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Biomedical subjects

M Molina

Publications and source records attributed to M Molina.

At least 145 records · Page 8Linked to original sources
PubMed1989

Effect of protein side chain amide group on the hydrogen-bond equilibrium in nucleobases studied by infrared and 13C-NMR spectroscopy.

Infrared spectra of 1:1 hydrogen-bonded complexes formed by derivatives of adenine and model molecules bearing the protein side chain amide group have been measured in chloroform solution. From the temperature dependence of hydrogen-bond formation, thermodynamic data on these complexes are determined. On the basis of these data, it is shown that the complexes consist of cyclic heterodimers, those that use the adenine N(1)H bond being favoured. Similarly infrared and 13C-NMR spectroscopy reveals that uracil-amide cyclic heterodimers formed through the uracil 4-carbonyl group are predominant. All of these results predict that Watson-Crick hydrogen bonds in adenine-uracil base-pairs may be opened to some extent, as proved in this work. The possible biological importance of these observations is also discussed.

Acetamides↗
PubMed1989

Purification and some properties of Candida albicans exo-1,3-beta-glucanase.

An exo-1,3-beta-glucanase was purified from blastoconidia of Candida albicans 1001. The purified enzyme appeared as a single protein band by PAGE, and split into two subunits (Mr approximately 63,000 and 44,000) when analysed by SDS-PAGE. The pI of the enzyme was 4 and a Km of 1.7 mg ml-1 was estimated for laminarin as substrate. Despite its very reduced activity on the synthetic substrate p-nitrophenyl beta-D-glucoside, C. albicans exo-1,3-beta-glucanase hydrolysed 1,3-beta-glucan by an exo-splitting mechanism and was inhibited by glucono-delta-lactone and by Hg2+ and Ag+ cations. The active exo-glucanase was mainly located in the periplasm, but it was also present inside the cytoplasmic membrane in small amounts and was secreted into the culture medium. The electrophoretic mobility of the enzyme from all three locations was the same.

Candida albicans↗
PubMed1989

[Corynebacterium D2-induced encrusted cystitis].

Two cases of patients with cystitis cystica secondary to urine infection, caused by resistant corynebacterium D2, are presented. The clinical features were important dysuria and frequency, alkaline urine Ph (Ph 8 and 9). The urine cultures were obtained with the standard techniques, after 72 hours of incubation. They were treated with vancomycin, ciprofloxacin and hydroxinamic acid with good response.

Aged↗
PubMed1989

[Ascites and pleural effusion. Study and follow-up of 79 patients].

We reviewed 79 patients with a picture of pleural effusion (EP) and ascites, who represented 8% of a total of 982 pleural effusions studied. Liver cirrhosis (CH), 37 cases (47%), disseminated carcinomatosis, 31 cases (39.5%), and congestive heart failure, 6 cases (7%), were the main causes. We made two groups of liver cirrhosis: A) liver cirrhosis with hydropic decompensation, 12 patients (15%), and B) liver cirrhosis with an additional complication added to the above, 25 patients (31.5%), this being infectious in 88% of the cases. In the B group there were cases of left hydrothorax, more features of effusion and a lower survival at 3 months of follow-up than in tha A group. Effusions of neoplastic origin were most frequently seen in tumors of the ovary, digestive system, lymphomas and undetermined origin. In malignant effusions, the cytology was positive in pleura in 60% and in ascites in 55%. Twenty percent of peritoneal fluids and 47% of pleural effusions were serohemorrhagic and 100% and 88%, respectively, were of exudative nature. In liver cirrhosis the ascites was serofibrinous and transudated (100% in group A and 85.5% in B) and the pleural effusion was a serofibrinous transudate except in the cases in which there was an added infection. We confirm the ominous prognosis of the coexistence of pleural effusion and ascites.

Adult↗
PubMed1989

[The feeding of young children with mild diarrhea. Study of the behavior of 20 mothers in a periurban area of Guatemala City].

To asses mothers' behavior in regard to their children's feeding when they were ill with diarrhea, 20 guatemalan periurban families with children under four years of age were observed throughout one day. The observations were repeated during children's recovery. Mothers did not deprive their children of either liquid or solid foods during the diarrheal process. The average amount of liquids children drank when ill did not differ from that drank during recovery. Most of the children's diets did not meet their requirements in neither of the two periods. In general, caloric and protein intakes were lower when children were ill than when they were healthy; similarly, their intake was lower when diarrhea lasted more than three days. These findings point out that the possible cause of the lower food consumption during illness was that children were anorexic. On the other hand, similarity of liquid intake during both periods probably was because children were not dehydrated. The problem of the children's low food consumption could be solved if mothers feed them more frequently during the day, or if they provide them meals with more caloric density.

Acute Disease↗
PubMed1988

Reconstruction of the yeast 2 micron plasmid partitioning mechanism.

The effect of the yeast 2 micron circle encoded REP1 and REP2 gene products on plasmid partitioning and copy number control was analyzed by removing the open reading frames from their normal sequence context and transcriptional control regions and directing their expression using heterologous promoters in [cir0] host strains. Both the REP1 and REP2 gene products are directly required at appropriate levels of expression to reconstitute the 2 microns circle partitioning system in conjunction with REP3 and the origin of replication. The level of expression of REP2 appears to be critical to re-establishing proper partitioning and may also play a role in monitoring and thereby regulating the plasmid copy number. Constitutive expression of the REP1 and REP2 open reading frames using heterologous expression signals can be used to reconstruct efficient plasmid partitioning even in the absence of FLP-mediated plasmid amplification and a functional D open reading frame.

DNA Replication↗
PubMed1988

The prophylactic effect of diphenylhidantoin in the kindling effect on reptiles (Gallotia galloti).

1. Lizards Gallotia galloti received daily 3 mg/kg body wt of diphenylhidantoin (DPH) over a period of 15 days and at the same time the animals were kindled. 2. The progression of the kindling effect was evaluated by counting the number of spontaneous epileptiform potentials, the duration of afterdischarges and the duration of electroencephalographic spontaneous seizures. 3. The diphenylhidantoin treated group, relative to controls presented: (a) significant reduction in the duration of afterdischarges and spontaneous electroencephalographic seizures; and (b) increased frequency of the spontaneous epileptiform potentials.

Animals↗
PubMed1988

Yeast beta-glucanases: a complex system of secreted enzymes.

The complement of glucan-hydrolysing enzymes produced by yeast species is considered to be relevant to morphogenesis, since this polysaccharide is the major structural component of the yeast cell wall. beta-glucanase systems of different species consist of both 1,3-beta- and 1,6-beta-hydrolases, which exert their action by either an exo- or an endo-splitting mechanism. The diversity of beta-glucanase systems, even among related species, is striking. The enzymes are produced for export, and the active forms of some of them seem to be generated upon secretion. Genetic approaches and the cloning of the glucanase genes are being used to clarify the biological role of the different enzymes. These also offer a possibility for genetic analysis of the functions related to cell wall dynamics with potential applications in biotechnology.

Gene Expression Regulation, Fungal↗