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C Aguilar

Publications and source records attributed to C Aguilar.

13 recordsLinked to original sources
PubMed1992

X-ray analyses of peptide-inhibitor complexes define the structural basis of specificity for human and mouse renins.

X-ray analyses have defined the three-dimensional structures of crystals of mouse and human renins complexed with peptide inhibitors at resolutions of 1.9 and 2.8 A, respectively. The exquisite specificity of renin arises partly from ordered loop regions at the periphery of the binding cleft. Although the pattern of main-chain hydrogen bonding in other aspartic proteinase inhibitor complexes is conserved in renins, differences in the positions of secondary structure elements (particularly helices) also lead to improved specificity in renins for angiotensinogen substrates.

Amino Acid Sequence↗
PubMed1992

Sustained benefits of hearing aids.

This study was designed to evaluate long-term benefits of hearing aids in elderly individuals with hearing loss. A primary care cohort of 192 elderly, hearing-impaired veterans (mean age 72 +/- 6, 97% White, 94% retired) were assessed at baseline and at 4, 8, and 12 months after hearing aid fitting. Drop-out rates at 4, 8, and 12 months were 5%, 13%, and 16%, respectively. Outcome assessments included several quality-of-life scales: Hearing Handicap Inventory in the Elderly (HHIE), Quantified Denver Scale of Communication Function (QDS), Geriatric Depression Scale (GDS), and the Short Portable Mental Status Questionnaire (SPMSQ). All quality-of-life areas improved significantly from baseline to 4-month post-hearing aid fittings (p < 0.05). Social and emotional (HHIE), communication (QDS), and depression (GDS) benefits were sustained at 8 and 12 months, whereas cognitive changes (SPMSQ) reverted to baseline at 12 months. We conclude that hearing aids provide sustained benefits for at least a year in these elderly individuals with hearing impairment.

Aged↗
PubMed1992

Correlates of successful hearing aid use in older adults.

OBJECTIVE: To evaluate whether age, education, functional handicap, degree of hearing loss, amount of hearing and speech recognition gain achieved with hearing aid, locus of control, visual acuity, manual dexterity, number of comorbid diseases, and number of medications predict which elderly individuals with hearing loss are likely to benefit from hearing aids. DESIGN: A logistic regression prediction model for hearing aid benefit was developed on a training set of 89 individuals and verified in a test set of 87 individuals. Hearing aid success was assessed 4 mo after hearing aid adminstration. It was defined by assessing hearing aid satisfaction, functional handicap change post-hearing aid, and number of hours of weekly hearing aid use. SETTING: All patients were elderly male veterans from the Audie L. Murphy Memorial Veterans Hospital. There were no differences in demographic or clinical characteristics in training versus test set individuals. RESULTS: Several variables, including baseline perceived functional handicap, education, number of medications, and age correlated with individual success measures. However, no variables consistently correlated with all success measures. The accuracy of prediction rules for success utilizing the variables ranged from 75 to 88% in the training set, and 54 to 84% in the test set. CONCLUSION: Although certain baseline factors were statistically significantly related to individual measures of successful hearing aid use, no factors were good enough to consistently differentiate successful from unsuccessful hearing aid candidates.

Age Factors↗
PubMed1992

Biguanide related lactic acidosis: incidence and risk factors.

The objective of this study was to evaluate in an open population the incidence and risk factors of biguanide related lactic acidosis. All patients currently treated in the Department of Diabetes and Lipid Metabolism of the Instituto Nacional de la Nutrición and their records were reviewed for the present use or history of administration of biguanides. The study was complemented with a revision of all admissions of diabetic patients to the emergency room during 1987-1990. In the outpatient study, 235 cases were included. No case of lactic acidosis was found. A high percentage of the biguanide treated patients had one or more lactic acidosis related risk factors. In the emergency study, 609 admissions of 273 patients were included. In 17 patients a metabolic non-ketotic acidosis was diagnosed. The frequency of non-ketotic acidosis for the different treatments was: 29.4 cases x 1000 emergency admissions for sulphonylurea treated group, 32 for sulphonylurea plus phenformin treated and 47.94 for type II insulin treated patients. All cases had severe precipitant diseases that can cause lactic acidosis with or without associated biguanide administration. No metformin related cases were found. The conclusions of this study are that biguanides in general and metformin in particular are not associated with a high risk of lactic acidosis. Severe systemic dysfunction associated with intercurrent diseases, frequently observed in diabetic patients, is the main determinant for the appearance of lactic acidosis.

Acidosis, Lactic↗
PubMed1990

Quality-of-life changes and hearing impairment. A randomized trial.

OBJECTIVE: To assess whether hearing aids improve the quality of life of elderly persons with hearing loss. SETTING: Primary care clinics at a Bureau of Veterans Affairs hospital. PATIENTS: One hundred and ninety-four elderly veterans who were identified as being hearing impaired from a screening survey involving 771 consecutive clinic patients. Of the original 194, 188 (97%) completed the trial. INTERVENTION: Subjects were randomly assigned to either receive a hearing aid (n = 95) or join a waiting list (n = 99). MAIN ENDPOINTS: A comprehensive battery of disease-specific and generic quality-of-life measures were administered at baseline, 6 weeks, and 4 months. MEASUREMENTS AND MAIN RESULTS: Persons assigned to the two groups were similar in age, ethnicity, education, marital status, occupation, and comorbid diseases. At baseline, 82% of subjects reported adverse effects on quality of life due to hearing impairment, and 24% were depressed. At follow-up, a significant change in score improvements for social and emotional function (34.0; 95% CI, 27.3 to 40.8; P less than 0.0001), communication function (24.2; CI, 17.2 to 31.2; P less than 0.0001), cognitive function (0.28; CI, 0.08 to 0.48; P = 0.008), and depression (0.80; CI, 0.09 to 1.51; P = 0.03) was seen in subjects who received hearing aids compared with those assigned to the waiting list. Six drop-outs (three per group), no crossovers, and no significant changes in cointerventions were seen. Average, self-reported, daily aid use in the hearing aid group was 8 hours. CONCLUSION: Hearing loss is associated with important adverse effects on the quality of life of elderly persons, effects which are reversible with hearing aids.

Aged↗
PubMed1990

A critical reevaluation of the Quantified Denver Scale of Communication Function.

The Quantified Denver Scale of Communication Function (QDS) is a 25 item questionnaire developed to measure communication difficulties in adults with hearing impairment. This study reassessed the constructs, reliability, and validity of the scale, and developed a 5 item short version. The QDS was administered to 238 elderly individuals (137 with and 101 without hearing loss). Factor analysis using this sample identified only two subscale constructs as opposed to four originally proposed constructs. The validity of the new revised two-construct model was verified by four independent investigators who labeled the two constructs as measuring self isolation and communication function. The internal reliability of the revised scale was 0.97 and of both construct subscales was 0.95. Overall test-retest reliability was 0.73. Validity examined by comparing the revised scale with another well-known handicap measure, the Hearing Handicap Inventory for the Elderly, was adequate: overall scale correlations were 0.73 and subscale correlations ranged from 0.64 to 0.72. The accuracy of the revised QDS for discriminating between individuals with and without hearing loss was 73%. Stepwise discriminant analysis generated a 5 item short version scale which contained two questions from the long communication subscale and three from the long self-isolation subscale. The accuracy of the short QDS was 74%. We conclude that the revised QDS is a reliable and valid scale that can be used to assess self isolation and communication function in elderly individuals with hearing loss, and that a new 5 item short version performs as well as the original 25 item scale.

Aged↗
PubMed1990

Discriminating and responsiveness abilities of two hearing handicap scales.

Several scales exist for screening handicap and assessing rehabilitation in elderly individuals with hearing loss. There are few comparative studies, however, to suggest which scales perform best. Using receiver-operating curves and responsiveness indices, we examined the relative discriminating ability and sensitivity to detect change of four scales: a long and short version of the Hearing Handicap Inventory in the Elderly (HHIE-L, HHIE-S), and a long and short version of the Revised Quantified Denver Scale of Communication Function (RQDS-L, RQDS-S). All scales were administered to 137 elderly veterans with hearing loss and 101 elderly veterans without hearing loss. Follow-up testing to determine relative ability to detect change was assessed in hearing impaired individuals only after they had used a hearing aid for 4 months. Discriminative accuracy for correctly identifying individuals with hearing loss were: HHIE-L 78%, HHIE-S 79%, RQDS-L 73%, and RQDS-S 74%. Overall differences between the HHIE-S and the RQDS-S were not statistically significant (p = 0.06). True positive results were greater with the HHIE-S compared to the RQDS-S (p = 0.03). Responsiveness indices were: HHIE-L 1.78, HHIE-S 1.86, RQDS-L 1.04, and RQDS-S 1.07. Differences between the HHIE-S and the RQDS-S were statistically significant (p less than 0.05). We conclude short versions of the HHIE and RQDS are as accurate and sensitive for detecting change as long versions, and the HHIE-S is a superior versatile instrument for screening and assessing rehabilitation in elderly individuals with hearing impairment.

Aged↗
PubMed1990

Association between hearing impairment and the quality of life of elderly individuals.

Hearing impairment is one of the most common chronic health problems of elderly Americans. Although adverse effects on quality of life are thought to be considerable, they have not been rigorously evaluated. This study was designed to identify the types and extent of dysfunction experienced by elderly individuals with hearing loss, and to define the most appropriate measures for assessing this dysfunction. Elderly male veterans attending a primary care clinic were screened for hearing loss and had their quality of life assessed with a comprehensive battery of disease-specific and generic measures. Of 472 people who had their hearing tested, 106 had hearing loss. Hearing loss was associated with significant emotional (P = .0001), social (P = .0001), and communication (P = .02) dysfunction. Most individuals (66%) perceived these dysfunctions as severe handicaps even though audiologic loss revealed only mild to moderate impairment (pure tone average loss, 27-55 dB). Adverse effects were best detected with disease-specific rather than generic functional status measures. We conclude that hearing impairment is associated with important adverse effects on the quality of life of elderly individuals, and that these effects are perceived as severe handicaps even by individuals with only mild to moderate degrees of hearing loss.

Activities of Daily Living↗
PubMed1988

Relative efficacy of vasodilator therapy in chronic congestive heart failure. Implications of randomized trials.

We examined existing evidence concerning the relative efficacy of various vasodilator agents in chronic congestive heart failure. Only randomized placebo-controlled trials with clinical end points and treatment durations of four weeks or more were selected from an exhaustive search of the English-language medical literature. Twenty-eight trials involving 1976 patients were found. Treatment durations of the trials varied from one month to two years. Patients with symptomatic heart failure despite digitalis and diuretic therapy were studied; most were middle-aged men and approximately half had coronary artery disease. Results of the trials were appraised by three independent observers, and mortality and functional status outcomes were pooled in a meta-analysis. All vasodilator agents except hydralazine hydrochloride were associated with improvements in functional status. Angiotensin converting-enzyme inhibitors were the only agents associated with both decreased mortality (odds ratio, 0.51; 95% confidence interval, 0.34 to 0.75) and improved functional status (odds ratio, 4.53; 95% confidence interval, 3.46 to 5.92). The optimal timing for initiation of these agents was not established.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1985

Adenosine triphosphatase activities in plasma liver membranes of rats treated with DDT and toxaphene.

The effect of exposure to chlorinated insecticides (DDT and toxaphene) on Na+,K+-ATPase, Mg2+-ATPase and Ca2+-ATPase activities of the plasma membrane of hepatocytes was determined. Acute treatment with DDT (200 mg per kg body weight) or toxaphene (110 mg per kg body weight) produced a significant decrease in Na+,K+-ATPase activity (80% and 85%, respectively) 24 h after treatment. DDT also produced a 30% decrease in Mg2+-ATPase and Ca2+-ATPase activity, but toxaphene treatment did not modify these enzymes. The effect of exposure to daily doses of DDT (30 mg per kg body weight) or toxaphene (16.5 mg per kg body weight) for a period of 3.5 months was also studied. Animals were sacrificed at 15-day intervals and results showed that Na+,K+-ATPase activity decreased 80% from the beginning of each treatment and the activity remained low throughout the treatment period. DDT, but not toxaphene, also led to a decrease in Mg2+-ATPase (20%) and Ca2+-ATPase (35%) activity. The low values observed from the beginning remained low throughout the treatment period. We believe that the general mechanism of ATPase inhibition by organochloride compounds could be the result of its interaction with membrane lipid components, although some differences could arise from differences in their spatial structure.

Adenosine Triphosphatases↗
PubMedDate not supplied

[Scheduled autotransfusion in orthopedic surgery].

We report the results of a programmed autotransfusion protocol applied to 22 patients undergoing orthopedic surgery. The number of extractions depended on the surgical needs and on the scheduled time for surgery. Among the total amount of blood used in this study, 81.7% corresponded to the volume previously given by the patient. This volume was sufficient for autologous transfusion in 17 patients. The remaining 18.3% of volume corresponded to homologous blood. We compared the hematologic data obtained at the beginning of the protocol and at the immediate pre and postoperative phase. We found statistical differences among hemoglobin levels, hematocrit, mean corpuscular hemoglobin, and mean corpuscular volume. We conclude that programmed autotransfusion constitutes an ideal method to compensate blood losses during surgery. This method may be the future for hemotransfusion in programmed surgery.

Adolescent↗