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Biomedical subjects

M A Torres

Publications and source records attributed to M A Torres.

At least 19 recordsLinked to original sources
PubMed1992

Identification and characterization of an actin-binding site of CapZ.

A mAb (1E5) that binds the COOH-terminal region of the beta subunit of chicken CapZ inhibits the ability of CapZ to bind the barbed ends of actin filaments and nucleate actin polymerization. CapZ prepared as fusion proteins in bacteria or nonfusion proteins by in vitro translation has activity similar to that of CapZ purified from muscle. Deletion of the COOH-terminus of the beta subunit of CapZ leads to a loss of CapZ's ability to bind the barbed ends of actin filaments. A peptide corresponding to the COOH-terminal region of CapZ beta, expressed as a fusion protein, binds actin monomers. The mAb 1E5 also inhibits the binding of this peptide to actin. These results suggest that the COOH-terminal region of the beta subunit of CapZ is an actin-binding site. The primary structure of this region is not similar to that of potential actin-binding sites identified in other proteins. In addition, the primary structure of this region is not conserved across species.

Actin Cytoskeleton↗
PubMed1992

Accuracy of intraocular pressure measurements with two different tonometers through bandage contact lenses.

The intraocular pressure (IOP) of nine cadaver eyes was set by a manometer at 10 mm Hg increments from 10 to 50 mm Hg. Pressure measurements at each of these settings were taken using the Digilab Pneumatonometer and Tono-Pen to determine the accuracy of these instruments. In addition, four brands of therapeutic contact lenses were placed on the eyes, and IOPs were measured through them to determine whether or not comparable IOPs could be obtained through a range of bandage contact lenses. We found a significant difference (p < or = 0.0000) between the measurements obtained by the two instruments at a given manometric setting. Digilab Pneumatonometer's pressures correlated well with manometric pressures. Tono-Pen consistently underestimated manometric pressures. At 50 mm Hg, Digilab Pneumatonometer's mean measurement was 47.5 mm Hg, whereas Tono-Pen's mean was only 38.9 mm Hg. IOPs assessed through all contact lenses were comparable to the measurements without lenses. Multiple regression of score showed that the measured pressure was explained by manometric pressure (81%), the choice of instrument used (5.5%), and the lens thickness (0.09%). The Pierson correlation coefficient was 0.93. This study showed that Pneumatonometer could accurately measure IOP with and without a therapeutic contact lens, but Tono-Pen was equally inaccurate with and without lenses, giving false low measurements.

Analysis of Variance↗
PubMed1991

Variant cDNAs encoding proteins similar to the alpha subunit of chicken CapZ.

Chicken adult muscle and liver cDNA libraries were screened with a cDNA, alpha 1, previously isolated from a chicken embryo library by screening with antibodies against the alpha subunit of chicken CapZ. cDNAs with a new coding region, called alpha 2, were found in addition to ones with the alpha 1 coding region. alpha 2 predicts a protein sequence that matches exactly the N-terminal sequence of 5 peptides prepared from CapZ alpha purified from chicken muscle, while the protein sequence predicted by alpha 1 matches the peptides well, but not exactly. The predicted protein sequences of alpha 1 and alpha 2 are very similar to each other, and they are similar to those of the alpha subunit of capping protein from Dictyostelium [Hartmann et al., J. Biol. Chem. 163:5254-5254, 1989] and an actin-binding protein from Xenopus [Ankenbauer et al., Nature 342:822-824, 1989]. Other conserved features of the predicted primary and secondary structures are noted. Chicken alpha 1 and alpha 2 are transcribed in all of 7 adult chicken muscle and non-muscle tissues in comparable amounts by Northern analysis. alpha 2 has four poly(A)+RNA transcripts, one of which is rare in liver. alpha 1 has two transcripts. alpha 1 and alpha 2 are encoded by different single-copy genes by Southern analysis of chicken genomic DNA.

Actin Depolymerizing Factors↗
PubMed1991

Therapeutic dilemmas in external ocular diseases.

Three ocular conditions continue to pose therapeutic dilemmas for the practising clinician. Acanthamoeba keratitis, which presents with ocular pain, redness, tearing, photophobia and lid oedema, should be considered in any chronic, progressive corneal ulceration that is unresponsive to conventional treatment. Although the best treatment for this infection has yet to be defined, surgery should be reserved for those patients with progressive destructive disease or corneal penetration. Topical antibiotics and oral ketoconazole may be beneficial, as may surgical debridement in conjunction with topical antibiotic-antifungal combinations. However, since more than two-thirds of reported cases involve contact lens wearers, patients should be instructed as to the importance of regular lens care regimens. Giant papillary conjunctivitis occurs more frequently in soft contact lens wearers than in those wearing hard lenses, but may also occur in association with ocular prostheses, cataract surgery and corneal transplants. Symptoms of increased lens awareness, mucus accumulation, itching and blurred vision occur. Stopping use of contact lenses usually improves or eliminates these irritating effects, but is not always practical. Thus, resolution or improvement of symptoms while the patient continues to wear contact lenses is desirable, making lens hygiene essential in treatment. Pharmacological treatment includes the use of topical corticosteroids and agents that stabilise mast cells, such as cromolyn sodium. The dry eye syndrome can occur alone or as a part of Sjögren's syndrome. The irritation, redness, and other symptoms associated with ocular dryness are usually treated by preparations of either mucomimetics, polyvinyl alcohol or cellulose derivatives, which provide moisture and prevent evaporation from the surface of the eye.

Acanthamoeba Keratitis↗
PubMed1990

Treatment of generalized systemic sclerosis.

Over the years, many encouraging uncontrolled studies extolling treatments of SSc have appeared, but initial impressions were not corroborated when controlled trials were done. This article points out that certain recent studies have effectively ruled out the use of some specific therapies for the general treatment of systemic sclerosis. Thus, sufficient data has been generated to rule out the use of n-acetylcysteine, colchicine, chlorambucil, cyclofenil, and DMSO, at least in disease of longer duration. Ketanserin and prostaglandin infusions probably also belong in this group, as they affect only Raynaud's phenomenon. Angiotensin enzyme inhibitors, while probably life-saving in renal crises, do not seem to affect the underlying systemic sclerosis per se. Another group of drugs has only limited supportive data and await well-controlled trials to prove or disprove their effectiveness. These include: 5-fluorouracil, D-penicillamine, drugs affecting platelet function (dipyridamole), and para-aminobenzoic acid. There are a few treatments which have potential. Factor XIII has only limited data using controlled trials, but what does exist seems positive. Apheresis is encouraging, although the success of this treatment modality may be dependent upon a "combination" approach. Ongoing studies with gamma-interferon, photopheresis, and the mast cell stabilizer ketotifen appear exciting, and we await reports of their use in scleroderma. On another level, new insights into genomic alterations in skin fibroblasts and T-cell proto-oncogene expression have contributed to the understanding of the pathogenesis of this disease at the cellular level and new methods to measure change in disease will help gauge response to therapy. Thus, we look forward to more definitive treatment of SSc in the future.

Humans↗
PubMed1986

Anal continence following Soave procedure. Analysis of results in 100 patients.

The Soave procedure is an increasingly popular procedure for the definitive therapy of patients with ulcerative colitis. The authors present their experience with 100 patients in whom total proctocolectomy, rectal mucosal stripping, and ileoanal anastomosis (generally using an S-pouch) were carried out. The physiological and anatomical basis of continence is presented, and anastomosis at the top of the columns of Morgagni is recommended. Of the 100 patients in whom this procedure was performed, there was no mortality either in-hospital or later. Of the 12 patients in whom the anastomosis was done 1 cm above the top of the columns (and thus columnar epithelium was retained), six have recurrent anorectal disease, but all are continent both day and night. Three patients in whom the anastomosis was done at the dentate line have had difficulty with continence; two are now continent, but one, after being totally incontinent for 4 years, has required a permanent ileostomy. Of the 69 patients in whom the anastomosis was done at the top of the columns of Morgagni, five are incontinent at night only and two have seepage during both day and night. Thus, if the anastomosis is done at the level recommended, namely, at the top of the columns of Morgagni, retaining no columnar epithelium and anastomosing the ileal pouch to transitional epithelium (which the authors believe not to be subject to the disease of ulcerative colitis), daytime continence will be achieved in 97% and total day and night continence in 90%. The evidence presented suggests that a properly done pull-through procedure with ileoanal anastomosis is the procedure of choice for ulcerative colitis.

Adolescent↗
PubMed1985

Topical ketoconazole for fungal keratitis.

Six patients (five men and one woman, 19 to 57 years old) with laboratory-proven fungal corneal infections were successfully treated with topical ketoconazole, a synthetic imidazole derivative. No signs of progression of the corneal infection were seen after the antifungal therapy was initiated. The clinical signs of corneal infection disappeared after three (Aspergillus infections) to seven weeks (Fusarium infections) of ketoconazole therapy. In all cases, posttreatment visual acuities were better than pretreatment visual acuities. No significant biomicroscopic signs of ocular surface toxicity were noted.

Administration, Topical↗
PubMed1985

[Nutritional status of children under 6, according to land tenure, in rural areas of the State of Pernambuco, Northeast of Brazil].

The purpose of this investigation was to analyze the distribution of protein-energy malnutrition, anemia and hypovitaminosis A in relation to accessibility and size of rural lands. About 689 families from the Agreste rural area (Pernambuco, North-East Brazil) were studied. A total of 1,257 children under 6 years of age were distributed in four groups according to the size of the land. The nutritional status was assessed according to the criteria of Gómez, Ariza-Macías and Seoane-Latham, modified by Batista Filho. In accordance with the Gómez' method, 55.1% of the children suffered from some degree of malnutrition. About 67.0% of the landless families suffered from malnutrition, in contrast to 25% of the landowners who had 50 or more than 50 hectares of land (p less than 0.01). Hemoglobin was determined in 976 children; 38.9% of them suffered from anemia. No significant differences were detected among the several groups of land tenants. Serum retinol levels were measured in 412 children and a high incidence of hypovitaminosis A was detected: 24% had serum retinol levels below 20 mcg/100 ml. No significant association was found in relation to the different land tenure groups. These data demonstrate a high prevalence of protein-energy malnutrition, anemia and hypovitaminosis A. A significant correlation between protein-energy malnutrition and the size of the land was also found, demonstrating that this region is one of the most affected by food and nutritional problems.

Anemia↗
PubMed1978

Synergism of fosfomycin-ampicillin and fosfomycin-chloramphenicol against Salmonella and Shigella.

Ninety strains of Salmonella and 50 strains of Shigella were tested for susceptibility to fosfomycin, chloramphenicol, and ampicillin by the agar dilution method. Drug interaction between fosfomycin-ampicillin and fosfomycin-chloramphenicol was studied by the agar dilution method. The fractional inhibitory concentration was calculated. The combination of fosfomycin-ampicillin was synergistic against Salmonella in 74 cases, additive in 7, indifferent in 7, antagonistic in none, and nonevaluable in 2; against Shigella it was synergistic in 27 cases, additive in 9, indifferent in 14, and antagonistic in none. The combination of fosfomycin-chloramphenicol was synergistic against Salmonella in 56 cases, additive in 9, indifferent in 13, nonevaluable in 12, and antagonistic in none; against Shigella it was synergistic in 29 cases, additive in 10, indifferent in 9, nonevaluable in 2, and antagonistic in none. Killing curves with combinations of each antimicrobial agent showed that the cultures that had proven to be indifferent by the agar dilution method showed a bactericidal effect until h 4, with posterior regrowth of the culture after this time period. For the strains in which synergism was demonstrated, total bactericidal activity was reached at 24 h.

Ampicillin↗