Fermi-edge singularity and band-filling effects in the luminescence spectrum of Be- delta -doped GaAs.
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Journal Article↗
Biomedical subjects
A Ruiz
Publications and source records attributed to A Ruiz.
Cellobiose oxidase from Phanerochaete chrysosporium can be cleaved by papain into two domains.
Cellobiose oxidase from the white rot fungus Phanerochaete chrysosporium has been purified to homogeneity by a new method. The enzyme has been cleaved by papain into two fragments: one containing the heme group and one containing the flavin group. The flavin fragment can oxidize cellobiose and is reoxidized by oxygen. Cellobiose oxidase binds to cellulose to approximately the same extent as cellobiohydrolase I. The cellulose-binding site is located on the flavin domain. The enzyme cannot be totally displaced from cellulose by cellobiose, and it is still active when adsorbed to cellulose. The possible role of the enzyme in lignocellulose degradation is discussed.
Amino Acids↗
Cytogenetics, flow cytometry, cytophotometry and morphometry of 22 cases of primary breast carcinoma. A comparative study.
Cytogenetic, flow cytometric, cytophotometric and morphometric analyses were performed on 22 previously untreated, primary solid breast carcinomas. Although the cell nuclei as the primary object of these studies were the same in all the tumors, distinct features were evaluated in each case to determine to what degree the results obtained by these techniques are comparable. From the cytogenetic viewpoint, six tumors had a modal number in the diploid range, seven were in the triploid range, and two in the tetraploid range; seven tumors had no modal number. These data correlate with the flow cytometry and cytophotometry results obtained, with DNA values slightly higher than their respective chromosomal modes. However, no correspondence between chromosomal modes and mean nuclear area was found. Chromosomal markers have been identified that particularly affect chromosomes 1 (p11, q21-qter), 11 and 16, although no common markers existed in all cases. Cytogenetics is the most sensitive technique, but the low yield (22 out of 140 tumors assayed) considerably restricts its value in any prospective breast cancer study.
Adult↗
The 1,4-beta-D-glucan cellobiohydrolases from Phanerochaete chrysosporium. I. A system of synergistically acting enzymes homologous to Trichoderma reesei.
A physico-chemical and structural characterization of three 1,4-beta-D-glucan cellobiohydrolases (EC. 3.2.1.91), isolated from a culture filtrate of the white-rot fungus Phanerochaete chrysosporium, reveals that the cellulolytic enzyme secretion pattern and thus the general degradation strategy for P. chrysosporium is similar to that of Trichoderma reesei. Partial sequence data show that two of the isolated enzymes, i.e., CBHI, pI 3.82 and CBH62, pI 4.85, are homologous with CBHI and EGI from T. reesei; while, the third, i.e., CBH50, pI 4.87, is homologous to T. reesei CBHII. Limited proteolysis with papain cleaved each of the three enzymes into two domains: a core protein which retained full catalytic activity against low molecular weight substrates and a peptide fragment corresponding to the cellulose binding domain, in striking similarity to the structural organization of T. reesei. CBHI and CBH62 have their binding domain located at the C-terminus, whereas in CBH50 it is located at the N-terminus. It is evident that synergistically acting cellobiohydrolases is a general requirement for efficient hydrolysis of crystalline cellulose by cellulolytic fungi.
Amino Acid Sequence↗
Transcortical aphasia. Importance of the nonspeech dominant hemisphere in language repetition.
While a relative preservation of repetition in acute transcortical aphasia (TA) has usually been associated with the functional integrity of the speech dominant (left) perisylvian area, recent amytal data (Bando et al., 1986) have suggested a fundamental role of the nondominant (right) hemisphere in language repetition. The neuroradiological correlates of repetition were studied in a consecutive series of 21 patients with acute TA. A similar frequency of either perisylvian or extraperisylvian pathology was found. In 2 patients with perisylvian pathology, the injection of amytal in the hemisphere contralateral to the lesion abolished repetition. Positron emission tomography (PET) in another patient revealed marked hypometabolism over the entire left cortical mantle ipsilateral to a basal ganglia lesion, suggesting that preserved repetition was carried out by right hemisphere structures. This was confirmed in a second patient with left extraperisylvian pathology, in whom a second lesion in the right hemisphere resulted in impaired repetition. These findings suggest that the spared contralateral hemisphere may subserve residual repetition in some transcortical aphasic patients with a lesion within or outside the speech-dominant perisylvian area.
Aged↗
Genetic variance for body size in a natural population of Drosophila buzzatii.
Previous work has shown thorax length to be under directional selection in the Drosophila buzzatii population of Carboneras. In order to predict the genetic consequences of natural selection, genetic variation for this trait was investigated in two ways. First, narrow sense heritability was estimated in the laboratory F2 generation of a sample of wild flies by means of the offspring-parent regression. A relatively high value, 0.59, was obtained. Because the phenotypic variance of wild flies was 7-9 times that of the flies raised in the laboratory, "natural" heritability may be estimated as one-seventh to one-ninth that value. Second, the contribution of the second and fourth chromosomes, which are polymorphic for paracentric inversions, to the genetic variance of thorax length was estimated in the field and in the laboratory. This was done with the assistance of a simple genetic model which shows that the variance among chromosome arrangements and the variance among karyotypes provide minimum estimates of the chromosome's contribution to the additive and genetic variances of the trait, respectively. In males raised under optimal conditions in the laboratory, the variance among second-chromosome karyotypes accounted for 11.43% of the total phenotypic variance and most of this variance was additive; by contrast, the contribution of the fourth chromosome was nonsignificant. The variance among second-chromosome karyotypes accounted for 1.56-1.78% of the total phenotypic variance in wild males and was nonsignificant in wild females. The variance among fourth chromosome karyotypes accounted for 0.14-3.48% of the total phenotypic variance in wild flies. At both chromosomes, the proportion of additive variance was higher in mating flies than in nonmating flies.
Animals↗
Comparison of implantation and early development of human embryos fertilized in vitro versus in vivo using transvaginal ultrasound.
Several reports in the literature suggest delayed implantation of in vitro-fertilized human embryos compared to in vivo-fertilized eggs. The use of high-frequency transvaginal transducers for early detection of pregnancy has allowed the identification of the gestational sac with very low serum human chorionic gonadotropin (beta-hCG) levels. Thus, the present study evaluated whether retarded implantation can be identified using this novel technology. We studied 13 single pregnancies after in vitro fertilization (IVF) and 14 pregnancies after artificial insemination either by husband (n = 6) or donor (n = 8). In the IVF patients, oocytes were retrieved 35 hours after hCG administration. Embryo transfer occurred approximately 48 hours after retrieval. Artificial insemination was performed 24 and 48 hours after hCG administration. Transvaginal ultrasound scans and serum beta-hCG levels were evaluated every 3 days starting day 12 post-hCG administration. Serum beta-hCG levels rose in parallel when in vitro- and in vivo-fertilized embryos were compared. Similarly, there was no difference between groups in the mean time needed to detect early embryonic structures, such as the embryonic sac, yolk sac, and heartbeats, or the growth rate of the gestational sac. In conclusion, there was no difference in detecting implantation and early embryonic development of human embryos fertilized in vivo versus in vitro as ascertained by ultrasound scans and serum beta-hCG levels. An embryonic sac is detected 23-24 days after hCG administration in pregnancies achieved by assisted reproductive techniques.
Amnion↗
Association between diarrhoea and shedding of group A and atypical groups B to E rotaviruses in suckling pigs.
The frequency of shedding of rotavirus in faeces of diarrhoeic piglets was studied in 2 farms. In farm I, where 82% of the litters had diarrhoea, group A rotavirus was detected in 52/117 (44%) faeces of pigs with diarrhoea while atypical groups B to E rotaviruses were detected in 2/117 (2%) faeces of diarrhoeic piglets that came from litters where group A rotavirus had also been found. In farm II where the morbidity due to diarrhoeas was lower (57% of the litters had diarrhoea), 8/141 (6%) faeces of piglets with diarrhoea had group A rotavirus and 4/141 (3%) had groups B to E atypical rotaviruses. It was concluded that group A and groups B to E rotaviruses can coexist in the same farm but group A rotavirus seems to induce more diarrhoeas in piglets.
Animals↗
Failed in vitro fertilization of human oocytes: a cytogenetic analysis.
OBJECTIVE: To investigate possible causes of in vitro fertilization (IVF) failure. DESIGN: A retrospective cytogenetic study of human oocytes divided into four groups or, alternatively, into two groups according to fertilization rates and whether the patients became pregnant or not. Two additional groups included oocytes in which there was no or only partial fertilization. SETTING: Primary treatment of infertility in an institutional practice. PATIENTS, PARTICIPANTS: Two hundred fifty-three inseminated-unfertilized oocytes from 87 women entering the IVF program because of tubal, unknown, and male infertility. Immunological infertility was excluded. INTERVENTIONS: Ultrasound-guided transvaginal follicular aspiration. MAIN OUTCOME MEASURE(S): Planned after data collection. RESULTS: The rate of chromosome anomalies did not show any significant difference among the four groups established according to the fertilization rate and between pregnant and nonpregnant patients. Independently, our data identified male factor as responsible for 41%, chromosome anomalies 19.3%, oocyte immaturity 11.8%, and unknown etiology 41% of fertilization failures (based on analysis of 161 oocytes). CONCLUSIONS: Fertilization rate and pregnancy outcome after IVF are not related to the incidence of oocyte chromosome anomalies.
Analysis of Variance↗
Theoretical isoelectric points and electric charges of mutated human hemoglobin subunits.
Isoelectric point values have been determined from a theoretical standpoint for alpha, beta, gamma and delta human abnormal subunits bearing elimination or addition of 1-2 different aminoacids with acid-base residues. The charge distribution, in relation to pH values, of the four types of subunits are also reported. These values may be of interest both to predict the electrophoretic behaviour and to characterize human abnormal hemoglobins.
Amino Acid Sequence↗
High levels of Epstein-Barr virus in the oropharynx: a predictor of disease progression in human immunodeficiency virus infection.
The role of Epstein-Barr virus (EBV) on the progression of human immunodeficiency virus (HIV) infection is not well defined. The objective of this prospective study was to determine the prevalence of EBV excretion and the role that EBV might have on HIV disease progression. Fifty-two homosexual males were studied, all of whom had positive EBV serology. Twenty-four of the 27 HIV-seropositive and 14 of the 25 HIV-seronegative subjects had detectable levels of EBV DNA in oropharyngeal cells. In addition to a greater prevalence of detectable EBV, the level of excretion was higher among HIV-seropositives than among HIV-seronegatives, and higher among group III than among group II HIV-seropositive men. These results are consistent with earlier studies showing a relationship between immunosuppression and EBV reactivation. The EBV excretion levels in a control group of 52 age-matched heterosexual males were substantially lower than those found in the homosexual group. In a proportional hazards regression analysis EBV excretion was found to be the best single predictor of progression of HIV infection (P less than 0.001). HIV p24 core antigenemia (P = 0.048) and low EBNA (P = 0.024) were significant predictors independent of EBV excretion. Whether EV directly accelerates the time to progression or is merely a marker of underlying subclinical immunosuppression remains an open question.
Antigens, Viral↗
A novel surface antigen expressed by mature and activated rabbit T-lymphocytes.
The monoclonal antibody (Mab) 93C6 was used to identify a surface molecule expressed by mature and activated rabbit T-lymphocytes. This antigen was virtually absent in cells of the thymus (5% positive cells). All 93C6-positive cells expressed the rabbit pan-T marker L11-135 and proliferated in response to concanavalin A (Con A). When lymphocytes were activated in the presence of Con A, the expression of the 93C6 molecule was quantitatively increased. Con A stimulation alone did not markedly enhance expression of this antigen by thymocytes, but stimulation with both Con A and interleukin-2 (IL-2) resulted in a population of thymocytes that expressed the antigen in a manner quantitatively similar to that of mature T-cells in other tissues.
Animals↗
A low Km nucleoside 3'(2'),5-bisphosphate 3'(2')-phosphohydrolase from rat liver.
In the course of an investigation on the occurrence in rat liver of a specific hydrolytic activity on adenosine 2',5'-bisphosphate, a nucleoside 3'(2'),5'-bisphosphate 3'(2')-phosphohydrolase was purified following standard procedures. The enzyme hydrolyzes the phosphate group joined to the 3' or the 2' position of the following nucleotides (relative velocities indicated in brackets): PAdoP (100), PCydP (95), PGuoP (80), PAdo2'P (40), PdAdoP (4), SPAdoP (18). Other nucleotides were not substrates of the reaction: NADP+, PAdoPP, PPGuoP, AdoP, PAdo, GuoP, PGuo, ADP, ATP, cAMP, adenosine(3')phospho(5')adenosine. The Km values determined for PAdoP and PAdo2'P were 10 and 7 microM, respectively. Two isoforms were separated by chromatography on a Mono Q column. Both isoforms were kinetically indistinguishable, presenting a pI value of 5.35, a molecular mass of 38 kDa, pH optimum of 8.0, and strictly required Mg2+ or Mn2+. An enzymatic activity similar to the one described here has already been reported in guinea pig liver [5]. These authors however only obtained 1 enzymatic form with Km values of 3.1 and 1.8 mM for PAdoP and PAdo2'P, respectively. The potential physiological role of this enzyme in the metabolism of sulphate is also considered. The previously registered number EC 3.1.3.7 could be applied to this activity.
Adenosine Diphosphate↗
Weight reduction in massive obesity associated with focal segmental glomerulosclerosis: another evidence for hyperfiltration?
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Adult↗
[Prevalence of psychiatric disorders in an outpatient service of general medicine].
A psychiatric evaluation was performed in 100 patients attending the outpatient clinic of a large general university hospital. Psychiatric diagnosis followed the DSM-III-R criteria. 66 were female and the mean age was 50 years. The clinical diagnosis for the consulting problem related mainly to cardiovascular, metabolic, gastrointestinal and respiratory problems. Some psychiatric disorder was present in 55% of patients, mainly in the area of mood and adaptation problems. A psychiatric diagnosis was made by the general physician in only 14 patients and was labelled as neurosis of anxiety state. Our results show a high prevalence of psychiatric disorders in patients who consult in general clinics. A better psychiatric training of clinicians in charge of primary medical care is needed.
Adult↗
[Immobilization of microbial lactase].
Lactase (beta-D galactoside-galactohydrolase, E.C.3.2.1.23) is a relevant enzyme to the dairy industry as it modifies undesirable functional and nutritional properties derived from the lactose content in milk and dairies, and as a way of recovering or upgrading cheese whey. This latter aspect has been considered to develop an enzyme catalyst suitable for the continuous hydrolysis of whey permeate. The selection of enzyme and support and the immobilization procedure has been reported previously. Results obtained in the immobilization of fungal lactase on activated chitin have prompted us to scale-up the procedure, a system being developed in which the enzyme is immobilized within the reactor (in situ). Results are presented for the in situ immobilization of lactase with and without recirculation of the reagents. Previous procedure was reproduced, although moderate profiles of activity were generated through the catalyst bed which were not eliminated by recirculation. Packed bed reactors with immobilized lactase were operated at varying flowrates and lactose concentrations, results being compared, in terms of substrate conversion and reactor productivity, with a theoretical model based on the corresponding kinetic expression and ideal flow regime. Deviations are significant at high flowrates which is attributed to backmixing and channeling through the catalyst bed. The model fits reasonably well at low flowrates and high feed substrate concentration. Productivity was 58 g of glucose/l.h at 40 ml/h of 120 g/l of lactose. Stability of the immobilized lactase was assessed in long-term reactor operation with whey permeate (35 g/l of lactose) at 40 degrees C and pH 4.0. Operational half-life was 120 days.
Dairy Products↗
[A survey of the use of psychopharmaceuticals in patients admitted to a university hospital for adults].
We performed a survey concerning the use of psychotropic drugs among 223 patients admitted to a university hospital in November 1986. 39% of patients were receiving some psychotropic drug, and 73% of these corresponded to benzodiazepines. Insomnia and anxiety were reported as the main causes for drug use. Patients above age 50 were most affected. 61% of drugs had been in use for more than 6 months. These results confirm previous findings regarding psychotropic drug use in adults.
Adult↗
[Spontaneous tendon rupture in disseminated lupus erythematosus. A clinical case].
A 37-year-old female with systemic lupus erythematosus and chronic treatment with steroids developed spontaneous bilateral rupture of tendons of both quadriceps muscles below the patella. Surgical treatment was undertaken with good results. The histologic features and a review of the literature are included.
Accidental Falls↗