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Biomedical subjects

E Ramos

Publications and source records attributed to E Ramos.

At least 145 records · Page 8Linked to original sources
PubMed1990

Dual-energy radiographic absorptiometry of the lumbar spine: clinical experience with two different systems.

Dual-energy radiographic absorptiometry (DRA) of the lumbar spine was performed in 222 subjects (aged 17-92 years) of both sexes with use of two different systems. In a sub-group of 21 patients, results were compared with those obtained by means of dual-photon absorptiometry (DPA) of the lumbar spine. There was a high correlation among the results obtained with three instruments (r = .9, P less than .0001), and interconversion factors were calculated. Data conversion based on these regression equations may be useful for comparing results from one laboratory to another.

Absorptiometry, Photon↗
PubMed1990

Effect of balanced amino acid solution on protein metabolism after surgery. A clinical study.

The aim of this study was to investigate the nitrogen-sparing effect of hypocaloric parenteral nutrition (HPN) with a balanced amino acid supply compared with that of a standard Rose's formula. Eighteen well-nourished patients with colorectal cancer were randomly distributed into 3 groups: I control, II Study group, III Rose's formula. The amount of non-protein calories was similar in both groups: 8 kcal/kg administered as glucose, and 1.33 g of amino acid/kg was also infused during 5 days. There were no differences in the plasma protein levels of total proteins, albumin, and transferrin, but retinol-binding protein was higher in group II compared with the control. Nitrogen balance was significantly better in group II than in group III during the 3rd and 4th days. There were differences in the concentration of aspartic acid and glycine in the plasmatic aminograms between groups II and III. It was concluded that the balanced amino acid solution does not significantly improve a patient's nutritional state. Nor have we observed that the balanced amino acid solution causes fewer modifications in the plasma aminograms. However, it does achieve a slight improvement in the nitrogen balances and the synthesis of retinol-binding protein.

Amino Acids↗
PubMed1990

Extraskeletal chondromas.

1. Extraskeletal chondromas occur in three variants: (a) as multiple nodules of synovial chondromatosis within a joint, (b) as a solitary lesion in association with articulations, within or adjacent to them, and (c) as an isolated cartilagenous lesion in the soft tissues, mostly of the hands and feet. 2. There are no histological characteristics which could differentiate articular, para-articular and soft tissue chondromas among themselves. 3. The latter two groups of extraskeletal chondromas are rare and frequently exhibit areas of immature cartilage with worrisome histologic features which could mislead the pathologist to an overdiagnosis of chondrosarcoma. 4. As a general rule, no matter how worrisome the histologic appearance of an extraskeletal, well delimited cartilagenous tumor may be, metastasis have not been recorded. Local recurrences are not infrequent after inadequate surgical removal; however, the tumor can always be controlled by adequate wide re-exision or resection. 5. Two cases of extraskeletal chondromas, one para-articular in the knee and the other in the soft tissue of the arm, have been presented with an exhaustive review of the literature on the subject. 6. It is of interest to note that our para-articular chondroma represents the first case reported in the literature where computerized tomography was utilized in the diagnosis. 7. The location of a soft tissue chondroma in the upper arm is extremely rare and only one previous case has been reported in said location.

Adult↗
PubMed1989

A mutation in the insulin receptor gene that impairs transport of the receptor to the plasma membrane and causes insulin-resistant diabetes.

Insulin binds to a receptor on the cell surface, thereby triggering a biological response within the target cell. Mutations in the insulin receptor gene can render the cell resistant to the biological action of insulin. We have studied a family in which two sisters have a genetic form of insulin-resistant diabetes mellitus. The technique of homozygosity mapping has been used to demonstrate that the mutation causing diabetes in this consanguineous family is genetically linked to the insulin receptor gene. The two insulin-resistant sisters are homozygous for a mutation encoding substitution of valine for phenylalanine at position 382 in the alpha-subunit of the insulin receptor. Transfection of mutant insulin receptor cDNA into NIH3T3 cells demonstrated that the Val382 mutation impaired post-translational processing and retarded transport of the insulin receptor to the plasma membrane. Thus, the mutation causes insulin resistance by decreasing the number of insulin receptors on the surface of the patients' cells.

Cells, Cultured↗
PubMed1989

Quantitative dual-energy radiographic absorptiometry of the lumbar spine: in vivo comparison with dual-photon absorptiometry.

Quantitative dual-energy radiographic absorptiometry (DRA) and dual-photon absorptiometry (DPA) were compared to determine the best means of assessing bone density. Both methods were used to evaluate the lumbar spine in 107 women (aged 35-84 years [mean, 64 years]) referred for evaluation of osteoporosis risk. High correlation was documented between measurements derived by the two techniques, with a .95 linear regression coefficient for the total spine density measurement. Age-related regression equations were similar in slope but manifested different intercepts. Bone mineral density values derived with DRA were consistently lower than those obtained with DPA (conversion equation: DPA density = [1.067 X DRA density] + 0.163). Besides the inherent imperfections of each system, it was found that inaccurate identification of intervertebral spaces on the low-resolution DPA images introduced errors in patient data. DRA may replace DPA as the dedicated projectional densitometric procedure of choice for technical reasons, but at present a conversion equation must be used to compare DRA data to DPA data.

Adult↗
PubMed1989

Axial bone density in rheumatoid arthritis: comparison of dual-energy projection radiography and dual-photon absorptiometry.

The usefulness of dual-energy projection radiography (DEPR) in the evaluation of rheumatoid arthritis was compared with that of dual-photon absorptiometry (DPA). Bone density measurements of the lumbar spine and the proximal femur were obtained with DPA in 75 patients (45 women and 30 men). For comparison, the bone density of the lumbar spine was measured with DEPR in a subset of 52 patients (33 women and 19 men). High correlation was documented between DEPR and DPA measurements of the lumbar spine. No significant relationship between bone density and age was observed, in contrast to the known relationship in healthy subjects regardless of sex, site of measurement, or measurement technique. Bone density values in the spine and the proximal femur were significantly reduced for both sexes as compared with matched normative data. Interlevel variation in lumbar vertebral density as measured with DEPR was not significantly different in patients with rheumatoid arthritis as compared with control subjects. Significant correlation between bone density determination and body weight, as well as duration of menopause, was noted, whereas duration of disease, functional status, and cumulative corticosteroid dose were not predictive. Rheumatoid arthritis did not appear to influence the relationship between DEPR and DPA measurements of the spine, and neither method nor site of measurement exhibited a consistent advantage in discriminating patients with rheumatoid arthritis from healthy control subjects.

Absorptiometry, Photon↗
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↗
PubMed1988

[Quality characterization of several bolognas in Mexico. III. Sensorial evaluation by an untrained panel].

In a study on the quality evaluation of bologna, the major processed meat product of greater consumption in Sonora, Mexico, the quality of commercial brands, available in local markets, was investigated. As part of it, the sensory or organoleptic aspect of factors influencing the acceptance of bologna by consumers was included. The factors considered were: flavor, texture, appearance and color. The acceptance-preference of each product was determined using a hedonic scale and a balanced incomplete block design. The results were then statistically analyzed by the F-test for difference among treatments. Student's "t" test for population means, and multiple range for acceptance and frequency of preference. Findings revealed there were differences in flavor, texture and appearance among the bologna brands. The most relevant factors causing these differences were: saltiness, fluor flavor, stickiness, dryness, and uniformity of color. Significant differences in the color scores among the different brands were also detected, but this was not the case for overall color.

Color↗
PubMed1987

Metal chelates as urographic contrast agents for magnetic resonance imaging. A comparative study.

Paramagnetic metal chelates including Fe-EDTA, Fe-CDTA, Fe-DTPA, and Gd-DTPA were compared as intravenous urographic contrast agents for magnetic resonance (MR) imaging in rats. Each compound, administered intravenously at three different doses (0.05, 0.1, and 0.2 mmol./kg.), was rapidly excreted through the kidneys yielding renal signal enhancement between 5 min. and 50 min. after injection. Gd-DTPA was most effective vor the enhancement of the renal parenchyma and pelvis. Lesser enhancement was achieved by administration of Fe-CDTA followed by Fe-EDTA and Fe-DTPA. Enhancement of skeletal muscle and liver parenchyma could not be achieved with any of the compounds included in this study. We conclude that the iron chelates mentioned above are less effective as urographic agents for MR imaging than Gd-DTPA.

Animals↗
PubMed1985

Alternative vascular access in patients lacking veins for standard arteriovenous fistulae.

We have evaluated the Hickman catheter and Hemasite access port as means to re-establish vascular access in patients lacking veins for conventional arteriovenous fistulae. The Hemasite is more convenient, but is also costlier, requires more surgical skill to implant, and is more frequently associated with major infections. One-half of the Hemasites have failed because of infection. As a result, the long-term survival rate is lower for Hemasite graft, although the differences noted have not yet reached statistical levels of significance.

Adult↗
PubMed1984

[Elaboration, by linear programming, of new products from cereals and legumes].

The differing contents of essential amino acids in cereals and legumes bring about an overall increase in protein quality when these foods are consumed together. This study describes a least cost formulation method for preparing products based on cereals and legumes using linear programming. The mixture was formulated under different constraints; from a nutritional standpoint, a given amino acid pattern, and another one on a technological feasibility constraint, which depends on the type of product to be elaborated. From the formulation based on wheat, chick-pea, sorghum, and soybean flours, three products were developed: bread, tortillas and cookies; from these, bread was selected for further evaluation. The product was chemically evaluated by proximate analysis composition, and amino acids were determined by HPLC. Biological evaluation was performed by the PER and RPV methods, obtaining a PER of 1.69 for the developed bread product, and of 0.68 for the control bread. The RPV for the developed product was 64.31% of lactoalbumin and 23% for the control bread, which represents an increase of 41%. The sensory evaluation results did not indicate significant differences in taste, texture, color or overall acceptability of the developed bread product as compared to the control.

Amino Acids, Essential↗
PubMed1984

Hepatic injury during doxorubicin therapy.

Six patients with acute lymphoblastic leukemia manifested liver dysfunction related to doxorubicin hydrochloride therapy. Other causes, eg, infection, hepatitis, posttransfusion reaction, and leukemic infiltration were ruled out. There was close correlation between the administration of doxorubicin and the appearance of hepatic dysfunction. Doxorubicin may produce an idiosyncratic reaction and must be considered a drug with potential liver toxicity.

Adolescent↗
PubMed1983

Cytosine arabinoside induced liver damage: histopathologic demonstration.

Two patients with acute leukemia developed abnormal liver function tests after the administration of cytosine arabinoside. Other possible causes for such abnormalities were not likely. In both patients a close chronologic relationship between the administration of the drug and the appearance of the laboratory abnormalities was noted. The liver damage was also documented by biopsy. To our knowledge this is the first time that the hepatotoxic effects of cytosine arabinoside are histologically demonstrated.

Adult↗
PubMed1982

[Aicardi syndrome].

The association in young girls of flexion spasms of early beginning, partial or total agenesis of the corpus callosum, severe chororetinopathy and frequent skeletal anomalies is known as the Aicardi syndrome. On occasion of two observations a review of the literature is made.

Abnormalities, Multiple↗