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At least 919 records · Page 51Linked to original sources
PubMed1995

[Class II dento-skeletal dysmorphism. Observations apropos of orthodontic-surgical treatment].

The Classe II maxillofacial deformities are common, varied in their expression and most frequently have both dental and skeletal components. For this reason, combined orthodontic-surgical treatment is well suited to correction of problems from which the patient suffers. Several clinical deductions are presented which pertain to diagnosis and treatment of Class II vertical excess deformities.

Adolescent↗
PubMed1997

[A forecasting trial of the dento-skeletal and cutaneous facial profile, as a function of sex, in Class II, division 1 malocclusion, using regression analysis of the coordinates].

For a pattern of 36 leucoderm subjects, aged 12 years, with Class II, division 1, prediction of results are been calculated, in each sex, proceeding bony and cutaneous points coordinates, in axis defined by S-N, with "regression" method. Bony, dental and cutaneous profiles expected 3 years afterwards can be established in a personalized way, as well as correspondent security limits. A logical make easy utilisation of this process.

Adolescent↗
PubMed2002

Methyl jasmonate as an allelopathic agent: sagebrush inhibits germination of a neighboring tobacco, Nicotiana attenuata.

Artemisia tridentata ssp. tridentata is the dominant and defining shrub in the Great Basin Desert, with well-documented allelopathic tendencies that have generally been ascribed to its most abundantly released secondary metabolites. However, as a minor component, sagebrush releases a highly biologically active substance, methyljasmonate (MeJA), which is known to function as both a germination inhibitor and promoter in laboratory studies. Nicotiana attenuata is a tobacco species native to the Great Basin Desert and grows in newly burned juniper-sagebrush habitats for 2-3 yr following a fire. With a combination of field and laboratory studies, we examined the role of MeJA release from sagebrush by both air and water transport in inhibiting N. attenuata seed germination. We demonstrated that sagebrush interacts allelopathically with the seed bank of N. attenuata through its release of MeJA. In the field, seeds buried 0-40 cm from sagebrush plants for 4 months in net bags had significantly reduced germination compared to seeds buried similarly but protected in plastic bags. Moreover, germination on soils collected from underneath sagebrush plants was reduced by 60% compared to seeds placed on soils collected between sagebrush plants or outside of the sagebrush population. Exposure to A. tridentata seeds and seedlings did not affect N. attenuata germination, suggesting that established sagebrush plants only influence the tobacco's seed bank. In the laboratory, exposure of seeds to sagebrush emissions resulted in germination delays of up to 6 d. Exposure to volatile and aqueous MeJA also inhibited germination of N. attenuata seeds at quantities that are released naturally by sagebrush: 3.5 microg/hr and 1.12 microg/seed cup (56 ng/seed), respectively. A. tridentata seeds were significantly more resistant to MeJA, being inhibited at 336 microg MeJA (16.8 microg/seed), 300 times greater than the level of aqueous MeJA required to inhibit N. attenuata seeds. MeJA inhibited N. attenuata germination regardless of the seed's dormancy state and the specific epimer (trans- or cis-) of MeJA. Germination on sagebrush chaff that had been heated to reduce MeJA content was negatively correlated with the amount of MeJA remaining in the chaff. Germination of a nondormant, conspecific tobacco, N. trigonophylla, which grows in the same area but is not associated with fire, is less sensitive than N. attenuata to the extracts of sagebrush litter, but similarly sensitive to MeJA. Additionally, four of five other tobacco species that are not known to be associated with sagebrush are less sensitive to MeJA, suggesting an evolved sensitivity to MeJA. To determine the proportion of germination inhibition of a sagebrush extract that could be attributed to MeJA, we serially diluted sagebrush extracts with water and restored the quantity of MeJA of the original extract by adding appropriate quantities of synthetic MeJA; 16-60% of the inhibitory activity of the original extract could be attributed to the MeJA. We conclude that MeJA release from sagebrush plays an allelopathic role for N. attenuata seed banks, but other unidentified compounds are also involved.

Acetates↗
PubMedDate not supplied

Antimicrobial compounds from Coleonema album (Rutaceae).

Coleonema album, a member of the South African fynbos biome, was evaluated for its antimicrobial activity associated with its secondary metabolites. Ethanol- and acetone-based extracts obtained from plants from two different geographical areas were analyzed. A bioassay-guided fractionation methodology was followed for rapid and effective screening for the presence of bioactive compounds. The TLC-bioautographic method, used to screen the plant extracts for antimicrobial activity and localization of the active compounds, indicated the presence of a number of inhibitory compounds with activity against the microorganisms (E. coli, B. subtilis, E. faecalis, P. aeruginosa, S. aureus, M. smegmatis, M. tuberculosis, C. albicans, C. cucumerinum) tested. Evaluation of the inhibitory strength of each extract by the serial microdilution assay indicated that the C. album extracts inhibited effectively all the microorganisms, with the minimum inhibitory concentrations in the low mg ml(-1) range. Identification and structural information of the bioactive components were obtained by a combination of preparative TLC and LC-MS. It revealed the presence of coumarin aglycones which were responsible for the observed antimicrobial activities. The results of this study indicate that C. album possesses strong antimicrobial activity against a wide range of microorganisms that warrants further investigation into the use of the extracts or their active constituents as a potential source for novel drugs.

Anti-Bacterial Agents↗
PubMed1994

Determination of 7 alpha-hydroxy-4-cholesten-3-one level in plasma using isotope-dilution mass spectrometry and monitoring its circadian rhythm in human as an index of bile acid biosynthesis.

A highly sensitive and specific method has been developed for determination of the level of 7 alpha-hydroxy-4-cholesten-3-one in plasma. This method is based on a stable isotope-dilution technique by gas chromatography-selected-ion monitoring mass spectrometry. 7 alpha-Hydroxy-4-cholesten-3-one was extracted from plasma by saltingout extraction, and then purified by serial solid-phase extractions. The extract was treated with O-methylhydroxyl-amine hydrochloride and then dimethylethylsilylated. The resulting methyloxime-dimethylethylsilyl ether derivative was quantified by gas chromatography-selected-ion monitoring mass spectrometry with a high-resolution mode. The plasma levels of 7 alpha-hydroxy-4-cholesten-3-one were correlated with the cholesterol 7 alpha-hydroxylase activity to a higher degree than those of any other form of 7 alpha-hydroxycholesterol (r = 0.84, n = 16, p < 0.0001). The present method was applied to monitor the circadian rhythm of 7 alpha-hydroxy-4-cholesten-3-one levels in human plasma. It was concluded that the plasma level of 7 alpha-hydroxy-4-cholesten-3-one is a useful index for the monitoring of bile acid biosynthesis in the human liver.

Adult↗
PubMed1986

Chromatographic characterization of adult and foetal rat insulin.

Foetal rat pancreatic rudiments explanted on day 14 of gestation were grown in organ culture in medium enriched with amino acids. The size of the insulin granules was increased, resulting in an insulin granule volume fraction greater than the volume fraction measured in pancreas grown in vivo. The pancreas was extracted and the insulin compared. Serial dilution curves of extracts of adult pancreas and pancreas grown in vitro are parallel in the insulin radioimmunoassay, whereas extracts of pancreas of foetus developing in utero appear immunologically different. Adult and foetal rat insulin (in utero) were purified using chromatography on OPTI UP C12, cellulose thin-layer chromatography plates, cellulose acetate foil electrophoresis and finally high-performance liquid chromatography. The ratio of insulin I to insulin II was found to be 1.5 for the adult and 2.7 for the foetus. These results show that there is an unequal expression of the two non-allelic genes controlling insulin biosynthesis in foetal and adult rat pancreas.

Animals↗