Plasma nitric oxide metabolite levels increase during successive exercise stress testing – A link to delayed ischemic preconditioning?

BACKGROUND:

Animal studies have shown that nitric oxide is involved in delayed ischemic preconditioning.

OBJECTIVES:

To determine whether plasma nitrates and nitrites (NO_x⁻, as measure of nitric oxide) are modified by two consecutive effort tests and whether these changes translate into clinical improvement

METHODS:

Twenty-two patients with ischemic heart disease each performed two effort tests at 24-h intervals. Plasma NO_x⁻ level was determined and compared before and after both stress tests. Peak effort, double product at peak effort and maximal ST segment depression were considered clinical endpoints and were compared between the two tests.

RESULTS:

Plasma NO_x⁻increased slightly after the first exercise test compared with pretest value (17.05±1.6 μmol/mL versus 15.38±1.4 μmol/mL). In turn, after the second test there was a significant rise in NO_x⁻ level (23.65±2.2 μmol/mL versus 15.10±1.3 μmol/mL, P<0.03). The pretest values were almost identical between the two tests. Peak effort and double product at peak effort remained unchanged between the two tests. Although ischemic stress was the same, ST depression was significantly lower (P<0.01) for the second test (0.85±0.06 mm versus 1.73±0.16 mm).

CONCLUSION:

Our study shows an increased plasma NO_x⁻level after the second of two consecutive exercise stress tests at 24-h intervals, along with a decrease of electrocardiographic consequences of approximately the same ischemic stress. These findings are consistent with experimental data in animals, which point to nitric oxide as a trigger and effector of ischemic preconditioning.     

Predictors for contrast media-induced nephropathy and long-term survival: prospectively assessed data from the randomized controlled Dialysis-Versus-Diuresis (DVD) trial

BACKGROUND:

Among the numerous studies concerning contrast media-induced nephropathy (CIN), there was no prospective trial that provided data on the long-term outcomes.

OBJECTIVES:

To prospectively assess predictors of CIN and long-term outcomes of affected patients.

METHODS:

Four hundred twelve consecutive patients with serum creatinine levels of 115 μmol/L to 309 μmol/L (1.3 mg/dL to 3.5 mg/dL) undergoing elective coronary angiography were included. Patients were randomly assigned to periprocedural hydration alone, hydration plus onetime hemodialysis or hydration plus N-acetylcysteine.

RESULTS:

Multivariate logistic regression identified the following as predictors of CIN within 72 h (equivalent to an increase in creatinine 44.2 μmol/L [0.5 mg/dL] or more) : prophylactic postprocedural hemodialysis (OR 2.86, 95% CI 1.07 to 7.69), use of angiotensin-converting enzyme inhibitors (OR 6.16, 95% CI 2.01 to 18.93), baseline glomerular filtration rate (OR 0.94, 95% CI 0.90 to 0.98) and the amount of contrast media given (OR 1.01, 95% CI 1.00 to 1.01). With regard to long-term outcome (mean follow-up 649 days), multivariate Cox regression models found elevated creatinine levels at 30 days (hazard rate ratio [HRR] 5.48, 95% CI 2.85 to 10.53), but not CIN within 72 h (HRR 1.12, 95% CI 0.63 to 2.02), to be associated with increased mortality. In addition, independent predictors for death during follow-up included left ventricular ejection fraction lower than 35% (HRR 4.01, 95% CI 2.22 to 7.26), serum phosphate (HRR 1.64, 95% CI 1.10 to 2.43) and hemoglobin (HRR 0.80, 95% CI 0.67 to 0.96).

CONCLUSION:

From the present prospective trial, performance of post-procedural hemodialysis, use of angiotensin-converting enzyme inhibitors, reduced baseline glomerular filtration rate and amount of contrast media were independent predictors of CIN within 72 h after catheterization. Assessing renal function after 30 days, rather than within 72 h, seemed to be more predictive for patients’ long-term survival.     

Serum levels of homocysteine in mice with malignant tumours

BACKGROUND:

Oxygen radicals and malondialdehyde (MDA) are tumourigenic. Homocysteine generates oxygen radicals. The possibility exists that hyperhomocysteinemia is a risk factor for cancer.

OBJECTIVE:

To investigate if serum levels of homocysteine and MDA are elevated in mice with malignant tumours.

METHODS:

Levels of serum homocysteine and MDA were estimated in 22 control and 22 tumour-bearing Balb/c mice.

RESULTS:

Serum homocysteine levels in control and tumour-bearing mice were 3.01±0.26 μmol/L and 4.05±0.46 μmol/L, respectively. The serum levels of MDA were 6.23±0.72 nmol/mL and 11.60±1.72 nmol/mL, respectively, in control and tumour-bearing mice.

CONCLUSION:

These results suggest that cancer in mice is associated with an increase in serum levels of homocysteine and the lipid peroxidation product MDA. It is, however, not known if this rise in homocysteine and MDA is due to cancer or if this rise causes cancer.     

Effects of a short course of inhaled corticosteroids in noneosinophilic asthmatic subjects

BACKGROUND:

Noneosinophilic asthma has been regarded as a distinct phenotype characterized by a poor response to inhaled corticosteroids (ICS).

OBJECTIVE:

To determine whether noneosinophilic, steroid-naive asthmatic subjects show an improvement in asthma control, asthma symptoms and spirometry after four weeks of treatment with ICS, and whether they further benefit from the addition of a long-acting beta-2 agonists to ICS.

METHODS:

A randomized, double-blind, placebo-controlled, multicentre study comparing the efficacy of placebo versus inhaled fluticasone propionate 250 μg twice daily for four weeks in mildly uncontrolled, steroid-naive asthmatic subjects with a sputum eosinophil count ≤2%. This was followed by an open-label, four-week treatment period with fluticasone propionate 250 μg/salmeterol 50 μg, twice daily for all subjects.

RESULTS:

After four weeks of double-blind treatment, there was a statistically significant and clinically relevant improvement in the mean (± SD) Asthma Control Questionnaire score in the ICS-treated group (n=6) (decrease of 1.0±0.5) compared with the placebo group (n=6) (decrease of 0.09±0.4) (P=0.008). Forced expiratory volume in 1 s declined in the placebo group (−0.2±0.2 L) and did not change in the ICS group (0.04±0.1 L) after four weeks of treatment (P=0.02). The open-label treatment with fluticasone propionate 250 μg/salmeterol 50 μg did not produce additional improvements in those who were previously treated for four weeks with inhaled fluticasone alone.

CONCLUSION:

A clinically important and statistically significant response to ICS was observed in mildly uncontrolled noneosinophilic asthmatic subjects.     

Effects of three and eight weeks oral administration of bis(maltolato)oxovanadium(IV) on plasma homocysteine and cysteine levels in streptozotocin-induced diabetic rats

BACKGROUND:

Diabetes mellitus is one of the leading causes of illness and death in North America. Cardiovascular diseases are a common secondary complication in the diabetic population. One of the important risk factors identified for the development of cardiovascular disease is an elevation in the sulfur amino acid, homocysteine. Although the exact mechanism(s) that underlie the relationship between elevated plasma homocysteine levels and cardiovascular disease remain unclear, it has been suggested that endothelial dysfunction produced by modestly elevated blood homocysteine concentrations may account for an increased risk of both arterial and venous occlusive disease.

OBJECTIVES:

The present study examined the effects of three- and eight-weeks bis(maltolato)oxovanadium(IV) (BMOV) treatment on plasma concentrations of homocysteine and cysteine in both control and streptozotocin (STZ) diabetic rats.

METHODS:

Diabetes was induced in male Wistar rats by a single intravenous injection of STZ (60 mg/kg) in normal saline. Control animals received normal saline only. Animals were further randomized into treated and untreated groups. Treated animals received BMOV orally, dissolved in tap water, while untreated animals only received tap water. Three or eight weeks postinduction of diabetes, blood samples were obtained by cardiac puncture from the animals. Plasma harvested from each blood sample was used to determine glucose, insulin, homocysteine and cysteine concentrations.

RESULTS:

There was a significant decrease in plasma homocysteine levels in the diabetic (three- and eight-week study) groups compared with their respective controls (three-week study: diabetic group 3.1±0.7 μmol/L and control group 6.1±0.7 μmol/L; eight-week study: diabetic group 4.3±0.5 μmol/L and control group 6.9±1.0 μmol/L). Plasma cysteine levels were significantly decreased in the diabetic and diabetic treated groups (eight-week study) compared with their respective control groups (diabetic group 90.2±32.3 μmol/L and control group 177.9±36.7 μmol/L). BMOV treatment restored plasma homocysteine concentrations in diabetic animals to concentrations found in nondiabetic animals.

CONCLUSIONS:

Taken together, these findings suggest that STZ-induced diabetes may result in decreased plasma homocysteine and cysteine levels and that BMOV treatment may increase plasma homocysteine concentrations to nondiabetic concentrations. These results may provide further insight on how this insulin-enhancing/mimetic agent modifies plasma homocysteine metabolism.     

Renal effects of long-term treatment with 5-aminosalicylic acid

BACKGROUND:

A number of case reports link the use of 5-aminosalicylic acid (5-ASA) to interstitial nephritis in patients with inflammatory bowel disease (IBD).

OBJECTIVE:

To investigate whether the long-term use of 5-ASA has harmful effects on renal function in patients with IBD.

METHODS:

A retrospective analysis of 171 consecutive outpatients with Crohn’s disease or ulcerative colitis was conducted. Serum creati-nine levels and body weight were measured before and after treatment to calculate the creatinine clearance (CrCl) rate.

RESULTS:

In 171 patients (93 women, 78 men), the mean (± SD) dose of 5-ASA was 3.65±0.85 g/day with a cumulative dose of 11±7.7 kg over an interval of 8.4±5.9 years. Serum creatinine concentrations increased from 76.8 μmol/L to 88.7 μmol/L (n=171; P<0.0001) and the CrCl rate fell significantly from 104.6 mL/min to 93.1 mL/min (n=81; P<0.0001). There was one case of interstitial nephritis reported. Treatment groups included mesalamine (74.3%), sulfasalazine (15.2%) and combination (sulfalsalazine/mesalamine [10.5%]) with treatment durations of 7.2±4.5, 12.3±8.7 and 11.2±6.7 years, respectively. The duration of treatment was the most important covariate for change in CrCl and when analyzed by treatment group, those treated with sulfasazine had a strong correlation (r=−0.54, P=0.0145), while nonsignificant in the mesalamine group (r=0.06, P=0.7017). The decline in CrCl was negatively correlated with the pretreatment CrCl rate (r=−0.34; P=0.0024) and positively correlated with the mean daily dose of 5-ASA (r=0.32; P=0.0034).

CONCLUSION:

The present study is the first to demonstrate a significant dose- and treatment duration-dependant decline in CrCl. The risks need to be further evaluated because 5-ASA is widely used for long-term maintenance therapy in patients with IBD.     

Vitamin K1 supplementation to improve the stability of anticoagulation therapy with vitamin K antagonists: a dose-finding study

Background

Poor anticoagulant stability in patients using vitamin K antagonists is a risk factor for both bleeding and thrombosis. In previous studies supplementation with low dose vitamin K₁ was shown to improve the stability of anticoagulant control. We set up a study to confirm earlier reports and to determine the optimal daily dose of vitamin K₁ in preparation of a large study with clinical endpoints.

Design and Methods

Four hundred patients from two anticoagulation clinics starting with vitamin K antagonists, independently of a possible history of instable anticoagulation, were randomized to receive either placebo or 100, 150 or 200 μg of vitamin K₁ together with their treatment with vitamin K antagonists. The treatment was administered for 6 to 12 months. Anticoagulation stability, expressed as the percentage of time that the International Normalized Ratio was within the therapeutic range, was compared between the groups.

Results

After adjustment for age, sex, vitamin K antagonist used, anticoagulation clinic and interacting drugs as confounding factors the difference in percentage of time with the International Normalized Ratio within the therapeutic range between the placebo group and the vitamin K₁ groups was 2.1% (95% CI: −3.2% – 7.4%) for the group taking 100 μg, 2.7% (95% CI: −2.3% –7.6%) for the group taking 150 μg and 0.9% (95% CI: −4.5% – 6.3%) for the group taking 200 μg vitamin K₁ group, in favor of the vitamin K₁ groups. The patients from both the 100 μg group and the 150 μg group had a 2-fold higher chance of reaching at least 85% of time with the International Normalized Ratio within the therapeutic range. There were no differences in thromboembolic or hemorrhagic complications between the groups.

Conclusions

In patients starting vitamin K antagonists, supplementation with low dose vitamin K₁ resulted in an improvement of time that anticoagulation was within the therapeutic range. Differences between doses were, however, small and the improvement is unlikely to be of clinical relevance. For future studies we recommend selecting only patients with instable anticoagulant control. (This study was registered at www.isrctn.org as ISRCTN37109430)     

Low-molecular-weight proteins as prognostic markers in idiopathic membranous nephropathy

Summary

Background

Accurate prediction of prognosis in idiopathic membranous nephropathy (iMN) allows restriction of immunosuppressive therapy to patients at high risk for ESRD. Here we re-evaluate urinary low-molecular-weight proteins as prognostic markers and explore causes of misclassification.

Design, setting, participants, & measurements

In a cohort of 129 patients with serum creatinine concentration <135 μmol/L and proteinuria ≥3.0 g/10 mmol, urinary α1- (uα1m) and β2-microglobulin (uβ2m) excretion rate was determined. Urinary α1m and uβ2m-creatinine ratio was also obtained. We defined progression as a rise in serum creatinine ≥50% or ≥25% and an absolute level ≥135 μmol/L.

Results

Median survival time was 25 months, and 47% of patients showed progression. The area under the receiver operating characteristic curve for uβ2m was 0.81 (95% CI: 0.73 to 0.89). Using a threshold value of 1.0 μg/min, sensitivity and specificity were 73% and 75%, respectively. Similar accuracy was observed for the uβ2m-creatinine ratio with sensitivity and specificity of 75% and 73%, respectively, at a threshold of 1.0 μg/10 mmol creatinine. Similar accuracy was found for uα1m and uα1m-creatinine ratio. Blood Pressure and cholesterol contributed to misclassification. Repeated measurements improved accuracy in patients with persistent proteinuria: the positive predictive value of uβ2m increased from 72% to 89% and the negative predictive value from 76% to 100%.

Conclusions

Urinary excretion of uα2m and uβ2m predict prognosis in iMN. A spot urine sample can be used instead of a timed sample. A repeated measurement after 6 to 12 months increases prognostic accuracy.     

Comparison of adverse effects related to pegylated interferon-based therapy for patients with chronic hepatitis B and chronic hepatitis C in Taiwan

Purpose

Pegylated interferon (Peg-IFN)-based therapy is effective in treating chronic hepatitis B (CHB) and C (CHC) but frequently induces adverse events (AEs). This study was conducted to compare the incidence of Peg-IFN-based therapy-associated AEs in Taiwanese patients with CHB and CHC.

Methods

Fifty-six patients with CHB and 103 age-, sex- and treatment duration-matched patients with CHC were enrolled. Patients with CHB were treated with Peg-IFN-α-2a 180 μg/week for 24 weeks (HBeAg⁺, n = 31) or 48 weeks (HBeAg⁻, n = 25); patients with CHC were treated with Peg-IFN-α-2a 180 μg/week plus ribavirin 1,000–1,200 mg/day for 24 weeks (genotype 2/3, n = 57) or 48 weeks (genotype 1, n = 46).

Results

Significantly higher incidences of Peg-IFN-related AEs, especially neuropsychiatric symptoms, and ribavirin-associated skin manifestations were observed in patients with CHC compared with those with CHB, with either the 24- or 48-week regimen. Frequencies of laboratory abnormalities, except for anemia, were comparable in both groups. Neither group showed overt hepatic decompensation. Frequency of dose reduction was similar between the groups. Substantially higher rates of early termination and severe AEs were observed in patients with CHC.

Conclusions

Patients with CHB treated with Peg-IFN had fewer AEs than patients with CHC treated with Peg-IFN/ribavirin. All patients were treated safely.     

Efficacy and safety of lixisenatide in Japanese patients with type 2 diabetes mellitus inadequately controlled by sulfonylurea with or without metformin: Subanalysis of GetGoal‐S

Aims/Introduction

This was a subanalysis of Japanese patients included in the glucagon-like peptide-1 receptor agonist AVE0010 in patients with type 2 diabetes mellitus for glycemic control and safety evaluation (GetGoal-S) study – a 24-week, randomized, placebo-controlled study of lixisenatide in patients with type 2 diabetes mellitus inadequately controlled by sulfonylurea with or without metformin.

Materials and Methods

In GetGoal-S, 127 Japanese patients received the once-daily prandial glucagon-like peptide-1 receptor agonist lixisenatide 20 μg/day or a matching placebo. The primary outcome was change in glycated hemoglobin.

Results

At week 24, lixisenatide significantly reduced mean glycated hemoglobin (least squares mean difference vs the placebo −1.1% [12 mmol/mol, P < 0.0001]), and significantly more lixisenatide patients reached glycated hemoglobin targets of <7% (53 mmol/mol) and ≤6.5% (48 mmol/mol) vs the placebo. Lixisenatide produced statistically significant reductions in 2-h postprandial plasma glucose (least squares mean difference vs the placebo −8.51 mmol/L, P < 0.0001) and glucose excursion vs the placebo, and significantly reduced fasting plasma glucose (least squares mean difference vs the placebo −0.65 mmol/L, P = 0.0454). Bodyweight decreased with both lixisenatide and the placebo (least squares mean change −1.12 kg for lixisenatide, −1.02 kg for placebo). The overall incidence of adverse events was similar for lixisenatide and the placebo (84.2 and 82.4%, respectively), the most frequent being gastrointestinal disorders (52.6% for lixisenatide vs 29.4% for placebo). The incidence of symptomatic hypoglycemia was higher with lixisenatide vs the placebo (17.1 and 9.8%, respectively), with no cases of severe symptomatic hypoglycemia in either group.

Conclusions

In the Japanese subpopulation of the GetGoal-S study, lixisenatide produced a significant and clinically relevant improvement in glycated hemoglobin, with a pronounced improvement in postprandial plasma glucose, and a good safety and tolerability profile.     

Fracture is additionally attributed to hyperhomocysteinemia in men and premenopausal women with type 2 diabetes

Aims/Introduction

Data on hyperhomocysteinemia in relation to fractures in diabetes are limited. We aimed to explore the relationship between plasma total homocysteine concentrations and fractures in men and premenopausal women with type 2 diabetes.

Materials and Methods

Diabetic and control participants (n = 292) were enrolled in a cross‐sectional hospital‐based study. Bone mineral density and fractures were documented by dual energy X‐ray absorptiometry and X‐ray film, respectively. Plasma total homocysteine concentrations were measured using fluorescence polarization immunoassay. Risk factors for low bone mineral density or fractures and determinants of homocysteine were obtained from blood samples and the interviewer questionnaire.

Results

Plasma total homocysteine levels were higher in diabetic participants with fractures than without (8.6 [2.1] μmol/L vs 10.3 [3.0] μmol/L, P = 0.000). Diabetic participants with fractures had similar bone mineral densities as control participants. The association of homocysteine with the fracture was independent of possible risk factors for fractures (e.g., age, duration of diabetes, glycated hemoglobin, body mass index, thiazolidenediones and retinopathy) and determinants of homocysteine concentration (e.g., age, sex, serum folate and vitamin B₁₂, renal status and biguanide use; odds ratio 1.41, 95% confidence interval 1.05–2.03, P = 0.020). Furthermore, per increase of 5.0 μmol/L plasma homocysteine was related to the fracture, after controlling for per unit increase of other factors (odds ratio 1.42, 95% confidence interval 1.12–1.78, P = 0.013).

Conclusions

Plasma total homocysteine concentration is independently associated with occurrence of fractures in men and premenopausal women with type 2 diabetes. Future prospective studies are warranted to clarify the relationship.     

Edaravone reduces mitochondrial damage due to reperfusion injury following leg ischemia in rats

PURPOSE:

Free radicals have been implicated in reperfusion injury. It was shown that the free radical scavenger edaravone might suppress reperfusion injury in rat extremities. The present study aimed to elucidate how edaravone suppresses reperfusion injury, focusing on its effect on the mitochondrial structure and glycogen storage in the lower extremity muscles.

METHODS:

Sixteen male Lewis rats (mean [± SD] weight 497±32 g) were divided into two groups and injected with either 3.0 mg/kg of edaravone (edaravone group, n=8 rats) or the same dose of saline (control group, n=8 rats) into the peritoneal cavity. The rat reperfusion injury models were created by clamping the bilateral common femoral arteries for 5 h, then declamping. The muscles were harvested more than 5 h after the start of reperfusion. The mitochondrial damage, defined as mitochondrial swelling, was examined using a transmission electron microscope at ×30,000 original magnification (n=3 for each rat). Glycogen storage, defined as a positive periodic acid-Schiff stain area, was examined using computerized densitometry (n=5 sections for each rat).

RESULTS:

The mitochondria in the control group demonstrated marked swelling (mean mitochondrial size = 0.169±0.059 μm²). However, the mitochondria in the edaravone group had significantly less swelling (mean mitochondrial size = 0.102±0.036 μm²; P<0.01). The mean percentage of positive periodic acid-Schiff stain was also significantly higher in the edaravone group than in the control group (51.7±6.8% versus 7.3±2.1%; P<0.01).

CONCLUSION:

The results suggested that edaravone reduces mitochondrial damage due to reperfusion injury, resulting in a high level of glycogen storage.     

Effects of cigarette smoke, nicotine and cotinine on red blood cell hemolysis and their -SH capacity

BACKGROUND:

Smoking is a leading cause of premature death. Red blood cell (RBC) membrane lipids are rich in polyunsaturated fatty acids; therefore, the effect of oxygen on RBC membranes is more prominent than on other body tissues. The attachment of peroxidants to RBC membranes can result in hemolysis.

OBJECTIVES:

The present study was conducted to assess the sensitivity of RBCs to 2,2′-azo-bis-(2-amidinopropane) dihydrochloride in smokers and nonsmokers. The effect of cigarette smoke, nicotine (1 μg/mL, 1.5 μg/mL and 2.5 μg/mL) and cotinine (1.25 μg/mL, 2.5 μg/mL and 5 μg/mL) on RBC hemolysis was also examined.

RESULTS:

RBC hemolysis in smokers was 21.6% higher than in non-smokers (P<0.05). Cigarette smoke increased 2,2′-azo-bis-(2-amidino-propane) dihydrochloride-induced RBC hemolysis by 281.7%. Nicotine inhibited RBC hemolysis by 36.7% at the highest concentration used, but increased RBC hemolysis at the lower concentrations. Cotinine caused a 13.8% increase in RBC membrane peroxidation at the highest concentration used and its effects were dose-dependent. At their highest concentrations, nicotine and cotinine decreased -SH groups by 50%.

CONCLUSIONS:

The present study confirms the results from previous studies of the oxidative and destructive effects of cigarette smoke, which are detrimental to the health of both active and passive smokers.     

Phase II,randomized, open,controlled study of AS03‐adjuvanted H5N1 pre‐pandemic influenza vaccine in children aged 3 to 9 years: follow‐up of safety and immunogenicity persistence at 24 months post‐vaccination

Background

An AS03-adjuvanted H5N1 influenza vaccine elicited broad and persistent immune responses with an acceptable safety profile up to 6 months following the first vaccination in children aged 3–9 years.

Methods

In this follow-up of the Phase II study, we report immunogenicity persistence and safety at 24 months post-vaccination in children aged 3–9 years. The randomized, open-label study assessed two doses of H5N1 A/Vietnam/1194/2004 influenza vaccine (1·9 μg or 3·75 μg hemagglutinin antigen) formulated with AS03_A or AS03_B (11·89 mg or 5·93 mg tocopherol, respectively). Control groups received seasonal trivalent influenza vaccine. Safety was assessed prospectively and included potential immune-mediated diseases (pIMDs). Immunogenicity was assessed by hemagglutination-inhibition assay 12 and 24 months after vaccination; cross-reactivity and cell-mediated responses were also assessed. ({"type":"clinical-trial","attrs":{"text":"NCT00502593","term_id":"NCT00502593"}}NCT00502593).

Results

The safety population included 405 children. Over 24 months, five events fulfilled the criteria for pIMDs, of which four occurred in H5N1 vaccine recipients, including uveitis (n = 1) and autoimmune hepatitis (n = 1), which were considered to be vaccine-related. Overall, safety profiles of the vaccines were clinically acceptable. Humoral immune responses at 12 and 24 months were reduced versus those observed after the second dose of vaccine, although still within the range of those observed after the first dose. Persistence of cell-mediated immunity was strong, and CD4⁺ T cells with a T_H1 profile were observed.

Conclusions

Two doses of an AS03-adjuvanted H5N1 influenza vaccine in children showed low but persistent humoral immune responses and a strong persistence of cell-mediated immunity, with clinically acceptable safety profiles up to 24 months following first vaccination.     

Effects of chromium malate on glycometabolism,glycometabolism‐related enzyme levels and lipid metabolism in type 2 diabetic rats: A dose–response and curative effects study

Aims/Introduction

The present study was designed to evaluate the effect of chromium malate on glycometabolism, glycometabolism-related enzyme levels and lipid metabolism in type 2 diabetic rats, and dose–response and curative effects.

Materials and Methods

The model of type 2 diabetes rats was developed, and daily treatment with chromium malate was given for 4 weeks. A rat enzyme-linked immunosorbent assay kit was used to assay glycometabolism, glycometabolism-related enzyme levels and lipid metabolism changes.

Results

The results showed that the antihyperglycemic activity increased with administration of chromium malate in a dose–dependent manner. The serum insulin level, insulin resistance index and C-peptide level of the chromium malate groups at a dose of 17.5, 20.0 and 20.8 μg chromium/kg bodyweight were significantly lower than that of the model, chromium trichloride and chromium picolinate groups. The hepatic glycogen, glucose-6-phosphate dehydrogenase and glucokinase levels of the chromium malate groups at a dose of 17.5, 20.0 and 20.8 μg chromium/kg bodyweight were significantly higher than that of the model, chromium trichloride and chromium picolinate groups. Chromium malate at a dose of 20.0 and 20.8 μg chromium/kg bodyweight significantly changed the total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides levels compared with the chromium trichloride and chromium picolinate groups.

Conclusions

The results showed that chromium malate exhibits greater benefits in treating type 2 diabetes, and the curative effect of chromium malate is superior to chromium trichloride and chromium picolinate.     

Comparison Pharmacokinetics of Two Concentrations (0.7% and 1.0%) of Nasulin?, an Ultra-Rapid-Acting Intranasal Insulin Formulation

Background

This pharmacokinetic (PK) study was designed to characterize the dose response of two concentrations (0.7% and 1%) of a nasal spray of recombinant regular human insulin in combination with cyclopentadecalactone (CPE-215), a compound that enhances absorption of molecules across mucous membranes (Nasulin™, CPEX Pharmaceuticals). Nasulin has been effective in lowering blood glucose in both normal subjects and diabetes patients, and additional dosing options would allow greater titration flexibility.

Method

A five-period crossover study of 24 healthy, nonsmoking subjects (ages 18-50, basal metabolic index <33 kg/m², weight >70 kg) were studied. Subjects were in a fasted state for 5 h before and 45 min after administration for PK assessment and were then given a meal. Each spray contained 100 μl. Doses tested were 25, 35, 50, 70, and 100 U. Maximum concentration (C_max) and area under the curve (AUC) were estimated for each dose group. Glucose measurements were also performed.

Results

A dose response (slope of the natural log response versus dose) was demonstrated by baseline-adjusted C_max of 22, 27, 56, 62, and 84 μU/ml for the 25, 35, 50, 70, and 100 U doses (p < .0001), respectively, and by baseline-adjusted AUC_{(0–45 min)} values of 491, 592, 1231, 1310, and 1894 μU/ml/min (p < .0001). Glucose AUC_{(0–45 min)} determinations also demonstrated a pharmacodynamic (PD) dose response.

Conclusions

Proportional and linear dose responses for both PK and PD parameters were demonstrated for the two concentrations, making multiple doses available for clinical development.     

Protective effect of flavonoids against red blood cell hemolysis by free radicals

BACKGROUND:

Flavonoids are polyphenolic substances with antioxidant properties, and they are found in different vegetables and fruits. Epidemiological studies have shown that the consumption of flavonoids reduces the prevalence of cardiovascular diseases. The use of synthetic antioxidants, however, has been limited because of their toxicity. Therefore, medical researchers have intensified their quest to find natural antioxidants.

OBJECTIVES:

To investigate the effect of several pure flavonoids, such as kaempferol, quercetin, morin and rutin, on red blood cell hemolysis and evaluate their -SH capacity as an indicator of membrane protection.

METHODS:

The rate of hemolysis and cell membrane -SH capacity were determined by spectrophotometry. Red blood cell peroxidation was induced using 2,2′-azo-bis-(2-amidinopropane) dihydrochloride. The effect of each flavonoid on hemolysis was examined at three concentrations (0.5 μg/mL, 5 μg/mL and 10 μg/mL), however, only the greatest concentration (10 μg/mL) of each flavonoid was used to study the effect on -SH groups.

RESULTS:

In all cases, the antioxidant activity was dose-dependent. Rutin showed the highest inhibitory effect on hemolysis among flavonoids (42.5%). The protective effect of kaempferol, rutin and morin against -SH group oxidation measured 7.7%, 23.3% and 26.4%, respectively.

CONCLUSIONS:

Results showed that flavonoids and flavonoid-containing plants can be used as natural antioxidants for the treatment and prevention of disease conditions, the pathogenesis of which is mediated by lipid peroxidation.     

Edaravone suppresses postoperative reperfusion injury in rat lower extremity: An immunohistological study

PURPOSE

The present study evaluated whether the free radical scavenger edaravone (Radicut [Mitsubishi Pharma Co, Japan]) can suppress lower extremity postoperative reperfusion injury by evaluating muscle cell viability with immunohistological stain (cytochrome c oxidase stain).

METHODS

Eight Lewis male rats (460 g to 510 g) were divided into two groups. In the control group, postoperative reperfusion injury models were created by clamping the bilateral common femoral arteries for 5 h and then releasing. In the other group, 9.0 mg/kg of edaravone was administered before clamping the bilateral common femoral arteries. After 5 h of reperfusion, the bilateral triceps muscles in both groups were stained with cytochrome c oxidase stain (each n=4 × 2). The positive areas of cytochrome c oxidase stain were measured and compared, using computerized densitometry (National Institutes of Health Image program, version 1.61).

RESULTS

In the control group, the lower triceps muscles were not stained with cytochrome c oxidase. In the edaravone group, the lower triceps muscles were strongly stained with cytochrome c oxidase. The positive areas of cytochrome c oxidase stain were significantly greater in the edaravone group (133,000±12,000 μ²/mm², P<0.01) compared with the control group (8000±1300 μ²/mm²).

CONCLUSION

The present study suggests that the preoperative administration of 9.0 mg/kg of edaravone may suppress postoperative reperfusion injury in a rat model.     

Prevention of contrast-induced nephropathy in diabetic patients with impaired renal function: A randomized,double blind trial of sodium bicarbonate versus sodium chloride-based hydration

Aims

Diabetes mellitus and decreased renal function are important risk factors for contrast-induced nephropathy (CIN) in which oxidative stress damage may play a role. Alkalinization with sodium bicarbonate (NaHCO₃) has been proposed as a means of reducing free-radical mediated renal injury; however, the effectiveness of NaHCO₃ treatment to prevent CIN in high-risk patients remains uncertain.

Methods

We performed a prospective, randomized, double blind, sodium chloride (NaCl) hydration-controlled study of NaHCO₃ in 120 diabetic patients with impaired renal function (serum creatinine ≥100 μmol/L) undergoing an elective procedure with use of low-osmolar contrast media. The primary endpoint was the incidence of CIN defined as creatinine increase of ≥25% and/or ≥44 μmol/L within 2 days after contrast. Secondary end-points were maximal changes in serum creatinine and estimated glomerular filtration rate. Urine F₂-isoprostane levels were also assessed as measure of oxidative stress.

Results

There were no significant group differences in baseline characteristics except for the marginally lower age of the NaHCO₃ treated patients (63 ± 11 vs. 67 ± 10 years; p = 0.05). CIN occurred in 7 (11.5%) and 5 (8.5%) patients of the NaHCO₃ and NaCl groups, respectively (p = 0.76; incidence rate ratio 1.35; 95% CI 0.37–5.41). No significant differences were seen in secondary outcome measures and changes in the parameter of oxidative stress.

Conclusions

In diabetic patients with renal function impairment sodium bicarbonate does not confer protection against contrast-induced nephropathy greater than sodium chloride-based hydration. Its specific role in mitigating oxidative stress damage in CIN is also not supported by our data.     

The anti-cancer drug, phenoxodiol, kills primary myeloid and lymphoid leukemic blasts and rapidly proliferating T cells

Background

The redox-active isoflavene anti-cancer drug, phenoxodiol, has previously been shown to inhibit plasma membrane electron transport and cell proliferation and promote apoptosis in a range of cancer cell lines and in anti-CD3/anti-CD28-activated murine splenocytes but not in non-transformed WI-38 cells and human umbilical vein endothelial cells.

Design and Methods

We determined the effects of phenoxodiol on plasma membrane electron transport, MTT responses and viability of activated and resting human T cells. In addition, we evaluated the effect of phenoxodiol on the viability of leukemic cell lines and primary myeloid and lymphoid leukemic blasts.

Results

We demonstrated that phenoxodiol inhibited plasma membrane electron transport and cell proliferation (IC₅₀ 46 μM and 5.4 μM, respectively) and promoted apoptosis of rapidly proliferating human T cells but did not affect resting T cells. Phenoxodiol also induced apoptosis in T cells stimulated in HLA-mismatched allogeneic mixed lymphocyte reactions. Conversely, non-proliferating T cells in the mixed lymphocyte reaction remained viable and could be restimulated in a third party mixed lymphocyte reaction, in the absence of phenoxodiol. In addition, we demonstrated that leukemic blasts from patients with primary acute myeloid leukemia (n=22) and acute lymphocytic leukemia (n=8) were sensitive to phenoxodiol. The lymphocytic leukemic blasts were more sensitive than the myeloid leukemic blasts to 10 μM phenoxodiol exposure for 24h (viability of 23±4% and 64±5%, respectively, p=0.0002).

Conclusions

The ability of phenoxodiol to kill rapidly proliferating lymphocytes makes this drug a promising candidate for the treatment of pathologically-activated lymphocytes such as those in acute lymphoid leukemia, or diseases driven by T-cell proliferation such as auto-immune diseases and graft-versus-host disease.