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Biomedical subjects

M Lugo

Publications and source records attributed to M Lugo.

At least 19 recordsLinked to original sources
PubMed2001

Nevirapine pharmacokinetics in pregnant women and in their infants after in utero exposure.

The safety, toxicity and pharmacokinetics of nevirapine were studied in HIV-infected pregnant women beginning chronic therapy late in the third trimester and in their infants. Initial dose pharmacokinetic profiles in the pregnant women were similar to those seen in nonpregnant adults. Serum nevirapine concentrations fell below the 100-ng/ml target concentration by Day 7 of life in four infants, suggesting that nevirapine elimination is accelerated in these infants compared with newborns whose mothers receive only a single intrapartum nevirapine dose.

Adult↗
PubMed2001

Combined effect of context change and retention interval on interference in causality judgments.

Four experiments studied the effects of context change and retention interval on retroactive interference in human causal learning. Experiment 1 found evidence of retroactive interference. Experiment 2 found that either a 48-hr retention interval or a change in the context after the interference treatment decreased retroactive interference. An interaction between context change and retention interval effects was also found, eclipsing the context change effect after the 48-hr retention interval. Experiments 3 and 4 found additivity between context change and retention interval effects when participants were remained of the difference between physical contexts before the test, independently of whether the context change involved a return to the original acquisition context. These results add to the evidence suggesting that spontaneous forgetting is caused by a change in either the physical or the temporal contexts where information is acquired.

Adolescent↗
PubMed1998

The accuracy of finger tension for estimating intraocular pressure after penetrating keratoplasty.

BACKGROUND AND OBJECTIVE: Intraocular pressure (IOP) estimation by Goldmann tonometry is inaccurate in the immediate postoperative period after penetrating keratoplasty. For this reason, many corneal surgeons use a finger tension (FT) IOP estimation technique in the early post-keratoplasty period. The authors performed a prospective clinical study to evaluate the accuracy of this traditional technique. PATIENTS AND METHODS: FT estimates were performed by three experienced corneal surgeons on 68 patients on the first and second days after penetrating keratoplasty. These estimates were compared with MacKay-Marg (MM) tonometry readings for these patients. RESULTS: The mean confident FT from the pooled data of the three surgeons exceeded the MM reading by 5.0 mm Hg (22.6 vs. 17.6). The mean FT exceeded the MM reading by only 3.9 mm Hg for the most accurate surgeon. Some observers were significantly more accurate than others, however, lid edema and tenderness of the globe markedly diminished the FT accuracy of all of the observers at significance levels of P < .001 and P < .01, respectively. Among all of the FT estimates, in only one patient (2%) did the FT underestimate the MM reading by more than 10 mm Hg. CONCLUSION: The authors' results suggest that for some patients, and for some surgeons, the FT or digital method of IOP estimation remains useful for detecting elevated IOP early after corneal transplantation if the proper technique is used and substantial lid edema and patient discomfort are absent.

Fingers↗
PubMed1993

Transforming growth factor beta 1 selectivity stimulates immunoglobulin G2b secretion by lipopolysaccharide-activated murine B cells.

Bacterial lipopolysaccharide (LPS) has been reported to induce immunoglobulin (Ig)G2b class switching, yet we observed strain differences in IgG2b secretion in response to this mitogen. Specifically, BALB/c B cells, unlike those from DBA/2, synthesized relatively low amounts of IgG2b relative to IgG3, IgG1, or IgM. This report demonstrates that transforming growth factor (TGF) beta 1, previously shown to induce IgA class switching, selectively stimulates IgG2b secretion by BALB/c resting B cells activated with LPS. This activity was specifically reversed with a neutralizing anti-TGF-beta 1 antibody. The ability of TGF-beta 1 to act directly on highly purified membrane (m)IgM+ mIgG2b- cells to stimulate IgG2b production, stimulate an increase in IgG2b-secreting cells, and selectively increase the steady-state levels of germline gamma 2b RNA, suggests that it promotes IgG2b class switching. In this regard, addition of anti-TGF-beta antibody to cultures of DBA/2-derived resting B cells activated by LPS, alone, led to selective reduction in IgG2b secretion, indicating that endogenous TGF-beta 1 accounts for the high IgG2b secretory response observed in that strain. Finally, TGF-beta 1 failed to stimulate IgG2b secretion by B cells activated with dextran-conjugated anti-IgD antibody. We propose that TGF-beta 1 is a switch factor for the murine IgG2b subclass for appropriately activated B cells. In combination with other data, this would show that all six non-IgM, non-IgD isotypes in the mouse can be selectively induced by specific cytokines.

Animals↗
PubMed1993

Metabolic responses when different forms of carbohydrate energy are consumed during cycling.

This study examined the effects of consuming the same amount of carbohydrate in solid form, liquid form, or both on metabolic responses during 2 hrs of cycling at 70% peak VO2 and on cycling time-trial performance. Subjects consumed 0.4 g carbohydrate/kg body mass before and every 30 min during exercise. The liquid was a 7% carbohydrate-electrolyte beverage and the solid was a sports bar (1171 kJ) in which 76%, 18%, and 6% of total energy was derived from carbohydrate, fat, and protein, respectively. Blood obtained at baseline, before exercise, and every 30 min was analyzed for glucose, insulin, lactate, hemoglobin, hematocrit, and plasma volume. There were no differences among the treatments for the blood parameters. Total carbohydrate oxidation and time-trial performance were also similar among treatments. Under thermoneutral conditions with equal liquid ingestion, the metabolic and performance responses are similar when consuming carbohydrate as a liquid, solid, or in combination during prolonged, moderate intensity cycling.

Adult↗
PubMed1990

Topical anesthetic abuse.

Topical ocular anesthetic abuse is a serious disorder causing keratitis and persistent epithelial defects. It may be the result of either prescription by the patient's eye care practitioner, theft from the practitioner's office, or occult additives in therapeutic medications. The authors report observations of six individuals suffering from this disorder which suggest that persistent epithelial defects, corneal stromal ring infiltrates, disproportionate pain, and prescription or nonprescription substance abuse may be factors involved. Penetrating keratoplasty was required to treat corneal perforation in two patients, and permanent corneal structural damage was noted in two eyes. Two eyes had a relentless downhill course culminating in enucleation. Because five of the six patients were diagnosed and treated as having presumed Acanthamoeba keratitis during the course of their disease, topical ocular anesthetic use should be included in the differential diagnosis of chronic keratitis and may masquerade as Acanthamoeba keratitis. The authors believe that practitioners should not prescribe or dispense topical anesthetics and should avoid clinical settings which provide an opportunity for the theft of topical ocular anesthetics.

Acanthamoeba Keratitis↗
PubMed1988

Pseudophakic bullous keratopathy.

We reviewed the records of all patients with pseudophakic bullous keratopathy (271 eyes, 251 patients) seen during a six-month period to determine predisposing factors, associated problems, current management, and visual outcome. Pseudophakic bullous keratopathy was associated most frequently with anterior chamber intraocular lenses in general (155 of 271), and with Leiske style lenses in particular (100 of 271). It was associated with a visual acuity of 20/200 or less in 206 eyes and a visual acuity of counting fingers or less in 129 of the eyes at the initial examination. Penetrating keratoplasties had been performed in 189 of the eyes. After penetrating keratoplasty, 108 of 189 of the eyes had a visual acuity of 20/200 or less (mean follow-up, 15 months). Visual acuity improved with longer follow-up, and among patients with a minimum follow-up of two years, 23 of 36 eyes had a visual acuity of 20/100 or better. Most grafts were clear (145 of 189). Pseudophakic bullous keratopathy was associated with marked visual loss, which was permanent despite clear grafts in 29 of 92 eyes followed-up for one year or longer.

Aged↗
PubMed1988

Penetrating keratoplasty for pseudophakic bullous keratopathy. Management of the intraocular lens.

Management of the intraocular lens (IOL) at the time of penetrating keratoplasty (PK) for pseudophakic bullous keratopathy has been based on lens-related factors and coexisting anterior segment abnormalities. The authors reviewed the results of PK for 102 cases of pseudophakic bullous keratopathy (43 anterior chamber, 50 iris-supported, and 9 posterior chamber) with respect to: (1) the type of IOL, (2) coexisting abnormalities, and (3) management of the IOL at surgery. Graft failure after 2 years of follow-up was: (1) retained iris-supported IOLs, 9%; (2) retained anterior chamber IOLs, 60%; (3) retained posterior chamber intraocular lenses (PC IOL), 0%; (4) removed IOLs, 9%; and (5) exchanged IOLs, 20%. After 5 years of follow-up, 13 of 13 PKs with retained closed-loop anterior chamber IOLs had failed. Visual results were best in eyes with retained iris-supported, rigid anterior chamber or PC IOLs and when the IOL was removed without replacement. The authors recommend that closed-loop anterior chamber lenses and unstable lenses of any type be removed or exchanged and that well-fixated PC IOLs and iris-clip IOLs be retained at the time of PK for pseudophakic bullous keratopathy.

Aged↗
PubMed1988

The incidence of preoperative endothelial dystrophy in pseudophakic bullous keratopathy.

To investigate the contribution of endothelial dystrophy to the subsequent development of pseudophakic bullous keratopathy, we retrospectively reviewed the clinical records and histopathologic specimens of pseudophakic patients who had undergone penetrating keratoplasty for corneal decompensation. Conclusive evidence of endothelial dystrophy was found in a majority (18 of 27, 67%) of patients who developed pseudophakic bullous keratopathy following implantation of a posterior chamber intraocular lens. By contrast, the incidence in a comparable group of 51 pseudophakic bullous keratopathy patients with anterior chamber intraocular lenses was low (six of 51, 12%) (P less than 0.01). In analyzing the relative risk of post-surgical corneal decompensation, one cannot implicate a particular intraocular lens without considering pre-existing endothelial dystrophy.

Anterior Chamber↗
PubMed1987

Corneal wedge resection for high astigmatism following penetrating keratoplasty.

Fourteen corneal wedge resections performed between April 1980 and January 1986 at the Wills Eye Hospital were retrospectively reviewed. Mean pre-operative refractive (subjective) astigmatism was 8.13 diopters (D), with a range of 3.75 to 15.0 D. Following wedge resection, the mean residual astigmatism was 3.04 D, with a range of 0 to 5.0 D. Although the mean keratometric astigmatism measurements were generally similar to the astigmatism measured during refraction, there was little correlation between them on a case-by-case basis. Corneal wedge resection appears to remain an effective and moderately predictable technique for managing high astigmatism following penetrating keratoplasty.

Adolescent↗
PubMed1986

Ocular rosacea in blacks.

In three black men (57, 64, and 61 years old) with the ocular manifestations of rosacea, the diagnosis was not initially suspected because the pathognomonic skin changes of rosacea were obscured by the skin hyperpigmentation. Ocular involvement ranged from blepharitis and conjunctival hyperemia to sight-threatening problems such as corneal neovascularization, thinning, ulceration, and perforation. Treatment with oral tetracycline and topical corticosteroids appeared to be as effective in these patients as in previously described white patients.

Black People↗
PubMed1986

Computerized scoring and graphing of the Farnsworth-Munsell 100-hue color vision test.

The Farnsworth-Munsell 100-hue test is a sensitive and accurate test of color discrimination. A major disadvantage of the test is the laborious and time-consuming calculation needed to score the results and plot them on a chart for interpretation. We present a computer program, written in Microsoft's BASIC language, that performs the calculation and reports both the individual color cap error scores (from which the graph is plotted) and the total error score. If used with an IBM personal computer (or compatible) capable of graphics, the program plots a graph in a modified polar coordinate format that can be printed on a dot-matrix printer.

Color Perception↗
PubMed1986

A simple BASIC computer program to individualize the SRK formula.

A computer program written in BASIC language that calculates, updates, and stores the A value used in the formula for the determination of intraocular lens power is presented. It has the structure of a subroutine, and can either be easily integrated into an already existing larger program or it can function independently of another program.

Computers↗
PubMed1985

A simple database computer program for ophthalmic use.

We have written a program in BASIC language which stores, recalls, and manipulates a limited amount of clinical information that we use in teaching and clinical practice. The program runs on an IBM personal computer with Microsoft DOS and BASIC. An illustrative search routine uses simple data simulation of the results of argon laser trabeculoplasty therapy for open-angle glaucoma.

Computers↗
PubMed1985

A dose-response study of piloplex for duration of action.

The duration of reduction in intraocular pressure after single-dose administration of three concentrations of piloplex and the vehicle of the drug was evaluated in 12 patients with open-angle glaucoma in a randomized, double-masked, crossover study. Piloplex lowered intraocular pressure in a dose-related fashion, with a duration of action of at least 14 hours.

Adult↗
PubMed1984

Metaplasia. An overview.

Metaplastic changes are common lesions found at widespread locations, occurring in both reactive and neoplastic tissues. Metaplasia has the following characteristics: (1) it can arise not only as a proliferation and transformation of immature (stem) cells, but also as a direct or indirect transformation of mature cells; (2) through metaplasia, a given cell may exhibit epithelial, mesothelial, or mesenchymal characteristics, regardless of the tissue of origin; and (3) its importance lies in that metaplastic changes can often be symptomatic and may simulate tumors clinically, grossly, or histologically.

Cell Differentiation↗