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PubMed1984

Regulation of the permeability of the medaka fish embryo chorion by exogeneous sodium and calcium ions.

We questioned if the optically transparent noncellular chorion, or egg envelope, which encapsulates the entire medaka fish (Oryzias latipes) embryo might in some way constitute a permeability barrier to high concentrations of the diuretic called amiloride. More specifically, we questioned if removal of cations from the exogenous environment of the medaka embryo might make the chorion more permeable to amiloride and thereby make the fish embryos more sensitive to the inhibitory and lethal effects of this drug. To test this question, chorion-encapsulated medaka embryos were exposed to: deionized-distilled water, to Yamamoto-Ringer's (Y-R) solution, to Yamamoto-Ringer's containing choline chloride as a substitute for NaCl, and to isotonic NaCl solution in the presence of and in the absence of amiloride. Briefly, the prediction that the medaka embryos would be most sensitive to amiloride's inhibitory effects in distilled water was confirmed. Further studies showed that the presence of Na+ or of Ca2+ alone in the culture solution gave partial protection against the lethal effects of the amiloride. Electron probe X-ray microanalysis studies indicated that addition of Ca2+ and other cations to the culture solution caused the concentrations of cations to increase in the chorion, and that increase was correlated to a visible decrease in the permeability of the chorion to the amiloride. This decreased permeability of the chorion apparently protected the embryo from the amiloride. The decreased permeability of the chorion to amiloride, which occurred in the presence of the cations present in Y-R solution, was found to be reversible once the cations were washed from the chorion. Key words medaka, chorion, Na+, Ca2+ permeability, x-ray microanalysis, Oryzias latipes, egg envelope.

Amiloride↗

PubMed1994

Restricted hypotonic swelling of peripheral nerve myelin in streptozocin-induced diabetic rats.

Experimental diabetic neuropathy includes the non-enzymatic glycosylation (or glycation) of the major proteins of peripheral nerve myelin. We have used X-ray diffraction to determine whether such glycation affects myelin membrane structure and interactions in peripheral nerves from experimental diabetic rats. Streptozocin at 60 mg/kg was injected intraperitoneally to induce diabetes; controls were pair-fed and age-matched. Animals were sacrificed periodically from 2 weeks to after 1 year. The dissected sciatic nerves were tied off and incubated overnight at room temperature in hypotonic saline of defined pH and ionic strength or in distilled water. Such treatments have been shown to result in systematic changes of myelin period, which can be detected using X-ray diffraction, and which may indicate alterations in inter-membrane interactions owing to changes in composition. We observed no differences in repeat periods between control and diabetic nerves at pH 4.0 and 7.4, and ionic strength 0.01, 0.02, 0.06, 0.15, and 0.18; however, we did detect a significant difference (P < .02) in their maximum extent of swelling in distilled water: control nerves showed a period of 292 A (s.d. 23 A; n = 12) compared to 272 A (s.d. 19 A; n = 11) for diabetic nerves. To determine whether this difference in swelling was due to an alteration in the properties of the apposed, extracellular surfaces of the myelin membranes or to the connective tissue in peripheral nerve, we compared the X-ray patterns from peripheral nerve myelin isolated by sucrose density gradient centrifugation from sciatic nerves of diabetic and control rats. No difference in the patterns was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1982

Stability assay of allantoin in lotions and creams by high-pressure liquid chromatography.

A high-pressure liquid chromatographic method for indicating stability is described for the rapid quantitative analysis of allantoin in lotions and creams. Allantoin was extracted from the preparations using distilled water containing 70% (v/v) methanol and separated from interferences by reversed-phase chromatography. The separation was carried out using an amino column (250 X 4.5-mm i.d.) and a mobile phase of distilled water containing 70% (v/v) acetonitrile. Quantitation was accomplished using a UV detector at 220 nm. The assay has a relative standard deviation of approximately 1.7% (n = 10) and the average recovery from laboratory prepared samples was 100%.

Allantoin↗

PubMed1984

Simultaneous determination of nitrate and nitrite in toothpastes by high-performance liquid chromatography.

A stability-indicating analytical method is described for the simultaneous determination of nitrate, and if present, its reductive degradation product, nitrite, in toothpastes. Nitrate and nitrite were extracted from the toothpaste using distilled water and separated from other water-soluble excipients by two RP-8 columns (250 mm X 4 mm i.d.) using a mobile phase containing 0.2% (w/v) sodium acetate and 2.5% (v/v) glacial acetic acid in distilled water. A UV detector set at 313 nm was used for quantitation. The method was applied to commercial toothpastes containing 5% potassium nitrate and yielded an average recovery of 100.1% with a relative standard deviation of 1.43%. Average recovery of nitrate and nitrite from spiked samples were 100.6% and 96.4%, respectively. The minimum detectable concentration for nitrite was 50 micrograms/g of toothpaste.

Chromatography, High Pressure Liquid↗

PubMed1987

A new simplified assay for the quantitation of theophylline and its major metabolites in urine by high-performance liquid chromatography.

A high-performance liquid chromatographic technique is presented for the simultaneous determination of theophylline, 3-methylxanthine, 1-methyluric acid, 1,3-dimethyluric acid, and caffeine in urine using beta-hydroxyethyl theophylline (BHET) as an internal standard. Following centrifugation of the sample, 2 mL of urine was placed onto a Sep-Pak C18 cartridge (Waters Associates, Milford, MA, USA) that was prepared with 5 mL of methanol followed by 10 mL of distilled water. The compounds were eluted with 2.5 mL of a methanol:water (50:50) mixture. An aliquot of the filtered urine sample (100 microL) was added to 40 microL of an internal standard solution (BHET; 100 micrograms/mL). Distilled water (60 microL) was added to yield a volume of 200 microL. The mixture was vortexed and centrifuged, and 100 microL was injected onto a C8 column maintained at 55 degrees C. Inter- and intraday variability of the assay for all compounds was less than 5.7%. Sensitivity ranged from 0.10 microgram/mL for caffeine to 0.68 microgram/mL for 1-methyluric acid. Drugs commonly coadministered with theophylline did not interfere with the assay.

Asthma↗

PubMed1994

Modification of the U.S.P. dissolution method for the analysis of norethindrone and ethinyl estradiol tablets.

A modification of the U.S.P. dissolution method for the quantitation of norethindrone and ethinyl estradiol tablets is proposed. This modification consists of the use of distilled water as the dissolution medium instead of 0.1 N hydrochloric acid (HCl) and/or neutralization of 0.1 N HCl with sodium carbonate prior to analysis. Statistical analysis of the results indicate that there are no significant differences between the dissolution in 0.1 N HCl and the dissolution in distilled water (p < 0.05) for norethindrone and ethinyl estradiol.

Chromatography, High Pressure Liquid↗

PubMed1975

An inverse dose response of 5-methyl cytidine on multiple primary spontaneous tumors and their regressions in mice.

Ten series mice of C3H/ST inbreds with spontaneous tumors have received 5-methyl cytidine (total 500 mice). Graded single doses of (1) 3.86, (2) 2.57, (3) 2.06, (4) 1.54, (5) 1.03, (6) 1.54, (7) 1.03, (8) 0.51, (9) 0.26, and (10) 0.13 mg/injection (three times weekly) were used. In series 1-5 the 5-methyl cytidine was dissolved in distilled water, and in series 6-10, the nucleoside was dissolved in physiological salt solution. In doses administered, series 4-5 overlapped with series 6-7. The number of mice that showed a regression of tumor increased in the successive series (48%-63% in series 1-5 and 25%-73% in series 6-10). As the number of mice with regressing tumors increased, the percentage of mice showing multiple primary tumors also increased. The administration of the nucleoside in physiological salt solution altered the inhibitory effect of 5-methyl cytidine on spontaneous tumors. For example, in physiological salt solution the 0.51 mg/injection gave as much inhibitory action as 1.03 mg/injection in distilled water. An inverse dose response is thus indicated between the amount of 5-methyl cytidine injected and the inhibition of spontaneous tumors in mice (percentage of regression and number of multiple primary spontaneous tumors are the criteria of inhibition considered).

Animals↗

PubMed2004

Hydrocarbon type analysis by thin-layer chromatography with flame-ionization detection: vacuum gas oils, heavy feeds, and hydroprocessed products.

Thin-layer chromatography with flame-ionization detection (TLC-FID) provides quantitative hydrocarbon type data as well as distribution of aromatics by ring number. This method has been applied to obtain amounts of saturates, aromatics, and polars in heavy oil distillates such as light vacuum gas oils and heavy vacuum gas oils derived from different crude sources. TLC-FID chromatograms and resultant quantitative hydrocarbon type data show that these distillates vary markedly in aromatic contents and aromatic ring types. Similar observations are made with several fluid catalytic cracking feeds. Effects of process parameters such as operating pressure and temperature on hydroconversion of aromatics and polars from a heavy oil are assessed by TLC-FID. It has been demonstrated that there is a preferential reduction of higher polycyclic aromatic hydrocarbons and polars with an increase of both hydrogen partial pressure and reactor temperature.

Journal Article↗

PubMed2005

A comparison between different techniques for the isolation of rosemary essential oil.

Traditional hydrodistillation (HD), supercritical fluid extraction (SFE), organic solvent extraction (SE), and water microwave assisted hydrodistillation (MAHD) techniques were compared and evaluated for their effectiveness in the isolation of rosemary essential oil. The microwave assisted hydrodistillation technique was optimized in terms of both delivered power and time duration. The extracts/distillates were analyzed by GC and GC-MS. Microwave distillation, which exploits the physical action of microwaves on plants, showed a series of advantages over the other approaches: low cost, use of water in sample pre-treatment step, greatly reduced isolation time, and attainment of high quality essential oil distillate. Moreover, the absence of environmental impact of this innovative technique was also emphasized.

Gas Chromatography-Mass Spectrometry↗

PubMedDate not supplied

A method for the solvent extraction of low-boiling-point plant volatiles.

A new method has been developed for the extraction of volatiles from plant materials and tested on seedling tissue and mature leaves of Arabidopsis thaliana, pine needles and commercial mixtures of plant volatiles. Volatiles were extracted with n-pentane and then subjected to quick distillation at a moderate temperature. Under these conditions, compounds such as pigments, waxes and non-volatile compounds remained undistilled, while short-chain volatile compounds were distilled into a receiving flask using a high-efficiency condenser. Removal of the n-pentane and concentration of the volatiles in the receiving flask was carried out using a Vigreux column condenser prior to GC-MS. The method is ideal for the rapid extraction of low-boiling-point volatiles from small amounts of plant material, such as is required when conducting metabolic profiling or defining biological properties of volatile components from large numbers of mutant lines.

Alcohols↗

PubMed2004

Insecticidal effects of essential oils from various plants against larvae of pine processionary moth (Thaumetopoea pityocampa Schiff) (Lepidoptera: Thaumetopoeidae).

Along with sulfate turpentine, the essential oils obtained by steam distillation from nine plant species naturally grown in Turkish forests were tested at three different concentrations to evaluate their effectiveness against the larvae of pine processionary moth (Thaumetopoea pityocampa Schiff). The results indicated that the essential oils from the nine species and sulfate turpentine were effective against the larvae of T pityocampa. The most effective essential oil in the control of the larvae was steam-distilled wood turpentine, followed by thyme herb oil, juniper berry oil, laurel leaf oil, lavender flower oil, eucalyptus leaf oil, lavender leaf oil, cypress berry oil, essential oil of styrax and sulfate turpentine, respectively, in terms of mean mortality time. It is therefore feasible to use these essential oils as environment-friendly insecticides in the control of T pityocampa.

Animals↗

PubMed2002

Antistress effects of bacosides of Bacopa monnieri: modulation of Hsp70 expression, superoxide dismutase and cytochrome P450 activity in rat brain.

The antistress effect of bacosides of Brahmi (Bacopa monnieri, BBM), dissolved in distilled water, was -studied in adult male Sprague Dawley rats by administering oral doses of 20 and 40 mg/kg for 7 consecutive days. In half of the animals treated with 20 or 40 mg/kg of BBM, stress was given 2 h after the last dose. Stress was also administered to the animals treated with distilled water alone. BBM, at both doses, did not induce a significant change in the expression of Hsp70 in any brain region studied while stress alone produced a significant increase in the Hsp70 expression in all the brain regions. A significant decrease in the activity of superoxide dismutase (SOD) was evident in the hippocampus with the lower dose of BBM and in animals given stress alone, while an increase in the activity of SOD was observed in the brain regions with the higher dose of BBM. An increase in the activity of cytochrome P450 (P450) dependent 7-pentoxyresorufin-o-dealkylase (PROD) and 7-ethoxyresorufin-o-deethylase (EROD) was observed in all the brain regions after exposure to stress alone and with both doses of BBM although the magnitude of induction of P450 expression was less with a higher dose of BBM. Interestingly, stress when given to the animals pretreated with BBM for 7 days resulted in a decrease in Hsp70 expression in all the brain regions with a significant decrease occurring only in the hippocampus. Likewise the activity of SOD was found to be further reduced in all the brain regions in the animals treated with the lower dose of BBM followed by stress. However, when stress was given to the animals pretreated with the higher dose of BBM, a significant increase in the enzyme activity was observed in the cerebral cortex and in the rest of the brain while the activity of SOD was reduced to a much greater extent in the cerebellum and in the hippocampus. Likewise, the activity of P450 enzymes was found to be restored to almost control levels in the animals given stress and pretreated with the higher dose of BBM, while a lesser degree of induction, compared with animals treated with BBM or stress alone, was observed in the animals pretreated with the lower dose of BBM and given stress. The data indicate that BBM has potential to modulate the activities of Hsp70, P450 and SOD thereby possibly allowing the brain to be prepared to act under adverse conditions such as stress.

Administration, Oral↗

PubMed2003

The comparative effect of novel Pelargonium essential oils and their corresponding hydrosols as antimicrobial agents in a model food system.

Essential oils and their corresponding hydrosols, obtained after distillation of various scented Pelargonium (Geraniaceae) leaves were assessed for their antimicrobial activity in a model food system. Both the essential oils and hydrosols were used at 1000 ppm in broccoli soup, previously inoculated with Enterobacter aerogenes (at 10(5) cfu g(-1)) and Staphylococcus aureus (at 10(4) cfu g(-1)). The results showed a complete inhibition of S. aureus in the broccoli soup by the essential oils of 'Sweet Mimosa', 'Mabel Grey', P. graveolens, 'Atomic Snowflake', 'Royal Oak', 'Attar of Roses' and a lesser effect by 'Chocolate Peppermint' and 'Clorinda'; the hydrosols, however, had a potentiating effect on the bacterial population in the food. Both extracts showed a complete inhibition of S. aureus in the Maximum Recovery Diluent (MRD). Antibacterial activity against E. aerogenes in the broccoli soup was generally very much reduced: only the essential oil of 'Mabel Grey' showed complete inhibition and virtually no reductions in colonies were seen with the other essential oils; the hydrosols again caused an increase in bacterial colonies. All the essential oils, bar Chocolate Peppermint showed complete inhibition of E. aerogenes in MRD, but the hydrosols showed no effect. The results strongly suggest that the residual hydrosols from distillation of these plant essential oils have no potential as antibacterial agents in foods, in contrast to most of the essential oils, which show potential against some micro-organisms, but only in some food systems. The problem of food component interference and its possible management is discussed.

Brassica↗

PubMed2006

Systemic effect of crude extract from rhizome of Drynaria fortunei on bone formation in mice.

The structure of the bones of mice with and without consumption of Gusuibu extracts were compared. Twenty 8-week-old male BALB/c mice were divided into two groups. In the control group ten mice were daily fed a normal diet and distilled water for drinking. In the Gusuibu group ten mice were daily fed a normal diet and distilled water mixed with Gusuibu extract for drinking. The mice were kept for 5 weeks and were then killed. Using micro-computed tomography, 20 micro-tomographic slices with an increment of 0.25 mm were acquired to cover the proximal end of the left tibia of each mouse. Quantitative morphometry of the bone structure was performed. The results showed that consumption of Gusuibu extract increased the bone volume/tissue volume ratio by 6.45%. The bone trabeculae were increased by 10.00% in number so that the bone density was increased. To conclude, Gusuibu extract taken orally increased bone density.

Animals↗

PubMed1981

SEM cryofracture study of ovarian follicles of immature rats.

Follicles were examined with the scanning electron microscope (SEM) following preparation of cryofractured specimens of rat ovaries. After perfusion fixation with 2.5% glutaraldehyde buffered at pH 7.4 with 0.1M cacodylate, ovaries were trimmed of fat and decapsulated, fixed for an additional 12 hours, washed in distilled H2O for 20 hours and postfixed in 1% OsO4 in distilled H2O for 30 minutes. Following a brief wash, ovaries were dehydrated in a linear gradient of dist. H2O/ethanol, frozen in Freon 22, cryofractured under liquid nitrogen, brought to 1 degree C in ethanol, and critical point dried from CO2. Follicles cleaved through their oocytes were examined with SEM to determine the ultrastructural characteristics of developing and atretic follicles revealed by cryofracture. Cytoplasmic arrays of parallel sheets, nucleoli and microvilli were prominent structures of cryofractured oocytes. Numerous cytoplasmic projections of granulosa cells and oocyte microvilli penetrated the zonae pellucida of preantral follicles. The numbers of oocyte microvilli were greatly diminished in large antral follicles. Other structures made prominent by cryofracture included cell nuclei, a microvillous border at the granulosa-theca boundary, and numerous holes in the cytoplasm of thecal cells which correspond in size and distribution to the liquid droplets in these cells. The soluble proteins and glycoproteins of the follicular fluid were visualized as a homogeneous granular precipitate. The disappearance of oocyte microvilli and granulosa cell projections from the zonae pellucida and the blebbing of granulosa cells at the surface of the antral cavity appeared characteristic of an early stage of follicular atresia. Increased numbers of holes in thecal cells, oocyte fragmentation, and extensive dissociation and fragmentation of granulosa cells were typical of more advanced stages of atresia.

Animals↗

PubMed1985

Carcinogenicity bioassays of bromoacetaldehyde and bromoethanol--potential metabolites of dibromoethane.

1,2-Dibromoethane (DBE) and two of its potential metabolites, bromoethanol (BE) and bromoacetaldehyde (BA), were tested for carcinogenicity in male and female B6C3F1 mice using 30 animals of each sex per group. The carcinogen DBE was included in this assay as a positive control. The compounds were administered in distilled drinking water using equimolar concentrations, 4 mmol, of the chemicals. The dose chosen was based on subchronic bioassays of three months' duration. The chronic tests were continued for approximately 450 days in the case of DBE and approximately 560 days for both BE and BA. DBE induced squamous carcinomas of the forestomach in 22 females and 26 males and squamous papillomas of the esophagus in 3 females. BE induced squamous papillomas of the forestomach only in 10 females and 9 males. BA did not induce a significant incidence of tumors of the forestomach. Significant tumor incidences at other sites were not observed in any groups including the distilled water control group. Based on these findings, it is unlikely that BE or BA are activated carcinogenic intermediates of DBE.

Acetaldehyde↗

PubMed1985

Lead-induced early lesions in the brain of the chick embryo.

A single dose consisting of a solution of lead nitrate containing 1 mg lead in 0.1 ml distilled water was injected into the air chamber of chicken eggs on the tenth day of incubation. The injected embryos were killed 24, 48, or 72 hours after the injection. Control embryos were injected with a similar volume of distilled water or of an equimolar calcium nitrate solution on the tenth day and killed 72 hours after. Portions of the optic lobes were processed for their electron microscopic study. Multiple hemorrhagic foci appeared 24 hours after the administration of lead. Red blood cells were found to exit the blood vessels through the spaces between otherwise normal-looking endothelial cells; tight junctions were always found blocking the interendothelial spaces except during the migration of red blood cells through them. Vacuolization of the cytoplasm and mitochondrial swelling and disorganization were observed in the endothelial cells only during the third day after the injection. Similarly, histological and ultrastructural alterations of nerve cells were only found on the third day after the treatment. Hemorrhagic foci were never found in control embryos. Our observations are consistent with the idea that the hemorrhages constitute the primary lesion produced by lead. They also suggest that the hemorrhages are not the result of rupture of previously altered endothelial walls but occur by diapedesis through the interendothelial clefts.

Animals↗

PubMed1991

Marked increase in the teratogenicity of the combined administration of the industrial solvent 2-methoxyethanol and radiofrequency radiation in rats.

Limited published animal research reports synergistic teratogenic effects following combined hyperthermia (induced by elevated ambient temperature) and administration of chemical teratogens. Radiofrequency (RF) radiation is widely used in occupational environments. Since RF radiation also elevates the body temperature of, and is teratogenic to, exposed animals, concurrent RF radiation and chemical agent administration may enhance teratogenicity. The present exploratory study, consisting of preliminary dose-finding studies and the primary study, was designed to investigate whether concurrent exposure of rats to RF radiation and the industrial solvent 2-methoxyethanol (2ME) can enhance the developmental toxicity of either agent acting alone. Preliminary dose-finding studies using small numbers of rats investigated the ability of various RF radiation conditions and doses of 2ME to produce external malformations (primarily of the paws) when administered on gestation day 13. Based on these preliminary studies, RF radiation exposure [sufficient to elevate rectal temperature to 42.0 degrees C (4 degrees C above normal for rats) for 30 min] and 2ME administration (150 mg/kg) were selected for the primary study. In the primary study, groups of 18 to 27 pregnant rats were administered RF radiation exposure and distilled water gavage, 2ME gavage and sham RF exposure, RF radiation exposure and 2ME gavage concurrently, or sham RF exposure and distilled water gavage. Pregnant rats were sacrificed on gestation day 20, and the offspring were examined for external malformations. Combined exposures enhanced the adverse effects produced by either experimental agent alone (no malformations were detected in the double sham group). Mean fetal malformations/litter increased from 14% after 2ME and sham RF (15/26 litters affected, with an average of 2 fetuses/litter malformed) and 30% after RF radiation and water gavage (10/18 litters affected, with an average of 4 fetuses/litter malformed), to 76% after the combined treatment (18/18 litters affected, with an average of 12 fetuses/litter malformed). In addition to a significant increase in the frequency of malformations, the severity of malformations also was enhanced by the combination treatment (on a relative severity ranking scale, the 2ME severity score was less than 1, the RF score was 3, and the combination score was 6). This study provided evidence of synergism between RF radiation and 2ME administration, but additional research will be required to characterize the extent of synergism between these two agents. Potential interactive effects between chemical and physical agents need to be investigated to determine the extent to which such interactions should impact occupational exposure standards.

Animals↗