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Biomedical subjects

C Aguilar

Publications and source records attributed to C Aguilar.

At least 91 records · Page 5Linked to original sources
PubMed1995

Reinforcing properties of the neuropeptide substance P in Carassius auratus: evidence of dopaminergic system involvement.

The aim of the present study was to investigate whether neuropeptide substance P (SP) has reinforcing effects in Carassius auratus and whether this effect could be related to dopaminergic neurotransmission. For this purpose fishes were put in a three-compartment box in which one compartment gave access to two others that did not directly link. The time spent in each compartment was registered for 10 min to determine a possible preferred compartment. Twenty-four hours later, the fish were given one of the following intraperitoneal treatments: a) Group VEH, injected with the vehicle of substance P; b) Group SP25, injected with SP, 25 micrograms/kg body wt.; c) Group SP50, injected with SP, 50 micrograms/kg; or d) Group HALO, injected with haloperidol (2 mg/kg) 30 min before an injection of SP (50 micrograms/kg). Immediately after the treatment the fish were kept for 30 min in the compartment preferred least the day before. On the next day the fish were retested for 10 min to verify the time spent in each compartment. The results indicate that SP at the dose of 50 micrograms/kg enhanced the time spent on the paired compartment, and that the pretreatment with haloperidol abolished this enhancement. It is suggested that SP has reinforcing effects in C. auratus that may be mediated by the dopaminergic system.

Animals↗
PubMed1995

[Surgery for the repair of renal arteriovenous fistula and its hemodynamic impact].

The case of a 42-year-old woman with an arteriovenous fistula on the left kidney is described. Twenty-six years before presentation, a percutaneous renal biopsy had been obtained. The patient presented with arterial hypertension, angina and dyspnea. We studied the hemodynamic parameters before and after surgical repair of the fistula. Pulmonary artery pressure was very high but fell to normal after surgery, indicating that the fistula was responsible for hemodynamic complications that increased the level of surgical risk.

Adult↗
PubMed1995

[Carotid endarterectomy using cervical plexus block].

To evaluate the efficacy and level of patient satisfaction, as well as the incidence of neurological manifestations, hemodynamic changes and other perioperative complications of cervical plexus block. This was a prospective study of 52 patients undergoing carotid endarterectomy under superficial and deep cervical plexus block. The anesthetic technique was effective in all cases. Supplementation with local anesthetic was needed for 25% of the patients and none required general anesthesia. The technique was considered good by 92% of the patients, who stated that would accept the same technique in case of having to undergo surgery on the contralateral carotid artery. Hypertension was the hemodynamic change observed most often (in 30%) during surgery. No serious complications related to the anesthetic technique were observed, though transient dysphonia was the most frequently seen effect (in 36.5%). Eight (15.4%) patients showed neurological signs when the carotid was clamped, with symptoms resolving with placement of a shunt. Two deaths due to myocardial infarction occurred after surgery and 1 patient suffered a permanent cerebrovascular accident. Regional anesthesia with deep and superficial cervical plexus block during carotid endarterectomy allows for continuous evaluation of the patient's neurological status and facilitates the selective use of intraluminal shunt for the prevention of stroke accident during surgery. The technique is well-tolerated by patients, does not make surgery more difficult, does not give rise to serious complications and the incidence of local complications is low.

Aged↗
PubMed1994

Hypertension in the elderly. Implications and generalizability of randomized trials.

OBJECTIVE: To estimate morbidity and mortality benefits of drug therapy for hypertensive elderly subjects, compare these benefits with effects in younger subjects, and provide a framework for generalizing results derived from trials to actual patients. DATA SOURCES: A literature search using MEDLINE from 1966 to 1993, references from reviews and trial articles, and experts. STUDY SELECTION: Randomized trials lasting at least 1 year that evaluated effects of drug treatment on morbidity and mortality outcomes in hypertensive persons. DATA EXTRACTION: Four independent reviewers appraised protocol characteristics and quality of selected trials. DATA SYNTHESIS: There were 13 trials involving 16,564 elderly persons (age 60 years and older). The prevalence of cardiovascular risk factors, cardiovascular disease, and competing comorbid diseases was lower among trial participants than the general population of hypertensive elderly persons. When the six large high-quality trials were combined, trial results showed 43 subjects (95% confidence interval [CI], 31 to 69) and 61 subjects (95% CI, 39 to 141) needed to be treated for 5 years to prevent one cerebrovascular event and one coronary heart disease event, respectively. Including the other seven trials did not change the results significantly. Only 18 subjects (95% CI, 14 to 25) needed to be treated to prevent one cardiovascular event (cerebrovascular or cardiac). Twelve trials in primarily younger and middle-aged adults involved approximately 33,000 persons. For all outcomes except cardiac mortality, two to four times as many of the younger subjects as the older subjects needed to be treated for 5 years to prevent morbid and mortal events. No significant effect on cardiac mortality was seen among younger subjects, while 78 older subjects (95% CI, 50 to 180) needed to be treated to prevent a fatal cardiac event. CONCLUSIONS: Randomized trials demonstrate that treating healthy older persons with hypertension is highly efficacious. Five-year morbidity and mortality benefits derived from trials are greater for older than younger subjects. Extrapolating benefits from trials to individual patients is difficult, but should take into account multiple issues including the patient's risk factors, preexisting cardiovascular disease, and competing comorbid illnesses.

Age Factors↗
PubMed1994

A randomized trial of physical rehabilitation for very frail nursing home residents.

BACKGROUND: Past studies suggest multidisciplinary interventions that include physical therapy (PT) can improve function of nursing home residents. This trial specifically evaluates effects of PT for frail long-stay nursing home residents. DESIGN: Randomized, controlled trial. SETTING: One academic nursing home and eight community nursing homes. PATIENTS: A total of 194 elderly nursing home residents dependent in at least two activities of daily living residing in the nursing home for at least 3 months. INTERVENTIONS: Patients were randomized to individually tailored one-on-one PT sessions or friendly visits (FVs) three times a week for 4 months. Physical therapy included range-of-motion, strength, balance, transfer, and mobility exercises. MAIN OUTCOME MEASURES: Performance-based physical function assessed by the Physical Disability Index; self-perceived health status assessed with the Sickness Impact Profile; observer-reported activities of daily living; and falls. RESULTS: Eighty-nine percent and 92% of PT and FV sessions, respectively, were attended; 5% and 9% of subjects dropped out in the PT group and FV group, respectively. Compared with the FV group, the PT group experienced no significant improvements in overall Physical Disability Index, Sickness Impact Profile, or activities of daily living scores. A 15.5% improvement in the mobility subscale of the Physical Disability Index was seen (95% confidence interval [CI], 6.4% to 24.7%); no benefits in range-of-motion, strength, or balance subscales were found. Compared with the FV group, the PT group used assistive devices for bed mobility tasks less often (P = .06) and were less likely to use assistive devices and wheelchairs for locomotion (P < .005). There were 79 falls in the PT group vs 60 falls in the FV group (P = .11). Charge for the 4-month PT program was $1220 per subject (95% CI, $412 to $1832). CONCLUSION: This standardized physical therapy program provided modest mobility benefits for very frail long-stay nursing home residents with physical disability due to multiple comorbid conditions.

Activities of Daily Living↗
PubMed1994

Experience of an intravenous therapy team at the Instituto Nacional de Cancerología (Mexico) with a long-lasting, low-cost silastic venous catheter.

Means of vascular access are fundamental in the management of cancer. However, since current intravenous devices for long-term treatment are expensive and necessitate a high degree of education among medical personnel, in developing countries they are impractical for use in most of the population. We describe the use of a nontunneled, low-cost, long-lasting Silastic catheter (LLSC), cared for by an intravenous therapy team (IVTT), in 462 patients with cancer. The rate of infectious complications was 0.66 infections per 1,000 catheter-days, which is as low as that reported in association with other catheters in developed countries. Neutropenia and skin and/or soft-tissue infections were significant risk factors associated with LLSC-related infections. We believe that use of this catheter may be an alternative for patients with cancer who need chemotherapy, as long as an IVTT is established for its care. Our experience could be useful for practitioners in countries with similar socioeconomic characteristics.

Antineoplastic Agents↗
PubMed1994

The Sickness Impact Profile for nursing homes (SIP-NH)

BACKGROUND: Valid, feasible measures of functional status are needed to evaluate the expanding nursing home population. This study attempts to increase relevance and reduce respondent burden of the Sickness Impact Profile (SIP) for nursing home residents while maintaining internal consistency and validity. METHODS: 231 residents from one academic and four community nursing homes, aged > or = 60 with a Mini-Mental State Exam score > or = 11, were study participants. Nominal group process was used to identify items and/or categories for removal. Candidate items were those that: represented restrictions of the nursing home environment, had weak item-total score correlations, and/or made minimal contribution to category internal consistency. Reduction was constrained by: minimum correlation of r = .90 between SIP and Sickness Impact Profile for Nursing Homes (SIP-NH) scores, coefficients alpha that fell within 95% confidence regions about predicted alpha. Convergent and discriminant validity were evaluated with the Katz Activities of Daily Living, Physical Disability Index, Geriatric Depression Scale, and Folstein Mini-Mental State Exam. RESULTS: The SIP-NH contains 66 items, a 51.5% reduction. Correlations between the SIP-NH and SIP were: total score r = .98, Physical dimension r = .97, and Psychosocial dimension r = .97. Alpha coefficients all fell within the 95% confidence regions. The SIP and the SIP-NH did not differ in correlations with validating instruments. CONCLUSIONS: The SIP-NH reduces respondent burden and has acceptable internal consistency and external validity. Potentially useful for discriminatory and predictive purposes, responsiveness to change will require longitudinal evaluation.

Activities of Daily Living↗
PubMed1994

Methods for screening for hearing loss in older adults.

Two common screening tools for detecting hearing loss, the Hearing Handicap Inventory for the Elderly-Screening Version (HHIE-S) and Audioscope, are compared. One hundred eighty-five consecutive patients over age 60 at a primary care clinic received both screening tests followed by pure tone audiometry. Three criteria for hearing loss was considered: Speech Frequency Pure Tone Average > or = 25 dB; High Frequency Pure Tone Average > or = 25 dB; and Ventry and Weinstein's criteria of a 40 dB loss at 1.0 or 2.0 kHz. Ranges of respective operating characteristics for the Audioscope versus the HHIE-S were: sensitivities 0.64 to 0.96 versus 0.29 to 0.63; specificities 0.80 to 0.91 versus 0.75 to 0.93; and positive likelihood ratios 4.86 to 7.52 versus 2.42 to 4.27. Most patients preferred screening with the Audioscope (60%) over the HHIE-S (13%). The Audioscope is preferred by patients, and outperforms the HHIE-S using a variety of reference standard definitions.

Aged↗
PubMed1994

Respiratory toxicity of copper.

Respiratory toxicity of copper was tested in Wistar rats by spraying copper sulfate (330 g/l spray) for daily periods of 1 hr in a self-contained chamber for up to 10 days. The respiratory toxicity was compared with that from intraperitoneal administration of 1 mg Cu/mg body weight and with adequate control rats. Analysis of tissue Cu and Zn was done in lung, liver, kidney, and plasma by using atomic absorption spectrophotometry. Similar organ and subcellular distribution of both elements were found between the two treated groups, and only statistically significant higher levels of Cu were found in plasma and liver. After exposure, Cu and Zn were basically associated with a low-molecular-weight component, which eluted as metallothionein in the postmicrosomal fractions.

Administration, Inhalation↗
PubMed1993

Crystallization and preliminary crystallographic characterization of aspartic proteinase-A from baker's yeast and its complexes with inhibitors.

The aspartic proteinase from yeast vacuoles, proteinase-A, has been crystallized with and without non-hydrolysable transition-state analogue inhibitors. The native enzyme crystals belong to the space group I2(1)2(1)2(1), with two molecules per asymmetric unit. The inhibitor complex crystals are trigonal with space group P3(2)21 and with one molecule in the asymmetric unit. Preliminary X-ray analysis of both native enzyme and its complexes indicate that the complexes diffract to higher resolution than the native crystals. This is probably due to reduced flexibility in the enzyme-inhibitor complex.

Aspartic Acid Endopeptidases↗
PubMed1993

Falls: an examination of three reporting methods in nursing homes.

OBJECTIVE: To examine the concordance of various fall reporting methods and to use the results to recommend a preferred method of ascertaining fall frequency for residents of nursing homes, both for research and in the collection of federally mandated nursing home data. DESIGN: A cohort study followed for 858 patient months, with a mean individual follow-up of 6.6 months. MEASUREMENTS: Falls were independently ascertained monthly by three methods: review of administrative incident reports, nursing home chart abstraction, and structured interview of subjects. Concordance of events was assessed using measures of simple agreement and Kendall's Tau-b. Simple correlation and multiple regression were used to evaluate the relation of age, sex, gender, depression, mental status, and functional status with degree of concordance between self-reported falls and chart-recorded falls. SETTING: One academic and six community nursing homes in San Antonio, Texas. PARTICIPANTS: 131 long-stay nursing home residents, greater than 60 years of age, dependent in at least two activities of daily living, and mildly cognitively impaired. RESULTS: Falls were ascertained in 74 of the 131 individuals; 53 subjects fell 124 times by incident report, 58 had 140 falls according to chart review, and 66 subjects self-reported 232 falls. Greatest agreement between reporting methods was shown for incident report and chart review, with a Kendall's Tau-b of 0.88; self-report and chart-review agreement was 0.56; and self-report and incident agreement was 0.53. Estimated total fall events were more often (P = 0.001) identified by chart review (92%) than incident report (82%). Although concordance was higher for non-fallers, no significant relationships were observed between concordance and age, sex, race, depression, mental status, and functional status. Also, there was no systematic relationship between length of follow-up and degree of concordance. CONCLUSIONS: Fall frequency varies by ascertainment method, with chart review reflecting a greater number of fall events than the traditionally counted incident reports.

Accidental Falls↗
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↗