Biomedical subjects

R Estrada

Publications and source records attributed to R Estrada.

At least 37 records · Page 2Linked to original sources

PubMed1996

[Investigation of corticospinal dysfunction in multiple sclerosis and motoneuron diseases using motor evoked potentials].

INTRODUCTION: The introduction of motor evoked potentials (MEP) into neurological practice has been very useful in the study of motor disorders, especially in patients with motor neurone diseases (MND) and multiple sclerosis (MS). MATERIAL AND METHODS: Forty patients with MS, twenty with MND and sixty-four apparently normal control were studied, to evaluate the use of MEP in such patients. Bilateral recordings were made from the abductor pollicis brevis and tibialis anterior. The variables studied were: cortical latency, radicular latency, central conduction time, motor excitation threshold coefficients of amplitude, duration and number of phases. RESULTS: There were significant differences in most variables when the control group and the patients were compared, and also between the two subgroups of patients (Wilk's lambda = 0.4197; p < 0.05). CA analysis significantly increased the sensitivity of the study (90.4%) with respect to analysis of latencies and central conduction times (70.4%). When analysis of the coefficients of duration and of phases was included, specificity increased by approximately 30% in both groups of patients. CONCLUSIONS: The great sensitivity of MEP as a neurophysiological diagnostic tool in investigation of corticospinal bundle lesions was demonstrated.

Adult↗

PubMed1995

Protein reverse staining: high-efficiency microanalysis of unmodified proteins detected on electrophoresis gels.

A methodology is presented for efficiently gaining structural information from electrophoresed proteins after on-gel detection by imidazole-sodium dodecyl sulfate-zinc reverse staining. As a consequence of reverse staining, (a) protein bands arise transparent against a deep white-stained background, limits of detection being in the femtomole range; (b) there is no loss of image when the gel is kept in distilled water (even during years); and (c) protein bands result immobilized, i.e., they do not diffuse upon gel storage. To recover reverse-stained proteins or fragments thereof from the gel, the immobilization of bands must first be abrogated by chelating the zinc ions from stain (protein mobilization). We had originally described mobilization at low pH by using citric acid. Here, we improve this procedure regarding the protein electrotransfer. We demonstrate that mobilization is efficiently done at neutral to alkaline pH by short-term (5 to 10 min) incubation of the gel in a buffer containing glycine or dithiothreitol prior to transfer. Moreover, mobilization was most simply performed by just adding the zinc chelating agent to the transfer buffer. Reverse staining and the new mobilization procedure made electrotransferring single protein bands from gel onto small-sized (13 x 5 mm2) PVDF membrane pieces in mini sandwich-like assemblies practical. Equipment is described for the protein electroblotting in such minisandwiches. Microsequence analysis of the electroblotted proteins showed initial yields in the range of those achieved when the transfer was done from unstained control gels. Protein bands kept in the reverse-stained gel for prolonged time periods (even for as long as 2 years) could be similarly analyzed.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrophoresis, Polyacrylamide Gel↗

PubMed1995

Modification of the fungi-fluor and the genetic systems fluorescent antibody methods for detection of Pneumocystis carinii in bronchoalveolar lavage specimens.

Four hundred forty-five bronchoalveolar lavage specimens from patients with the human immunodeficiency virus were preserved in Saccomano's fixative and stained for Pneumocystis carinii cysts by a modified method with Fungi-Fluor Solution A (Polysciences, Warrington, Pa) and the Genetic Systems Pneumocystis carinii Immunofluorescence Antibody (Genetic Systems Corp, Seattle, Wash). The majority of patients had been treated for suspected P carinii pneumonia for a few days prior to collection of bronchoalveolar lavage specimens. P carinii cysts were detected in 194 (43.6%) specimens. Both stains identified P carinii in 166 (37.3%) specimens and were negative in 251 (56.4%), yielding a concordance rate of 93.7%. P carinii cysts were detected in 25 (5.6%) specimens by the Genetic Systems stain only, and in 3 (0.7%) specimens by the Fungi-Fluor stain only. The sensitivity for detecting cysts of P carinii was significantly greater with the Genetic Systems stain (P < .01).

Bronchoalveolar Lavage Fluid↗

PubMed1993

Soluble CD23 in human immunodeficiency virus type 1 infected patients.

The level of sCD23 produced in the course of human immunodeficiency virus (HIV) infection was measured in patients grouped according to the Centers for Disease Control by using an immunoradiometric assay. Soluble CD23 was evaluated in supernatants of peripheral blood mononuclear cell (PBMC) (10(6) cells/ml) stimulated by phytohemagglutinin (PHA). Compared with healthy controls (m +/- S.D. = 1.0 +/- 0.34 U/ml, n = 7), higher values were observed in some of the patients of group II (asymptomatic) (m +/- S.D. = 2 +/- 1.33, n = 9) and some of the patients of group IV (AIDS) (m +/- S.D. = 1.3 +/- 1.40, n = 8). Those results prompted us to compare the plasma levels of sCD23 in group II and group IV HIV-infected patients and in healthy individuals. Soluble CD23 plasma levels in healthy patients (n = 42) ranged from 0 to 1.5 U/ml (m +/- S.D. = 0.9 +/- 0.33), in group II patients (n = 17) from 0 to 3 U/ml (m +/- S.D. = 0.92 +/- 0.83) and in group IV patients (n = 73) from 0 to 2.9 U/ml (m +/- S.D. = 1.15 +/- 0.71). The differences between the patients and the healthy individuals were not statistically significant but individual sCD23 values higher than 2 U/ml were obtained in 6% of the group II patients and 16.7% of the group IV patients. Increased values of sCD23 were obtained in plasma from patients with secondary infectious diseases (groups IV-Cl and IV-C2) and from patients without secondary infectious diseases (group II, group IV-A and group IV-B).(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗

PubMed1993

Ectopic pregnancy with undetectable serum and urine beta-hCG levels and detection of beta-hCG in the ectopic trophoblast by immunocytochemical evaluation.

BACKGROUND: Ectopic pregnancies associated with negative urine or serum pregnancy test by radioimmunoassay usually demonstrate either nonviable trophoblast or absent production of beta-hCG by the ectopic pregnancy. CASE: We report a patient with intra-abdominal hemorrhage caused by a ruptured ampullary ectopic pregnancy who had undetectable serum and urine beta-hCG levels (less than 5 mIU/mL). Immunoperoxidase staining of the ectopic trophoblastic tissue obtained at surgery revealed both beta-hCG and placental alkaline phosphatase. CONCLUSION: Negative serum and urine pregnancy tests can occur even though beta-hCG produced by the viable ectopic trophoblastic tissue can be demonstrated by immunoperoxidase staining.

Adult↗

PubMed1993

Frequency of positive tests for cytomegalovirus in AIDS patients: endoscopic lesions compared with normal mucosa.

Ten patients with the acquired immunodeficiency syndrome and an endoscopic erosive/ulcerative lesion in esophagus (4), stomach (3), or colon (3) were prospectively studied with multiple biopsies (244 biopsies from 33 sites) to determine: 1) the frequency of positive tests for cytomegalovirus (CMV) in the lesions versus normal mucosa, 2) the influence of number of biopsies on the rate of positivity. As seen on histology, five out of 10 lesions had cytomegalic cells, but only six of 45 (13%) of the biopsies taken from lesions that were positive showed the diagnostic changes. Immunoperoxidase was positive in two of the lesions with cytomegalic cells, but the positive staining occurred in only three of 35 (9%) biopsies from the histologically positive lesions. Culture was positive in one of 10 lesions, and the rate of positivity did not depend on number of cultures sent or number of biopsies per culture. Polymerase chain reaction was positive in six of 10 lesions, including all lesions positive by either histology (5), immunoperoxidase stain (2), or culture (1). The frequency of a biopsy being positive for CMV in normal mucosa was found to be 4%, 0%, 17%, and 28% by histology, immunoperoxidase stain, culture, and polymerase chain reaction, respectively. In AIDS patients at high risk for CMV, histologic evidence of CMV infection is uncommon in normal mucosa but is frequent in suspicious lesions. However, the frequency of diagnostic histology is highly dependent on the number of biopsies taken and the diligence of the pathologist. Polymerase chain reaction has the potential to become a rapid test to rule out CMV infection in gastrointestinal tissue.

AIDS-Related Opportunistic Infections↗

PubMed1993

Benign vulvar melanosis.

Large melanotic lesions of the vulva are uncommon, but they may present a diagnostic problem. Eleven cases of benign vulvar melanosis are reported. The clinical features, histologic characteristics and differential diagnosis are described and analyzed.

Adult↗

PubMed1992

Effects of pregnant mare's serum gonadotropin treatment on follicular populations and ovulation rates in prepuberal gilts with two morphologically different ovarian types.

Two experiments were conducted to determine the effects of pregnant mare's serum gonadotropin (PMSG) on follicular populations and ovulation rates in prepuberal gilts with grape-type (GT) and honeycomb-type (HT) ovaries. The follicular populations were determined at 170 d of age (d 0) and 19 d after PMSG (d 19). In Exp. 1, the mean number of macroscopic follicles of Classes 2 and 3 was greater (P less than .05) in GT (n = 11) than in HT (n = 32) ovaries at d 0, whereas the mean number of those of Class 1 was greater (P less than .05) in HT ovaries. At d 19, no difference was observed between the two ovarian types for any class of follicles. The PMSG-induced ovulation rates were comparable between the two ovarian types (8.3 vs 7.9, GT vs HT, respectively; P greater than .10). In Exp. 2, the microscopic follicular populations were determined on right and left ovaries removed, respectively, on d 0 and 19. At d 0, GT ovaries (n = 5) contained a greater number of Class 5 nonatretic (P less than .01) and atretic (P less than .02) follicles than did HT ovaries (n = 5), whereas at d 19 the mean number was not statistically different between the two ovarian types (P greater than .10). In contrast, gilts with HT ovaries contained a greater (P less than .01) number of Class 4 atretic follicles than gilts with GT ovaries at d 0, whereas at d 19 the mean number was not statistically different between the two ovarian types (P greater than .10).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

[Hematologic values and serum enzymes in horses inoculated with snake venoms for the production of antivenins in Costa Rica].

Blood components were studied in six horses immunized with snake venoms for the production of polyvalent antivenom in Costa Rica. No significant changes in hemoglobin or hematocrit throughout the immunization period were observed, whereas a significant increment in total serum proteins occurred in the second half of the immunization process, probably due to an increased synthesis of immunoglobulins. There were no significant changes in creatine kinase, but a slight increment was detected in both transaminases, although they did not exceed normal limits. These findings suggest the absence of relevant tissue damage in skeletal muscle, cardiac muscle and liver. In agreement with these results, horses did not develop signs of systemic poisoning, presenting only minor alterations at the site of venom injection, such as oedema, abscesses and fistulas. The development of anti-phospholipase A2 antibody response showed a prominent individual variability, as previously described.

Animals↗

PubMed1992

Bleeding from a Meckel's diverticulum after the use of ibuprofen.

A Meckel's diverticulum is an unusual site of gastrointestinal bleeding in adults. Bleeding often results from ulceration of ileal mucosa that lies adjacent to ectopic gastric mucosa. We report on a 27-yr-old man who bled from a Meckel's diverticulum after receiving oral ibuprofen, a nonsteroidal antiinflammatory drug. Examination of the resected diverticulum revealed fundal-type gastric mucosa with inflammation, submucosal hemorrhages, erosions and ulceration in the absence of Helicobacter pylori. The ileal mucosa was spared in this patient. These features suggest that oral ibuprofen caused damage to the ectopic gastric mucosa, precipitating significant hemorrhage. This is the first report in the English literature of such an occurrence.

Adult↗

PubMed1992

Prevalence of active Chlamydia trachomatis infection at the time of exploratory laparotomy for ectopic pregnancy.

Cultures of the fallopian tube, cul-de-sac, and cervix were obtained from 50 patients undergoing exploratory laparotomy for ectopic pregnancy. Chlamydia trachomatis was cultured from the cervix in four patients (8%). All the cultures from the fallopian tube or cul-de-sac were negative. Immunofluorescent stain of deparaffinized cross-sections of fallopian tube at the site of tubal involvement with the ectopic pregnancy failed to reveal any C trachomatis inclusions.

Adolescent↗

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↗