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Biomedical subjects

M Robles

Publications and source records attributed to M Robles.

31 records · Page 2Linked to original sources
PubMed1992

Renal involvement in primary antiphospholipid syndrome.

Our objective was to define the renal involvement in primary antiphospholipid syndrome (APS). We studied 20 patients with primary APS. Fourteen were women, mean age 34.4 years. None met ARA criteria for systemic lupus erythematosus. All patients underwent complete renal function studies. The presence of hypertension was also investigated. Renal disease was found in 5 patients, and was characterized by proteinuria, hypertension and renal failure. Kidney biopsy was performed in these 5 patients, showing thromboses of the microvasculature, mesangiolysis, mesangial interposition, electron lucent subendothelial material and ischemic obsolescence of glomeruli. Arterioles showed luminal narrowing due to medial hypertrophy, mucoid thickening of the intima, thrombosis and fibrosis. We found renal disease in 25% of our patients with primary APS. Biopsy findings were consistent with a thrombotic microangiopathy involving both arterioles and glomerular capillaries.

Adolescent↗
PubMed1990

Müller cell GFAP expression exhibits gradient from focus of photoreceptor light damage.

High intensity (ca. 150 foot-candles), cumulative fluorescent light exposure regimes of 40 or 60 minutes to pigmented Long Evans rats were sufficient to elicit glial fibrillary acidic protein immunoreactivity (GFAP-IR) in Müller cells, when the animals are sacrificed 7 days post-exposure. Exposure to only 20 minutes of cumulative light or sacrifice immediately after exposure was not sufficient to initiate GFAP-IR in Müller cells. A gradient of GFAP-IR was observed extending from an approximately circular focus superior to the optic disc to the peripheral retina, whether or not there was morphological damage to the photoreceptors observable at the light microscopic level. Photoreceptor lesions produced by laser photocoagulation elicited the same gradient of GFAP-IR, and showed that GFAP-IR was not a reflection of a central to peripheral gradient of light received by the retina. Excessive light exposure initiated a signal which induced GFAP expression in Müller cells. This signal appeared to require a dark period and may be a diffusible factor that moves through extracellular pathways.

Animals↗
PubMedDate not supplied

Comparison of different injection forms in CT examination of the upper abdomen.

BACKGROUND: The optimal technique for administration of intravenous contrast medium in computed tomography (CT) remains controversial. Therefore, we analyzed the influence of variable-rate injection protocols. METHODS: A double-blind, parallel-group study was conducted in 60 patients studied with the same helical CT contrast-enhanced protocol. Patients were randomly distributed into three groups: monophasic (123 mL at 2.5 mL/s), biphasic (123 mL, 60 mL at 1.5 mL/s and then 63 mL at 2.5 mL/s), and sigmoid (0.6 mL/s ending at 2.5 mL/s). Contrast-enhancement efficacy was evaluated by attenuation coefficient measurements. RESULTS: The monophasic injection protocol produced a statistically higher liver, inferior vena cava, and portal enhancement than did the low-high biphasic and sigmoid protocols. The biphasic protocol produced a statistically higher enhancement in the superior aorta. The enhancement obtained with the monophasic protocol was always higher than or equal to those obtained with the biphasic protocol in all measurement protocols except in the superior aorta and the aortic bifurcation. CONCLUSIONS: A monophasic injection produces better parenchymal and venous enhancement. When arterial enhancement is important, a low-high biphasic protocol can be used. A sigmoid protocol, with the parameters used in our series, is significantly less effective.

Contrast Media↗
PubMedDate not supplied

A model for improving medication use in home health care patients.

OBJECTIVES: (1) To develop a model for the identification and resolution of problems associated with suboptimal medication use in elderly patients receiving home health care; (2) To select the most important identifiable problems and develop structured procedures for their resolution. DESIGN: Expert panel review, problem selection, and development of a problem resolution model and guidelines. SETTING: Home health care. PARTICIPANTS: A panel with expertise in home health nursing, pharmacy, clinical pharmacology, gerontology, pharmacoepidemiology, and health services research. INTERVENTIONS: A list of potential problems associated with the most frequently used classes of drugs was compiled for review by the panel. Problems that were controversial or that could not be identified in the home care setting were excluded. Panel members individually ranked the remainder. Detailed procedures for identification and resolution of the 15 top-ranking problems were developed. MAIN OUTCOME MEASURES: Not applicable. RESULTS: Potential medication problems were defined by both drug use and symptoms or clinical signs associated with specific adverse effects, to ensure that clinically relevant problems would be identified. The model developed for problem assessment and resolution was centered on the drug utilization review (DUR) coordinator and the attending home health nurse. Following guidelines developed by the panel, the DUR coordinator advises the home health nurse about identified problems and how to resolve them. One of these practitioners, usually the nurse, then contacts the attending physician to explain their concerns, offer potential solutions, and request instructions. CONCLUSION: A potentially useful model for the identification and resolution of medication problems in the home health care setting was developed. This model is currently being evaluated in a randomized controlled trial.

Aged↗
PubMedDate not supplied

Fatal fungaemia due to Sporothrix schenckii.

A clinical case is reported of a 78-year-old male with antecedents of diabetes and alcoholism who was hospitalized because he showed cutaneous lesions on the face and extremities suggesting cutaneous tuberculosis, but after a first histological study cutaneous leishmaniasis was erroneously diagnosed. Because of some unusual characteristics of the patient, the skin biopsies were carefully re-examined, as well as blood smears, which revealed elongated yeast form-like cells suggestive of Sporothrix schenckii. The diagnosis was confirmed when the fungus grew in mice and in Sabouraud cultures inoculated with blood samples from the patient. It is recommended that Sp. schenckii is included in the differential diagnosis of ulcerative cutaneous lesions in patients from Mexican humid areas.

Aged↗
PubMedDate not supplied

Emotional auditory paradigm in neuroimaging: a base for the study of psychosis.

INTRODUCTION: Since the arrival of neuroimaging numerous studies have tried to analyze the differences between emotional and non-emotional response. The majority of these studies use visual approach (faces) and begin with data in normal subjects. The present study introduces a new paradigm for the study of emotional response based on auditory approach and designed specifically for the study of psychoses. METHOD: The most frequent words heard by psychotic patients with auditory hallucinations were analyzed. They were classified according to five categories which were compared with 13 other words with the same structure but with a neutral emotional valency. This paradigm was applied to see the cerebral activation with functional magnetic resonance imaging (fMRI) in 10 right handed healthy males. RESULTS: In the preliminary analysis a clear differentiation is observed depending on the type of stimulus applied (emotional or non-emotional), both in the intensity of activation (right and left temporal cortex) as in the activation of specific areas (right precentral and supramarginal gyrus) only with the emotional stimulus. CONCLUSIONS: The present paradigm allows the observation of a differentiation in the cerebral activation to emotional auditory stimulus and could be of utility in the study of psychotic patients.

Affect↗
PubMedDate not supplied

Takayasu's arteritis in Mexico: a clinical review of 44 consecutive cases.

OBJECTIVES: To review our experience in clinical diagnosis of the non-specific arteritis called Takayasu's arteritis (TA), and to assess its possible relationship with previous mycobacterial infections as judged by delayed hypersensitivity skin test. METHODS: We examined 44 consecutive patients in Mexico City. All of them fulfilled the ACR criteria for the classification of TA and had a characteristic panaortogram in the absence of any other arterial or systemic disease. RESULTS: Forty-three of our patients were Mexican mestizos; only one had a Caucasian appearance. 38 were women, and the age at diagnosis ranged from 15 to 64 years with a mean of 32 and a median of 35. Age at onset of the symptoms was under 30 years in most cases. Five patients had type I disease, and 4 had type II. Most had a diffuse arteritis (type III), and in seven cases involvement of the pulmonary artery (type IV) was recognized. All patients showed abnormal peripheral pulses and blood pressure differences, 35 had systemic arterial hypertension and 7 pulmonary hypertension. A noisy vascular auscultation was very common and cardiac ailments were also found in many cases. Systemic complaints such as fever, weight loss and malaise were present in the active stages of the disease. Arthritis did occur in a single case, arthralgia was frequent and inflammatory nodules involving the shin, perimalleolar area, and the antero-external surface of the distal leg were also common. Polyclonal hypergammaglobulinemia was a frequent finding in active and inactive cases; leukocytosis with neutrophilia, accelerated ESR and high fibrinogen, however, did occur when the disease was active. Eight of our patients had a previous diagnosis of tuberculosis, and 81% developed a delayed skin reactivity to PPD (2U old tuberculin). None had a bacteriologic diagnosis of tuberculosis or mycobacterial disease. CONCLUSION: Non-specific arteritis, or Takayasu's disease, frequently affects young women of colored race in Mexico. Late diagnosis is common and cardiovascular features dominate the clinical picture. Arterial compromise is widespread and may involve the pulmonary artery and its branches. Most cases are inactive and morbidity results from systemic arterial hypertension and heart disease; active cases have systemic complaints and laboratory abnormalities suggestive of ongoing inflammation. The close relationship between Takayasu's arteritis and previous contact with Mycobacterium tuberculosis was again confirmed in our series, although further studies are necessary to clarify this probable relationship.

Adolescent↗