A knitted garment using intarsia technique for Heart Rate Variability biofeedback: Evaluation of initial prototype.

Heart rate variability (HRV) biofeedback is a method based on paced breathing at specific rate called resonance frequency by giving online feedbacks from user respiration and its effect on HRV. Since the HRV is also influence by different factors like stress and emotions, stress related to an unfamiliar measurement device, cables and skin electrodes may cover the underling effect of such kind of intervention. Wearable systems are usually considered as intuitive solutions which are more familiar to the end-user and can help to improve usability and hence reducing the stress. In this work, a prototype of a knitted garment using intarsia technique is developed and evaluated. Results show the satisfactory level of quality for Electrocardiogram and thoracic electrical bioimpedance i.e. for respiration monitoring as a part of HRV biofeedback system. Using intarsia technique and conductive yarn for making the connection instead of cables will reduce the complexity of fabrication in textile production and hence reduce the final costs in a final commercial product. Further development of garment and Android application is ongoing and usability and efficiency of final prototype will be evaluated in detail.

Protective effects of melatonin against oxidative stress in flow cytometry-sorted buffalo sperm.

Previous reports of the ability of melatonin to scavenge a variety of toxic oxygen and nitrogen-based reactants suggest that melatonin could be an effective antioxidant for protecting sperm. In this study, flow cytometry and laser tweezers Raman spectroscopy were used to evaluate the effect of melatonin on buffalo sperm quality to optimize sperm sex-sorting procedures. In fresh sperm incubated in the presence or absence of melatonin (10(-4) m) for 1, 24, 48 h or 72 h at 27°C, the mitochondrial activity was significantly higher than in a non-melatonin control (p < 0.05). Also, during the flow-sorting process, sperm in melatonin-supplemented groups had higher (p < 0.05) mitochondrial activity than the control. The intensity of Raman spectra from sperm frozen in media supplemented with melatonin was significantly weaker than that for non-melatonin-treated groups, except for a band at 1302 per cm. Thus, melatonin helps to protect buffalo sperm from reactive oxygen species induced by staining, sorting and freezing and increases semen quality after the freezing-thawing processes. Furthermore, the results indicate the high potential of the laser tweezers Raman spectroscopy technique for rapid, effective and non-invasive assessment of the quality of sperm cells.

Litiasis prostática: cálculos silentes / Prostatic calculi: silent stones

Introducción y objetivos: En la práctica urológica se encuentran con frecuencia cálculos prostáticos durante la resección transuretral de la próstata. Nuestro objetivo era demostrar las propiedades físicas y químicas de los cálculos prostáticos, así como determinar la posible relación entre la inflamación de la próstata y los cálculos prostáticos. Métodos: Se incluyó en el estudio a pacientes consecutivos (excluidos los sujetos con PSA≥4ng/ml y urolitiasis) sometidos a resección transuretral de la próstata (RTUP) en quienes se observaron cálculos prostáticos. Se analizó la composición química de los cálculos prostáticos obtenidos de cada paciente durante la RTUP, que se observaron también al microscopio electrónico (MEB) para determinar su estructura y morfología superficial. El uroanatomopatólogo valoró las muestras para emitir el diagnóstico definitivo y determinar la existencia y el grado de la inflamación. Resultados: Se incluyó en el estudio a cinco pacientes. Se obtuvieron de cada paciente al menos tres (de 3–8) muestras de cálculos (con un diámetro de 1–5mm). Los cálculos tenían una composición mixta de fosfato cálcico y carbonato cálcico. En la MEB se observó que los cálculos tenían una superficie lobular formada por pequeñas esferas. El examen histopatológico de las muestras de RTUP reveló hiperplasia prostática benigna acompañada de inflamación entre leve e intensa. Conclusiones: Los cálculos prostáticos son cálculos de calcio precipitados concéntricamente situados dentro de los conductillos prostáticos con una morfología granular arracimada. Estos cálculos prostáticos parecen ir acompañados de inflamación histopatológica (AU)

Introduction and Objectives: Prostate stones are frequently encountered during transurethral resection of the prostate in urology practice. We aimed to demonstrate the physical and chemical properties of prostate stones. We also aimed to determine possible relationship between inflammation of prostate gland and prostate stones. Methods: The consecutive patients (excluding subjects with PSA≥4ng/ml and urolithiasis), who underwent TURP operation and who were observed to have prostatic calculi during TURP, were included in the study. The prostatic stones obtained from each patient during TURP were analysed for chemical composition and observed under electron microscopy (SEM) for structure and surface morphology. The pathological specimens were assessed by the uropathologist for the final diagnosis and existence and degree of inflammation. Results: Five patients were included in the study. From each patient at least three (range 3–8) samples of stones (diameter varying from 1mm up to 5mm) were obtained. The stones were made of mixed composition of calcium phosphate and calcium carbonate. The stones were found to have lobular surface made up of small spheres under SEM. Histopathological examination of the TURP specimens revealed being prostatic hyperplasia accompanied with inflammation of mild to severe degree. Conclusions: Prostatic stones are concentrically precipitated calcium stones within the prostatic ductuli with granular grape like morphology. Histopathological inflammation seems to be associated with these prostatic calculi (AU)

Comparison of osteogenesis of human embryonic stem cells within 2D and 3D culture systems.

The objective of this study was to compare the osteogenic potential of human embryonic stem cells (hESCs) within two- and three-dimensional (2D and 3D) culture systems. hESCs of the H1 line (Wicell Inc., Madison, Wisc., USA) were induced to form embryoid bodies (EBs) through 5 days of suspension culture within non-adherent culture dishes. Following enzymatic dissociation, the EB-derived single cells were seeded on either novel 3D porous PLGA scaffolds or 2D culture dishes with the same total cell number. Osteogenic differentiation was induced through culture media supplemented with dexamethasone, L-ascorbic acid and beta-glycerophosphate. After 3 weeks of in vitro culture, quantitative and qualitative assays of osteogenic differentiation were conducted. Osteocalcin secretion and alkaline phosphatase (AP) activities were detected at significantly higher levels within 3D culture compared with the 2D system. Subsequently, the cell-scaffold constructs were implanted in iliac crest defects of immunosuppressed rabbits. After 4 weeks, the constructs were subsequently explanted and characterized by histology and X-ray analysis. Formation of new bone was detected within and around the implanted scaffolds. The results demonstrate that the osteogenic differentiation of human embryonic stem cells is enhanced in a 3D culture system compared to a 2D culture environment. Upon implantation in situ, the differentiating human embryonic stem cells can contribute positively to the repair and regeneration of bone defects.

α-Tocopherol and l-ascorbic acid increase the in vitro development of IVM/IVF swamp buffalo ( Bubalus bubalis) embryos.

This study was conducted to investigate the effects of capacitating agents added at in vitro fertilization (IVF) and antioxidants supplemented during in vitro culture (IVC) on the development of buffalo embryos. In experiment I, in vitro embryo development of buffalo embryos was compared when the IVF medium was supplemented with heparin, caffeine and calcium ionophore A23187 either alone or in combination. There was no significant difference (P > 0.05) in the cleavage rates of oocytes among the treatment groups but the development rate to the blastocyst stage and the cell numbers of blastocyst in the heparin-treated group were significantly higher (P < 0.05) than that of other treatments. In experiment II, in vitro embryo development of buffalo embryos was compared when IVC medium was supplemented with either α-tocopherol (250 and 500 µM) or l-ascorbic acid (250 and 500 µM). The rate of development to the blastocyst stage of embryos cultured in medium supplemented with 250 µM α-tocopherol (33%, 41/123) and 250 µM l-ascorbic acid (31%, 38/123) was significantly higher (P < 0.05) than that of those cultured in medium alone (19%, 20/108) but not significantly different (P < 0.05) from medium supplemented with either 500 µM α-tocopherol (24%, 30/123) or 500 µM l-ascorbic acid (25%, 33/133). These results suggest that buffalo spermatozoa treated with heparin were suitable for IVF and that α-tocopherol and l-ascorbic acid added during IVC increased the rate of buffalo embryo development.

Treatment of osteoporosis with TheraCyte-encapsulated parathyroid cells: a study in a rat model.

INTRODUCTION: The purpose of this study was to evaluate parathyroid function at monthly intervals following the implantation of TheraCyte-encapsulated live human parathyroid cells into ovariectomized rats and to determine the effect on bone mineral density (BMD) 4 months after ovariectomy ( 3 months after implantation). METHODS: Parathyroid tissues were obtained from patients undergoing surgery for secondary hyperparathyroidism. In total, 21 Sprague-Dawley rats divided randomly into three groups were subjected to one of three treatments: (1) implanted with TheraCyte A-encapsulated 4x10(6) live parathyroid cells; (2) implanted with TheraCyte B-encapsulated 4x10(5) live parathyroid cells; (3) a sham operation; the control group. Rats were ovariectomized 1 month prior to the implantation of the TheraCyte. Blood was drawn at the time of implantation and at monthly intervals thereafter for 3 months to check the levels of calcium, phosphorus and intact parathyroid hormone (iPTH). The BMD of the lumbar spine (L1-L5) and of the left femoral bone was measured with dual-energy-X-ray absorptiometry (DEXA) 1 month after ovariectomy and 3 months after implantation of the TheraCyte (4 months after ovariectomy). RESULTS: We found that the viability ratio of cryopreserved tissues was between 55 and 79% after thawing. In the control group, the BMD of the lumbar spine (L1-L5) had not decreased significantly (p=0.237) nor had the BMD of the left femoral bone increased significantly (p=0.063) 3 months after implantation. In the TheraCyte A group, the BMD of both the lumbar spine (p=0.018) and left femoral bone (p=0.018) had increased significantly 3 months after implantation. In the TheraCyte B group, the BMD of both the lumbar spine (p=0.017) and the left femoral bone (p=0.025) had also increased significantly 3 months after implantation. Serum iPTH levels were higher in the TheraCyte A group than in the TheraCyte B group (p=0.006), and higher in the TheraCyte B group than in the control group (p=0.040). Serum calcium levels were not significantly higher in the TheraCyte group A than in the TheraCyte B group or in the control group. Serum phosphorus levels were not significantly different between the TheraCyte A and TheraCyte B groups. CONCLUSIONS: Implantation of TheraCyte A-encapsulated 4x10(5) live parathyroid cells and TheraCyte B-encapsulated 4x10(6) cells can increase the BMD of ovariectomized rats within 3 months of implantation. Neither cause high serum calcium and low phosphorus concentrations.

Oral administration of paclitaxel affects the distribution and metabolism of 2-aminofluorene in various tissues of Sprague-Dawley rats.

To evaluate the question of whether or not paclitaxel affects the distribution and metabolism of chemical carcinogens such as 2-aminofluorene (AF) on Sprague-Dawley rats were examined. The AF, acetylated AF and AF metabolites were determined and examined by using high performance liquid chromatography. After having received AF only, AF with paclitaxel at the same time and paclitaxel pretreated for 24 h then treated with AF for 24 h, urine, stool and tissues such as liver, kidneys, stomach, colon, bladder and blood were collected and assayed for AF and its metabolites. Compared to the control group, paclitaxel caused an increase of the metabolites excreted in urine and stool. The major metabolite excreted in urine and stool was 9-OH-AAF. The liver is the major metabolism center and the major residual metabolite of AF in the liver was also 9-OH-AAF.

Analysis of three lupane type triterpenoids in Helicteres angustifolia by high-performance liquid chromatography.

Kang-chih-ma is the dried roots and stems of Helicteres angustifolia (Sterculiaceae) and a commonly used folk herbal drug in Taiwan. It possesses antidotal, analgesic, anti-inflammatory and anti-bacterial effects and is also known as a kind of tumor inhibitory plant. To evaluate the quality of H. angustifolia, a simple, rapid and accurate high-performance liquid chromatographic (HPLC) method was developed for the assay of three lupane type triterpenes: 3beta-acetoxy-27-benzoyloxylup-20(29)-en-28-oic acid methyl ester (methyl helicterate), 3beta-acetoxy-27-benzoyloxylup-20(29)-en-28-oic acid, and 3beta-acetoxy-27-(p-hydroxyl) benzoyloxylup-20(29)-en-28-oic acid methyl ester. The present HPLC system used an Inertsil ODS-2 column by gradient elution with acetonitrile and water as the mobile phase and detected at UV 230 nm. Regression equations revealed good linear relationships (correlation coefficients: 0.9922-0.9997). The relative standard deviations of these three constituents ranged between 1.05-3.14% (intraday) and 2.12-4.38% (interday). The contents of these three constituents of the heartwood and the bark of the roots of H. angustifolia in five different samples have also been determined.

Western and Chinese antirheumatic drug-induced T cell apoptotic DNA damage uses different caspase cascades and is independent of Fas/Fas ligand interaction.

Spontaneous or therapeutic induction of T cell apoptosis plays a critical role in establishing transplantation tolerance and maintaining remission of autoimmune diseases. We investigated the mechanisms of apoptosis induced by Chinese and Western antirheumatic drugs (ARDs) in human T cells. We found that hydroxychloroquine, Tripterygium wilfordii hook F, and tetrandrine (Tet), but not methotrexate, at therapeutic concentrations can cause T cell death. In addition, Tet selectively killed T cells, especially activated T cells. Although ARD-induced cytotoxicity was mediated through apoptotic mechanisms, Fas/Fas ligand interaction was not required. We further demonstrated that the processes of phosphatidylserine externalization and DNA damage along the ARD-induced T cell apoptotic pathway could operate independently, and that selective inhibition of DNA damage by caspase inhibitors did not prevent T cells from undergoing cell death. Moreover, we found that Tet- and Tripterygium wilfordii hook F-induced T cell DNA damage required caspase-3 activity, and hydroxychloroquine-induced T cell DNA damage was mediated through a caspase-3- and caspase-8-independent, but Z-Asp-Glu-Val-Asp-fluomethyl ketone-sensitive, signaling pathway. Finally, the observation that ARD-induced activation of caspase-3 in both Fas-sensitive and Fas-resistant Jurkat T cells indicates that Fas/Fas ligand interaction plays no role in ARD-induced T cell apoptosis. Our observations provide new information about the complex apoptotic mechanisms of ARDs, and have implications for combining Western and Chinese ARDs that have different immunomodulatory mechanisms in the therapy of autoimmune diseases and transplantation rejection.

Bacteriologic and clinical efficacy of ofloxacin 0.3% versus ciprofloxacin 0.3% ophthalmic solutions in the treatment of patients with culture-positive bacterial keratitis.

PURPOSE: To compare the efficacy and safety of ofloxacin 0.3% ophthalmic solution with ciprofloxacin 0.3% ophthalmic solution in patients with culture-positive bacterial keratitis. METHODS: Patients with a microbiologic diagnosis of bacterial keratitis were included in this double-masked, parallel-group study and were randomized to treatment with either ofloxacin 0.3% or ciprofloxacin 0.3% ophthalmic solution. One drop of the study medication was instilled during the daytime according to the following schedule: every half-hour on study day 1, every hour on days 2 through 4, and every 2 hours on days 5 through 21. Healing, the primary outcome measure, was defined as complete reepithelialization, accompanied by nonprogression of stromal infiltrate for 2 days. Secondary outcome measures included signs and symptoms of infection. Patients were monitored throughout the study period for any adverse events. RESULTS: A total of 217 patients completed the study: 112 were treated with ofloxacin and 105 were treated with ciprofloxacin. Streptococcus pneumoniae was the most commonly encountered pathogen in all patients. Complete corneal reepithelialization occurred in 85% of those treated with ofloxacin and in 77% of those treated with ciprofloxacin (p = 0.32). The average time to corneal ulcer healing was 13.7 days in those treated with ofloxacin and 14.4 days in those treated with ciprofloxacin. Both treatments were well tolerated with no patient discontinuing the study because of side effects. CONCLUSION: Ofloxacin 0.3% and ciprofloxacin 0.3% ophthalmic solutions are effective and safe in the treatment of patients with culture-positive bacterial keratitis.

Functional replacement of the essential ESS1 in yeast by the plant parvulin DlPar13.

A functionally Pin1-like peptidyl-prolyl cis/trans isomerase (PPIase(1)) was isolated from proembryogenic masses (PEMs) of Digitalis lanata according to its enzymatic activity. Partial sequence analysis of the purified enzyme (DlPar13) revealed sequence homology to members of the parvulin family of PPIases. Similar to human Pin1 and yeast Ess1, it exhibits catalytic activity toward substrates containing (Thr(P)/Ser(P))-Pro peptide bonds and comparable inhibition kinetics with juglone. Unlike Pin1-type enzymes it lacks the phosphoserine or phosphothreonine binding WW domain. Western blotting with anti-DlPar13 serum recognized the endogenous form in nucleic and cytosolic fractions of the plant cells. Since the PIN1 homologue ESS1 is an essential gene, complementation experiments in yeast were performed. When overexpressed in Saccharomyces cerevisiae DlPar13 is almost as effective as hPin1 in rescuing the temperature-sensitive phenotype caused by a mutation in ESS1. In contrast, the human parvulin hPar14 is not able to rescue the lethal phenotype of this yeast strain at nonpermissive temperatures. These results suggest a function for DlPar13 rather similar to parvulins of the Pin1-type.

[Separation and determination of ephedrine alkaloids and 2,3,5,6-tetramethyl pyrazine in Ephedra herba by HPLC].

A sensitive and reliable high performance liquid chromatographic method(HPLC) has been developed for the first time for the simultaneous determination of the active ingredients of ephedrine alkaloids and 2,3,5,6-tetramethyl pyrazine (TMP) in Ephedra herba crude drug and two Chinese traditional medicines (Xiao-er qingfeiwan and Lu-si kewan). The HPLC assay was performed on a reversed phase C18 column (Nova-Pak C18, 3.9 mm i.d. x 150 mm) by using methanol-0.02 mol/L KH2PO4-acetic acid-triethyl amine (4:96:0.2:0.01, V/V) as mobile phase for the ephedrine alkaloids analysis and methanol-H2O-acetic acid (35:65:0.5, V/V) as mobile phase for TMP analysis. Regression equations revealed the linear relationships (correlation coefficients: 0.991-0.998) between the peak area of each constituent (E, PE, NE, NPE, TMP) and its concentration. The detection limits for E, PE, NE, NPE and TMP were 0.4 mg/L, 0.1 mg/L, 0.03 mg/L, 0.02 mg/L and 0.03 mg/L, respectively, and the recoveries ranged between 92%-103%. The contents of E, PE, NE, NPE, TMP in Ephedra herba, traditional medicine Xiao-er qingfeiwan and Lu-si kewan were determined respectively. The relative standard deviations (RSD) of the contents ranged between 1.1%-3%.

[Genetic control of the biotransformation of plant terpenoids by Pseudomonas strain SP.1K1]. / Geneticheskii kontrol' biotransformatsii terpenoidov rastitel'nogo proiskhozhdeniia s pomoshch'iu shtamma Pseudomonas SP.1K1.

Bacterial strain Pseudomonas sp. 1K1 can grow on sesquiterpene lactones isolated from medicinal plants of Kazakhstan due to 18-kb conjugative plasmid. This plasmid is stable in heterologous environment (E. coli and B. subtilis), which was proven by transformation transfer. The possibility of using salicylate as p1K1 selective agent has been demonstrated.

[Determination of ferulic acid in chuanxiong and in animal serum and cerebrospinal fluid by reversed-phase high performance liquid chromatography].

An easy, rapid and sensitive method for the determination of ferulic acid(FA) in Chuanxiong extracts, animal (mouse) serum and cerebrospinal fluid by RP-HPLC has been developed. The FA was separated on an ODS column, Nova-Pak C18(3.9 mm i.d. x 150 mm) and detected at the wavelength of 320 nm. The mobile phase was methanol-water-acetic acid (35:65:0.5, V/V), with a flow rate of 0.8 mL/min. The detection limit of FA was 1.7 micrograms/L(S/N = 3) and the calibration curve was linear within the range of 0.85 mg/L-4.00 mg/L(r = 0.99904, n = 6). The mean recovery from animal serum and cerebrospinal was 95%-102%.

The evaluation of the therapeutic effect of tao-shang-tsao on alpha-naphthylisothiocyanate and carbon tetrachloride-induced acute liver damage in rats.

The hepatoprotective effects of Tao-shang-tsao, Ixeris laevigata Sch.-Bip. var. oldhami Kitam., were studied on cholestatic hepatitis induced by alpha-naphthylisothiocyanate (ANIT, 100 mg/10 ml/kg, in olive oil, i.p.) and acute hepatitis induced by carbon tetrachloride (20% CCl4/olive oil, 1.5 ml/kg, i.p.) in rats by post-treatment with the crude methanolic extracts of I. laevigata (0.3, 1.0, and 2.0 g/kg) orally in the therapeutic model. Hepatoprotective activity was monitored by estimating the serum transaminases concentrations and histopathological changes in the livers of experimental rats. It was found that the I. laevigata extract significantly decreased the acute elevation of serum transaminases by biochemical examination. According to pathohistological studies in the liver of experimental rats, the crude I. laevigata extract ameliorates the central necrosis, fatty change or proliferation of bile duct epithelium focal necrosis caused by ANIT or CCl4-induced hepatitis rats.

Morphological, immunohistochemical and quantitative studies of murine brain mast cells after mating.

The mast cell is one of the immune cells, and can be triggered behaviorally to increase in the CNS of the sexually active dove. In the present study, we used ICR mice to investigate the number of brain mast cells in mated (one male with three female mice), non-mated (housed with female mice, but no mating) and control (four male mice housed together in one cage) male mice. We found that at least 40% of mated male mice had significant more mast cells than the maximum value seen in the controls, and that a significant correlation existed between the distribution index of mast cells and the postcoitum date. These mast cells were especially numerous in the thalamus and velum interpositum (VIP). Morphological observations showed that the increased mast cells were ultrastructurally similar to those in the controls, and displayed gonadotropin-releasing hormone (GnRH)-like immunoreactivity. Based on the facts that the number of brain mast cells in the male mice increased significantly after mating and that the change in the distribution of mast cells in the VIP and the thalamic parenchyma correlated well with time postcoitum, we speculate that, after mating, mast cells may migrate from the VIP to the thalamic parenchyma along the vascular tree of the brain. These results strongly suggest that mast cells are involved in the interaction among the immune, endocrine, and nervous systems in the mated male mouse brain.

Renal tubular acidosis, hypokalemic paralysis, rhabdomyolysis, and acute renal failure--a rare presentation of Chinese herbal nephropathy.

We encountered a 66-year-old Chinese man presented with hypokalemic paralysis, rhabdomyolysis and acute renal failure after administration of mixed Chinese herbs. Proximal renal tubular acidosis and selective glucosuria were the main tubular dysfunctions. The renal failure recovered smoothly and rapidly after resuscitation and the tubular function abnormalities regained spontaneously after medicine withdrawal. It should be recognized that renal tubular acidosis with hypokalemic paralysis, rhabdomyolysis and subsequent acute renal failure may develop after taking Chinese mixed herbal medicine.

A missense mutation of mouse OCTN2, a sodium-dependent carnitine cotransporter, in the juvenile visceral steatosis mouse.

Carnitine is an essential cofactor for the mitochondrial beta-oxidation of long-chain fatty acids. The juvenile visceral steatosis (JVS) mouse, an animal model of systemic carnitine deficiency, is inherited in an autosomal recessive manner. Recently, a human OCTN2 gene encoding a sodium-dependent carnitine cotransporter was isolated and mapped to human chromosome 5q31. Since the mouse jvs locus was assigned to the region of chromosome 11 where it is syntenic to human chromosome 5q31, we isolated the mouse octn2 gene and screened for its mutation in the jvs mouse. DNA sequencing analysis disclosed a missense mutation from CTG (Leu) to CGG (Arg) at codon 352 located within the sixth transmembrane domain of octn2. This amino acid replacement possibly causes the conformational change of the protein that leads to dysfunction of the gene product. Hence, we conclude that octn2 is a candidate gene responsible for the JVS mouse.

Effect of calcitriol treatment on psoriasis in hemodialysis patient: a case report.

The case of a 67-year-old man who has had psoriasis with multiple joints involvement for 30 years and renal failure for 1 year is described. He was admitted because of uremic symptoms and exacerbation of psoriasis. Hypocalcemia and low serum active 1.25(OH)2D3 were also observed. Hemodialysis, oral 1.25(OH)2D3 and CaCO3 supplement were employed. Interestingly, the psoriasis strikingly improved. The relationships among psoriasis, renal failure, 1.25(OH)2D3, serum calcium level and dialysis are discussed.

Rapid correction of metabolic acidosis in chronic renal failure: effect on parathyroid hormone activity.

To investigate the effect of rapid correction of chronic metabolic acidosis on circulating intact parathyroid hormone (I-PTH) activity by free calcium clamp in chronic renal failure, 18 patients were enrolled in this study. Metabolic acidosis was corrected by continuous bicarbonate infusion while plasma ionized calcium was clamped at the preinfusion level throughout the entire procedure. The plasma pH, bicarbonate, total CO2, sodium, serum total calcium and 1,25(OH)2 vitamin D3 levels increased significantly while serum concentrations of I-PTH, alkaline phosphatase and albumin showed significant decreases after bicarbonate infusion. The plasma ionized calcium, potassium, serum magnesium and inorganic phosphorus levels showed no significant difference before and after bicarbonate infusion. These results demonstrate that rapid correction of metabolic acidosis attenuates circulating PTH activity in chronic renal failure and may underline the importance of maintaining normal acid-base homeostasis particularly in the presence of secondary hyperparathyroidism.