Bactericidal activity of metal-mediated peroxide-ascorbate systems

Model systems containing ascorbate, hydrogen peroxide, and divalent copper or cobalt have been shown to possess marked bactericidal activity. At equivalent concentrations, copper-containing systems were more bactericidal than the corresponding mixtures containing cobalt. Cobalt at concentrations below 10⁻⁴ M did not appreciably augment microbicidal activity, whereas systems containing copper at concentrations as low as 5 × 10⁻⁶ M were still capable of causing some bacterial death. Manganese was inactive. None of these systems was as potent as the well known myeloperoxidase-peroxide-halide system. The mechanisms of action of these systems are not as yet clear. The possibility that they function through the generation of superoxide (O₂⁻), hydroxyl radical (OH·), or other free radicals was explored through the use of superoxide dismutase and several free radical scavengers. It seems likely at present that the two active metal-mediated systems function via separate mechanisms. The copper system acts with dehydroascorbate, whereas the cobalt system does not. Activity in the cobalt system appears to depend upon the generation of free radicals.     

Antioxidant Activities In Vitro and Hepatoprotective Effects of Nelumbo Nucifera Leaves In Vivo

Background

Herbal medicines played a major role in the treatment of hepatic disorders, and a number of medicinal plants and their compounds were widely used for the treatment of these disorders, and oxidant stress injury was one of the mechanism of liver injury.

Materials and Methods

Antioxidant activity of Nelumbo nucifera leaves (NU) extracts was assayed by the methods of scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzo-thiazoline-6-sulfonicacid) (ABTS) radical and ferric reducing antioxidant power (FRAP) in vitro. By intraperitoneal injection carbon tetrachloride (CCl₄) to establish acute liver injury model in mice, the levels of Glutamic-pyruvic transaminase (GPT), glutamic-oxaloacetic transaminase (GOT), superoxide dismutase (SOD) and the content of and maleicdialdehyde (MDA) were detected to evaluate hepatoprotective effect of NU using corresponding test kit.

Results

EtOAC (NUEA) and n-BuOH extracts (NUBU) of N. nucifera leaves had good scavenging DPPH and ABTS radical activity and ferric reducing antioxidant power in vitro. DPPH radical scavenging activity and ferric reducing antioxidant power of NUEA (IC₅₀= 6.68±0.29 µg/mL, RACT₅₀=1749.82±67.03 µmol/g) and NUBU (IC₅₀= 4.61±0.01 µg/mL, RACT₅₀=1995.27±135.71 µmol/g ) were higher than that of BHT (IC₅₀=8.76±0.20 µg/mL, RACT₅₀=1581.68±97.41 µmol/g) and Dangfeiliganning (IC₅₀=28.06±0.17 µg/mL, RACT₅₀=1028.55±3.28 µmol/g). ABTS radical scavenging activity of NUEA (IC₅₀= 5.32±0.12 µg/mL) and NUBU (IC₅₀= 8.16±0.27 µg/mL) were higher than that of Dangfeiliganning (IC₅₀= 9.76±0.16 µg/mL). Thus, hepatoprotective effect of NUEA and NUBU was evaluated on CCl₄-induced acute liver injury mice. The results showed that the levels of GOT and GPT in each treatment group significantly decreased (p<0.001 and p<0.01, p<0.05, respectively) except for the group of NUEA (130.8 mg/kg) (p>0.05). The contents of malondialdehyde (MDA) in liver in groups of NUEA (523 mg/kg), NUBU (840.5 and 420.5 mg/kg, repectively) had significant decrease (p<0.001 and p<0.05, respectively), and the level of SOD in liver for each treatment group could significantly decrease (p<0.001, p<0.05, respectively).

Conclusion

NUEA and NUBU had significantly hepatoprotective effect for Calcium tetrachloride CCl₄-induced liver injury, which might be attributable to its antioxidant activity.     

Anti-Inflammatory,Cytotoxic and Antioxidant Effects of Methanolic Extracts of Drypetes Sepiaria (Euphorbiaceae)

The aim of this study was to investigate in vitro antioxidant, anti-inflammatory and cytotoxic activities of the petroleum ether, ethyl acetate, methanol and aqueous extracts obtained from leaves of Drypetes sepiaria (Euphorbiaceae). Total phenolic and flavonoid contents of these crude extracts were determined as gallic acid and quercetin equivalents, respectively. In in vitro antioxidant method, methanol extract exhibited higher free radical scavenging activity compared to standard compound, ascorbic acid with IC₅₀ of 95.43µg/ml (DPPH) and 67.05µg/ml (ABTS). Methanol extract was able to inhibit inflammation by in vitro about 85–90% (HRBC stabilization method) and in vivo about 40–45% (Paw oedema method) anti-inflammatory assays compared to standard produced 50.04% at 6h period. In cytotoxicity assay (MTT assay) methanolic extract exhibited IC₅₀ of 10µg/ml. In apoptosis (flow cytometric assay), the control group showed normal caspase 3 activity in the SiHa cells which was 0.24%, and increased up to 40% after treatment.     

Antioxidant Activity In Vitro and Hepatoprotective Effect of Phlomis Maximowiczii In Vivo

Background

A number of medicinal plants and there compounds played a major role in the treatment of hepatic disorders. They were widely used for the treatment of these disorders, and oxidant stress injury was one of the liver injury mechanisms. The present study evaluated the antioxidant activity and the hepatoprotective effect of each extracts of Phlomis maximowiczii.

Materials and Methods

The antioxidant activity was assayed by the methods of ABTS, FRAP and DPPH in vitro. Hepatoprotective effect of P. maximowiczii extracts was examined using carbon tetrachloride-induced acute liver injury in mice.

Results

P. maximowiczii n-butanol (PMBU) extract, ABTS (IC₅₀=18.96 µg/mL), DPPH (IC₅₀=25.15 µg/mL), and FRAP (RACT₅₀=2775.6±144.18 µmol/g), showed higher scavenging capacity than that of P. maximowiczii ethyl acetate (PMEA). The n-butanol extract could significantly reduce the level of GPT, GOT and MDA (P<0.05, P<0.001 and P<0.001, respectively) and increase the level of SOD (P<0.001), respectively.

Conclusion

The antioxidant activity of n-butanol extract in vitro was related with the level of MDA and SOD in vivo, and hepatoprotective effect of n-butanol extract also had relationship with its antioxidant activity in vivo.     

Anti-Inflammatory and Antioxidant Activities of Methanol Extracts and Alkaloid Fractions of Four Mexican Medicinal Plants of Solanaceae

Background

Methanol extracts and alkaloid fractions of different parts of four plant species belonging to Solanaceae family and used in Mexican traditional medicine were investigated for their total phenolic contents, anti-inflammatory and antioxidant properties.

Materials and Methods

The total phenolic compounds of each extract was determined according to the Folin-Ciocalteu method, while the in vitro radical scavenging activities of the extracts were assessed using the DPPH and ABTS radicals. The in vivo anti-inflammatory activity was determined using the TPA-induced mouse ear edema model.

Results

The methanol extracts contained the highest concentrations of phenolic compounds and also exhibited the best reducing power on the DPPH and ABTS radicals, in a concentration-dependent fashion. However, the anti-inflammatory activity did not follow the same trend, as some alkaloid fractions that showed low radical reducing power exhibited the strongest anti-inflammatory activity.

Conclusion

The methanol extract obtained from the flowers of Nicotiana glauca presented the best overall performance with the largest amount of phenolic compounds (111 µg garlic acid equivalents/g of extract), the best antioxidant activity (94.80% inhibition of DPPH and 97.57% of ABTS) and the highest anti-inflammatory activity (81.93% inhibition of the inflammation).     

Antioxidant Activity and Inhibitory Effect of Some Commonly Used Medicinal Plants Against Lipid Per-Oxidation in Mice Brain

Background

The present study compares the protective properties of aqueous extracts of six medicinal plants, Phyllanthus emblica, Terminalia chebula (black and yellow), Terminalia arjuna, Balsamodendron Mukul and Alium sativum against lipid per-oxidation in mice brain.

Methods

The antioxidant activities were analyzed by lipid per-oxidation assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay, total antioxidant activity and metal chelation.

Results

The extracts (fruits and bark) showed inhibition against thiobarbituric acid reactive species (TBARS) induced by pro-oxidant (10 µM FeSO4) in mice brain. Moreover, the free radical scavenging activities of the extracts was evaluated by the scavenging of DPPH radical (IC₅₀, 23.23±1.2 µg/ml (Phyllanthus emblica), 20.24±0.9 µg/ml (Terminalia chebula yellow) and 17.33±1.1 µg/ml (Terminalia chebula black), 19.44±0.45 µg/ml (Terminalia arjuna), 56.59±2.1 µg/ml (Balsamodendron Mukul) and < 200 µg/ml (Alium sativum).

Conclusion

The higher antioxidant and inhibitory effect of Terminalia chebula black in this study could be attributed to its significantly higher phenolic content, Fe(II) chelating ability, reducing ability and free radical scavenging activity. Therefore oxidative stress in brain could be potentially prevented by the intake of these plants.     

Antioxidant and SGC-7901 Cell Inhibition Activities of Rhizoma Dioscoreae Bulbiferae. Ethanol Extracts

The objective of this research was to study the pharmacology of Dioscorea bulbifera L. on antioxidant and anticancer activity. Alcohol extracts of Dioscorea bulbifera L. were made out by different concentration alcohol; they were tested by Hydroxyl radical scavenging test, reducing capacity test and total antioxidant capacity test. In the anticancer test, MTT test was used to study the inhibition rate. The results told that 70% ethanol extracts could scavenge most DPPH· at 2mg/ml. The rate was 55.2%; 80% ethanol extract could clear the most ·OH. The clearance rate was 51.2%. 80% ethanol crude extracts possessed the strongest reducing ability per gram of the extract equal to 49.3µmol Fe^{2 +}. Different concentrations of the extracts could inhibit the proliferation of line SGC-7901, and with the concentration increased, the inhibition rate was gradually increased.     

Antioxidant effect of 4-nerolidylcatechol and α-tocopherol in erythrocyte ghost membranes and phospholipid bilayers

4-Nerolidylcatechol (4-NC) is found in Pothomorphe umbellata root extracts and is reported to have a topical protective effect against UVB radiation-induced skin damage, toxicity in melanoma cell lines, and antimalarial activity. We report a comparative study of the antioxidant activity of 4-NC and α-tocopherol against lipid peroxidation initiated by two free radical-generating systems: 2,2′-azobis(2-aminopropane) hydrochloride (AAPH) and FeSO₄/H₂O₂, in red blood cell ghost membranes and in egg phosphatidylcholine (PC) vesicles. Lipid peroxidation was monitored by membrane fluidity changes assessed by electron paramagnetic resonance spectroscopy of a spin-labeled lipid and by the formation of thiobarbituric acid-reactive substances. When lipoperoxidation was initiated by the hydroxyl radical in erythrocyte ghost membranes, both 4-NC and α-tocopherol acted in a very efficient manner. However, lower activities were observed when lipoperoxidation was initiated by the peroxyl radical; and, in this case, the protective effect of α-tocopherol was lower than that of 4-NC. In egg PC vesicles, malondialdehyde formation indicated that 4-NC was effective against lipoperoxidation initiated by both AAPH and FeSO₄/H₂O₂, whereas α-tocopherol was less efficient in protecting against lipoperoxidation by AAPH, and behaved as a pro-oxidant for FeSO₄/H₂O₂. The DPPH (2,2-diphenyl-1-picrylhydrazyl) free-radical assay indicated that two free radicals were scavenged per 4-NC molecule, and one free radical was scavenged per α-tocopherol molecule. These data provide new insights into the antioxidant capacity of 4-NC, which may have therapeutic applications for formulations designed to protect the skin from sunlight irradiation.     

In Vitro Analysis of Antioxidant Activities of Oxalis Corniculata Linn. Fractions in Various Solvents

As part of our search for natural antioxidants, this work presents an evaluation of antioxidant activities of methanolic extract of Oxalis corniculata and its sub-fractions in hexane, chloroform, ethyl acetate, n-butanol and water. The total phenolic contents in terms of µg of gallic acid equivalents per mg of dried mass were approximately 21.0, 28.2, 34.5, 162.0, 70.0, and 49.2 in methanolic, hexane, chloroform, ethyl acetate, n-butanolic and aqueous fractions respectively, while the flavonoid contents in these solvents were 362.4, 214.1, 317.1, 177.1, 98.8 and 53.5 respectively in terms of µg of rutin per mg of dried mass. In DPPH assay, the ethyl acetate fraction showed the highest free radical scavenging activity, 24.0% with 1 mg/mL concentration. The second strongest fraction was chloroform (21.5%). The EC₅₀ and TEC₅₀ values of the methanolic extract were 3.63 mg/mL and 23 min respectively. The FRAP values in terms of µg of ascorbic acid equivalents per mg of dried mass for these solvents were 288.0, 1705.3, 437.1, 72.0, 28.0, and 44.0 respectively while total antioxidant activity measured by phosphomolybdate assay in terms of µg of ascorbic acid equivalents per mg of dried mass were 50.0, 117.0, 78.6, 57.8, 3.4 and 8.3 respectively. All the samples showed remarkable ability to inhibit lipid peroxidation exhibiting much better and sustainable peroxidation inhibitory activity than the standard butylated hydroxyanisole.     

Fetal in vivo continuous cardiovascular function during chronic hypoxia

AbstractAlthough the fetal cardiovascular defence to acute hypoxia and the physiology underlying it have been established for decades, how the fetal cardiovascular system responds to chronic hypoxia has been comparatively understudied. We designed and created isobaric hypoxic chambers able to maintain pregnant sheep for prolonged periods of gestation under controlled significant (10% O₂) hypoxia, yielding fetal mean P_aO2 levels (11.5 ± 0.6 mmHg) similar to those measured in human fetuses of hypoxic pregnancy. We also created a wireless data acquisition system able to record fetal blood flow signals in addition to fetal blood pressure and heart rate from free moving ewes as the hypoxic pregnancy is developing. We determined in vivo longitudinal changes in fetal cardiovascular function including parallel measurement of fetal carotid and femoral blood flow and oxygen and glucose delivery during the last third of gestation. The ratio of oxygen (from 2.7 ± 0.2 to 3.8 ± 0.8; P < 0.05) and of glucose (from 2.3 ± 0.1 to 3.3 ± 0.6; P < 0.05) delivery to the fetal carotid, relative to the fetal femoral circulation, increased during and shortly after the period of chronic hypoxia. In contrast, oxygen and glucose delivery remained unchanged from baseline in normoxic fetuses. Fetal plasma urate concentration increased significantly during chronic hypoxia but not during normoxia (Δ: 4.8 ± 1.6 vs. 0.5 ± 1.4 μmol l⁻¹, P<0.05). The data support the hypotheses tested and show persisting redistribution of substrate delivery away from peripheral and towards essential circulations in the chronically hypoxic fetus, associated with increases in xanthine oxidase‐derived reactive oxygen species.

Abbreviations

HIF

hypoxia‐inducible factor

IUGR

intrauterine growth restriction

NO

nitric oxide

•O₂⁻

superoxide anion

ROS

reactive oxygen species

XO

xanthine oxidase

     

The metabolism of C9 in normal subjects and in patients with autoimmune disease

The metabolism of the ninth component of complement (C9) was studied in eight healthy subjects and nine patients with autoimmune disease, including seven with systemic lupus erythematosus (SLE) and one each with mesangial IgA nephropathy and mixed essential cryoglobulinaemia. In normal subjects the metabolic parameters (mean ± s.d.) were: fractional catabolic rate (FCR): 2.92 ± 0.36%/h, plasma half-life (T_1/2): 42.5 ± 6.7 h, and extravascular/intravascular distribution ratio (EV/IV): 0.56 ± 0.12. In patients the FCR was 3.38 ± 0.70%/h, the T_1/2 was 37.6 ± 10.2 h, and the EV/IV was 0.55 ± 0.19. Patients with reduced total serum haemolytic activity (i.e. CH₅₀ < 68% of normal human serum (NHS), n = 7) had significantly higher FCR (3.57 ± 0.67%/h) and shorter T_1/2 (33.5 ± 6.8 h) than the control group (both P< 0.05). The plasma concentration of the terminal complement complex (i.e. soluble TCC or SC5b-9) was higher in patients (median (range): 515 (300–1879 μg/l)) than in normal subjects (313 (229–402 μg/l); P< 0.01) and showed a positive correlation with the FCR of C9 (r =0.61, P< 0.01). Plasma C9 production rate was also greater in patients (0.11 ± 0.05 mg/kg per h) compared with control subjects (0.07 ± 0.03 mg/kg per h, P< 0.05), and was associated with a higher C9 concentration in patients’ sera (76 ± 13 mg/lversus 61 ± 14 mg/l, P< 0.05). These results demonstrate that C9 is rapidly metabolized in normal humans and that hypercatabolism occurs in patients with autoimmune disease and complement activation. This was despite the presence of normal or elevated serum C9 levels and normal compartmental distribution.     

Potential of Neuroprotective Antioxidant-Based Therapeutics from Peltophorum Africanum Sond.(Fabaceae)

There is ample scientific and empirical evidence supporting the use of plant-derived antioxidants for the control of neurodegenerative disorders. Antioxidants may have neuroprotective (preventing apoptosis) and neuroregenerative roles, by reducing or reversing cellular damage and by slowing progression of neuronal cell loss. Although demand for phytotherapeutic agents is growing, there is need for their scientific validation before plant-derived extracts gain wider acceptance and use. We have evaluated antioxidant potential of Peltophorum africanum (weeping wattle), a plant widespread in the tropics and traditionally used, inter alia, for the relief of acute and chronic pain, anxiety and depression. The dried leaves, bark and root of P. africanum were extracted with acetone. Thin layer chromatograms were sprayed with 0.2% 2,2-diphenyl-1-picryl hydrazyl (DPPH) in methanol for screening for antioxidants. Quantification of antioxidant activity was assessed against 6-hydroxy-2, 5,7,8-tetramethylchromane-2-carboxylic acid (Trolox) and L-ascorbic acid (both standard antioxidants), using two free radicals, 2,2′-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) and DPPH, respectively. Results of our study show that the bark and root extracts had higher antioxidant activity than L-ascorbic acid and Trolox, a synthetic vitamin-E analogue. The respective TEAC (Trolox Equivalent Antioxidant Capacity) values for the bark and root extracts, and Trolox were 1.08, 1.28 and 1.0. EC₅₀ values for L-ascorbic acid (5.04 µg/mL) was more active than the leaf 6.54 (µg/mL), but much less active than the bark (4.37 µg/mL) and root (3.82 µg/mL) extracts. Continued work on P. africanum, and other plants rich in antioxidants, may avail neuroscientists with potent neuroprotective antioxidant therapeutics.     

Assessment of phytochemicals and antioxidant activities of raw and germinating Ceiba pentandra (kapok) seeds

To determine the significance of germination on phytochemical constituents and non-enzymatic antioxidant activities of Ceiba pentandra seed extracts. Phytochemicals and antioxidant activities of raw and germinating seeds of Ceiba pentandra were estimated by different methods. The levels of phytochemical constituents were influenced by germination and increased except alkaloids and tannins, which were decreased significantly during germination. Among non-enzymatic antioxidants like DPPH, FRAP, reducing assay and hydroxyl radical scavenging activity all showed improved activity compared with non-germinating seeds. This may be due to various reactive oxygen species (ROS) that were generated as by-products of metabolism during germination. This group of ROS included superoxide radicals (O₂), hydrogen peroxide radicals (H₂O₂) and hydroxyl radicals (OH). The formation of these oxygen radicals resulted in the accumulation of lipid hydroperoxides by radical chain oxidation via phospholipids peroxy radicals within membranes. Therefore, it was hypothesized that this could be related to the increase of antioxidant activity in large unilamellar vesicles observed in germinated seeds. The implication of this study is that the Ceiba pentandra seeds as natural antioxidant agents and put forward the possibility of employing for therapeutic potential.     

The egress of oxygen from human HbO(2) in solution and in the erythrocyte

1. Spectrophotometric measurements, using the rapid-mixing constantflow and stopped-flow techniques, have been made of the rate of egress of oxygen from human HbO₂ in solution and in erythrocytes.

2. By 1:20 dilution in a medium containing a high concentration of carbon monoxide k₄, the rate constant of the reaction Hb₄O₈ → Hb₄O₆+O₂ has been determined. At pH 7·4 and 20° C, k₄ in solution was 42·0 sec^-1 and within the intact cell 41·4 sec^-1. The respective activation energies were 19·3 and 18 kcal.

3. The rate of dissociation of HbO₂ to Hb, after mixing an erythrocyte suspension with Na₂S₂O₄, was identical, over at least 50% of the reaction, with the change of HbO₂ to HbCO above.

4. An analysis of the data indicates that the cell membrane has little or no resistance to the passage of oxygen and the internal contents are effectively mixed.

     

A Study of Extraction Process and In Vitro Antioxidant Activity of Total Phenols from Rhizoma Imperatae

The study investigated the extraction method of Rhizoma Imperatae and its antioxidant activity, and provided a basis for its rational development. The extraction method of Rhizoma Imperatae was determined using orthogonal design test and by total phenol content, its hydroxyl radical scavenging ability was measured by Fenton reaction, and potassium ferricyanide reduction method was used to determine its reducing power. The results showed that the optimum extraction process of Rhizoma Imperatae was a 50-fold volume of water, 30 °C, three times of extraction with 2 h each. Its IC₅₀ for scavenging of hydroxyl radicals was 0.0948 mg/mL, while IC₅₀ of ascorbic acid was 0.1096 mg/mL; in the ferricyanide considerable reduction method, the extract exhibited reducing power comparable to that of the ascorbic acid. The study concluded that Rhizoma Imperatae extract contains relatively large amount of polyphenols, and has a good anti-oxidation ability.     

The metabolism of autologous IgM and 19S rheumatoid factor in rheumatoid arthritis

The turnover of autologous preparations of radio-iodine labelled IgM and 19S rheumatoid factor was studied and compared in patients with severe rheumatoid disease. The IgM was isolated by block electrophoresis and column chromatography. 19S rheumatoid factor was isolated by a combination of euglobulin precipitation, column chromatography, and absorption onto and acid-elution from solid aggregated IgG.

Ten studies were made in seven patients, five with IgM, and five with 19S rheumatoid factor. In two patients the turnovers of 19S rheumatoid factor and IgM were studied simultaneously.

The turnover of IgM was similar to that reported for normal subjects and patients with other diseases: fractional catabolic rate 0·14–0·18, plasma and whole body T_½ 3·7–6·5 days, with 65–77% intravascular localization. The absolute catabolic rate for IgM was elevated (8–60 mg/kg/day).

The turnover of 19S rheumatoid factor isolated from serum was comparable in fractional catabolic rate (0·15–0·19) plasma and whole body T_½ (3·9–6·0 days) and intravascular localization (62–88%). No evidence of rapid catabolism of the `immune' elimination type was obtained.

     

Clinical effects of sevoflurane anesthesia induction with a portable inhalational anesthetic circuit in pediatric patients

Introduction

Pediatric anesthesia induction with sevoflurane usually needs a special vaporizer and gas source, which limits its use to the operating room (OR). Many children feel anxious and cry when entering the OR because of being separated from their parents, which impairs anesthesia safety and their physical and mental health. In this study, we used a portable circuit to perform sevoflurane anesthesia induction outside the OR, assessed its effects and compared them with those of ketamine anesthesia in pediatric patients.

Material and methods

One hundred children had anesthesia induced with either sevoflurane (sevoflurane group) through the portable inhalational anesthetic circuit, or ketamine by intramuscular injection (ketamine group), then were transferred to the OR. Peak inspired concentration (Cp) and steady state concentration (Cs) of sevoflurane were measured. Heart rate (HR) and saturation of peripheral oxygen (SpO₂) were monitored. Time for anesthesia induction, awakening, leaving the OR and duration of the operation were recorded. The patients’ reaction during anesthesia was also analyzed.

Results

The Cp and Cs of sevoflurane were correlated with bodyweight. Compared with the ketamine group, the sevoflurane group showed shorter time for anesthesia induction (28 ±7 s vs. 195 ±34 s, p < 0.0001), awakening (11.2 ±3.6 s vs. 63.5 ±6.7 s, p < 0.0001) and leaving the OR (20.5 ±5.6 s vs. 43.4 ±10.6, p < 0.0001), less noncooperation during anesthesia induction (10% vs. 80%, p < 0.0001), lower HR (130 ±16 beats/min vs. 143 ±19 beats/min, p = 0.0004) and higher SpO₂ (98.9 ±0.9% vs. 96.1 ±2.5%, p < 0.0001) on arrival at the OR.

Conclusions

Pediatric anesthesia induction by sevoflurane with the portable inhalational anesthetic circuit is convenient, safe and effective outside the OR.     

Calcium-phosphate metabolism parameters and erythrocyte Ca2+ concentration in autosomal dominant polycystic kidney disease patients with normal renal function

Introduction

The aim of this study was to assess calcium-phosphate metabolism of autosomal dominant polycystic kidney disease (ADPKD) patients with a special consideration to the following serum parameters: calcium (Ca²⁺), inorganic phosphate (Pi), parathyroid hormone (PTH) and intracellular erythrocyte calcium ([Ca²⁺]_i) concentrations.

Material and methods

The study included 49 adult ADPKD patients (19 males, 30 females) aged 36 ±11 years with normal renal function and no diagnosis of diabetes as well as 50 healthy controls (22 males, 28 females) matched for age and gender. Serum concentrations of sodium (Na⁺), potassium (K⁺) and magnesium (Mg²⁺) ions and Pi were determined with an indirect ion-selective method, while Ca2+ concentration was measured with a direct ion-selective method. The PTH was detected using a radioimmunometric method. [Ca²⁺]_i concentration was determined with the Ca²⁺ sensitive fluorescent dye Fura-2 method.

Results

In the ADPKD group, when compared to controls, the following concentrations were significantly higher: serum Ca²⁺ (1.18 ±0.06 mmol/l vs. 1.15 ±0.06 mmol/l, p = 0.0085), [Ca²⁺]_i (146.9 ±110.0 nmol/l vs. 96.5 ±52.7 nmol/l, p = 0.0075), serum Na+ (139.4 ±2.7 mmol/l vs. 138.5 ±2.1 mmol/l, p = 0.060, borderline significance), and PTH (15.5 ±6.8 pg/ml vs. 13.6 ±5.3 pg/ml, p = 0.066, borderline significance), while serum Mg²⁺ was significantly lower (0.81 ±0.09 mmol/l vs. 0.85 ±0.05 mmol/l, p = 0.021). In the ADPKD group we observed significant negative correlations of PTH with Ca²⁺ serum concentrations (Rs = –0.32, p = 0.025) and with estimated glomerular filtration rate (Rs = –0.31, p = 0.033).

Conclusions

The erythrocyte Ca²⁺ concentration is elevated in ADPKD patients with normal renal function. It may result from a dysfunction of mutated polycystins which can affect various aspects of electrolyte metabolism.     

The effect of membrane fixed charges on diffusion potentials and streaming potentials

1. Electrical potential differences (p.d.''s) have been measured across an in vitro preparation of rabbit gall-bladder.2. When the gall-bladder separates identical bathing solutions, the p.d. is always zero, regardless of the composition of the bathing solution. Hence the gall-bladder is symmetrical: i.e. the mucosal and serosal cell membranes have the same relative permeability coefficients.3. Osmotic water flow causes streaming potentials of up to 20 mV, of a sign indicating greater permeability to cations than to anions.4. At constant osmolarity, streaming potentials increase slightly with NaCl concentration. Streaming potentials decrease considerably with changes in osmolarity resulting from changes in NaCl concentration.5. Diffusion potentials resulting from electrolyte concentration gradients are fitted well by the constant-field equation with the relative permeability coefficients P_Na = 1·00, P_Cl = 0·33, P_K = 2·3. These permeability coefficients are independent of osmolarity and of salt concentration.6. Relative to 0·25 mM-Ca, 5 mM-Ca reduces streaming potentials by 40%, NaCl diffusion potentials by 62%, and potassium diffusion potentials by 43%.7. The aqueous channels through which water and electrolytes traverse the cell membranes of the gall-bladder contain negative fixed charges, which are blocked by Ca. The physiological significance of the charges may be to reduce chloride permeability and thereby to increase the effectiveness of the gall-bladder in concentrating bile.8. The effect of pH, and analogy with surface charges of other cells, suggest that the charges are organic acids of low pK_a.     

Variation of Antioxidant Activity and Phenolic Content of Some Common Home Remedies with Storage Time

The variation of antioxidant activity and total phenolic content of some plants commonly used as home remedies were screened on the basis of air drying time of (short term and long term air) the dried plant Ocimum sanctum (leaf), Cucumis sativus (Seed), and ethanolic extracts of Capsicum frutescens (Seed) and Coriandrum sativum (Seed). Antioxidant activities and total phenolic content values were estimated using DPPH reagent and Folin Ciocalteu reagent methods respectively. The antioxidant activity in short term air dried Ocimum sanctum plant methanol extract (IC₅₀ = 0.03 ± 0.01 mg/l) was the highest among the other plant extracts. However, Coriandrum sativum plant ethanol extract produced higher phenolic content (70.24±3.4/66.57±4.1 mg/g) than other plant extracts. It was found that there was no correlation between antioxidant and phenolic content of these plant extracts.