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Biomedical subjects

E Hernandez

Publications and source records attributed to E Hernandez.

At least 163 records · Page 9Linked to original sources
PubMed1986

Presumed Sexual Isolation in Yeast Populations during Production of Sherrylike Wine.

The three stages in wine production in the Montilla-Moriles region of Spain are (i) fermentation, (ii) film formation in vessels, and (iii) aging, all of which selected three yeast populations. All isolates from the three stages were classified as Saccharomyces cerevisiae. The distribution of characteristics of sugar fermentation (sucrose, galactose, maltose), Li tolerance, and Cu tolerance was different in the strains isolated in the three stages. This finding suggests that sexual isolation in the yeast populations prevents the random distribution of taxonomic characters.

Journal Article↗
PubMed1986

Investigation of aflatoxin contamination in commercial Spanish peanuts.

In the present study aflatoxin contamination was investigated with 102 peanut samples. Only 11 samples showed contamination by that mycotoxin. Concentration was less than 15-20 micrograms/kg in all the contaminated samples. Aflatoxin B1, B2, G1, and G2 were detected in the above-mentioned samples. No significant difference was found between shell and shelled peanuts owing to aflatoxin contamination.

Aflatoxin B1↗
PubMed1985

Interaction between bisantrene and radiation.

The interaction between Bisantrene, a new anthracene derivative, and radiation was studied in vitro. Chinese hamster lung (V-79-171) cells grown as monolayers were exposed to three different concentrations (0.4 mcg/ml, 2 mcg/ml, 10 mcg/ml) of Bisantrene for 120 min. during their exponential growth phase. Immediately after drug exposure, the cells were irradiated with escalating doses of radiation (100-1200 rad). Isoeffect curves (99% cell kill) were calculated using dose-survival curves generated for each modality. Curve I assumed that the agents act by independent mechanisms; Curve II assumed that the agents act by a similar mechanism. The dose combinations of the two modalities producing a 99% kill were plotted against the calculated isoeffect curves. The experimental points were found to lie along the calculated lines. Pre-treatment with Bisantrene prior to radiation resulted in an additive effect, similar to that reported with Adriamycin.

Animals↗
PubMed1985

Clearance of intravitreal fluorouracil. Normal and aphakic vitrectomized eyes.

The ocular pharmacokinetics of 5-fluorouracil (5-FU) after intravitreal administration in the rabbit are described for the first time. Following a 1 mg intravitreal injection of C-14 labeled 5-FU in the phakic nonvitrectomized eye, a peak level of 664 micrograms/ml is achieved which declines to 7.8 micrograms/ml at 24 hours. For the aphakic vitrectomized eye comparable values are 669 micrograms/ml at 0.1 hour and 0.21 micrograms/ml at 24 hours. 5-FU is cleared more than two times more rapidly in aphakic vitrectomized eyes than normal eyes during the first 12 hours following injection. Following this, when the actual concentrations are relatively low, the rate of clearance appears relatively similar for both groups of eyes. Although it is difficult to extrapolate from previous in vitro results, potentially therapeutic vitreous concentrations are present in normal rabbit eyes for up to 72 hours following a single intravitreal injection.

Animals↗
PubMed1985

Insulin antibodies retard and insulin accelerates growth and differentiation in early embryos.

The physiologic function of insulin in early embryonic life is unknown. We have shown that insulin is present in unfertilized eggs and in chick embryos at 2-3 days of development, even before the emergence of the endocrine pancreas. To define insulin's role, we exposed 2-day-old chick embryos to anti-insulin antibodies and followed their development up to day 5. Antibody-treated embryos had a higher rate of growth retardation and death by days 3-5 of embryogenesis, compared with controls. Among the survivors, biochemical maturation was delayed at days 4 and 5; weight, protein, total creatine kinase activity, and creatine kinase-MB were decreased in antibody-treated embryos. By contrast, insulin (50 ng/embryo) administered to 2-day-old embryos yielded nearly symmetrical stimulatory results. These findings suggest that endogenous insulin plays a probable physiologic role regulating growth and differentiation in early embryos. In addition, the findings provide some clues to a possible function for insulin produced outside the organism's own beta cells.

Animals↗
PubMed1985

Peritoneal cytology in stage I endometrial cancer.

Peritoneal lavage fluid for cytologic study was obtained in 73 patients undergoing primary surgery for stage I endometrial adenocarcinoma. Preoperative irradiation was not used. Malignant cells consistent with endometrial adenocarcinoma were present in eight (11 percent) cases. There was no significant difference in the proportion of patients with "positive peritoneal cytology" when patients with grade 1 and 2 tumors, five of 45 (11 percent), were compared with those with grade 3 and adenosquamous tumors, three of 28 (10.7 percent), between deeply invasive tumors, two of 20 (10 percent), and those with superficial or no invasion, six of 52 (11.5 percent), between stage IA, six of 42 (14.5 percent) and stage IB disease, two of 31 (6.5 percent). The prevalence of positive peritoneal cytology in this series of 73 patients who received no preoperative irradiation is similar to that reported in other series where preoperative irradiation was used. No correlation between positive peritoneal cytology and other reported poor prognostic indicators in stage I endometrial adenocarcinoma was found.

Adenocarcinoma↗
PubMed1984

Interobserver variability in the interpretation of epithelial ovarian cancer.

The interobserver diagnostic reproducibility for epithelial ovarian neoplasia was studied. The histologic sections of 68 ovarian tumors from 34 patients were independently reviewed by two pathologists from different institutions, without knowledge of the clinical course. Each observer rendered 68 diagnoses. The interobserver agreement rate for histologic type was 60% and for histologic grade 66%. In the 23 instances in which a discrepancy in grade occurred, 5 (23%) were disagreements in the diagnosis of borderline versus malignant tumors. On analysis of the diagnostic variability with regard to histologic type, one observer (A) classified 60% of the tumors as undifferentiated, while the other observer (B) classified 59% of the tumors as serous. In an attempt to understand the reasons for the diagnostic disagreements, the observers were asked to simultaneously reexamine the material. This occurred 6 months after the initial review and they were unaware of their original diagnoses. The diagnostic differences with regard to histologic type were mainly due to (1) tumor cell heterogeneity, and (2) difficulty in discriminating between serous and undifferentiated tumors. The differences in grade were largely related to the use of different criteria. Observer A used mitotic counts while observer B used glandular pattern and its replacement by solid sheets of epithelium. Observer B consistently assigned a higher grade to the tumors. In making therapeutic decisions, clinicians should be aware of the interobserver diagnostic variability and the reasons for this variability.

Carcinoma↗
PubMed1984

5-fluorouracil: new applications in complicated retinal detachment for an established antimetabolite.

Long-term reattachment of the retina following the development of proliferative vitreoretinopathy is often prevented by the occurrence of cellular reproliferation. 5-fluorouracil, a synthetic pyrimidine analog, is a potent inhibitor of fibroblast proliferation in cell culture and an animal model of tractional retinal detachment. Doses of up to 1.0 mg, when administered intravitreally to rabbits, result in no demonstrable retinal toxicity by microscopic and electrophysiologic criteria. The first 22 consecutive patients with advanced forms of proliferative vitreoretinopathy were treated with a combination of periocular and intraocular 5-fluorouracil, in addition to scleral buckling and vitrectomy. Retinal reattachment was achieved in 60% of patients at 6 months postoperatively. No serious systemic or ocular complications were observed although delayed healing of corneal epithelial defects occurred in 18% of cases and subtle subepithelial scarring in 31.8%. In combination with standard vitrectomy techniques, post-operative fluid gas exchange, and photocoagulation, periocular and subconjunctival 5-fluorouracil appears to improve the prognosis for longterm retinal reattachment following the development of proliferative vitreoretinopathy.

Adolescent↗
PubMed1984

The lens capsule and rubeosis iridis: an angiographic study.

In 15 pigmented rabbits a pars plana lensectomy, vitrectomy and giant retinal tear with bullous retinal detachment were produced with maintenance of an intact anterior lens capsule. The incidence of subsequent rubeosis iridis, as detected angiographically, was compared with that in a control group of animals in whom the anterior lens capsule was not preserved but whose management was identical in all other respects. The rubeosis in the rabbits was angiographically identical to that seen in humans following vitrectomy, with immediate formation of a mossy hyperfluorescent surface membrane that leaked fluorescein extensively into the anterior chamber in the late phase of the angiography. It was possible to distinguish true neovascularization from breakdown of the blood-ocular barrier by the time and extent of the fluorescein leakage. Preservation of an intact anterior lens capsule reduced the incidence of unequivocal (florid) rubeosis from 73% to 33% (p less than 0.05).

Animals↗
PubMed1984

Tumor heterogeneity and histopathology in epithelial ovarian cancer.

The histopathology of the original and the persistent or recurrent epithelial ovarian cancer in 34 patients was simultaneously reviewed by two pathologists. The time between removal of the primary tumor and removal of the persistent or recurrent tumor ranged from four to 132 months (median, 13 months; mean, 25 months). The initial operation was followed by multiagent chemotherapy in 23 patients, single-agent chemotherapy in seven, radiation and chemotherapy in two, radiation in one, and no therapy in one patient. In four of the 34 primary tumors, a mixed tumor composition was initially identified. In comparing the initial histopathology with that of persistent or recurrent tumors, a change was identified in nine patients. In four patients, the tumor changed from a mixed to an undifferentiated histologic type; in four patients there was a change from a lower to a higher tumor grade, and two of these patients also had a change in tumor cell type from serous to undifferentiated. In the ninth patient, the tumor changed from a large cell undifferentiated to a small cell undifferentiated carcinoma. The observed changes could be the result of 1) modification of the tumor by cytotoxic therapy, 2) spontaneous dedifferentiation of the initial tumor, 3) tumor cell heterogeneity with preferential growth of one cell type over the others, or 4) the development of a second primary tumor.

Carcinoma↗
PubMed1983

Alternating multiagent chemotherapy for advanced ovarian cancer.

A chemotherapy regimen consisting of hexamethylmelamine (H) 150 mg/m2 orally days 1-14, cyclophosphamide (C) 500 mg/m2 IV day 1 of a 28-day cycle with Adriamycin (A) 40 mg/m2 IV day 1 alternating with cis-diamminechloroplatinum (C-P) 50 mg/m2 IV day 1 every other cycle was administered to 29 patients with advanced epithelial ovarian cancer. Toxicity to this regimen included alopecia, nausea, and vomiting in all patients. Mild paresthesias occurred in four patients. Hematologic toxicity required only minimal dose modification. There was no cardiac, renal, or auditory toxicity. The clinical response rate of 55% and median survival of 14 months compare favorably with that of other reported series. This chemotherapy regimen seems to be well tolerated without jeopardizing the patients' response.

Adenocarcinoma↗
PubMed1983

Regional assignment of the human gene for platelet-type phosphofructokinase (PFKP) to chromosome 10p: novel use of polyspecific rodent antisera to localize human enzyme genes.

Human phosphofructokinase (PFK; EC 2.7.1.11) is under the control of three structural loci which encode muscle-type (M), liver-type (L), and platelet or fibroblast-type (P) subunits; human diploid fibroblasts and leukocytes express all three loci. In order to assign the human PFKP locus to a specific human chromosome, in this study, we have examined ten human X rodent somatic cell hybrids for the expression of human P subunits using a mouse anti-human P subunit-specific antiserum in an active-enzyme-immunoprecipitation technique. In nine of ten hybrids studied, the expression of the PFKP locus segregated concordantly with chromosome 10 and none other, indicating that PFKP is located on chromosome 10; the discordancy rates for all the other chromosomes were 0.2 or greater. In the one discordant hybrid, only the long arm of chromosome 10 was retained and PFKP was not expressed. Human fibroblasts from a patient with duplication of the short arm of chromosome 10 consistently exhibited PFK activity values 180% of normal. These data indicate that human PFKP is located on the short arm of chromosome 10, and that a gene dosage effect is demonstrable in fibroblasts with a duplication of 10p. The use of rodent antihuman antibody combined with immunoprecipitation aided by staphylococci-bearing protein A may find general application in mapping human enzyme genes, when human and rodent gene-products are not distinguishable by other means.

Animals↗
PubMed1983

Nurse practitioner role in a chronic congestive heart failure clinic: in-hospital time, costs, and patient satisfaction.

The purpose of this study was to compare in-hospital time, medical costs, and patient satisfaction before and after the introduction of a nurse practitioner in a chronic heart failure clinic. The records of all patients who attended the NP chronic congestive heart failure clinic were reviewed. Questionnaires were mailed to all available patients to evaluate satisfaction. We compared the number of hospitalizations, inpatient hospital days, and total yearly cost, 1 year before and 1 year after the institution of the chronic congestive heart failure clinic. Fifteen patients were seen an average of every 3 weeks for 7 to 48 months for a mean follow-up period of 24 months. Ages ranged from 48 to 86 years, for a mean age of 65. All but three patients had class IV congestive heart failure. Twelve patients had coronary disease, two valvular heart disease and one congestive cardiomyopathy. Seven of the 15 patients died during the follow-up period, all but one of progressive congestive heart failure. The number of yearly hospitalizations per patient decreased from 2.8 to 0.7 and yearly hospitalized days per patient from 62 to 9 (p less than .01). Total yearly medical cost decreased $131,175. Patient satisfaction was unanimous. In-hospital time and yearly medical costs decreased markedly and patient satisfaction increased after institution of the NP chronic congestive heart failure clinic.

Aged↗