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Biomedical subjects

R Estrada

Publications and source records attributed to R Estrada.

At least 55 records · Page 3Linked to original sources
PubMed1991

Severe cholestatic jaundice associated with piroxicam.

A 62-year-old man with rheumatoid arthritis developed jaundice while taking piroxicam. A full evaluation including ultrasound, computerized tomography, endoscopic cholangiography, and liver biopsy confirmed the diagnosis of intrahepatic cholestasis. The patient's jaundice and all other liver function abnormalities normalized 4 months after he discontinued taking piroxicam. This is the first case report in the United States of severe liver toxicity associated with piroxicam. The six cases in the English-language literature are reviewed, featuring the presentation, patterns of liver injury, and outcome in each. Piroxicam should be considered as a potential cause of cholestatic jaundice when other more common etiologies have been excluded.

Biopsy↗
PubMed1991

Ovarian morphological conditions and the effect of injection of human chorionic gonadotropin on ovulation rates in prepuberal gilts with two morphologically different ovarian types.

The purpose of this experiment was to determine the ovulation rate after treatment with human chorionic gonadotropin (hCG) in two groups of gilts characterized by different ovarian morphology: grape-type (GT; n = 11) and honeycomb-type (HT; n = 7). At 170 d of age (d 0), gilts were examined by laparoscopy and ovarian type was determined by the distribution of macroscopic follicles present on the ovarian surface. Five to ten minutes after surgery, each gilt received a single injection (i.m.) of 750 IU of hCG. At d 0, GT ovaries had a greater number of large follicles (greater than or equal to 6 mm) than HT ovaries (10.0 +/- .5 vs 2.6 +/- .3; P less than .05), whereas HT ovaries had more small follicles (1 to 3 mm; HT: 42.3 +/- .8 vs GT: 26.7 +/- .9; P less than .05) and total follicles (HT: 59.4 +/- 2.3 vs GT: 52.2 +/- 1.5; P less than .05), although numbers of medium follicles (4 to 5 mm) were similar (GT: 15.6 +/- .8 vs HT: 14.6 +/- 1.7; P greater than .10). Number of induced corpora lutea (CL) per ovary was greater (P less than .05) in gilts with GT ovaries (10.59 +/- 2.9 CL) than in gilts with HT ovaries (5.21 +/- .66 CL). Total weight of luteal tissue (LT) per ovary and serum progesterone concentrations 8 d after induction of ovulation were greater in GT gilts than in HT gilts (GT: 6.37 +/- 1.09 g vs HT: 3.31 +/- .49 g for LT, P less than .05; GT: 21.08 +/- 4.76 ng/ml vs HT: 13.40 +/- 2.05 ng/ml for progesterone, P less than .07).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Follicular dynamics and dominance in Booroola x Finnish Landrace and Booroola x Suffolk ewes heterozygous for the F gene.

To study the influence of the F gene on follicular dynamics and dominance, 2-year-old Booroola x Finnish Landrace (BFL, N = 17) and Booroola x Suffolk (BS, N = 18) ewes were compared with contemporary purebred Finn (FL, N = 18) and Suffolk (S, N = 18) ewes. In Exp. 1, oestrous cycles of ewes were synchronized during the breeding season with progestagen-impregnated sponges. At sponge removal (Day 0), 14 days after insertion, ewes of each of the 4 genetic groups were assigned to Group 1 in which all follicles visible on both ovaries were destroyed by electrocauterization except for the largest (F1) which was marked, Group 2 in which all visible follicles on both ovaries were destroyed, or Group 3 in which the 3 largest follicles of both ovaries were identified as F1, F2 and F3 and marked. At 48 h after treatment (Day 2), follicular growth was evaluated. At Day 0, the mean number of small follicles (1-3 mm) was higher (P less than 0.05) for BS, S and BFL (35.8, 35.1 and 32.9) than FL (24.9) ewes. Large follicles (greater than or equal to 4 mm) were more numerous (P less than 0.05) in FL (3.5) than in BS (2.1) ewes, BFL and S ewes being intermediate. Diameter of the F1 follicle was larger (P less than 0.05) for S (7.6 mm) than FL, BS and BFL (5.8, 5.1 and 5.1 mm) ewes. In Group 1, all F1 follicles marked at Day 0 ovulated at oestrus after sponge removal for BFL, BS and S ewes while in FL ewes, 2 of 6 F1 follicles regressed. In ewes ovulating, only the F1 follicle ovulated except for one S ewe which shed one more ovum. In Group 2, there were no follicles greater than or equal to 4 mm at Day 2 and no ewes ovulated after treatment. In Group 3, the proportion of marked follicles that ovulated was higher for S ewes than in those of the prolific genotypes. The number of follicles not marked at Day 0 but ovulating (compared to the total number of ovulations) was higher in BFL, BS and FL (8/11, 9/13 and 9/13) than S (3/10) ewes. In Exp. 2, prolific (BFL + BS) and non-prolific (S) ewes were compared following destruction of follicles greater than or equal to 3 mm with the F1 left intact (Treatment 1) or destroyed (Treatment 2), 12 days after sponge insertion.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

Identification of features of metaplastic cells in sputum for the detection of squamous-cell carcinoma of the lung.

Digitized images of 1,556 squamous metaplastic cells from the sputum of 15 patients with confirmed squamous-cell carcinoma of the lung and 13 subjects without apparent neoplasia were analyzed to determine if features existed within these relatively normal cells that could be used to differentiate between the two populations. Results indicate that such marker features do exist. A cross-validation study using an additional 465 cells confirmed the conclusion that squamous metaplastic cells from patients with squamous-cell carcinoma of the lung do differ from those of subjects without cancer. While such marker features alone are not reliable enough to assist pathologists in the diagnosis of squamous-cell carcinoma of the lung, they might, in sufficient numbers, be used to identify patients for whom follow-up testing would be advised.

Biomarkers, Tumor↗
PubMed1989

Dominantly inherited olivopontocerebellar atrophy from eastern Cuba. Clinical, neuropathological, and biochemical findings.

A form of dominantly inherited olivopontocerebellar atrophy (OPCA) occurs commonly in persons of Spanish ancestry in northeastern Cuba. Its prevalence in the Province of Holguin is 41 per 100,000, a figure much higher than that found in western Cuba or in other parts of the world. The high prevalence is probably the result of a founder effect, but might be due to an interaction between a mutant gene and an unidentified environmental neurotoxin. We describe the clinical features of this disorder, and the neuropathological abnormalities in 7 autopsied patients. In addition, we report biochemical findings in plasma, cerebrospinal fluid (CSF) and urine obtained from 10 living OPCA patients. Quantitation of amino acids in fasting plasma showed a number of differences between the Cuban patients and healthy Canadian controls, but these are likely to have been caused by dietary differences. Amino acid concentrations in the CSF of the Cuban OPCA patients were similar to those of healthy Cuban controls, except for a decreased concentration of ethanolamine. Mean concentrations of dopamine metabolites were significantly low in the CSF of the OPCA patients, corresponding to neuronal depletion observed in the substantia nigra of autopsied cases. Examination of the patients' urines provided no evidence that either cyanide or 3-acetylpyridine is involved in causing this form of OPCA.

Adult↗
PubMed1989

[The development of the anti-phospholipase A2 antibody response in horses inoculated with venom for the production of polyvalent antisnake serum in Costa Rica].

The development of antibody response against phospholipase A2 activity of Bothrops asper venom was studied in a group of adult and healthy horses used in the production of the polyvalent antivenom at the Instituto Clodomiro Picado. Simultaneously, the general condition of the animals during the immunization schedule was also studied. There was a great individual variability in the immune response, although most of the horses studied reached the highest neutralizing titer after injection of doses of venom of 30 mg and 50 mg. On the other hand, in horses that had been previously immunized and were infected for a second immunization, the highest antibody titer was observed 16-22 days after inoculation. There were only mild alterations in the general condition of the horses as a consequence of venom inoculation. However, local abscesses, fistulae and fibrosis were observed at the site of venom injection. On the basis of the conspicuous individual variability observed, it is proposed that the immune response in horses used in the production of antivenom must be evaluated on individual basis, instead of working with pools of serum samples.

Animals↗
PubMed1988

Small-cell carcinoma of the ovary: an aggressive epithelial cancer occurring in young patients.

A case of small-cell carcinoma of the ovary occurring in a 33-year-old patient is described. At no time did the patient develop hypercalcemia. Despite aggressive cytoreductive surgery and multiagent chemotherapy, the patient expired after 13 months. These lesions must be differentiated from germ cell tumors or lymphoma. Review of the literature fails to reveal effective adjuvant therapy.

Adult↗
PubMed1988

Effects of litter size and light regimen imposed during lactation on ovarian follicular population at weaning in third-parity sows.

Sixteen third-parity sows maintained under two photoperiod treatments (16 h light: 8 h dark [16 h] or 4 h light: 20 h dark [4 h]) were assigned to be unilaterally ovariectomized (left ovary) at weaning on d 28 after farrowing a small litter (12 or fewer piglets; S) or a large litter (more than 12 piglets; L). Antral follicles were classified as atretic or nonatretic and divided into six size classes. The right ovary was obtained at slaughter, 16 d after estrus was detected. Number of antral follicles in the left ovary was greater (P less than .05) for L sows (540) than for S sows (427). Sows exposed to 16 h of light with large litters had a higher number of atretic follicles than all other groups (litter size x photoperiod interaction, P less than .05). Number of nonatretic follicles were similar between groups. However, when nonatretic follicles were classed by size (1 = smallest; 6 = largest), their distribution differed. In Class 1, L sows had more follicles than S sows (P less than .05). For Classes 3 and 4, photoperiod interacted with litter size to decrease the number of follicles in L 16 h sows (litter size x photoperiod interaction, P less than .05). These lower numbers of nonatretic follicles were related to a higher rate of follicular atresia in L 16 h sows. In Classes 2, 3 and 4, L 16 h sows had more atretic follicles than any other group (litter size x photoperiod interaction, P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Ultrastructural and ionic studies in global ischemic dog brain.

A time course of tissue ionic changes, and their relation to ultrastructural findings during reperfusion following a 15-min global ischemic brain insult was studied in a dog model. Parietal cortex was analyzed for Ca, Na, K, Mg and Fe in controls and after 10 min, 2, 4, and 8 h of reperfusion. After 8 h of reperfusion, the mean values (mumol/g tissue wet wt.) for Ca (control = 1.43, 8 h = 2.76) and Na (control 60.4, 8 h = 107.4) doubled and K (control = 90.4, 8 h = 48.5) decreased to half that of the control. Ultrastructural studies and subcellular localization of calcium in parietal cortex of in situ-fixed brains after 8 h showed cortical neurons with clumping of nuclear chromatin, dilatation of endoplasmic reticulum and disruption of plasma membranes. Large amounts of electron-dense precipitates of calcium were present within dilated astrocytic processes, synaptic vesicles, cytoplasm of edematous dendrites and mitochondria. Cortical neurons from postischemic dogs without reperfusion showed only slight chromatin clumping and edema of astrocytic processes, but no calcium accumulation. The large ionic shifts noted between 4 and 8 h of reperfusion, indicate a progressive inability of the cells to maintain normal transmembrane gradients of these ions and may reflect a membrane destructive process, as demonstrated ultrastructurally at 8 h. Enhanced calcium entry into the neuron during reperfusion appears to be a part of the cytotoxic mechanism leading to neuronal necrosis.

Animals↗
PubMed1987

Malignant fibrous histiocytoma of the broad ligament: a case report and literature review.

A case of malignant fibrous histiocytoma arising primarily in the broad ligament is described. This entity has not been previously reported. The patient's presentation and clinical course, including her partial response to Adriamycin and DTIC chemotherapy, are outlined. Clinical and pathologic features of tumors arising in the broad ligament are discussed.

Adnexa Uteri↗
PubMed1987

The reliability of cytopathologists' classifications of bronchial epithelial atypias from Kodachrome slides.

The accuracy of computerized cell image analysis techniques for classification of atypical cells is determined by comparing computer-generated classifications with those made by cytopathologists. This measure of accuracy depends not only on the reliability of the computer classifications but also on the reliability of the cytopathologists' classifications. This study reports on the observed reliability of cytopathologists' classifications of squamous epithelial atypias in sputum across cytopathologists and two different classification times. Results indicated the percentage agreement among cytopathologists and computerized cell image analysis techniques. It is recommended that, in the future, all analyses of computerized classification schemes by interpreted in light of the consistency of the cytopathologists' classifications.

Diagnosis, Computer-Assisted↗
PubMed1984

Cholecystoduodenocolic fistula with recurrent gallstone ileus.

The combination of cholecystoduodenocolic fistula with gallstone ileus is rarely seen. To our knowledge, there have only been six previous reports with these findings. A 66-year-old woman's condition was diagnosed preoperatively as small-bowel obstruction and communications between the gallbladder, duodenum, and colon. The small-bowel obstruction was successfully relieved by removing a large gallstone from the midileum, leaving the inflammatory mass in the right upper quadrant undisturbed. Three weeks later the small-bowel obstruction recurred. At reoperation two gallstones were found obstructing the midileum and were removed. The cholecystoduodenocolic fistula was dissected and the duodenum and colon were repaired. A cholecystostomy was done. The patient recovered and has been well four years later.

Aged↗
PubMed1984

Precision cell location and relocation techniques. An application for cell image analysis.

Two methods for precise cell location and relocation were developed at the Cell Image Analysis Laboratory, NASA, to increase the efficiency of the cell image acquisition process. The first method uses a Zeiss Zonax with a 10 micron scanning stage and automatically records cell coordinates on 5.25-inch floppy disks. The second method uses a Digital Positioning Device with a 10 micron scanning stage, and the cell coordinates displayed on light-emitting diodes (LEDs) are recorded manually. Because of its superior speed and automation, the Zonax was selected as the method of choice. By using a Zonax for off-line cell location and another Zonax for on-line cell relocation, more than three times the number of digitized images were collected in ten months than in the previous three years. Other beneficial applications of the cell location and relocation methods were realized in photomicrography, data base verification and cytopathology.

Computers↗
PubMed1983

Hurthle cell tumors of the thyroid gland.

Hurthle cell lesions of the thyroid gland, which are derived from follicular cells, occur in a variety of thyroid diseases. Hurthle cell neoplasms are generally easy to differentiate from non-neoplastic lesions, but the separation of benign from malignant Hurthle cell tumors is difficult on a purely histologic basis unless capsular or vascular invasion or metastases are present. Since this distinction is so difficult to make, the authors recommend treating all Hurthle cell neoplasms as potentially malignant. Treatment includes total thyroidectomy, peritracheal node dissection and if palpable jugular nodes are present, a regional node dissection. A series of 11 patients with this disease and the literature are reviewed to document these recommendations.

Adenoma↗
PubMed1983

Nuclear segmentation of bronchial epithelial cells by minimax and thresholding techniques. A comparison.

Two nuclear segmentation methods, Baky's minimax algorithm and thresholding, were compared on a sample of 879 atypical bronchial epithelial cells in sputum. Nuclear-cytoplasmic (N/C) ratios for all cells were determined by each segmentation method and compared to a visually determined value. Cells were categorized by atypia class (from metaplastic through malignant), by staining characteristics (orangeophilic and nonorangeophilic) and by method of digitization (either scanning microphotometry or video system). The method of digitization was confounded by subject differences. The results indicated that with most classes of atypia, N/C ratios determined by minimax were closer to the visually derived values than were those of thresholding, particularly with orangeophilic cells. Both methods become progressively less accurate, as compared to the visual procedure, as the degree of atypia increases.

Bronchi↗
PubMed1983

Hamartomatous polyps in Peutz-Jeghers syndrome. A light-, histochemical, and electron-microscopic study.

Multiple hamartomatous polyps from two patients with Peutz-Jeghers syndrome were studied using histochemical, electron-microscopic, and light-microscopic means. Using normal intestinal mucosa as control, mucosubstances containing sulfate, hexose and glycogen, as well as neutral and acid mucins, were detected. Electron-microscopic findings in different cellular populations of hamartomatous and normal mucosa were also evaluated. The results indicated the hamartomatous nature of such polypoid formations in Peutz-Jeghers syndrome. Review of the literature supports the possibility of genetic predisposition of these patients to develop unusual types of neoplasms in unexpected localizations.

Adult↗