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G Delgado

Publications and source records attributed to G Delgado.

At least 37 records · Page 2Linked to original sources
PubMed1999

Effect of xanthorrhizol, xanthorrhizol glycoside and trachylobanoic acid isolated from Cachani complex plants upon the contractile activity of uterine smooth muscle.

Xanthorrhizol, xanthorrhizol glycoside, and trachylobanoic acid, compounds isolated from medicinal plants that are grouped in the complex known as Cachani have been shown to inhibit the tonic contraction of rat uterus induced by: (a) depolarizing K+ solution (60 mM), (b) CaCl2 (1 mM), and (c) BAY K 8644 (0.3 microM) in a concentration-dependent manner (1-30 micrograms/mL). The inhibitory potency was displayed as follows: xanthorrhizol > xanthorrhizol glycoside > trachylobanoic acid. These results suggest that the assayed compounds might block voltage operated calcium influx in myometrial cells as they displayed a calcium-antagonistic activity. This effect is not due to peripheral receptor activation (beta 2-adrenergic, H2-histaminergic) as neither propranolol nor cimetidine modified the inhibitory effect of the compounds assayed. This is the first report showing that plants belonging to the Cachani complex may contain uterine smooth muscle bioactive substances.

Animals↗
PubMed1999

Biomineralization of carbonates by Marinococcus albus and Marinococcus halophilus isolated from the Salar de Atacama (Chile).

We studied the precipitation of carbonates in 17 strains of moderately halophilic, Gram-positive cocci belonging to two species: Marinococcus halophilus and Marinococcus albus, isolated from the Salar de Atacama (Chile). They were cultivated in solid and liquid laboratory media for 42 days at salt concentrations (wt/vol) of 3%, 7.5%, 15%, and 20%. The bioliths precipitated were studied by X-ray diffraction and scanning electron microscopy. M. halophilus formed crystals at each of the salt concentrations, with a maximum number of strains capable of precipitating carbonates at 7.5% and 15% salt concentrations. M. albus did not precipitate at 20% and showed a maximum at 7.5%. This behavior is similar to that of other gram-positive bacteria and differs from that found in gram-negative bacteria. The bioliths precipitated were spherical, generally isolated, with a size of 10-100 microm, varying with salinity. They were of magnesium calcite (CO3 Ca1-x Mgx) with Mg content increasing with increasing salinity and Mg/Ca molar ratio of the culture medium. These results demonstrate the active role played by M. halophilus and M. albus in the precipitation of carbonates.

Carbonates↗
PubMed1999

Two antimicrobial alkaloids from Bocconia arborea.

Two alkaloid constituents of Bocconia arborea showed considerable antimicrobial activity against gram-positive and gram-negative bacteria and Candida albicans. Bioactivity-guided fractionation with thin-layer bioautography led to the isolation of the two known benzophenanthridine alkaloids, dihydrochelerythrine and dihydrosanguinarine. The minimal inhibitory concentration was determined for each compound using a twofold serial dilution assay. The structures of these compounds were determined by 1H and 13C NMR analyses.

Alkaloids↗
PubMed1999

Genetic diversity and population structure of Vibrio cholerae.

Multilocus enzyme electrophoresis (MLEE) of 397 Vibrio cholerae isolates, including 143 serogroup reference strains and 244 strains from Mexico and Guatemala, identified 279 electrophoretic types (ETs) distributed in two major divisions (I and II). Linkage disequilibrium was demonstrated in both divisions and in subdivision Ic of division I but not in subdivision Ia, which includes 76% of the ETs. Despite this evidence of relatively frequent recombination, clonal lineages may persist for periods of time measured in at least decades. In addition to the pandemic clones of serogroups O1 and O139, which form a tight cluster of four ETs in subdivision Ia, MLEE analysis identified numerous apparent clonal lineages of non-O1 strains with intercontinental distributions. A clone of serogroup O37 that demonstrated epidemic potential in the 1960s is closely related to the pandemic O1/O139 clones, but the nontoxigenic O1 Inaba El Tor reference strain is not. A strain of serogroup O22, which has been identified as the most likely donor of exogenous rfb region DNA to the O1 progenitor of the O139 clone, is distantly related to the O1/O139 clones. The close evolutionary relationships of the O1, O139, and O37 epidemic clones indicates that new cholera clones are likely to arise by the modification of a lineage that is already epidemic or is closely related to such a clone.

Animals↗
PubMed1998

Cytotoxic isoflavans from Eysenhardtia polystachya.

Two new cytotoxic isoflavans, (3S)-7-hydroxy-2',3',4',5', 8-pentamethoxyisoflavan (1) and (3S)-3',7-dihydroxy-2',4',5', 8-tetramethoxyisoflavan (2), were isolated from the bark and trunks of Eysenhardtia polystachya (Leguminosae), together with the known constituents stigmasterol, isoduartin, cuneatin, 7-hydroxy-2',4', 5'-trimethoxyisoflavone, and 3,4-dimethoxy-8, 9-(methylenedioxy)pterocarpan. The structures of 1 and 2 were elucidated on the basis of spectroscopic methods. The antimicrobial, cytotoxic, and insecticidal potential of some of these compounds were evaluated. The isoflavans 1, 2, and isoduartin (2', 7-dihydroxy-3',4',8-trimethoxyisoflavan) displayed moderate cytotoxic activity against KB cell lines.

Animals↗
PubMed1998

Biomineralization of carbonates by Halomonas eurihalina in solid and liquid media with different salinities: crystal formation sequence.

Carbonate precipitation by 20 strains of the moderately halophilic species Halomonas eurihalina in both solid and liquid media was studied. The influence of salinity and temperature on the quantity and type of crystals precipitated was also investigated. Some strains of H. eurihalina formed crystals in all conditions tested. The mineral phases precipitated were magnesium calcite, aragonite and monohydrocalcite in variable proportions depending on various factors such as the type of growth medium employed and its salinity. Scanning electron microscopy and X-ray dispersive energy microanalysis were used to investigate the crystal formation sequence. The process of biolith formation was sequential. It started with chains or filaments of bacteria, giving way to discs which finally produced spherical forms of approximately 50 microns in diameter. We suggest a mechanism of carbonate crystal formation by H. eurihalina.

Carbonates↗
PubMed1998

New melampolides from Schkuhria schkuhrioides.

The novel melampolides (11R)-11,13-dihydro-schkuhriolide (7), (11S)-11,13-dihydro-schkuhriolide (8), and schkuhrioidiol (11), along with the known constituents, frutescin (1), schkuhriolide (2), frutescinic acid (4), allo-schkuhriolide (5), and epoxyschkuhriolide (6) were isolated from the aerial parts of Schkuhria schkuhrioides. The structures of the new compounds were determined by spectroscopic methods. Compounds 1, 2, 4, 5, and 6 displayed no significant cytotoxic or antimicrobial activities.

Animals↗
PubMed1998

Antimicrobial compounds detected in Bocconia arborea extracts by a direct bioautographic method.

BACKGROUND: Among the numerous in vitro methods for studying the antimicrobial activity of plant drugs, bioautography has found widespread applications, especially for the detection of new compounds in complex plant extracts. METHODS: This paper describes the results obtained during the application of the bioautographic method to detect antimicrobial compounds in a chloroformic extract of leaves and stems of Bocconia arborea, a plant used profusely in traditional medicine for the treatment of diverse infectious diseases. RESULTS AND CONCLUSIONS: The methods allows for the detection of spots of growth inhibition of cultures directly in the extract thin layer chromatographic plate previously dispersed with a broth culture containing the microorganisms. The procedure also allowed for the detection of the presence of several products in the B. arborea extract with considerable activity against five different microorganisms. Additionally, the method allowed the determination that the antimicrobial activity is due to compounds of probable alkaloid origin.

Anti-Infective Agents↗
PubMed1997

Maternal lipid intake during pregnancy and lactation alters milk composition and production and litter growth in rats.

The relationship between dietary fat content and milk composition, production and litter growth was studied in rats fed during pregnancy and lactation purified diets of equal energy density containing 2.5 or 20 g fat/100 g diet. A subsample of rats (HL-EP group) fed the high lipid (HL) diet but pair-fed on an energy basis with the low lipid (LL) diet group was also studied in a separate experiment. Food intake, dam body weight and litter weight were recorded daily. Rats were milked on d 14 of lactation. Milk lipid, lactose and protein concentration and milk production were measured. Lactating rats fed the HL diet had significantly higher energy intakes (P < 0.01) and milk production (P < 0.05) than rats fed the LL diet. Milk lipid concentration and daily milk volume and lipid production were significantly higher in the HL group. The HL-EP dams had significantly higher milk lipid, protein and lactose concentrations (P < 0.05) and tended to have higher daily lipid and energy outputs (P = 0.08) than LL rats. Birth weights of pups were similar among groups, but from d 6 on, the pups from the HL and HL-EP groups were significantly heavier (P < 0.05) than pups from the LL group. This investigation presents evidence that the milk fat concentration and the daily output of fat, protein and lactose of lactating rats are altered by dietary fat manipulations, which in turn affect growth of the litter.

Animals↗
PubMed1997

Antimalaric effect of an alcoholic extract of Artemisia ludoviciana mexicana in a rodent malaria model.

Chloroquine resistance of Plasmodium falciparum first and of P. vivax more recently, stimulated the search for new antimalarics. Chinese investigators have introduced new compounds obtained from extracts of Artemisia annua which possess an antimalaric active principle different from those of the drugs in use. In Mexico eight species of Artemisia have been described and among them just A. ludoviciana has been empirically used in the treatment of intermittent fever. To know whether mexican Artemisia had antimalaric activity several in vivo experiments were performed. Different type of extracts from two Artemisia species were prepared and assayed in five different doses on mice infected by Plasmodium yoelii yoelii, in a four-day test scheme. Here, only the results of the assays on ethanolic extract of A. ludoviciana are presented. The results of the in vivo experiments showed that the parasite reproduction was inhibited up to 98.6% at the fifth day, as compared with the controls; the ED50 was of 29.2 mg/kg and the SM50 of 28.7. We looked after the presence of artemisinin in the ethanolic extract, without success.

Animals↗
PubMed1997

[Infection by hepatitis B and C viruses in high-performance athletes].

It is reported the possible relationship between the infection caused by viral agents of predominantly parenteral transmission, such as the hepatitis B virus (HBV), the hepatitis C virus (HCV), and the human immunodeficiency virus (HIV) and the sports practice. It was conducted a study of seroprevalence of the infection by HBV and HCV in Cuban high performance athletes. Only 1.3% of positivity to the HBV infection was found. This positivity is related to the sports discipline they practice and some considerations are made on this regard.

Athletic Injuries↗
PubMed1996

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Journal Article↗
PubMed1996

Process of Carbonate Precipitation by Deleya halophila

Scanning electron microscopy and X-ray dispersive energy microanalysis were used to investigate the formation of carbonate crystals by Deleya halophila. The formation of calcium carbonate crystals (polymorphous aragonite) by D. halophila is a sequential process that commences with a nucleus formed by the aggregation of a few calcified bacterial cells and the subsequent accumulation of more calcified cells and carbonate, which acts to weld the bacteria together. The process leads to the formation of spherical bioliths measuring approximately 50 &mgr;m in diameter. The mechanism of carbonate precipitation by D. halophila under our working conditions represents a process of induced biomineralization.

Journal Article↗
PubMed1996

Bioactive polyacetylenes from Bidens pilosa.

From the methanolic extract of the whole plants of Bidens pilosa the new beta-D-glucopyranosyloxy-3-hydroxy-6(E)-tetradecen-8, 10,12-triyne besides a known polyine has been isolated and identified mainly by IR and NMR methods. The new compound showed overgrowing action against normal and transformed human cell lines in culture.

Alkynes↗
PubMed1996

[Mitomycin C for the treatment of superficial tumors of the bladder (Tis-Ta-T1) with one or more risk factors. Argentinian Cooperative Group of Oncourology (GCAO)].

OBJECTIVES: To determine the efficacy and toxicity of intravesical mitomycin C in superficial bladder tumors (Tis Ta T1) completely resected with one or more risk factors. (Protocol U. 01/90). METHODS: The patients received six instillations weekly of 40 mg mitomycin C within 15 days post-TUR of a superficial bladder tumor with one or more risk factors: histological grade 3, tumor size more than 3 cm and/or multicentric lesion. The patients were evaluated by cystoscopy every three months for the first two years and every six months thereafter. Toxicity was evaluated according to Miller's score. Tumor recurrence, disease-free interval and survival were analyzed. RESULTS: 126 patients were entered into the study; of these, 110 were evaluable. At 18 months mean follow-up (range 6-36 months), 77 patients (70%) remain disease-free; the mean time to recurrence was 13.8 months. There were no differences between patients with one, two or three risk factors or those who received or did not receive previous treatments. The patients tolerated the treatment well; there were no dropouts or systemic toxicity. CONCLUSIONS: 1. At 18 months mean follow-up, 77 of 110 patients (70%) remain disease-free; 2. The mean time to recurrence was 13.8 months; 3. Local toxicity was minimal; 4. There were no dropouts due to toxicity; 5. Systemic toxicity was not observed.

Adult↗
PubMed1996

[Bilateral Wilms' tumor. Current treatment].

Partial nephrectomy combined with chemotherapy has been the most effective treatment in bilateral Wilms tumors. We present two cases. The bilateral synchronous tumor are present in 4.2% and the metachronous tumor in 1.6%, in the world statistics. The synchronous bilateral Wilms tumor, Stage V, have an excellent prognosis: over 87% survival, compared to 40% of the metachronous bilateral Wilms tumors.

Antineoplastic Combined Chemotherapy Protocols↗