Mustafa Altay

Nebivolol improves renal function in patients who underwent angioplasty due to renal artery stenosis: a pilot study.

Renal artery stenosis (RAS) is a progressive disease and may lead to chronic kidney disease by deterioration of renal functions. Endothelial dysfunction is an important causative factor for kidney damage after RAS revascularization. Nebivolol, a new generation beta blocker induces endothelium-related arterial relaxation by nitric oxide (NO) and may improve endothelial dysfunction. This pilot study tested the effect of nebivolol on the glomerular filtration rate (GFR) in a series of 33 patients with severe RAS (>70%) who underwent revascularization. After revascularization, nebivolol was added to antihypertensive treatment in 17 randomly selected patients while 16 patients (control group) continued their standard treatment. Estimated glomerular filtration rate (eGFR), proteinuria as well as nitrite and nitrate levels were measured at baseline and 6 months after the revascularization procedure. Six months after revascularization, eGFR increased from 44.8 to 50.6 ml/min in the nebivolol group. In contrast, eGFR did not change in the control group. Nitrite/nitrate levels decreased to a significant extent both in the nebivolol and in the control group. Proteinuria decreased more in the nebivolol group compared to the control group. These pilot data support a full-fledged clinical trial, testing whether nebivolol may be beneficial in the post-revascularization phase in patients with RAS.

The relationship between oxidative stress and autoimmunity in Hashimoto's thyroiditis

OBJECTIVE We have aimed to study the relation between Hashimotos thyroiditis (HT) and thyroid autoantibodies and oxidative stress parameters in euthyroid, subclinical and overt hypothyroid stages. DESIGN AND METHODS A total of 124 patients were included in the study; 93 of whom were newly diagnosed with HT (31 patients in each of the euthyroid, subclinical hypothyroid and overt hypothyroid subgroups), aged over 18 and had not received any prior treatment and 31 of whom were healthy volunteers. RESULTS Total oxidant status (TOS) and oxidative stress index (OSI) levels were higher, and total antioxidant status (TAS) and total thiol and arylesterase levels were lower in the overt hypothyroid group compared to other groups. TOS and OSI levels increased, and TAS levels decreased significantly in each phase from euthyroid, subclinical hypothyroid, to overt hypothyroid subgroups among HT patients. There was a negative correlation between TAS, log (paraoxonase1) and paraoxonase1/HDL and anti-thyroid peroxidase and a negative correlation between anti-thyroglobulin and total thiol. It was also determined that overt hypothroidism was an individual predictor that effects all of the oxidative stress parameters, but not total thiol, levels. CONCLUSION Our results suggest that oxidative stress increases continuously during the development of subclinical hypothyroidism and overt hypothyroidism in patients with HT. To determine whether this is a cause or result, randomized, controlled trials that study the effect of antioxidant treatment on the development of overt hypothyroidism and its consequences, e.g., increase in total cholesterol levels, may be performed in euthyroid and/or subclinical hypothyroid patients with HT.

Comparison of incidence of peritonitis between peritoneal dialysis solution types

Background: Peritonitis is an important cause of morbidity and mortality in patients receiving peritoneal dialysis (PD). However, there are no data about the comparison of the incidence of peritonitis among PD solution types. The aim of the present study was to compare the incidence of peritonitis among PD solutions in PD patients treated either with Nutrineal or with Extraneal or with conventional glucose solutions. Materials and Methods: A total of 147 patients (60 female and 87 male) who underwent PD were included in the study. Of these patients, 47 used only glucose solutions (group I), 79 used glucose solutions combined with Extraneal (group II) and 21 used glucose solutions combined with Nutrineal (group III). The laboratory values and demographics of the patients were noted. Results: There was no significant difference in the frequency of peritonitis among the three groups. Peritonitis occurred in 14 of 47 patients (29.8%) in group I, in 28 of 79 patients (35.4%) in group II and in 6 of 21 patients (28.6%) in group III. Patients with serum albumin levels below 3 g/dl had a significantly higher peritonitis rate than patients with serum albumin levels above 3 g/dl (p < 0.05). Conclusion: We have shown that a low serum albumin level is an important risk factor for the development of peritonitis in CAPD patients. The PD solution does not appear to be a risk factor for the development of peritonitis in CAPD patients, although this question should be studied further with larger numbers.

The Impact of Levothyroxine Sodium Treatment on Oxidative Stress in Hashimoto's Thyroiditis

OBJECTIVE Although several studies reported increased oxidative stress in Hashimotos thyroiditis (HT), the effect of levothyroxine treatment on oxidative status is not studied extensively. Therefore, we conducted this study to investigate the effects of levothyroxine replacement on oxidative stress in HT. DESIGN AND METHODS Thirty-six patients recently diagnosed with HT-related hypothyroidism and 36 healthy controls were included in the study. Levothyroxine replacement was started to patients with hypothyroidism, and had been followed-up for 6 months. RESULTS Mean basal serum total antioxidant status (TAS), total thiol, arylesterase, and paraoxonase 1 (PON1) levels were significantly lower, and serum total oxidant status (TOS) and oxidative stress index (OSI) were significantly higher in the patients with hypothyroid than the controls. In the hypothyroid group serum TAS, total thiol, arylesterase, and PON1 levels increased and serum TOS and OSI levels decreased significantly after levothyroxine treatment. Pretreatment serum TAS, total thiol, PON1, and arylesterase levels were positively correlated with free levothyroxine (fT4) and negatively correlated with thyroid-stimulating hormone (TSH), antithyroid peroxidase (anti-TPO), and antithyroglobulin (anti-TG) levels. Also, pretreatment serum TOS and OSI levels were negatively correlated with fT4 levels and positively correlated with TSH, anti-TPO, and anti-TG. We have also found that the fT4 and anti-TPO levels are independent predictors of the oxidative stress parameters in stepwise multivariable linear regression analysis. CONCLUSION This study suggests that levothyroxine replacement decreases oxidant status and increases antioxidant status following the 6 months of levothyroxine replacement in hypothyroidism that develops in accordance with the HT.

Is disulphide/thiol ratio related to blood pressure in masked hypertension?

Abstract Dynamic thiol/disulphide homeostasis plays a critical role in numerous intracellular enzymatic pathways including antioxidant defence and detoxification. In this study, we sought to investigate dynamic thiol/disulphide homeostasis in patients with masked hypertension (MHT) and its relationship with blood pressure. Forty patients (23 men, 17 women) with newly diagnosed MHT and not yet on medical therapy, and 40 healthy volunteers (21 men, 19 women) were enrolled. Blood thiol/disulphide homeostasis was measured in both groups. Serum native and total thiol levels were measured using the novel, fully automated colorimetric method developed by Erel et al. Serum disulphide level was calculated as (serum total thiol − serum native thiol)/2. Native and total thiol levels (p = 0.001) and native thiol/total thiol ratio (p = 0.023) were found to be lower in patients with MHT when compared to those of the control group. Disulphide level and ratios of disulphide/native thiol and disulphide/total thiol were higher in patients with MHT than in the control group (p = 0.001). A positive correlation of systolic blood pressure (SBP) and diastolic blood pressure (DBP) was observed with disulphide/native thiol ratio (p < 0.001). Stepwise multivariable regression analysis showed disulphide/native thiol ratio to be an independent risk factor of SBP and DBP, and SBP to be an independent risk factor of disulphide/thiol ratio (p = 0.001). In this study, we found that dynamic thiol/disulphide homeostasis shifted towards disulphide formation due to thiol oxidation in patients with MHT. Prospective randomised controlled studies are required to elucidate whether abnormal thiol/disulphide status lies in the pathogenesis of MHT or is a consequence of MHT.

Acute Kidney Injury due to Rhabdomyolysis in H1N1 Influenza Infection

Acute kidney injury (AKI) is rarely reported in the clinical course of H1N1 infection and this condition is strongly related with increasing of mortality risk. However, there are no sufficient data about the development of AKI due to H1N1 infections. The recent reports were documented for elevation of creatinine phosphokinase levels in the course of influenza infection, but rhabdomyolysis was rarely reported. Herein, we present a 28-year-old female patient and a 19-year-old male patient with AKI in the course of H1N1 influenza infection due to rhabdomyolysis.

Retinal nerve fiber layer thickness in chronic renal failure without diabetes mellitus.

PURPOSE To evaluate the retinal nerve fiber layer (RNFL) thickness in patients with chronic renal failure (CRF) without diabetes mellitus by using optical coherence tomography (OCT). METHODS Sixty-six eyes of 33 patients with CRF were evaluated. Eighteen patients have been treated with hemodialysis (group 1) and 15 patients have been treated with peritoneal dialysis (group 2). The RNFL thicknesses were assessed before and after the hemodialysis in group 1. None of these patients had diabetes mellitus. Forty eyes of 20 age-matched normal control subjects were assessed in group 3. An RNFL thickness protocol was used to acquire circular scans of 3.4 mm in diameter around the optic nerve. For each eye, RNFL thicknesses were evaluated in 4 quadrants. All of the measurements were automatically calculated by the existing OCT software. All normal subjects and CRF patients underwent comprehensive ophthalmologic examination. The mean and quadrantal RNFL thickness values in patients with CRF were compared with the control group. RESULTS The mean RNFL thickness values in patients with CRF were statistically significantly lower than the control group. Differences between the RNFL thickness values in group 1 and group 2 and the predialysis and postdialysis measurements were not statistically significant. CONCLUSIONS The RNFL thickness in CRF without DM, which was measured by OCT-3, was found to be significantly decreased. The presence of CRF can be a source of false positive results and lead to overestimation of glaucomatous optic neuropathy.

Circulating levels of irisin is elevated in hypothyroidism, a case-control study

Objective Our objective in this study was to determine the relationship between irisin hormone, which has a similar effect with thyroid hormones on adipose tissue and the metabolism, and the thyroid functions and the obesity secondary to thyroid disease. Subjects and methods Seventy-four patients were included in the study, of the patients, 37 were newly diagnosed with Hashimotos thyroiditis related hypothyroidism but not started on a treatment yet, and the remaining 37 were healthy volunteers without a known disease. Serum thyroid stimulating hormone (TSH), free thyroxin (fT4), anti-thyroglobulin and anti-thyroid peroxidase were measured and thyroid ultrasonography was performed in both groups. Serum irisin levels were measured using the commercially available ELISA kit. The hypothyroidism group had higher levels of irisin compared to the control group (2.77 ng/mL vs. 2.15 ng/mL respectively; p = 0.017). Results The hypothyroidism group had higher median levels of irisin in the obese patients than those in the control group (3.10 ng/mL vs. 2.10 ng/mL respectively; p = 0.013). Irisin level was negatively correlated with age in the whole population and patients with hypothyroidism (r = -0.255, p = 0.028; r = -0.346, p = 0.036 respectively). Irisin level was positively correlated with TSH (r = 0.247, p = 0.034) but negatively correlated with the fT4 (r = -0.316, p = 0.006) in the whole population. Obesity, fT4 and irisin levels were identified to be independent predictors in the diagnosis of hypothyroidism in the multivariable logistic regression analysis. Conclusion To the best of our knowledge, this study is the first in literature to identify that obesity, irisin level and fT4 level are independent risk factors for hypothyroidism.

Comment on: low-dose quetiapine-induced severe rhabdomyolysis.

There are only few severe rhabdomyolysis reports following quetiapine overdose and therapeutic dosage.1–4 Here, we report a case of developing rhabdomyolysis after 6 months of quetiapine therapy. To our knowledge, this is the first case to describe rhabdomyolysis in a quetiapine-treated patient with chronic kidney disease taking therapeutic dosage. A 54-year-old man was admitted to the hospital with nausea, vomiting, myalgias, weakness of both hands and lower limb that caused a reduction in everyday activity for 10 days. He had a known medical history of chronic renal disease, coronary artery disease, hypertension, cerebrovascular disease, anxiety, and bipolar depression. He was treated with 20 mg/day of escitalopram supplementary to quetiapine 25 mg/day because of anxiety and bipolar depression 6 months ago. Moreover, medications included metoprolol 50 mg/day, olmesartan 10 mg/day, and acetylsalicylic acid 100 mg/ day. Both his physical examination and ECG (QTc interval) were normal. The patient’s laboratory findings were as follows: blood urea nitrogen 19.6 mmol/L, creatinine 264 μmol/L, creatinine phosphokinase (CPK) 3865 U/L (normal 0–170), aspartate aminotransferase (AST) 162 U/L, alanine aminotransferase (ALT) 75 U/L, and myoglobin 3157 ng/mL (normal 0–38.5); other laboratory values were within normal ranges. Urine dipstick chemical analysis suggested moderate blood presence but there were no erythrocytes identified by microscopic examination, suggesting myoglobulinuria. Serum quetiapine tests could not be performed because of technical difficulties. The patient was diagnosed with rhabdomyolysis based on his clinical presentation and laboratory values. After exception of other causes of rhabdomyolysis, quetiapine was discontinued. He was given extensive hydration including intravenous normal saline with bicarbonate. On the fourth admission day, CPK, AST, and ALT levels had dropped to 1272, 128, 68 U/L, respectively. Serum myoglobin was decreased to 566 ng/mL and serum creatinine decreased to 202 μmol/L. CPK, AST, ALT, and myoglobin were returned to normal levels after ten days. Our patient, who had no evidence of seizure or hints for intoxication, had depressive episodes for years and took escitalopram before. CPK level rapidly turned normal after quetiapine discontinued. Therefore, this patient was considered as rhabdomyolysis due to quetiapine treatment. The new generation antipsychotics (NGAs) are frequently prescribed as first-line drugs in the treatment of psychotic and mood disorders. CPK elevation has been observed during treatment with NGAs such as clozapine, loxapine, or olanzapine.5 However, only few cases about rhabdomyolysis associated with quetiapine have been reported so far.1–4 We described the first case of quetiapine-induced rhabdomyolysis in a patient with chronic renal disease. Quetiapine is primarily metabolized by sulfoxidation and oxidation with the cytochrome P450 (CYP) 3A4 isoenzyme and the 7-hydroxylated and the N-dealkylated metabolites are pharmacologically active.6 Escitalopram is metabolized by the CYP isoenzymes CYP2C19, CYP2D6, and CYP3A4. The combination of quetiapine with escitalopram may inhibit the elimination of quetiapine and consequently may increase drug level. One possible pathophysiological hypothesis explains CPK elevation during antipsychotic treatment as the result of a dysregulated sympathetic nervous system. According to this hypothesis, the inhibition of the sympathetic nervous system by dopaminergic neurons is suppressed by antipsychotic agents, and overdoses of catecholamines have been shown to lead to muscle cell necrosis.3 Moreover, our patient might have had a tendency to rhabdomyolysis because of having chronic kidney disease. In conclusion, NGAs are replacing traditional antipsychotics and are widely prescribed by clinicians. If there is a patient complaining about muscle pain during therapy with quetiapine, rhabdomyolysis should be suspected. In this situation, we suggest to have monitored closely muscle enzymes and renal functions, especially in patients with chronic kidney disease, while discontinuing quetiapine.

Peritonitis due to Pseudomonas stutzeri, an organism that may be difficult to culture.

prevented by keeping the bristles inside the sheath while the brush moves near the tip of the PD catheter. Moreover, the brush has an injection port that can be used to flush the catheter with heparinized saline during brushing and while advancing the brush toward the catheter tip without the need to remove the brush from the PD catheter between each trial of flushing. To confirm the patency of the catheter, a contrast can be injected through the same injection port while the brush is still inside the catheter.