Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:APRD00080 (Leaf)
 21,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of several dehydration treatments on the synaptonemal complex (SC), histone solubility in 2.0 M NaCl, and histone-DNA interaction in unfixed rat spermatocytes were evaluated. Freeze substitution with ethanol or dehydration with polyethylene glygol resulted in loss of the SC, preservation of histone solubility and DNA-histone salt linkages. Dehydration with ethylene gylcol or hexylene glycol resulted in preservation of SC with a clear delineation of attachment of the chromatin fibrils to the lateral elements, but a loss of histone solubility and histone-DNA linkages. Dehydration to a fifty percent concentration with glycerol with completion of dehydration with ethylene glycol had the same effect but also resulted in an even distribution of chromatin fibrils. Dehydration with glycerol alone resulted in clumping of chromatin and loss of SC structure, histone solubility and histone-DNA linkages. Partial dehydration to a fifty percent concentration with these three solvents followed by freeze substitution with ethanol resulted in the loss of SC structure and histone solubility but the preservation of histone-DNA linkages. It is likely that these nonaqueous solvents affected the histone hydrophobic groups and thereby altered histone conformation and interactions. These alterations, depending on the treatment used, resulted in the loss or preservation of SC, histone solubility and histone-DNA interactions thereby indicating that the hydrophobic interactions of the histones are crucial for the preservation of these feature of meiotic chromosomes. These results also demonstrate that neither does the preservation of the histone-DNA salt linkages suffice for the preservation of the SC nor does their disruption necessarily result in its loss. The lysine-rich histones, particularly that one unique to meiotic cells, may through their interactions play a crucial role in SC structure.
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PMID:Cytochemical and ultrastructural studies on the synaptonemal complex of rat spermatocytes. 32 69

Using fresh frozen, freeze-dried or cryostate sections from aldehyde fixed rat tissues 13 diazonium salts were tested as simultaneous coupling reagents for the localization of acid, neutral and alkaline hydrolases with azo indoxyl methods. Hexazotized new fuchsine and/or Fast blue B are the diazonium salts of choice for the demonstration of acid beta-galactosidase, neuraminidase, beta-N-acetylglucosaminidase, acid phosphatase, and non-specific esterase followed by hexazotized p-rosaniline. Fast blue VB, BB and RR and Fast violet B are recommended for the investigation of alkaline phosphatase and lactase, Fast garnet GBC for acid beta-galactosidase, glucosaminidase and lactase. Fast red B, RC, RL and TR and Fast black K can only be employed for lactase studies. The exact concentration of the coupling reagent depends on the activity of the enzyme and the organ imvestigated. On the average 0.01-0.02 ml unstable diazonium salt/ml and 0.3--1 microgram stable diazonium salt/ml are sufficient for the correct localization of these hydrolases. Freeze-dried cryostat sections yield the best results in the demonstration of lactase and alkaline phosphatase independent on the coupling reagent used. Sections from formaldehyde or glutaraldehyde fixed organs are superior for the localization of the other hydrolases; an exception is the investigation of acid beta-galactosidase and glucosaminidase with Fast garnet GBC. Then, excellent results are obtained also with freeze-dried material. Fresh frozen sections are suitable for the localization of lactase with hexazotized new fuchsine or p-rosaniline and of alkaline phosphatase with Fast blue VB and BB or violet B. The total activity of acid, neutral and alkaline hydrolases can be investigated using semipermeable membranes in combination with all unstable and stable diazonium salts of choice. Reliable osmification of the azoindoxyl dye is only possible if hexazotized p-rosaniline is employed for coupling; without further posttreatment all azoindoxyl dyes are extracted by ethanol, isopropanol or xylol. 7 incubation media are given for the demonstration of hydrolases with azoindoxyl methods at the level of light microscopy for routine studies and typical examples for the application of these methods are presented. A modified procedure is described for the freeze-drying of cryostat sections with the Edwards-Pearse tissue dryer EPD3.
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PMID:[Azoindoxyl methods for the investigation of hydrolases. IV. Suitability of various diazonium salts (author's transl)]. 36 63

The three-dimensional crystal structure of bovine trypsinogen at approximately pH 7.5 was initially solved at 2.6 A resolution using the multiple isomorphous replacement method. Preliminary refinement cycles of the atomic coordinates trypsinogen have been carried out first to a resolution of 2.1 A, and later to 1.9 A, using constrained difference Fourier refinement; During the process, structure factors Fc and phi c were calculated from the trypsinogen structure and final interpretation was based on an electron-density map computed with terms (2 Fo - Fc) and phases phic at a resolution of 1.9 A. Crystals of trypsinogen grown from ethanol-water mixtures are trigonal with space group P3121, and cell dimension a = 55.17 A and c = 109.25 A. The structure is compared with the bovine diisopropylphosphoryltrypsin structure at approximately pH 7.2, oirginally determined from orthohombic crystals by Stroud et al. (Stroud, R.M., Kay L.M., and Dickerson, R.E. (1971), Cold Spring Harbor Symp. Quant. Biol. 36, 125-140; Stroud, R.M., Kay, L.M., and Dickerson, R.E. (1974), J. Mol. Biol. 83, 185-208), and later refined at 1.5 A resolution by Chambers and Stroud (Chambers, J.L., and Stroud, R.M. (1976), Acta Crystallogr. (in press)). At lower pH, 4.0-5.5 diogen, with cell dimensions a = 55.05 A and c = 109.45 A. This finding was used in the solution of the six trypsinogen heavy-atom derivatives prior to isomorphous phase analysis, and as a further basis of comparison between trypsinogen and the low pH trypsin structure. There are small differences between the two diisopropylphosphoryltrypsin structures. Bovine trypsinogen has a large and accessible cavity at the site where the native enzyme binds specific side chains of a substrate. The conformation and stability of the binding site differ from that found in trypsin at approximately pH 7.5, and from that in the low pH form of diisopropylphosphoryltrypsin. The catalytic site containing Asp-102, His-57, and Ser-195 is similar to that found in trypsin and contains a similar hydrogen-bounded network. The carboxyl group of Asp-194, which is salt bridged to the amino terminal of Ile-16 in native trypsin or other serine proteases, is apparently hydrogen bonded to internal solvent molecules in a loosely organized part of the zymogen structure. The unusually charged N-terminal hexapeptide of trypsinogen, whose removal leads to activation of the zymogen, lies on the outside surface of the molecule. There are significant structural changes which accompany activation in neighboring regions, which include residues 142-152, 215-550, 188A-195. The NH group of Gly-193, normally involved in stabilization of reaction intermediates (Steitz, T.A., Henderson, R., and Blow, D.M. (1969), J. Mol. Biol. 46, 337-348; Henderson, R. (1970), J. Mol. Biol. 54, 341-354; robertus, J.D., Kraut, J., Alden, R.A., and Birkoft, J.J. (1972), Biochemistry 11, 4293-4303) in the enzyme, is moved 1.9 A away from its position in trypsin...
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PMID:Structure of bovine trypsinogen at 1.9 A resolution. 55 51

Three methods usually applied in preparing biological material for the scanning electron microscope were tested by the investigation of two species of amoebae with different content of water (Amoeba proteus, Vannella simplex). Air drying resulted in both the production of cell shrinkage and cell distortion. When the specimens were dryed from media with increasing vapour-pressure, more satisfactory preservation of surface structures could be obtained. The sequence of potency was: Ethanol, chloroform, isopentane, ethyl ether, freon 11 and freon 13. Short drying periods proved to be more favourable than long ones. Critical-point drying provided much better details of cell surface morphology in both amoebae species. However, some arteficial changes were still detectable as small breaks and destruction of the mucous layer. They must be attributed to the fixation and dehydration procedure. Freeze drying turned out to be superior to both air drying and critical-point drying. Specimens prepared by this method showed no visible differences in cell surface morphology compared to living cells. As a consequence of the relatively high content of water the preparation of A. proteus was more difficult than that of V. simplex.
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PMID:[Preparation of biological specimens for the scanning electron microscope (author's transl)]. 79 34

A rare case of spontaneous crystallization of the antibiotic substance was detected during submerged cultivation of Actinomyces hygroscopicus, strain 33x, under periodic conditions directly in the MTF 5L3 fermenter ("Marubishi"). Leaf-shaped plates of the antibiotic found in the cultural broth of the strain 33x were active against gram-positive and gram-negative microorganisms, yeasts, and fungi. The crystalline state of the structures was confirmed by the X-ray analysis. According to their UV spectrum (maximum at 233-234 nm in ethanol), the crystals belong to the group of nyphimycin A1-scopafungin, antibiotics produced by some cultures of Act. hygroscopicus.
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PMID:[Spontaneous crystallization of antibiotic substance during submerged fermentation of Actinomyces hygroscopicus]. 97 94

To determine whether the nuclei of mature mammalian spermatozoa are resistant to dehydrated conditions, nuclei of hamster and human spermatozoa were freeze-dried or treated with various dehydrating agents before injection into hamster oocytes. Freeze-dried nuclei remained capable of developing into pronuclei even after 12 mo of storage at 4 degrees C. The level of DNA synthetic activity in the sperm (male) pronucleus was comparable to that in the egg (female) pronucleus. Sperm nuclei that had been stored in 100% ethanol, 100% methanol, or chloroform-methanol (2:1) mixture for 20 days were also capable of developing into pronuclei. Even the nuclei that had been dehydrated ("fixed") with Carnoy's fluid could develop into morphologically normal pronuclei. However, the level of DNA synthesis in the pronuclei derived from these chemically dehydrated nuclei was generally lower than that in the female pronuclei. Although the genetic integrity of the dehydrated sperm nuclei is yet to be determined, nuclei of mature hamster and human spermatozoa appear to be fairly resistant to dehydrated conditions.
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PMID:The ability of dehydrated hamster and human sperm nuclei to develop into pronuclei. 139 32

A survey programme was organised in Lucknow and Farrukhabad, two towns of Uttar Pradesh, from March 1987 to July 1987. During the survey, the common folk medicine plants used by women were recorded and Ayurvedic and Unani drug encyclopedias were consulted for the antireproductive potential of these plants. Aqueous or 90% ethanol extracts of the plants of interest were studied in rats orally dosed for 10 days after insemination with special reference to effects on foetal development. Leaf extracts of Moringa oleifera and Adhatoda vasica were 100% abortive at doses equivalent to 175 mg/kg of starting dry material. Only the flowers of Acacia arabica and Hibiscus rosa-sinensis appeared to lack teratologic potential at the doses tested.
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PMID:Commonly used Indian abortifacient plants with special reference to their teratologic effects in rats. 160 72

Over the last four decades there has been extensive research into the links between diet and coronary heart disease. The most recent literature is reviewed in this position statement. The clinical and public health aspects of the National Heart Foundation's nutrition policy are based on this review. The key points are as follows: 1. Saturated fatty acids A high intake of saturated fatty acids is strongly associated with elevated serum cholesterol and LDL-cholesterol levels and increased risk of coronary heart disease. 2. The n-6 polyunsaturated fatty acids The n-6 polyunsaturated fatty acids (principally linoleic acid) lower serum cholesterol levels when substituted for saturated fats and probably have an independent cholesterol-lowering effect. 3. The n-3 polyunsaturated fatty acids (fish oils) The n-3 polyunsaturated fatty acids reduce serum triglyceride levels, decrease the tendency to thrombosis and may further reduce coronary risk through other mechanisms. 4. Monounsaturated fatty acids Monounsaturated fatty acids reduce serum cholesterol levels when substituted for saturated fatty acids. It is not clear whether this is an independent effect or simply the result of displacement of saturates. 5. Trans fatty acids Trans fatty acids may increase serum cholesterol levels and can be reckoned to be equivalent to saturated fatty acids. 6. Total fat Total fat intake, independent of fatty acid type, is not strongly associated with coronary heart disease but may contribute to obesity. Associations between total fat intake and coronary heart disease are primarily mediated through the saturated fatty acid component. 7. Dietary cholesterol Dietary cholesterol increases serum cholesterol levels in some people and may increase risk of coronary heart disease. 8. Alcohol A high intake of alcohol increases blood pressure and serum triglyceride levels and increases mortality from cardiovascular disease. Light alcohol consumption reduces the risk of coronary heart disease. 9. Sugar The consumption of sugar is not associated with coronary heart disease. 10. Sodium and potassium High salt intake is related to hypertension especially in the subset of "salt-sensitive" people. Potassium intake may be inversely related to hypertension. 11. Overweight and obesity Abdominal obesity increases the risk of coronary heart disease probably by adversely influencing conventional risk factors. 12. Vegetarianism A high intake of plant foods reduces the risk of coronary heart disease through several mechanisms, including lowering serum cholesterol and blood pressure levels.
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PMID:Diet and coronary heart disease. The National Heart Foundation of Australia. 163 Mar 69

Six thermotolerant yeasts were isolated at 37 degrees C from over-ripe grapes by serial dilution technique using glucose yeast extract medium. Purified yeast cultures were screened for ethanol production at 37 degrees C by batch fermentation, using cane molasses containing 20% sugars. Sugar conversion efficiency of these isolates varied from 66.0 to 88.5% and ethanol productivity from 1.11 to 1.73 ml/l/h. The highest ethanol producing isolate was exposed to UV radiations and 13 mutants were picked up from the UV treatment exhibiting 0.1 to 1.0%, survival. The UV mutants varied in cell size from parent as well as among themselves. Determination of ethanol produced by all the mutants revealed that only five mutants resulted in 4.5 to 6.2% increase in sugar conversion and 8.25 to 18.56% increase in ethanol concentration coupled with maximum ethanol productivity of 2.4 ml/l/h in 48 h of batch fermentation of cane molasses (20% sugars) at 37 degrees C temperature.
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PMID:Ethanol production by thermotolerant yeast and its UV resistant mutants. 172 18

Two studies were conducted to examine the interaction between sucrose and ethanol in normal young fasting adult males. The first experiment employed a 3 (100 g sugar, 35 g sugar, 0 g sugar) x 3 (alcohol, placebo and sober) factorial design, which was carried out double-blind using aspartame to ensure that all the drinks were equally sweet. Subjects were tested for mood, memory, subjective intoxication and psychomotor performance at baseline and at times up to 3.5 h after ingestion of the drinks. An alcohol by sugar interaction was seen at 0.5 after drinking. Sugar attenuated alcohol intoxication at this time without influencing blood alcohol levels. Contrary to previous reports, the combination of alcohol and sugar failed to produce significant hypoglycemia, or any of the adverse behavioral effects associated with hypoglycemia, at later times after drink ingestion. The second experiment involved a simpler design, carried out single-blind in which the subjects receiving no sugar did not get aspartame. This was to rule out the possibility that aspartame was exacerbating alcohol intoxication instead of sugar attenuating it. The second experiment also showed that sugar can attenuate alcohol intoxication in fasting humans without altering blood alcohol levels significantly.
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PMID:Effect of sucrose consumption on alcohol-induced impairment in male social drinkers. 174 11


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