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Biomedical subjects

L Lopez

Publications and source records attributed to L Lopez.

At least 37 records · Page 2Linked to original sources
PubMed1998

A project to reduce the burden of diabetes in the African-American Community: Project DIRECT.

Project DIRECT (Diabetes Interventions Reaching and Educating Communities Together) is the first comprehensive community diabetes demonstration project in the United States in an African-American community. This article describes its intervention components and evaluation design. The development and implementation of Project DIRECT has included the community since the project's beginning. Interventions are targeted in three areas: health promotion (improving diet and physical activity levels), outreach (improving diabetes awareness, detection of undiagnosed diabetes, and ensuring that persons with diabetes who are not receiving continuing diabetes care are integrated into the health-care system), and diabetes care (improving self-care, increasing access, and improving the quality of diabetes preventive care received within the health-care system). Evaluation will be internal (conducted by Project DIRECT staff to assess process outcomes in persons directly exposed to each specific intervention) and external (review of outcomes to assess the impact of the multi-intervention program at the level of the entire community). Because diabetes exacts a disproportionate toll among African Americans, the findings from this project should aid in developing strategies to lessen the burden of this disorder, particularly among minority populations.

Black or African American↗
PubMed1997

Clinical implications and possible association of malposition of the branch pulmonary arteries with DiGeorge syndrome and microdeletion of chromosomal region 22q11.

We describe a series of 10 patients with malposition of the branch pulmonary arteries (4 patients with crossing [crossed pulmonary arteries] and 6 patients without crossing), 2 of whom had a short main pulmonary artery segment that resulted in iatrogenic right pulmonary artery stenosis after pulmonary artery band placement. DiGeorge syndrome was seen in 5 patients and 4 had microscopic deletion of chromosomal region 22q11.

Adolescent↗
PubMed1997

Drug quantitation on a benchtop liquid chromatography-tandem mass spectrometry system.

The specificity and selectivity of LC-MS-MS is illustrated to explain why LC-MS-MS has become the method of choice for quantitation within the pharmaceutical industry. Two assays are described that demonstrate the facility with which new ion trap technology can utilize the selectivity and sensitivity of LC-MS-MS to quantitate trace level components within complex matrices, in particular human plasma. One assay undergoes a validation procedure and demonstrates the utility of this new technology for drug quantitation within a regulated environment.

Calibration↗
PubMed1997

Osteoarticular and muscle infectious lesions in patients with the human immunodeficiency virus.

Between 1988 and 1995, 1832 HIV positive patients were evaluated in our institution. We studied the epidemiologic, immunologic and bacteriologic data, laboratory tests, and X-Ray films in those with musculoskeletal infection. We reviewed twenty-one cases of musculoskeletal infection in twenty patients aged 23-35 years (mean 28,6 years, M:F= 15:5). In all of them risk factor for HIV was intravenous drug abuse. The number of CD4 positive lymphocytes ranged from 0,003 to 0,5 10(9)/l. Staphylococcus aureus was the organism responsible of the infection in twelve cases, all active intravenous drug abusers at the time the diagnosis was done. The remaining causative agents were: Mycobacterium tuberculosis (3 cases), Candida albicans (2 cases), Salmonella subgroup 1 (1 case), Neisseria gonorrhoeae (1 case), Pseudomona aeruginosa (1 case) and Streptococcus agalactiae (1 case). Fifteen infections were diagnosed between 1988 and 1991 and 6 between 1992 and 1995. Musculoskeletal infectious lesions in HIV positive patients in our country are related in the majority of cases to intravenous drug abuse. In the last four years due to a National medical health care plan conducted to educate this group of people the number of musculoskeletal infections is decreasing.

AIDS-Related Opportunistic Infections↗
PubMed1997

Magnetically recorded oscillatory responses to luminance stimulation in man.

Fast-frequency (ca. 100-110 Hz) oscillatory potentials superimposed on waves N2 and P2 of conventional broad-band VEP were magnetically recorded in man from occipital locations in response to monocular transient flash stimulation with full-field flashes (3.5 cd.s.m-2 intensity) and in spots (1, 1.5, or 2.0 cm in diameter). These oscillations proved replicable between- and within-subject and were phase-locked to retinal oscillatory potentials, with maximum correlation at approximately 35 ms and mean delay (as measured between the first measurable peaks) of 27.4 +/- 1.6 ms. When stimuli were in spots at increasing eccentricity (5, 15, or 25 degrees) from foveal fixation, broad-band VEP were recorded regardless of diameter and eccentricity of spot, whereas oscillatory responses were not detectable at eccentricity of, or greater than, 15 degrees. This observation suggests that broad-band VEP and the oscillatory response are generated by (partly) distinct neuronal populations and/or functional arrangements and that there is some functional connection between cortical oscillatory responses and stimulus-related events triggered in central retina.

Adult↗
PubMed1997

An invitational workshop on collaboration between quality improvement organizations and business coalitions.

BACKGROUND: The center for Clinical Quality Evaluation, in conjunction with The American Health Quality Association, Midwest Business Group on Health, National Business Coalition on Health, and the funder, the Agency for Health Care Policy and Research, conducted an invitational workshop January 14-15, 1997, in Washington, DC. A select group of federally designated peer review/quality improvement organizations (QIOs)--organizations that work at the local level to improve and promote the health status of Medicaid and Medicare beneficiaries--and business coalitions from nine states met to discuss public/private collaboration on community-based quality improvement projects. WORKSHOP AGENDA: The 1 1/2-day sessions included a keynote address by Chris Queram, MA, chief executive officer of the Employer Health Care Alliance, Madison, Wisconsin, who provided background and context on the principles of community-based collaboration; a presentation on an advanced QIO/business coalition collaborative case study by HealthInsight, Inc (the Utah QIO), and Business/Health Partnership (the Salt Lake City business coalition); a case study on a beginning QIO/business coalition collaborated by the Health Accountability Foundation, a partnership between IPRO (the New York State QIO) and the New York Business Group on Health (the New York City business coalition); small group breakout sessions, where participants from each state/local community and Washington, DC-based health associations and specialty societies met to identify common goals and opportunities to collaborate; report on the progress made by each small group; and discuss future plans for collaborating on quality improvement projects. CONCLUSIONS: Many of the participating QIOs and business coalitions have already begun collaborating on quality improvement projects.

Cooperative Behavior↗
PubMed1997

Glucose availability and the electrophysiology of the human visual system.

Glucose is a main energy source to neurons in brain (with limited storage capability) and retina (where it is stored in glial Müller cells and supplied upon demand). Glucose availability and visual function are related. Human positron emission tomography studies indicate increased blood flow and glucose metabolic rate in primary visual cortex during stimulation, with retinotopic distribution. Retinal electrophysiology covaries with glucose concentration in in vitro models as well as in humans, at comparable concentrations in the physiological range. The interactions between retinal electrophysiology (notably the electroretinogram b-wave) and glucose metabolism appear more stringent than for cortical evoked responses. K-channels regulated by intracellular ATP are thought to link neuron excitability (and electrophysiological activity) on the metabolic state. High-affinity sulphonylurea binding sites for K-channels are widely distributed in brain. K-channels conceivably modulate neurotransmitter release and are inactivated by elevated glucose concentrations and sulfonylurea drugs used to treat diabetes.

Electroretinography↗
PubMed1996

Breast cancer and lactation history in Mexican women.

The authors conducted a case-control study in Mexico City between September 1990 and December 1992 to determine whether a dose-response relation could be observed between duration of lactation and the risk of breast cancer. Cases, women aged 20-75 years, were identified through six hospitals in Mexico City (n = 349) and were interviewed to obtain data on risk factors for breast cancer, including a detailed history of lactation. Controls (n = 1,005) were selected from the general population using the Mexican national sampling frame. Parous women who had ever lactated had a reduction in breast cancer risk (age-adjusted odds ratio (OR) = 0.39, 95% confidence interval (CI) 0.25-0.62). A small decreasing trend of breast cancer risk in relation to duration of lactation (p < 0.001) was observed. Compared with parous women who had never breast-fed, women who had breast-fed for 12-24 months had an age-adjusted odds ratio of 0.47 (95% CI 0.27-0.83). A stronger protective effect was observed with lactation duration for the first live birth among pre- and postmenopausal women (for 4-12 months of lactation, OR = 0.56 (95 percent CI 0.32-0.96) and OR = 0.48 (95 percent CI 0.29-0.81) in pre- and postmenopausal women, respectively). Adjusting for potentially confounding factors modified these results only slightly. The declining trend in fertility and lactation among Mexican women could lead to a major epidemic of breast cancer such as that observed in Western countries.

Adult↗
PubMed1996

A neuromagnetic study of movement-related somatosensory gating in the human brain.

Neuromagnetic fields from the left cerebral hemisphere of five healthy, right-handed subjects were investigated under three different experimental conditions: (1) electrical stimulation of the right index finger (task S); (2) voluntary movement of the same finger (M); (3) M+S condition, consisting of voluntary movements of the right index finger triggering the electrical stimulus at the very beginning of the electromyogram. The three conditions were administered in random order every 5-8 s. In addition, the task somatosensory evoked fields (task SEFs) gathered during condition (1) were compared with control SEFs recorded at the beginning of the experiment during rest. In all subjects the overlay of somatosensory stimulation on movement provoked a decrement in brain responsiveness (gating) as determined by the amplitude of gated SEFs. The latter was found as the difference between the neuromagnetic fields during M+S condition (overlaying of movement and sensory stimulation) minus neuromagnetic fields under M condition (M only). The gating effect was found to begin approximately 30 ms after movement onset, and to last for the whole period of the ongoing movement. The theoretical locus of gating was estimated by dipole localisation of the difference between task SEFs and gated SEFS using a moving dipole model. The site of the "early" gating effect (< 40 ms) was found to be more anteriorly located than the "later" (> 40 ms) gating effect. The task SEFs were found to be larger (significant after 30 ms) than the control SEFs elicited under the basal condition. The results are discussed with respect to timing, mechanism (centrifugal and centripetal), locus and selectivity of gating. In addition, the results are discussed with regard to clinical application (measuring attentional deficits in patients with impairments of higher mental functions and measuring gating deficits in patients with disturbed sensorimotor integration.

Adult↗
PubMed1996

Combination of ondansetron and droperidol in the prophylaxis of postoperative nausea and vomiting.

The aim of this study was to compare the efficacy and safety of ondansetron plus droperidol with each drug alone or placebo in the prevention of postoperative nausea and vomiting (PONV). One hundred females, aged 18-65 yr, ASA physical status I-II, undergoing general anesthesia for elective abdominal surgery were included in a prospective, double-blind, placebo-controlled, randomized study. A standardized anesthetic technique and postoperative analgesia (ketorolac plus patient-controlled analgesia [PCA] with morphine) were used in all patients. Patients were randomly assigned to receive placebo (Group 1, n = 25), droperidol 2.5 mg with induction of anesthesia and 1.25 mg 12 h later (Group 2, n = 25), ondansetron 4 mg with induction (Group 3, n = 25), and ondansetron plus droperidol at the same doses as Groups 3 and 2, respectively (Group 4, n = 25). A complete response, defined as no PONV in 48 h, occurred in 28% of patients in Group 1, 60% in Group 2 (P < 0.05 vs Group 1), 56% in Group 3 (P < 0.05 vs Group 1), and 92% in Group 4 (P < 0.01 vs Groups 1, 2, and 3). Sedation was significantly greater with droperidol (Groups 2 and 4) for 12 h postoperatively. In conclusion, the combination of ondansetron plus droperidol was more effective than each antiemetic alone or placebo in the prevention of PONV in women undergoing elective abdominal surgery.

Adolescent↗