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)

Airborne dust is toxic for cells cultured in vitro and able to transform these cells to cancerous. The effect of extracts from atmospheric dust has been investigated. The dust samples were extracted by means of DMSO alone or in combination acetone-DMSO. Dosage of the extract was done according to its benzo(a)pyrene content (mug/ml medium). Dust extract with a concentration of 1 mug benzo(a)pyrene/ml exerted a toxic effect upon mouse macrophages (cell line IC-21) and human lymphocytes after stimulation. The degree of toxicity was estimated from the percentage of damaged cells seen in the dye exclusion test and from the amount of lactate dehydrogenase and lactate released into the medium in the case of macrophages. In the case of lymphocytes the degree of toxicity was estimated from the extent of inhibition of DNA synthesis. In the carcinogenicity test, hamster kidney cells were first treated with the extract and then incubated with Simian Virus (SV-)40. Treatment of the cell cultures with extract from airborne dust in a concentration of 0.01 and 0.1 mug benzo(a)pyrene/ml clearly enhances the rate of transformation caused by SV 40.
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PMID:[The effect produced by fine-dust extracts on cells in vitro, with particular regard to cancerogenic components (author's transl)]. 18 83

We have constructed a space-filling (Corey-Pauling-Koltun) model of an alternative structure for DNA. This structure is not a double helix, but consists of a pair of polynucleotide strands lying side by side and held together by Watson-Crick base pairing. Each of the two strands has alternating right- and left-handed helical segments approximately five base pairs in length. Sugar residues in alternating segments along a strand point in opposite directions. A structure slightly different from the present one proposed earlier by ourselves and another group and in which sugars in a strand all point in the same direction is ruled out. The present structure yields natural solutions to the problems of supercoiling of DNA and of strand separation during DNA replication. This model is energetically more favorable than the double helix.
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PMID:Some implications of an alternative structure for DNA. 27 99

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

A method is reported for considering tumour-host relationships, which consists in cultivation of human tumours jointly with autologous lymphocytes in an organ culture system and determining separately tumour and lymphocyte DNA synthesis before and after mixed culture. Some experiments explore variables of the new system. For mixed organ cultures the best conditions are: 4-day incubation, lymphocyte DNA ratio to tumour cell DNA less than 9:1 (2-10(6) lymphocytes/ml) and autologous serum. So far 41 tumours (20 mammary, 17 gastric, and 4 bronchial carcinomas) have been examined. 22 tumours showed satisfactory in vitro maintenance. In 50% of the mixed organ cultures, lymphocyte DNA synthesis proved to be higher than in lymphocyte control cultures. Blast counts in the cell smears are in good accord with results obtained by biochemical determination of DNA synthesis. 7 of the tumours studied have shown a pronounced reduction of DNA synthesis in the presence of lymphocytes. The present results underline the individuality of tumour-host relationships and suggest the necessity of determinations of the immune reactivity in cancer patients. Advantages and disadvantages of the method are discussed.
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PMID:Mixed organ culture as a tool for considering cellular tumor-host relationships in tumor patients. 97 Oct 45

Coke oven workers are exposed to high concentrations of polycyclic aromatic hydrocarbons. Only recently have methods been developed to try to assess the individual, biologically significant exposure. The only coke oven plant in Finland started to function in 1987, in Raahe, enabling the implementation of a cohort study among the workers to determine the usefulness of some currently available biomonitoring methods, e.g. methods of measuring PAH-DNA adducts. Urine and blood samples were taken several times from a sample of workers starting from before they worked at the plant. A questionnaire (smoking, diet, former and current occupations) was filled in by the workers at every sampling, and air samples (personal and stationary) were collected at the same time. The mean values of both benzo(a)pyrene diolepoxide (BPDE)-DNA adducts were measured by synchronous fluorescence spectrophotometry (SFS) and the antibodies to these adducts increased somewhat after the work at the plant started. However, all the adduct values were low, and no differences between the smokers and non-smokers at any time point were detected. Battery workers had slightly increased means of BPDE-DNA adducts compared to non-battery workers. Also, coke oven workers had slightly higher adduct values than age, sex and smoking matched controls.
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PMID:Assessment of PAH-exposure among coke oven workers. 130 31

Takayasu arteritis is a common cause of renovascular hypertension in India. Sensitization to infective agents, particularly mycobacterium tuberculosis or autoimmune disturbances have been incriminated in its pathogenesis. Twenty patients of Takayasu arteritis along with groups of normal individuals, patients of essential hypertension, autoimmune disorders, tuberculosis, and healthy tuberculin reactors were studied. Besides detailed immunological profiles including LE cell phenomenon, serum complement C3 levels, antibodies to single (SS) and double stranded (DS) DNA, rheumatoid factor, lymphocyte subsets, blast transformation to antigens including, phytohemagglutinin, PPD, pokeweed, and purified human aortal antigen (PHAA) were examined. Soluble protein from human aorta was fractionated into 9 peaks by DEASE-52 and Sephadex G-75 chromatography, and 25 micrograms of major protein fraction-II was used for blast transformation study. Blast transformation by PHAA was higher in Takayasu arteritis as compared to all other groups (P < 0.05). Blast transformation to PPD showed wide variation in all the groups, and was significantly higher only in tuberculin reactors as compared to controls. These observations support aortal sensitization to PHAA playing a role in pathogenesis of Takayasu arteritis and do not relate tuberculosis to Takayasu arteritis, at least immunologically. In addition, the ratio of CD-4 positive to CD-8 positive lymphocytes changing in favor of the former and the concomitant increase in B lymphocytes favor the presence of autoimmune disturbances in Takayasu arteritis.
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PMID:Immunopathogenesis of Takayasu arteritis. 136 Sep 78

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

Changes in the contents of DNA and RNA, RNA species, the synthesis rates of DNA and RNA, and the activity of DNase and RNase were investigated in the callus of tobacco (Nicotiana tabacum L. cv. Willow Leaf) during subculture and differentiation. The contents of DNA and RNA were higher in differentiating callus than that in subcultured callus. After day 12, the contents of DNA and RNA in differentiating callus rose continuously while the contents of DNA and RNA in subcultured callus remained constant. Changes in RNA species and its relationship to total RNA level were also analyzed. At the stage of shoot primordium formation in differentiating callus, the activity of RNase increased markedly and the synthesis rate of RNA increased continuously; while the RNase activity and the synthesis rate of RNA in subcultured callus were much lower during the same period. During the period of shoot growth, the synthesis rate of DNA in differentiating callus was elevated compared to that in subcultured callus. The results above suggested that the metabolism of nucleic acids in differentiating callus was more active than that in subcultured callus.
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PMID:[A comparative study on the metabolism of nucleic acids during the subculture and differentiation of tobacco callus]. 141 25

Crosses were produced between two lines of White Plymouth Rock chickens, one of which had been selected for low 8-week body weight for 31 generations (L) and the other of which was a bantam population (B). The parental lines, reciprocal F1s, reciprocal F2s and all possible back-crosses to each parental line (total of 16 populations) were available for study. Blood was obtained from 10 females within each population. DNA was extracted from blood mixes (equal amounts of blood from each individual) for each population, and from blood samples of each individual in the two parental lines. Fourteen line-specific DNA fingerprint (DFP) bands (those bands present in one parental population, but not in the other parental population) were analysed (eight from line L and six from line B). Regression analyses were conducted to compare the known proportion of genomic contribution from each parental population with values based on relative band intensity obtained with a scanning densitometer. The resulting regression coefficient of 1.004 demonstrated that DFP analysis of relative band intensity is an effective method of estimating the relative proportion of genome contributed by parental populations.
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PMID:Genetic distances estimated from DNA fingerprints in crosses of white Plymouth Rock chickens. 144 74

Serodiagnosis is useful when pathogens cannot be detected quickly or easily by conventional methods or have been eliminated by the patient. Taking the example of leptospirosis, the microscopic agglutination test to detect specific antibodies after leptospires have disappeared from the patient's bloodstream is of unsurpassed reliability. Unfortunately the test is used mainly in specialized laboratories that can culture leptospires to serve as live antigens. Freeze-dried leptospires may allow the application of the test on a wide scale. The ELISA is useful for the detection of IgM antibodies in humans as a sign of current or recent infection. ELISA results must be confirmed by the microscopic agglutination test. A simplified easy-to-read ELISA using broadly reactive antigen for the detection of all types of leptospires might be useful for a quick detection of acute human leptospirosis. Using an appropriate antigenic preparation the ELISA is useful for the detection of antibodies in animals, e.g. cattle. As for pathogen detection, DNA-based methods such as PCR are promising for an early, quick and specific diagnosis. Antigenic analysis by monoclonal antibodies and genetic analysis by restriction fragment length polymorphism are for the time being complementary methods for the characterization of leptospiral isolates.
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PMID:Serodiagnosis of bacterial diseases: problems and developments. 151 58


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