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Biomedical subjects

R Estrada

Publications and source records attributed to R Estrada.

At least 73 records · Page 4Linked to original sources
PubMed1983

Classification of bronchial epithelial atypias by the atypia status index.

The atypia status index (ASI) is a categorization method of classifying digitized images of atypical bronchial epithelial cells in sputum. The ASI is defined as a linear composite of features linearly related to atypia stage. Over 200 features were examined for more than 3,000 cells that had been classified by atypia stage (squamous metaplasia, mild, moderate or severe atypia and malignant) and staining characteristic (orangeophilia and nonorangeophilia). We reduced the number of features by using a selection process to minimize redundancy. The feature weights were optimized via a least-squares procedure. The 14 features selected accounted for over 60% of the variation of atypia stage and produced ASI values that were within one atypia stage of the criterion classification for over 90% of the cells. The results are consistent with the hypothesis of a progressive pattern in bronchial epithelial atypia and indicate the feasibility of using image analysis for mass screening of premalignant atypias in sputum from subjects considered to be at high risk for lung cancer.

Adult↗
PubMed1982

Meningeal myeloma.

A case of leptomeningeal myeloma is described and a brief review of the reported cases is made. Afflicted patients may be neurologically asymptomatic or may present with a clinical picture similar to carcinomatous and lymphomatous meningitis. Atypical plasma cells and monoclonal immunoglobulin in the cerebrospinal fluid (CSF) are the two most important findings for the diagnosis of leptomeningeal involvement in a patient with multiple myeloma.

Adult↗
PubMed1981

Duplication 3q: severe manifestations in an infant with duplication of a short segment of 3q.

A patient with duplication of a short segment of 3q (3q21 leads to 26) without apparent deletion of 3 or of other chromosomes provided a further opportunity to study manifestations of this abnormality. The proposita had a broad nasal bridge, anteverted nostrils, webbed neck, and clinodactyly V in addition to congenital heart disease, limb abnormalities, cleft palate, and severe developmental delay. The infant did not have the hirsutism and synophrys present in other cases.

Abnormalities, Multiple↗
PubMed1981

Freeman-Sheldon syndrome with unusual hand and foot anomalies.

A newborn with the characteristic facies of Freeman-Sheldon syndrome (whistling face syndrome) and unusual hand and foot anomalies is reported. Flexion contractures of fingers were so severe as to prevent their extension. Previously reported patients with similar hand anomalies had only mild to moderate limitation of extension. Over 75 percent of the 29 previous cases of this syndrome had equinovarus deformity. Not only was this deformity absent but the patient had polysyndactyly of the big toe, an anomaly not previously associated with this syndrome.

Abnormalities, Multiple↗
PubMed1981

Image analysis of atypical bronchial squamous epithelial cells. A quantitative and qualitative examination of squamous cell carcinogenesis.

Atypical bronchial squamous epithelial cells from cigarette smokers were digitized using a high-resolution microphotometric scanning system operating at a wavelength of 530 nm. All cells used for the purpose of developing a training set as well as those used as a test set were classified by a team of three cytopathologists. Reduction in the dimensionality of the feature space and cell classification were performed using a new system known as the atypia status index (ASI); this dual-purpose system will specifically classify cells into five distinct classes of progressive atypia as well as quantitate the degree of atypicality of each individual cell. The distribution of cellular ASI values was arranged from lowest to highest and plotted for each subject as a profile. The ASI range has well-defined intervals, representing the five different atypia classes used in the study (squamous metaplasia, mild atypia, moderate atypia, severe atypia and carcinoma). Subjects at different stages of carcinogenesis were found to have significantly different profiles (P less than 0.01). Changes in visual morphologic characteristics and their relation to changes in ASI values for the five different classes of atypia are presented.

Bronchi↗
PubMed1980

Aytpia status index of respiratory cells: a measurement for the detection and monitoring of neoplastic changes in squamous cell carcinogenesis.

A statistical procedure was developed for calculating an atypia status index (ASI) for cells from the bronchial mucosa. These indices represent the degree of abnormal changes in these cells and classify them as squamous metaplasia, mild atypia, moderate atypia, servere atypia or carcinoma. The classification accuracy of the procedure was more than 99% on trained data and was accomplished by minimizing the overlapping areas between the adjacent multivariate distributions of cell groups for selected features whose group means represent a monotonic function and for which the cell categories are distinguishable. The calculated ASI may reflect abnormal changes in the cell that may not be clearly evident visually. It appears that progression or reversal of bronchial epithelial atypia can be accurately monitored by studying the changes in the ASI, not only for preneoplasia but also for reactions to chemotherapy and various pulmonary infectious disease processes, such as influenza.

Adult↗
PubMed1979

Thyroid neoplasia following irradiation for medulloblastoma: report of two cases.

Thyroid neoplasms occurred in two patients 14 and 18 years after treatment with radiation for medulloblastoma. One patient has a papillary cancer and the other patient had multiple adenomas and a Hurthle cell adenoma. In addition, the latter case had foci of hyperplasia plus a microfollicular transformation, which has not been described in association with prior thyroid irradiation. The radiation doses delivered to the thyroid through posterior cervical spinal ports (2000--3000 roentgens) fall within the upper range of radiation dosage associated with induction of neoplastic changes within the thyroid.

Adenoma↗
PubMed1978

Clinical implications of a "nonspecific" transbronchial biopsy.

The diagnostic accuracy of transbronchial biopsy via fiberoptic bronchoscope was reviewed in 127 noncritically ill patients. Biopsy results were analyzed according to whether a "specific" pathologic diagnosis of neoplasm, granuloma or pneumonia, or a "nonspecific" diagnosis of inflammation, fibrosis or normal lung was made. The clinical significance of a "nonspecific" biospy specimen was evaluated by clinical follow-up of at least 12 months (mean 15 months) and by grouping patients according to the type of abnormality found on chest roentgenography. Clinical follow-up was available in 119 of these patients. The over-all "specific" diagnostic yield for biopsy with secretions was 49 per cent, with transbronchial biopsy being the sole means of specific diagnosis in 14 per cent of the patients with a peripheral mass lesion, in 18 per cent of the patients with localized infiltrative processes and in 52 per cent of the patients with diffuse infiltrative processes. In 64 (52 per cent) patients both biopsy specimens and secretions were diagnostically nonspecific. In 16 (77 per cent) patients with peripheral mass lesions but nonspecific biopsy findings and secretions, neoplasm was diagnosed by more invasive procedures. However, 22 (91 per cent) patients with localized and 12 (75 per cent) patients with diffuse infiltrative processes had benign clinical follow-up suggesting that open lung biopsy in such patients should be reserved for patients with obvious clinical or roentgenographic evidence of deterioration.

Biopsy↗
PubMed1977

[Status epilepticus. Study of 105 cases 1972-73].

We have analyzed 105 cases of Status Epilepticus of variable etiology, cared for over a period of 3 years at the "Instituto de Neurología y Neurocirugía". Age, sex, origin, duration of illness before attending the Institute, Conscience variations, clinical crisis types, condition of Status Epilepticus appearance and unleashing factors were considered. Various complementary investigations were performed, although dissimilar in each case. Follow up EEG's were realized in 60% of the patients and pretherapeutic EEG's were done in less than 50%. The necessary time to control the Status was explained, depending on its duration before commencing treatment. Of 93 surviving patients, it was possible to learn the cause of epilepsy only in 43. The necroscopy study of 12 cases demonstrated that death in 9 patients was inevitable for various causes (tumorous, infectious, vascular, etc.) almost always intricate. In other 3 autopsied patients, only signs of cerebral hypoxia and non-neurologic infectious complications were found. In the discussion, the hypoxia-edema-hypoxia mechanism is insisted upon, as well as the need of breaking this circle as an important part of the treatment of these patients.

Adolescent↗