PubMed Health⌕ Search

Biomedical subjects

M Valencia

Publications and source records attributed to M Valencia.

At least 37 records · Page 2Linked to original sources
PubMed1994

Echographic findings in infectious endophthalmitis.

OBJECTIVE: To correlate the initial echographic findings in eyes with infectious endophthalmitis with the visual prognosis and causative microorganism. DESIGN: A retrospective review of the clinical and standardized ocular echographic findings in eyes with infectious endophthalmitis was performed. SETTING: University-based ophthalmology department. STUDY PARTICIPANTS: One hundred thirty-seven eyes (136 patients) with infectious endophthalmitis that were evaluated by the ocular echography service of the Doheny Eye Institute, Los Angeles, Calif, between January 1, 1981, and December 31, 1992. RESULTS: Four findings on initial echography were associated with poor initial vision: dense vitreous opacities, retinal detachment, macular detachment, and choroidal detachment. Five findings on initial echography correlated with poor final vision: dense vitreous opacities, vitreous membranes, the presence of retinal detachment, the extent of retinal detachment, and the presence of choroidal detachment. Change (decrease) in vision during the follow-up period was associated with the presence of combined vitreous and subhyaloid opacities, retinal detachment, and choroidal detachment. All eyes with initially clear vitreous on ocular echography had either early streptococcal or culture-negative endophthalmitis. Advanced streptococcal endophthalmitis correlated with the most severe vitreous inflammation, vitreous membranes, and the most extensive posterior vitreous detachment, whereas gram-negative endophthalmitis correlated with choroidal detachment on initial echography. Stepwise logistic regression analysis revealed that the presence of choroidal detachment, not gram-negative microorganisms, was the principal predictor of poor visual outcome in these eyes. CONCLUSION: Ocular echography is a useful method in the clinical evaluation and treatment of infectious endophthalmitis, especially in eyes with opaque media.

Adolescent↗
PubMed1994

Encircling panretinal laser photocoagulation may prevent macular detachment after vitrectomy for proliferative diabetic retinopathy.

Macular detachment due to peripheral retinal tears that occur after pars plana vitrectomy for proliferative diabetic retinopathy can result in severe visual loss despite successful retinal reattachment. The authors reviewed the records of three patients who developed peripheral sclerotomy-related rhegmatogenous retinal detachments one to six months after vitrectomy for proliferative diabetic retinopathy, despite the absence of detectable sclerotomy-related retinal tears by indirect ophthalmoscopy and scleral depression at the conclusion of surgery. All three patients had received standard panretinal laser photocoagulation in a complete encircling pattern either prior to or during the initial vitrectomy. Clinically or echographically, each patient was seen to have a partial or complete annual peripheral sclerotomy-related rhegmatogenous retinal detachment delimited to the equator. In each of these three cases, posterior extension of the peripheral retinal detachment into the macular area was prevented by the most anterior row of the photocoagulation scars. Standard panretinal laser photocoagulation applied in a complete encircling pattern may be useful in the prophylaxis of macular detachment from sclerotomy-related retinal tears that occur after vitrectomy for proliferative diabetic retinopathy.

Aged↗
PubMed1994

Echographic findings in hemorrhagic disciform lesions.

PURPOSE: To examine the potential role of ocular echography in the evaluation of hemorrhagic disciform disease. METHODS: Using standardized ocular echography, the authors examined 85 eyes of 85 patients with hemorrhagic disciform lesions. RESULTS: Hemorrhagic disciform lesions are located in the subretinal pigment epithelial space and appear echographically as solid chorioretinal elevations characterized by a bumpy, lobulated surface with indistinct peripheral margins, irregular internal structure, and medium to high internal reflectivity. These lesions could be reliably differentiated from associated subretinal or suprachoroidal hemorrhage by ocular echography when the maximal height of the lesion was 1 mm or greater. CONCLUSIONS: Hemorrhagic disciform disease is usually complex with distinct components that may not be discernible on biomicroscopic or angiographic examination, in part because of overlying subretinal hemorrhage. Ocular echography provides a readily available clinical tool to define the components of hemorrhagic disciform disease more precisely. Improved characterization of hemorrhagic disciform lesions may improve understanding of the natural history and response to therapy of hemorrhagic age-related macular degeneration.

Aged↗
PubMed1993

Obstructive sleep apnea secondary to surgery for velopharyngeal insufficiency.

The files of 585 patients who had had pharyngeal flap surgery for the correction of velopharyngeal insufficiency were reviewed. Eighteen patients, ranging in age from 6 to 16 years, showed clinical symptoms of obstructive sleep apnea syndrome. All of these cases had a polysomnographic evaluation and videonasopharyngoscopy. Fifteen cases met the criteria for the diagnosis of obstructive sleep apnea syndrome and eventually underwent surgical treatment. A modified uvulopalatopharyngoplasty was done in 14 of the 15 cases. One patient had a prominent uvula flipping into the port of a Jackson's type pharyngoplasty, so a partial resection of the uvula was performed. Surgical treatment was successful in 14 of 15 cases, including the case with the partial uvular resection. In one case, severe sleep apnea persisted after surgery and a complete section of the flap was performed to correct the obstruction. Sizeable tonsils were found in 13 out of 15 cases, whereas flap width appeared unrelated to obstruction. Preoperative assessment of tonsillar tissue is of vital importance before pharyngeal flap surgery.

Adolescent↗
PubMed1990

[The rupture of surgical gloves in a general hospital].

We studied the incidence of rupture of surgical gloves used at a general hospital: A) new gloves (n = 114); B) gloves used at a major general, gynecological or urological operation (n = 258), and C) recirculating surgical gloves (n = 86). A special techniques based on transmission of an electrical signal through the rupture was used to identify rupture. Rupture was present in 8.8, 28 and 26% of surgical gloves in groups A, B and C, respectively. Type of surgery or surgeon involved did not influence rupture of gloves in group A. However, rupture increased in relation to the duration of surgery (40% incidence in operations lasting more than 90 min). Our results suggest the need for better quality control of new surgical gloves and glove change after 90 min of operation.

Chi-Square Distribution↗
PubMed1988

[Quality characterization of several bolognas in Mexico. II. Evaluation of the nutritive value of their proteins].

Bologna is the most widely consumed processed meat product in the State of Sonora, Mexico. In the study herein described, the nutritive value of the protein in each brand was evaluated by means of the protein efficiency ratio (PER). Additionally, protein apparent digestibility (Cr2O3) and protein digestibility, both in vivo and in vitro, were determined, as well as apparent digestible energy in the same products. Results revealed significant differences in PER (p less than 0.05) among the commercial bologna brands with respect to ANRC casein. Nevertheless, when tested against the specific contrast, no significant PER differences were detected among the six bologna brands, and the control. Neither was there any difference detected in regard to apparent digestible energy consumption, or protein digestibility in vitro or in vivo.

Analysis of Variance↗
PubMed1986

[A model of clinical intervention in a mental hospital].

The purpose of this paper is to present a clinical model of intervention in a mental hospital which refers to a psychosocial treatment and rehabilitation program for acute hospitalized psychotic patients. A method of applied research was utilized for the development of the model. The theoretical framework, objectives and areas of the program are described as well as the research and treatment team, the structure and functioning of the program. Some preliminary results and conclusions are also included.

Adolescent↗
PubMed1980

Drug consumption among the student population of Mexico City and its metropolitan area: subgroups affected and distribution of users.

The results of a survey based on a sample of 4,059 students attending intermediate and upper intermediate schools in Mexico City and its metropolitan area showed that the percentage of drug use "ever" by substance was the following: alcohol, 59; tobacco, 53.2; inhalants, 5.4; cannabis, 3.8; tranquilizers, 3.1; amphetamines, 2.7; sedatives, 1.3; opium, 0.91; LSD, 0.54; cocaine, 0.52; heroin, 0.29. Of the students reporting use "ever", the percentage reporting use of one of these substances "in the past months" ranged from 22.5 to 58.3. While there were more female students among the users of tranquilizers and stimulants, male students predominated among the users of other substances, with the difference being most pronounced among cannabis users. Older students were more involved with cannabis; in contrast, inhalants were more popular with younger students. The use of other substances varied little with age. Use of alcohol and cannabis was also most frequent among students of schools in middle, upper middle and upper class areas, whereas use of inhalants was most common among students attending schools in lower class areas.

Adolescent↗
PubMed1978

Solitary primary amyloidosis of urinary bladder. Light and electron microscopic study.

A fifty-four-year-old white woman with a history of episodic gross hematuria was diagnosed as having solitary primary amyloidosis of the urinary bladder involving a large segment of the dome and anterior wall. A segmental resection of the bladder was performed with good results. Electron microscopic examination of the lesion revealed evidence to indicate that amyloid in this case was produced by the fibroblasts within the lamina propria of the bladder. The mode of amyloidogenesis is identical to that noted in some of the previously published electron microscopic studies on localized amyloidosis of skin. Solitary primary amyloidosis of the urinary bladder is a rare lesion with only 46 cases having been previously reported in the literature.

Amyloid↗
PubMed1976

Luteinizing hormone and progesterone in women under postcoital contraception with D-norgestrel.

Luteinizing hormone (LH) and progesterone (Pg) levels in blood were measured simultaneously by radioimmunoassay during 53 menstrual cycles in order to investigate the effect of 400 mug of D-norgestrel, administered postcoitally, on pituitary and ovarian function. Of 31 control cycles, 2 appeared to be anovulatory, since the LH peak and subsequent Pg elevation were absent. Twenty-nine cycles showed typical LH surges in the middle of the cycle, followed by a manifold Pg increase. Twelve women received 5 to 13 tables of D-norgestrel. A total absence or at least marked suppression of LH and Pg elevations was observed. In a third group, D-norgestrel was administered on scheduled days. Each woman ingested one to four tablets between the 6th and 18th days of the cycle. Two or more tablets disturbed LH and Pg ovulatory patterns. Of four women who received a tablet on day 10, one failed to show characteristic ovulatory patterns and three exhibited a delay in the time of the LH and Pg increase. These results demonstrate that D-norgestrel in a postcoital regimen alters pituitary and ovarian function, strongly suggesting an antiovulatory effect.

Contraceptives, Postcoital↗
PubMedDate not supplied

Spontaneous separation in idiopathic vitreomacular traction syndrome associated with contralateral full-thickness macular hole.

PURPOSE: Vitreomacular traction syndrome (VMTS) and full-thickness macular hole are two different well-known entities that on follow-up may be subjected to clinical modifications. Precisely, a spontaneous separation of idiopathic VMTS occurred in three eyes of three patients relieving in addition traction of the posterior hyaloid that had led also to a focal macular retinal pigment epithelial detachment (RPE). An association to a full-thickness macular hole was observed in the contralateral eye of one of the patients. METHODS: This is a retrospective study of three patients evaluated with fluorescein angiography and documented with optical coherence tomography using the Stratus (OCT) model 3000, with scans analysis and protocols analysis, measuring the size and shape of vitreomacular adhesions, macular thickness changes before and after the spontaneous separation of the tractional posterior hyaloid adhesion. In addition, the vitreous was evaluated with contact lens slit lamp biomicroscopy and ultrasound. The associated contralateral macular hole in one of the patients was surgically treated. RESULTS: Two of the three eyes with spontaneous separation of the VMTS recovered 20/25 central visual acuity; the other eye maintained the initial 20/50 visual acuity. The treated macular hole recovered 20/100 corrected visual acuity. CONCLUSIONS: Spontaneous separation of posterior hyaloid is a possible outcome during follow-up of idiopathic VMTS that can be well evaluated and documented with OCT while macular fluorescein angiography may be silent in cases like these presently reported. Central vision recovery can be excellent following the spontaneous separation, which releases anterior-posterior traction including on the retinal pigment epithelium and decreases macular thickness as measured with OCT. Therefore, regarding management, the indication for vitrectomy should be delayed awaiting the spontaneous release of vitreomacular traction in 4 to 6 months. The association between idiopathic VMTS in one eye and full-thickness macular hole in the opposite eye of one patient is an important pathophysiologic consideration.

Aged↗
PubMedDate not supplied

Studies of nonsedative antihistamines. II. Assessment of its antihistaminic potency.

An analysis is made of the effectiveness of terfenadine at dosages of 60 and 120 mg, of cetirizine at a dose of 10 mg, and of loratadine and ebastine at a dose of 10 mg in inhibiting the papule induced by 20 mcg of intradermal histamine. Although all produced significant inhibition, cetirizine and terfenadine 120 mg showed a significantly greater inhibition coefficient than loratadine.

Adult↗
PubMedDate not supplied

[Substance P: immuno-allergic implications].

Substance P is a decapeptide which forms part of the group known as neuropeptides, that is, peptides released by some neurones such as the slow-conducting C fibres and the rapid-conducting A-delta fibres. These neurones belong to the category of non-adrenergic non-cholinergic nerves (NANC), which perform their action through a mechanism known as "axonic reflex". This mechanism is an antidromic stimulation which produces a secretion of neuropeptides, especially substance P. It is known that substance P, once released, is able to exert a number of actions including among others inflammatory and bronchospastic activities and a stimulation of the immunologic system. Other effects attributed to this substance are an increase in capillary permeability and oedema and the perpetuation of certain conditions such as asthma, rhinitis and chronic urticaria or hives. The production, metabolism and actions of this neuropeptide are described.

Animals↗
PubMedDate not supplied

Comparison between cetirizine and terfenadine: time-response study.

Six young healthy volunteers were used as experimental models to study the efficacy of cetirizine 10 mg and terfenadine 60 mg with regard to the onset of action and duration of the peripheral antihistaminic effect (cutaneous activity). For this purpose, 10 micrograms of histamine were used administered as intradermal injection at the internal border of the forearm at times 0', 30', 60', 90', 120', 180', 240', 360', 480' and 24 h after the intake of the drug, with a minimum interval of 7 days between one drug and the other. The inhibition of the cutaneous activity of histamine was assessed by planimetry of the papule transferred to adhesive paper. Both antihistamines were well tolerated by the oral route and our patients did not refer any anticholinergic side effects nor sedation, which are classically described in relation to first generation anti-H1 drugs. When comparing both antihistamines as to their ability to inhibit the response, there are no differences between them at 30', but from this time point up to 24 h cetirizine inhibits significantly more than terfenadine the response to histamine; cetirizine achieves its maximal effect at 180', while terfenadine does so at 240'; both drugs maintain their maximal effect antil 480' and, as was previously mentioned, at these doses cetirizine shows a higher percentage of inhibition than does terfenadine at equal time points.

Administration, Oral↗