Preanalysis in Serum Hepcidin Measurement.

BACKGROUND: Hepcidin is a 25-amino peptide hormone that regulates iron homeostasis. Its serum quantification helps to provide the right therapeutic choice in iron-deficiency anemia and anemia in chronic diseases. Diurnal levels of serum iron might affect hepcidin secretion during the day. Blood collection time is an important part of the preanalytical phase of its quantification. METHODS: During the period 2013 - 2014, we collected blood samples for serum hepcidin quantification in 100 healthy controls. The samples were collected in vacuettes with serum separator gel at three different times during the day: 07:30 - 08:30, 12:00 - 13:00, and 16:00 - 17:00 hours. Hepcidin levels were measured with an ELISA method. RESULTS: We found a significant difference in serum hepcidin levels during the chosen three blood taking times. The normal range for Bulgarian population is 3.05 µg/L - 37.75 µg/L. The measured levels were: at 07:30 - 08:30 hours 12.2 µg/L (5.5 µg/L - 23.6 µg/L), 12:00 - 13:00 hours 14.1 µg/L (7.1 µg/L - 27.2 µg/L), and 16:00 - 17:00 hours 16.5 µtg/L (9.9 µg/L - 29.6 µpg/L) 10.7 < r < 1.0; p < 0.5 between 07:30 - 08:30 and 12:00 - 13:00 hours and p < 0.05 between 07:30 - 08:30 hours and 16:00 - 17:00 hours and 12:00 - 13:00 hours and 16:00 - 17:00 hours]. No significant differences were found for transferrin saturation between measured groups [0.1 < r < 0.3; p > 0.5]. CONCLUSIONS: In order to obtain the most correct results for serum hepcidin quantification (especially in border to referent range levels) in the preanalytical phase, it is important to consider the time of blood sampling.

Zinc status in patients with chronic renal failure on conservative and peritoneal dialysis treatment.

BACKGROUND AND AIM: The physiological mechanisms regulating zinc homeostasis in humans have been elucidated and described, but the knowledge of zinc status and zinc distribution in the tissues and in the different biological compartments of patients with conservatively treated chronic renal failure (CRF) and on peritoneal dialysis is still insufficient. This investigation examines and compares zinc content in urine, erythrocytes, plasma, and outflow dialysis solution in a group of continuous ambulatory peritoneal dialysis (CAPD) patients, a group of patients with CRF on conservative treatment and in healthy controls. MATERIAL AND METHODS: Data from the last 6 months of 22 adult hemodialysis patients with a mean age of 61 ± 14 years were analyzed retrospectively. Dialysis vintage, normalized protein catabolic rate (nPCR), serum biochemical parameters, mid arm muscle circumference (MAMC) were determined as mean and standard deviation. Correlations between the variables were computed by coefficient p of Pearson. RESULTS AND CONCLUSION: In patients on CAPD treatment (group 3) compared to healthy controls (group 1) plasma zinc level was diminished (р<0.05), while erythrocyte zinc elevated (р<0.01). The investigation found out difference between plasma, erythrocyte and urine levels of zinc between the patients with chronic renal failure (group 2) on conservative treatment and those treated by CAPD (group 3), which proves, that continuous ambulatory peritoneal dialysis influences redistribution of zinc in human organism "per se".

Aluminum concentrations in serum of patients with intracranial tumors.

The concentration of serum aluminum was measured by electrothermal atomic absorption spectrometry in 71 patients with intracranial tumors. The data were compared with those from a reference group of 15 healthy adult individuals. The serum concentrations of aluminum were significantly increased (p < 0.01) in patients with malignant gliomas and meningiomas. The concentrations of serum calcium, known as an antagonist of aluminum, were normal in the same patients.

Selenium in the treatment of patients with brain gliomas. A pilot study.

The authors have added selenium tablets to the diet of 15 patients with malignant brain tumors. In twelve patients with glioblastoma multiforme this treatment didn't prolong the postoperative survival. Further clinical observations are necessary to precise the usefulness of selenium in cases of low-grade gliomas.

Excretory function of denervated kidney after inhibition of prostaglandin synthesis and furosemide administration in conscious dogs.

The experiments were carried out on unanaesthetized dogs with exteriorized ureters for separate urine collection from the left (denervated) and the right (intact) kidney. The osmolality and concentrations of sodium, potassium, calcium, magnesium, zinc, copper, chloride and creatinine were determined in the plasma as well as in the urine of the two kidneys. The function of the denervated and the innervated kidney was compared prior to and after indomethacin administration (5.0 mg/kg b.w.). The excretory function of both kidneys was also compared after furosemide treatment alone (0.5 mg/kg b.w.) as well as indomethacin pretreatment. Renal denervation increased urine flow rate, calcium and copper excretion. After administration, sodium excretion from the denervated kidney was higher than that from the intact one. Calcium excretion of the two kidneys did not differ significantly, while copper excretion from the denervated kidney was diminished, Furosemide administration after pretreatment with indomethacin did not lead to any difference between the denervated and intact kidney. The results show that renal nerves and prostaglandins participate jointly in the regulation of sodium, copper and calcium excretion. Renal prostaglandins do not change the response of the denervated kidney to furosemide as compared to the intact kidney.

Selenium concentrations in serum of patients with cerebral and extracerebral tumors.

The concentrations of serum selenium were measured by atomic absorption spectrophotometry in 139 patients with tumors in cranium cavity. The data from patients were compared with those from a reference group of 294 healthy adult individuals. The serum concentrations of selenium is significantly decreased (p less than 0.001) in patients with malignant tumors. The authors discuss the possibilities for treatment of malignant tumours of central nervous system with selenium.

Excretory function of intact kidney after contralateral denervation on unanaesthetized dogs.

The experiments were carried out on unanaesthetized dogs with exteriorized ureters. The left kidney was denervated. The function of the left and right kidneys was compared prior to and after furosemide administration, 0.2 mg/kg b. w. The function of the right intact kidney prior to and after left kidney denervation was also compared. The concentrations of sodium, potassium, chloride, calcium, magnesium, zinc, copper, urea, and creatinine in plasma and urine were determined. Denervation of the left kidney was followed by an increase of diuresis, calcium, and copper excretion from the denervated kidney. After furosemide administration the chloride excretion from the side of denervation was also observed to increase. The changes in the excretory function of the left kidney after denervation were not accompanied by changes in excretory function of right (intact) kidney. The excretory function of the intact kidney after denervation of contralateral kidney and furosemide administration did not differ from that prior to denervation and furosemide administration. In unanaesthetized dogs no changes in the excretory function of intact kidney were observed as a result of contralateral kidney denervation.