained from normal subjects (101.8 +/- 48.6 versus 165.13 +/- 8.9 microM of Pi hr-1.g-1; P less than 0.001) and the mean 86Rb uptake by U 937 cells was depressed by 38% after the addition of patients' sera. Subsequently, patients were put on a diet providing 0.3 g protein/kg body weight daily and supplemented with ketoacids. After three months of dietary treatment Na+ K(+)-ATPase activity increased to 142 +/- 48.3 (P less than 0.01) and reached normal values at the sixth month (162.8 +/- 54.70 microM of Pi hr-1.g-1; P less than 0.001) whereas 86Rb uptake increased by 23 percent when compared to initial values. These data suggest that among the different mechanisms which have been advanced to explain the defects in the Na+ pump observed in uremic patients, circulating inhibitors deriving from alimentary protein intake may affect cation transport.

The effect of an inhaled leukotriene antagonist, L-648,051, on early and late asthmatic reactions and subsequent increase in airway responsiveness in man.

We have investigated the protective effects of the inhaled cysteinyl leukotriene antagonist, L-648,051, on allergen-induced early asthmatic response (EAR) and late asthmatic response (LAR) and the subsequent changes in bronchial responsiveness to methacholine. Ten atopic men with asthma participated in a double-blind, crossover, placebo-controlled trial. All subjects had documented EAR and LAR to house dust-mite extract. Responsiveness to methacholine was measured the day before and the day after a standardized allergen-challenge test. L-648,051 was inhaled in two doses of 12 mg 20 minutes before and 3 hours after the allergen challenge. The response was obtained from FEV1 and flows from maximal (V40m) and partial (V40p) expiratory flow-volume curves. All subjects had an EAR and LAR during placebo therapy, but only a minority demonstrated an increase in methacholine responsiveness of more than one doubling dose. The ratio of V40m to V40p during methacholine challenge was higher than during both EAR and LAR (p less than 0.05). There was no difference between drug- and placebo-therapy periods in baseline function, EAR, LAR, ratio of V40m to V40p, and the allergen-induced hyperresponsiveness (p greater than 0.1). These results indicate that an effective aerosolized leukotriene antagonist in man does not protect against allergen-induced airflow obstruction, despite the evidence of an inflammatory response to allergen challenge. This suggests that either the potency or duration of activity of L-648,051 is limited or that leukotrienes C4 and D4 do not play a causative role in human allergic asthma.

Effects of keto-analogues on phosphocalcic and aminoacid metabolism in dialysed patients: a crossover study.

It has been suggested that calcium salts of keto-analogues (KA) have beneficial effects on phosphocalcic and aminoacid (AA) metabolism. To confirm this, their short-term effects were evaluated on chronic dialyzed patients. In a prospective, randomised, crossover study, eight and seven patients were put on KA (200 mg/kg/d) and assigned either a low-protein diet (LP:0.4 g/kg/d) or a normal one (NP: 1 g/kg/d) for 15 days. The two treatments were interchanged after 15 days of washout. KA.LP was accompanied by: a) decreases in calorie intake (12%; p = 0.001) and in blood concentrations of albumin (5%, p = 0.004), urea (32%, p = 0.001), phosphate (29%, p = 0.001), parathormone (27%, p = 0.008), isoleucine (24%, p = 0.04), 1 and 3 methyl-histidine (71%, p = 0.03; 24%, p = 0.005), valine (19%, p = 0.004) and hydroxyproline (85%, p = 0.009); b) increases in calcemia (9%, p = 0.002), cystathionine (991%, p = 0.0001) and threonine (22%, p = 0.04). KA.NP was accompanied by: a) decreases in phosphatemia (15%, p = 0.03) and parathormone (18%, p = 0.06); b) increases in calcemia (9%, p = 0.002), cystathionine (427%, p = 0.0001), and phenylalanine (28%, p = 0.013). Calcium salts of keto-analogues together with a low or normal protein diet thus seem to reduce blood concentrations of phosphates and parathormone, and raise calcium; however their action on aminoacids needs further investigation.

L-648,051, a novel cysteinyl-leukotriene antagonist is active by the inhaled route in man.

1. We have studied some of the pharmacological properties of inhaled L-648,051 which has been shown to be a selective cysteinyl-leukotriene (LT) antagonist in vitro and in vivo in various animal models. 2. The effects of three different doses (1.6, 6.0 and 12.0 mg) on the bronchoconstriction induced by inhaled LTD4 have been investigated in normal male subjects in a series of double-blind, placebo controlled studies. Furthermore, the specificity of the drug has been investigated by challenging subjects with histamine after pre-inhalation of 12.0 mg L-648,051. 3. At all doses L-648,051 partially blocked the bronchoconstriction induced by LTD4 inhalation in a dose related manner. At a dose of 12.0 mg, L-648,051 decreased the maximum fall in specific airways conductance (sGaw) (placebo, 49% vs L-648,051, 21%, P less than 0.01) and shortened the time to recovery from LTD4-induced bronchoconstriction (placebo, 41 min vs L-648,051, 19 min, P less than 0.01). 4. There was no evidence of partial agonist activity, and no effect on histamine-induced bronchospasm. Inhaled L-648,051 at all doses was well tolerated. 5. We conclude that LT antagonism is possible by the inhaled route in man. Inhaled L-648,051 is an active and selective LT-antagonist in man which is well tolerated and may prove to be a useful drug for assessing the role of leukotrienes in asthma and other lung diseases.

Terapia economizadora de proteínas no pós-operatório: efeitos experimentais do alfa-ceto-isocaproato / Postoperative protein sparing therapy: effects of alpha-keto-isocaproate

Os autores avaliaram experimentalmente em coelhos, os efeitos da infusäo do alfa-ceto-isocaproato na excreçäo urinária de nitrogênio no pós-operatório. A pesquisa foi realizada em três grupos de oito animais que após serem submetidos à laparotomia com manipulaçäo das alças intestinais, receberam no pós-operatório soluçäo salina, glicose a 5% e uma soluçäo contendo 1 mg/Kg de alfa-ceto-isocaproato. A quantificaçäo da perda urinária de nitrogênio pelo método Kjeldahl mostrou-se significativamente menor no grupo que recebeu o isocaproato quando comparada com os grupos salina e glicose. Com base nos dados da experimentaçäo os autores concluíram que o isocaproato apresenta um efeito de poupança de proteína refletido por uma excreçäo urinária de nitrogênio menor que quando se faz infusäo de soluçäo salina e glicose a 5% no pós-operatório

[Controlling renal osteopathy with keto acids]. / Beeinflussung der renalen Osteopathie durch Ketosäuren.

Starting from the results of former investigations the influence of the long-term treatment with the KA of the essential amino acids on the renal osteopathy is investigated. For this purpose we compared 27 patients with renal insufficiency (serum creatinine 981 +/- 354 mumol/l), who besides vitamin D had been treated with KA for at least 12 months, to a group of 50 patients (serum creatinine 778 +/- 273 mumol/l), who had received vitamin D over 19 +/- 9 months, and to a control group of 27 patients (serum creatinine 928 +/- mumol/l) without an adequate conservative therapy. While the control group showed the typical constellation in advanced renal insufficiency with hypocalcaemia, hyperphosphataemia, clearly increased PTH levels, clearly increased CT values and normal 25-OH-D concentrations, during the diettherapy and the vitamin D substitution a significant increase of the serum levels of calcium, 25-OH-D and CT as well as a significant decrease of the PTH and the anorganic phosphate in the serum developed. Under the combination therapy with KA and vitamin D despite the reduction of the phosphate binders another significant decrease of the PTH and the anorganic phosphate was observed. The mineral content of the bones was within the normal in the two therapy groups. The percentage of the normal histological findings of the bones was with 40.7% highest despite the advanced renal insufficiency in the simultaneous substitution with KA. While in the vitamin D group during the control biopsy after 12 months in 20.5% of the cases an improvement of the histological findings developed, this effect occurred under additional KA-therapy in 51.9% of the cases. The results allow the conclusion that by means of the long-term treatment with KA a favourable influence on the renal osteopathy develops.