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PubMedDate not supplied

[Chronic dialysis in Uruguay: mortality trends from 1981 to 1998]].

Uruguay is a developing country with 3.16 million inhabitants. Chronic dialysis treatment (CDT) expanded after the creation of a National Fund of Resources in 1980 who receives contribution from all inhabitants to finance, among others, the CDT and renal transplantation. During the 1981-1998 period, about 4,819 patients were treatment, 2,365 patients had died, 454 were transplanted and 51 patients were lost to follow-up due to change in residence. At the start of the treatment, mean age was 57.0 +/- 17.7 years, 37% were 65 or older than 65 year old, 61.3% were male and 98% of patients were white persons. The most common diseases responsible for End Stage Renal Disease were: hypertension (22%), chronic glomerulonephritis (19%) and diabetic nephropathy (15%). In 1998, there were 44 dialysis units in the country (13.6 units per million population--pmp), 100% of them had water treatment (reverse osmosis 96.8%) and reuse dialyzer. The most frequent causes of death were: cardiovascular and infection. In this paper, eighteen years of the mortality time course of CDT are analyzed. Annual mortality rate was expressed as deaths per 1,000 patients years at risk (M/1,000). The indirect standardization method was applied to adjust the mortality rate. Two populations were used as standard: the 1996 population of USRDS to adjust for age, sex, race and nephropathy and the 1996 Uruguayan general population to adjust for age. Standardized mortality rate (SMR) for each year was obtained dividing observed deaths by expected deaths. From 1981 to 1998, the incident population increased from 32 to 133 patients per million populations and the prevalent population from 28 to 639 pmp. There was a simultaneously increase in the prevalence of diabetic patients and of patients older than 65 years. The annual mortality rate decreased from 249 to 138 deaths per 1,000 patient years (M/1,000). The standardized mortality (SM) with the USRDS population as standard decreased from 452 in 1981 to 132 in 1998 and the SMR from 2.07 to 0.60. The SMR with the Uruguayan general population decreased from 17 to 4. In conclusion, these results are similar with those observed in developed countries. There has been a decrease both in the gross and the standardized mortality ratio in the period of observation.

Adult↗
PubMed2002

[Remediation of chromium-polluted soil using municipal solid waste compost].

A study on the feasibiltiy of remediation of Cr-polluted soil using municipal solid waste(MSW) compost was carried out. The result showed that organic matter(O.M.), Eh, pH and < 0.01 mm of clay would influence the bioavailability of chromium in the soil, and O. M. and Eh were the principal influencing factors in the dryfield and inundating soil, up to 73.40% and 55.5% of the contribution rate affecting the bioavailability of chromium, respectively. The osmosis of the soil was improved when compost was applied, but the quantity of movable chromium was reduced because chromium in soil was deoxidized and adsorbed. MSW compost could reduce the absorption of chromium by the tested plant. The yield of the plant grown in the dry soil was increased by 35.9% and the content of Cr in the plant was decreased by 48.9%. The effect was more notable in the inundating soil: 86.3% of the yield increased and 23.8% of the Cr content decreased. However, MSW compost could not increase the risk of other heavy metal pollution.

Chromium↗
PubMed2002

[Effect of a dialysis solution with icodextrin on ultrafiltration and selected metabolic parameters in patients treated with peritoneal dialysis].

BACKGROUND: To date, peritoneal dialysis has been performed almost exclusively using dialysis solutions containing glucose as the osmotic agent. Use of these solutions is fraught with problems regarding adequate fluid removal from the body and is also associated with undesirable metabolic effects; hence the search for alternative osmotic agents. A dialysis solution with the glucose polymer icodextrin generates ultrafiltration on the principle of colloidal osmosis. The aim of the study was to establish the effect of icodextrin-base dialysis solution on the magnitude of ultrafiltration and evaluate selected metabolic parameters of patients treated by ambulatory peritoneal dialysis. METHODS AND RESULTS: A total of 9 patients whose glucose-based solution was replaced by an icodextrin-based solution during the night-time exchange were evaluated. A control group of 9 patients used glucose-solution during all exchanges. Night-time bag ultrafiltration, blood pressure, and the serum levels of lipids, insulin, leptin, maltose, and amylase were determined before icodextrin administration (time 0), at one-month intervals (time 1, 2, 3), and one month after study completion (time 4). In icodextrin-treated patients, ultrafiltration rose from 246.5 +/- 60.5 ml (mean +/- SEM) at time 0 to 593.1 +/- 87.4 ml; p < 0.01, at time 1, to 547 +/- 67 ml; p < 0.05, at time 2, and to 586.7 +/- 58.8 ml; p < 0.01, at time 3, the icodextrin administration led to a rise in maltose from 0.02 +/- 0.01 g/l at time 0 to 0.1 +/- 0.1 g/l; p < 0.01, at time 1, to 1.0 +/- 0.09 g/l; p < 0.01, at time 2, and to 1.1 +/- 0.09 g/l; p < 0.01, at time 3, with a fall to zero values at time 4 (NS). Icodextrin administration was followed by a decrease in leptinemia from 34.6 +/- 17.2 ng/ml at time 0 to 21.7 +/- 8.9 ng/ml; p < 0.05, at time 1, to 21.4 +/- 9.5 ng/ml; p < 0.05, at time 2, and to 15.9 +/- 24.1 ng/ml; p < 0.05 at time 4. Insulin and lipid levels were not affected. There was no change in the above parameters in the control group. Icodextrin-treated patients reduced their antihypertensive medication, but not statistically significantly. CONCLUSION: Icodextrin administration significantly increase ultrafiltration thus providing for effective control of hydration status without the need for high-level glucose-based dialysis solutions. The use of a glucose polymer-based dialysis solution is associated with a significant yet reversible rise in serum maltose. The decrease in leptin may signal a reduction in body weight after replacing glucose in dialysis solutions with icodextrin, or enhanced rates of leptin elimination as a result of ultrafiltration-induced convective transport.

Adult↗
PubMed2002

Isolation of compounds from bleached kraft mill recovery condensates associated with reduced levels of testosterone in mummichog (Fundulus heteroclitus).

Previous studies have identified chemical recovery condensates as a primary source of hormonally active substances within a Canadian bleached kraft pulp mill. Although reverse osmosis treatment of condensates raises the exposure threshold that alters circulating levels of testosterone in mummichog (Fundulus heteroclitus), the responsible chemicals have not been characterized. In this study, a solid-phase extraction (SPE) method was developed to isolate chemical recovery condensate extractives for evaluation of hormonal activity. Condensates generated during softwood and hardwood pulp production were investigated for their relative potential to affect both circulating and gonadal production of sex steroids in mummichog. Mummichog were exposed to whole condensates, extracts from suspended particulates (> 1 microm), two fractions from SPE, and residual condensates after SPE. The distribution of bioactivity among condensate fractions was similar for both wood furnishes. In both sexes, significant depressions in circulating testosterone and in in vitro gonadal testosterone production were associated with exposure to whole condensates, particulate extracts, one SPE fraction, and residual material after SPE. An optimized SPE method subsequently demonstrated complete recovery of polar, bioavailable chemicals that reduced testosterone levels in both sexes. Characterizations of active fractions by gas chromatography-mass spectrometry (GC-MS) showed the presence of extractives with molecular masses > or = 240 amu possessing functionalities consistent with lignin degradation products. This study provides the first isolation of chemicals derived from pulp production associated with impaired reproductive performance in fish.

Animals↗
PubMedDate not supplied

Chronic peritoneal dialysis in the management of chronic renal failure.

Three patients with indwelling Tenckhoff catheters were maintained on peritoneal dialysis using an automated reverse-osmosis dialysis machine. All showed striking improvement. Peritonitis developed in two and necessitated catheter replacement in one. Strict aseptic technique in the dialysis procedure is emphasised, prevention of peritonitis being the key to success. Long-term peritoneal dialysis offers three advantages: it is a practical alternative to haemodialysis in selected cases, especially where trained personnel are few; it is simpler and cheaper.

Adult↗
PubMed2002

Pilot-scale testing membrane bioreactor for wastewater reclamation in industrial laundry.

A pilot-scale study of membrane bioreactor treatment for reclamation of wastewater from Berendsen Textile Service industrial laundry in Søborg, Denmark was carried out over a 4 month period. A satisfactory COD degradation was performed resulting in a low COD in the permeate (< 50 mg/l). To obtain satisfactory treatment, addition of nitrogen was necessary. The biodegradability of the permeate was very low (BOD5 < 2 mg/l). A hydraulic retention time of 1 d turned out to be sufficient at a sludge concentration of 10 g MLSS/l. Through addition of a cationic polymer, a satisfactory dewaterability of the sludge was reached. Membrane tests showed that operating at a trans-membrane pressure of 3 bar and a cross-flow velocity of 4 m/s, a flux of 120 l/m2h can be expected without using chemicals for membrane cleaning. The quality of the permeate was very good when comparing to the reuse quality demands of water to the wash processes. Reuse of the permeate in all rinsing steps requires additional treatment through reverse osmosis.

Biodegradation, Environmental↗
PubMed1975

Gram-negative water bacteria in hemodialysis systems.

Gram-negative bacteria can multiply relatively fast in a variety of hospital associated fluids ranging from distilled, deionized, reverse osmosis, and softened water, which are normally considered devoid of nutrients, to intravenous solutions and fluids associated with hemodialysis. Excessive levels of these bacteria in the dialysate of artificial kidney machines can be responsible for pyrogenic reactions or sepsis or both.

Gram-Negative Aerobic Bacteria↗
PubMed2002

Fluorescence technique for the characterization of natural organic matter in river water.

The complex nature of natural organic matter (NOM), and the impact of this matter on drinking water quality have necessitated the characterization studies of NOM. A fluorescence technique for the characterization of NOM in Malaysian river water is reported. Water samples from several river sampling sites were collected and concentrated using a low-pressure reverse osmosis (LPROM). Solid phase extraction (SPE) using C18 extraction cartridges were used to fractionate the water samples into humic and non-humic fractions. To differentiate and classify various types of humic substances, fluorescence was applied in emission, excitation and in synchronous-scan modes. A synchronous spectral profile was found to be able to differentiate humic and fulvic acids better than the emission or excitation spectra. Synchronous excitation spectra showed different spectral patterns for the water samples due to different origin. All water samples showed the presence of both fulvic and humic acids.

Benzopyrans↗
PubMed2003

[Determination of tolerance ability of platelet to the change of solution osmotic pressure and its significance].

In order to determine the tolerance ability of platelet to change of osmotic pressure in solution, the isotonic fresh platelets were exposed to a series of crystal salt solutions with osmotic pressure range from 47 to 611 mOsm for 15 minutes. Then the platelets were returned to isotonic condition and kept for 15 minutes. The expressions of phosphatidylserine and CD62p were assayed in platelets. The results showed that the phosphatidylserine and CD62p expressions were increased when the osmotic pressure of solution was below 238 mOsm, but no significant rise was detected when the platelets were exposed to 611 mOsm solution. No increases of positive rate of CD62p and phosphatidylserine were detected in platelets returned to isotonic condition. It is concluded that platelets are sensitive to hypoosmotic solution and tolerated to hyperosmotic solution. Exceeding the platelet safe volume limitation may lead to injure of platelet osmosis in crystal salt solution.

Blood Platelets↗
PubMed2003

Characteristics of the hypoosmosis-induced calcium response in isolated nerve terminals of rat brain.

BACKGROUND: Cerebral edema contributes significantly to morbidity and death in many common neurological disorders. Ca2+ ions play a important role in the development of pathophysiological reactions in nerve cells. The aim of our research was to elucidate the mechanism of the osmotically-induced entrance of Ca2+ into nerve terminals (synaptosomes) and to estimate the involvement of endoplasmic reticulum Ca2+ stores in intrasynaptosomal Ca2+-dependent processes in hypoosmotic swelling. MATERIAL/METHODS: Synaptosomes were isolated from rat brains. The rates of Ca2+ uptake were determined using 45Ca2+ as a radiotracer. Intracellular Ca2+ measurements were performed using Fura-2 as a cell calcium indicator. RESULTS: Entry into synaptosomes in hypotonic medium (230 mOsm) of osmosis-induced Ca2+ (45 Ca2+) was reduced by verapamil, Cd2+ or genistein to 50-60% of baseline. NEM and PCMB inhibit 45Ca2+ uptake. Swelling of synaptosomes is coupled with increased tyrosine kinase activity and oxidation of SH-groups of cysteine residues of the membrane proteins involved in Ca2+ transport. These membrane processes probably influence the properties of voltage-dependent L-type Ca2+ channels, which increase their conductivity to Ca2+. Activation of RyR- and Ins(1,4,5,)P3-stores were recorded. It was shown that the Ins(1,4,5,)P3-stores are a major source of the increase in [Ca2+]i in the cytoplasm with swelling of the synaptosomes. CONCLUSIONS: Osmotic swelling of synaptosomes leads to Ca2+ accumulation by intrasynaptosomal mitochondria. Excess Ca2+ ions stored in mitochondria inhibit oxidative phosphorylation. This causes an irreversible reduction in the energy status of nerve terminals, which can initiate pathophysiological processes in nerve cells.

Adenosine Triphosphate↗
PubMed1976

A synthesis of interstitial fluid regulation and lymph formation.

The interstitial fluid spaces are filled with a mat of collagen fibers, and the interstices of this mat contain a mucopolysaccharide gel ground substance. Both the collagen fibers and the gel are elastic structures that can be expanded or compacted. In the expanded state the collagen fibers are pushed far apart and pockets of free fluid develop witin the gel. In the compacted state the elastic recoil of the compressed collagen fibers and gel reticular fibrillae seems to cause suction on the fluid within the tissue spaces, thus creating a subatmospheric pressure. Measurements of interstitial fluid pressure using a perforated capsule method indicate that this is normally slightly negative (subatmospheric) in most soft tissues. However, even very slight extra filtration of fluid into the tissue spaces increases the interstitial fluid pressure toward more positive values, which in turn increases lymph flow. The increased lymph flow then decreases the interstitial fluid volume and pressure back toward normal because of two mechanism, 1) direct removal of fluid from the tissue spaces in the lymph, and 2) removal of protein from the interstitial fluid in the lymph, thus decreasing the interstitial fluid colloid osmotic pressure and allowing more effective osmosis of fluid directly from the interstitial spaces back into the capillaries.

Animals↗
PubMedDate not supplied

[Therapeutic systems and drug delivery. 4. The osmotic minipump].

For continuous delivery of substances to conscious experimental animals a miniature osmotic pump was developed. These pumps can be implanted subcutaneously or intraperitoneally. Then with self-powered force (osmosis) substance is released with constant rate over period of 1-4 weeks (model pending). These osmotic minipumps are widely used for investigation of various substances (e. g. anesthetics, anticancer agents, catecholamines, immunomodulators, peptides, steroids). By the means of osmotic minipumps until now more than 300 substances were applied and over 4,000 papers were published on the use of osmotic minipumps in pharmacology, toxicology, oncology, etc.

Animals↗
PubMed1992

[Water quality].

The quality of water is more and more important in the polluted world of today. The nephrologist is with his patients a great consumer of water; water for dialysis should be of the highest quality as each maintenance dialysis patient uses up to 150 liters 3 times per week for years, in direct contact with his blood through a very thin dialysis membrane. Water may be polluted at the collection-, treatment- or distribution centers or locally at the place of consumption. Aluminum, chloramine, pesticides, copper, herbicides and many other substances as well as bacteria, may be found in water. For these reasons the nephrologist uses a series of devices to clean or purify the water before use in his dialysis unit: softeners, de-ionisators, reverse-osmosis, charcoal filters, ultraviolet irradiation, a.o. A correct water circuit is important as well, as dead spaces could cause bacterial contamination. The ultra pure water has to be mixed before use in the dialyzer, with a concentrated electrolyte solution. The author discusses all these different aspects of water treatment in the particular situation of hemodialysis.

Dialysis Solutions↗
PubMed2003

[Component analysis of bone matrix via cell extraction].

OBJECTIVE: To investigate the preparation of bone acellular extra-cell matrix(AECM) and to analyze its component. METHODS: With low-osmosis theory and method of cell extraction by detergent, bone acellular extra-cell matrix was prepared. We observed morphologic changes with HE, Mallory-Heidenhain rapid one-step dyeing and Alcian blue dyeing and examined fibronectin(FN) and laminin(LN) with immunohistochemistry. RESULTS: Light microscope showed that the collagen fibers arranged regularly in AECM with blankness of bone lacunas by HE, Mallory-Heidenhain rapid one-step dyeing and that the region around bone lacunas was stained different degrees of blue-green by Alcian blue dyeing. The result of immunohistochemistry showed there are positive markers of FN and LN in ECM. CONCLUSION: This method for preparation of bone acellular extra-cell matrix is effective, and it can keep natural structure of collagen fibers and maintain components of ECM, such as proteoglycan, FN and LN.

Bone and Bones↗
PubMed2003

Oxidoreductive capability of boar sperm mitochondria in fresh semen and during their preservation in BTS extender.

The purpose of our study was to determine the effect of dilution and liquid-preservation of boar sperm on oxidoreductive capability of their mitochondria. The semen was diluted with BTS extender produced from water purified by destillation or by reverse osmosis. The spermatozoa were stored over a four-day period at 16-18 degrees C. The function of sperm mitochondria was assessed using the screening cytochemical test for NADH-dependent oxidoreductases (diaphorase/NADH, related to flavoprotein). Morphological assessment of cytochemical reaction was carried out using a light microscope. The intensity of the reaction was evaluated by means of a computer image analysing system (Quantimet 600S), measuring the integrated optical density (IOD) and mean optical density (MOD) of the reaction product (formazans) occurring in the sperm midpieces. In the non-diluted semen, intensive cytochemical reaction throughout the length of the sperm midpiece was observed. Furthermore, spermatozoa with the intensive reaction displayed the high optical density values. After dilution the semen with two variants of experimental extender, and as the conservation time expired, the cytochemical reaction was less intensive. Moreover, the absence of formazan deposits in various parts of the sperm midpiece was also noted. These morphological features corresponded to low values of optical density. These findings suggest that the dilution of semen and the time of sperm preservation may be critical factors that handicap energy metabolism of sperm mitochondria. The type of water used in preparing BTS extender does not have any significant effect on the oxidoreductive capability of sperm boar mitochondria.

Animals↗
PubMed2004

Strong nitrogenous and agro-wastewater: current technological overview and future direction.

Nitrogen input to our environment has increased tremendously during the last four decades. It has been recognized that most of the nitrogenous wastes are produced from animal farms and agro-industries, which discharge a large amount of nitrogen as well as organics. Various biological and physico-chemical means are considered or applied for nitrogen removal. Particularly, biological nitrite nitrification and denitrification, and struvite precipitation have received more attention as applicable processes for strong nitrogenous waste treatment. The advanced oxidation process appears to be more attractive than activated carbon adsorption in terms of the removal of refractory organics when a further treatment of biologically treated effluent is required. Technologies using membrane bioreactors were very effective for solids separation, while reverse osmosis was found to be efficient for water reuse purpose with sufficient removal of refractory organics and nitrogen along with biological treatment. Reuse or recycling of strong nitrogenous wastes and agro-wastewater will be a desirable direction for the future in order to prevent the nitrogenous and organic pollution.

Agriculture↗
PubMed2004

[Genetic study on 27 children with beta-thalassemia major and their parents in Sichuan area].

OBJECTIVE: This genetic analysis on 27 children with beta-thalassemia major and their parents was performed in an attempt to elucidate the characteristics of gene mutations, and to improve the early diagnosis and prevention of this disease in Sichuan area. METHODS: The hematologic studies of beta-thalassemia included the osmotic fragility of erythrocyte determined by brine osmosis method, the HbF qualitatively determined by one minute anti-alkaline method, the HbA2 assayed by acetyl-cellulose membrane electrophoresis and eluate photometric method, and the total hemoglobin measured by the ferric-cynade method. DNA was extracted from peripheral white blood cell with standard method (phenol-chloroform extract). Multiple allele specific polymerase chain reaction (MASPCR) was used for targeted DNA amplification and gene mutation analysis. RESULTS: It was found that the most common mutants in Sichuan area were CD17 (A-->T), CD41-42 (-TTCT) and IVS II -654 (C-->T). Their percentages were 43.64%, 36.36% and 14.54%, respectively. CONCLUSION: MASPCR method is a simple, effective and inexpensive method for genetic diagnosis of beta-thalassemia major. We identified 3 most common mutants in Sichuan by using MASPCR.

Adolescent↗
PubMed2004

Hyperparathyroidism.

Hyperparathyroidism is a disease characterized by hypercalcemia with hypophosphoremia resulting from increased secretion of parathyroid hormone (PTH). The disease may be divided into 3 forms: a) primary, b) secondary, c) tertiary (secondary refractory form). Primary hyperparathyroidism is rare in children; hyperplasia is more frequent during the early years of life (neonates and infants) and is difficult to distinguish from adenoma in children. The disease may be asymptomatic; elevated calcemia levels (>12 <13.5 mg/dl) are accompanied by anorexia, asthenia and persistent stipsis; severely elevated concentrations (>13.5 mg/dl) are accompanied by nausea, vomiting, polyuria due to osmosis, with dehydration and progressive onset of lethargy, stupor and coma. Osteopenia or osteitis fibrosa cystica may be present due to augmented bone resorption. Height and weight increases are altered due to anorexia and dehydration. Differential diagnosis includes iatrogenic causes of hypercalcemia (excessive vitamin D intake, prolonged immobilization, etc.) and idiopathic familial hypercalcemia. Emergency treatment is required in cases of extremely elevated hypercalcemia (Ca >13.5-14 mg/dl), due to risk of injury to the heart, the central nervous system, the gastrointestinal tract and the kidneys. The 4 cardinal points of treatment are: hydration, calciuresis, inhibition of bone calcium resorption, treatment of the cause underlying hyperparathyroidism. Secondary hyperparathyroidism is found in cases where chronic hypocalcemia is present, particularly in chronic renal failure, untreated deficiency rickets, chronic intestinal malabsorption, hepatobiliary disease, types I and II vitamin D-dependent rickets, tubular acidosis or Fanconi's syndrome. The tertiary form is distinguished by the autonomous nature of the parathyroid glands which have become hypertrophic/hyperplastic due to uncontrollable, chronic severe renal failure. It can also be of iatrogenic origin due to excessive intake of inorganic phosphates in familial hypophosphatemic rickets or chronic vitamin D deficiency.

Calcium↗