[Epidemic of Venezuelan equine encephalitis].
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
A Ruiz
Publications and source records attributed to A Ruiz.
Comparison of digital rectal examination, transrectal ultrasonography, and multicoil magnetic resonance imaging for preoperative evaluation of prostate cancer.
OBJECTIVE: A prospective study was designed to compare the potentials of digital rectal examination (DRE), transrectal ultrasound (TRUS), and magnetic resonance imaging (MRI) using integrated endorectal and pelvic phased-array coils for preoperative estimation of tumor volume and local extent of prostate cancer. METHODS: Evaluation of 20 consecutive patients undergoing radical retropubic prostatectomy included DRE, TRUS with a 7.5-MHz transducer, and MRI on a 1.5-tesla GE Signa system. Step sections (5 mm) of the entire specimen were performed, and tumor volume and percentage of gland involved were calculated. RESULTS: DRE, TRUS, and endorectal and pelvic phased-array MRI showed 50, 75, and 95% of the cancers, respectively. There was a linear correlation on MRI between predicted tumor volume and pathological tumor volume (r = 0.82, p < 0.0001), but not between predicted volume on DRE or TRUS and real volume. The accuracy for detecting extracapsular penetration was 60% for DRE and TRUS and 79% for MRI. The accuracy for detecting seminal vesicle invasion was 60% for DRE, 66 for TRUS, and 89% for MRI. The negative predictive value for extracapsular and seminal vesicle extension was highest for MRI (85 and 93%, respectively). The accuracy for tumor location in the apex of the prostate was 30% for DRE, 47 for TRUS, and 89% for MRI. CONCLUSIONS: MRI with integrated endorectal and pelvic phased-array coils satisfactorily predicted tumor volume and tumor extent preoperatively. Multicoil MRI can assist in decision making as it is valuable in the definition of patients that may benefit from surgery and can be of help for evaluating the risk of a positive margin, especially in the apical resection.
Aged↗
Nuclear medicine applications to the neuroimaging of AIDS. A neuroradiologist's perspective.
The human immunodeficiency virus (HIV) responsible for AIDS is reaching epidemic proportions in the United States and Europe. As new therapeutic modalities against HIV are uncovered and applied to treat prophylactically asymptomatic and therapeutically symptomatic HIV positive patients, imaging studies are no longer used just to characterize the organic-morphologic effects of HIV and opportunistic infections and neoplasms. This article discusses the current applications and contribution of nuclear medicine to the management of neurologically symptomatic HIV-positive patients.
AIDS Dementia Complex↗
Antimalaric effect of an alcoholic extract of Artemisia ludoviciana mexicana in a rodent malaria model.
Chloroquine resistance of Plasmodium falciparum first and of P. vivax more recently, stimulated the search for new antimalarics. Chinese investigators have introduced new compounds obtained from extracts of Artemisia annua which possess an antimalaric active principle different from those of the drugs in use. In Mexico eight species of Artemisia have been described and among them just A. ludoviciana has been empirically used in the treatment of intermittent fever. To know whether mexican Artemisia had antimalaric activity several in vivo experiments were performed. Different type of extracts from two Artemisia species were prepared and assayed in five different doses on mice infected by Plasmodium yoelii yoelii, in a four-day test scheme. Here, only the results of the assays on ethanolic extract of A. ludoviciana are presented. The results of the in vivo experiments showed that the parasite reproduction was inhibited up to 98.6% at the fifth day, as compared with the controls; the ED50 was of 29.2 mg/kg and the SM50 of 28.7. We looked after the presence of artemisinin in the ethanolic extract, without success.
Animals↗
[Quality and life style as risk factors in acute cerebrovascular disease].
INTRODUCTION: In some series of patients with acute cerebral vascular disease (CVD) it has been seen that, prior to the episode of CVD, the patients already had a poorer quality of life than other people of their age. The object of this study is to evaluate their previous life style and quality of life as risk factors (RF) in acute CVD. MATERIAL AND METHODS: A case-control study was done of a total of 151 patients admitted to two hospitals with acute CVD and 151 persons, who were not hospitalized and acted as the control group, paired (one to one) for age, sex and hospital. In both groups data were collected regarding basic general health, previous quality of life (Nottingham Health Profile-NHP-, life style and self-perception of social support. The relative risks were estimated by calculating the odds ratios and conditional logistic regression. RESULTS: Regular moderate physical exercise acts as a protective factor with an OR of 0.32 (IC 95%: 0.14-0.76). Consumption of tobacco and alcohol increased the risk of CVD but did not reach statistical significance. No relationship was found between perceived social support and risk of CVD. Physical mobility, evaluated using the NHP showed a statistically significant negative association with acute CVD (OR: 0.32; IC 95%: 0.14-0.71). CONCLUSIONS: Our results seem to suggest that the previous overall quality of life cannot be considered a RF in acute CVD, except for physical mobility as evaluated on the NHP. Reduction of this constitutes a RF and moderate physical exercise behaves as a protective factor.
Acute Disease↗
[Stressful life events as risk factors in acute cerebrovascular disease].
INTRODUCTION: The influence of psychosocial stress on the origin of acute cerebral vascular disease (CVD) has received very little attention. The objective of this paper is to evaluate the role of psychosocial stress due to events occurring in daily life as a risk factor (RF) in acute CVD. MATERIAL AND METHODS: A case-control study was done of a total of 151 patients who were admitted to two hospitals with acute CVD and 151 persons, who where not hospitalized and acted as the control group, paired (one to one) for age, sex and hospital. In both groups data were collected regarding basic general health, consumption of tobacco and alcohol and stressful incidents (SI) in their lives during the previous two years. The stress derived from SI was measured on the 'Inventory of SI and Recent Experiences' of Holmes and Rahe. The frequency of serious SI was also considered. The relative risks were estimated by the odds ratio calculations. RESULTS: A positive association was found for the RF defined in relation to acute CVD. We did not find any relationship between psychosocial stress derived from SI and risk of acute CVD (either when considering scores on the Holmes and Rahe Inventory or evaluation of serious SI). CONCLUSIONS: Psychosocial stress from SI does not seem to represent a RF in acute CVD.
Acute Disease↗
Expression and synthesis of the Na,K-ATPase beta 2 subunit in human retinal pigment epithelium.
Na,K-ATPase in the retinal pigment epithelium (RPE) is apically localized, whereas in most other tissues this pump is found predominantly in the basolateral membrane domain. As part of our investigations into the molecular aspects of this pump in the RPE, we have cloned the cDNA and characterized the expression of the gene encoding the beta 2 subunit isoform of Na,K-ATPase in human, rat and bovine RPE and in the bovine choroid plexus. We have also detected the beta 2 isoform polypeptide in the human RPE (hRPE). Comparison of complete coding sequences derived from cloned cDNAs revealed that all beta 2 sequences from RPE, and the choroid plexus, differed uniformly at positions: P51/L, M121/I, and L148/R from the published sequences for human retina and liver. However, analysis of 10 RT-PCR clones derived from 5 fetal and 2 adult human retinas sequenced in our laboratory, revealed that only the P51/L residue was different with the hRPE beta 2 subunit sequence. Northern blot analysis indicated a 3.4-kb RNA transcript for the beta 2 subunit, a 4.5-kb RNA for the alpha 1 subunit and a doublet of 2.3 and 2.6 kb for the beta 1 subunit, respectively. alpha 1 (100 kDa), beta 1 (45 kDa) and beta 2 (65 kDa) isoforms were detected in hRPE extracts by immunoblotting. No alpha 2 and alpha 3 RNA transcripts were found in the hRPE. Quantification of beta 2 mRNA by RT-PCR revealed 2.7 x 10(5) molecules per ng of poly A+ RNA. This is similar to the beta 1 isoform levels reported previously from our laboratory. These data demonstrate the coexistence of significant amounts of alpha 1, beta 1 and beta 2 Na,K-ATPase subunits in the RPE. It is therefore reasonable to suggest that both alpha 1 beta 1 and alpha 1 beta 2 heterodimers are present in these cells.
Adult↗
Stability of immobilized penicillin acylase under reactive conditions.
Explore the source record for details and available documents.
Bacterial Proteins↗
TIMP-3 is expressed in the human retinal pigment epithelium.
TIMP-3 is the most recent member of the tissue inhibitor of metalloproteinases (TIMP) family. In the present study, we describe the expression of TIMP-3 messenger RNA (mRNA) by the retinal pigment epithelium of the normal human eye (hRPE). In addition to the three predominant transcripts of approximately 5.1, 2.8, and 2.4 Kbp found in several other human tissues at adult and fetal stages. The hRPE also expresses two RNA species of 1.2 and 1.0 Kbp. Based on the sequence analysis of cDNA clones isolated from a hRPE cDNA library, the use of alternate polyadenylation signals could account for the expression of these smaller transcripts. The possibility of an alternative mechanism of regulation of the expression of TIMP-3 by the RPE is not discarded. The number of RNA transcripts specific for TIMP-3 per nanogram of poly A+ RNA was quantified by RT-PCR. 9.6 x 10(5) transcripts per nanogram of polyA +RNA were found at the adult stage and 1.2 x 10(6) transcripts per nanogram of polyA +RNA were detected at the fetal stage. These findings were supported by the predominant labeling in the RPE layer of retinal tissue sections in in situ hybridization experiments. All of these data support the hypothesis that the production of TIMP-3 by the RPE may be crucial for the maintenance of Bruch's membrane, the complex layer of extracellular matrix that provides a structural substrate for the RPE in the healthy retina and is perturbed during the ageing process and in Sorby's Fundus Dystrophy a inherited disease.
Adult↗
Characterization of the 3' UTR sequence encoded by the AQP-1 gene in human retinal pigment epithelium.
The complete 3' UTR sequence encoded by the human aquaporin-1 gene is reported. The sequence encompassed by two cDNA clones showed, 33 nucleotides of 5' UTR sequence, a coding sequence of 807 nucleotides and 1886 nucleotides corresponding to the complete 3' UTR sequence. High similarity with 3' UTR sequences from rat and mouse counterparts was found. Northern blot analysis of several human tissues revealed a 2.8 kbp transcript. These data confirm the existence of water channels in the human retinal pigment epithelium.
Animals↗
Desensitization and internalization of adenosine A1 receptors in rat brain by in vivo treatment with R-PIA: involvement of coated vesicles.
Chronic treatment of rats with R-PIA 'in vivo' desensitized adenosine A1 receptor-mediated inhibition of adenylyl cyclase in brain plasma membranes and increased basal and forskolin-stimulated adenylyl cyclase. The adenosine A1 receptor agonist CHA (cyclohexyl adenosine) inhibited forskolin-stimulated adenylyl cyclase in synaptic plasma membranes from control rats but failed to do so in membranes isolated from rats treated with R-PIA. This loss of response was accompanied with a significant decrease in both, total number of adenosine A1 receptors and steady-state level of alpha-Gi in synaptic plasma membranes. An increase in the steady-state level of alpha-Gs in synaptic plasma membranes was also observed by R-PIA treatment. Concurrently, a significant increase of adenosine A1 receptors was observed in microsomes and coated vesicles. These results demonstrate adenosine A1 receptor desensitization in rat brain by 'in vivo' treatment with R-PIA and suggest a role for coated vesicles in the internalization of G-protein coupled receptors.
Adenosine↗
A novel null mutation in the rhodopsin gene causing late onset autosomal dominant retinitis pigmentosa.
Explore the source record for details and available documents.
Base Sequence↗
Hypersecretion of follicle-stimulating hormone (FSH) on estrous afternoon in rats treated with RU486 in proestrus.
1. Intact or ovariectomized (OVX) cyclic rats injected or not with RU486 (4 mg/0.2 ml oil) from proestrus onwards were bled at 0800 and 1800 h on proestrus, estrus and metestrus. Additional RU486-treated rats were injected with: LHRH antagonist (LHRHa), estradiol benzoate (EB) or bovine follicular fluid (bFF) and sacrificed at 1800 h in estrous afternoon. LH and FSH serum levels were determined by RIA. 2. RU486-treated intact or OVX rats had decreased preovulatory surges of LH and FSH, abolished secondary secretion of FSH and hypersecretion of FSH in estrous afternoon. The latter was decreased by LHRHa and abolished by EB or bFF. In contrast, EB induced an hypersecretion of LH in RU486-treated rats at 1800 h in estrus. 3. It can be concluded that in the absence of the proestrous progesterone actions, the absence of the inhibitory effect of the ovary in estrus evoked a LHRH independent secretion of FSH.
Animals↗
Intracytoplasmic sperm injection: a treatment for extreme oligospermia.
PURPOSE: We evaluated the efficacy of intracytoplasmic sperm injection in patients with extreme oligospermia. MATERIALS AND METHODS: A total of 67 intracytoplasmic sperm injection cycles was attempted in 58 infertile couples in which the husbands had extreme oligospermia (less than 100,000 spermatozoa per ml. ejaculate). RESULTS: Fertilization was achieved in 65 of 67 cycles. Mean fertilization rate per cycle was 66.4%. A total of 18 clinical pregnancies was obtained, for a pregnancy rate of 26.8% per started cycle. There were 4 miscarriages and 8 live births from 5 deliveries. Nine pregnancies are ongoing. CONCLUSIONS: Intracytoplasmic sperm injection in patients with extreme oligospermia is associated with high fertilization rates and offers the chance of pregnancy to these otherwise intractably infertile couples.
Adult↗
Lyme neuroborreliosis masquerading as a brainstem tumor in a 15-year-old.
A 15-year-old boy had onset of unilateral facial weakness. A few days later, he experienced mild vertigo, double vision, and headache. Examination confirmed a peripheral right seventh nerve weakness in addition to an internuclear ophthalmoplegia. The neurologic features suggested a pontine glioma. A T2-weighted MRI scan revealed demyelinating lesions in the pons and in several areas of the cerebrum, including the periventricular region. Subsequent history revealed that he had been diagnosed with Lyme arthritis 7 years earlier while living in Connecticut. The radiographic studies favored a diagnosis of multiple sclerosis. However, studies of blood and cerebrospinal fluid established a diagnosis of Lyme neuroborreliosis.
Adolescent↗
Dynamics of gametic disequilibria between loci linked to chromosome inversions: the recombination-redistributing effect of inversions.
The total gametic disequilibrium between two loci linked to polymorphic inversions can be partitioned into two types of components: within and between chromosome arrangements. The within components depend on the gametic disequilibrium within each chromosome arrangement. The between components depend on the locus-inversion disequilibria. This partitioning has practical applications and is indispensable for studying the dynamics of these systems because inversions greatly reduce recombination in the heterokaryotypes while allowing free, and sometimes different, recombination in each of the homokaryotypes. We provide equations for the per generation change of the various disequilibria for systems with two and three chromosome arrangements, and the general recursive equations predicting the disequilibria after any number of generations for the case of two arrangements. Simulation studies were carried out using different values of the recombination parameters and all possible initial conditions. The results show a complex convergence to linkage equilibrium in inversion systems. The various disequilibria can have local maxima and minima while approaching equilibrium and, moreover, their dynamics cannot be described, in general, using a single parameter, i.e. an effective recombination rate. We conclude that the effects of inversions on gametic disequilibria must be carefully considered when dealing with disequilibria in inversion systems. The formulae provided in this paper can be used for such purpose.
Alleles↗
The E280A presenilin 1 Alzheimer mutation produces increased A beta 42 deposition and severe cerebellar pathology.
Missense mutations in the presenilin 1 (PS1) gene cause the most common form of dominant early-onset familial Alzheimer's disease (FAD) and are associated with increased levels of amyloid beta-peptides (A beta) ending at residue 42 (A beta 42) in plasma and skin fibroblast media of gene carriers. A beta 42 aggregates readily and appears to provide a nidus for the subsequent aggregation of A beta 40 (ref. 4), resulting in the formation of innumerable neuritic plaques. To obtain in vivo information about how PS1 mutations cause AD pathology at such early ages, we characterized the neuropathological phenotype of four PS1-FAD patients from a large Colombian kindred bearing the codon 280 Glu to Ala substitution (Glu280Ala) PS1 mutation. Using antibodies specific to the alternative carboxy-termini of A beta, we detected massive deposition of A beta 42, the earliest and predominant form of plaque A beta to occur in AD (ref. 6-8), in many brain regions. Computer-assisted quantification revealed a significant increase in A beta 42, but not A beta 40, burden in the brains from 4 PS1-FAD patients compared with those from 12 sporadic AD patients. Severe cerebellar pathology included numerous A beta 42-reactive plaques, many bearing dystrophic neurites and reactive glia. Our results in brain tissue are consistent with recent biochemical evidence of increased A beta 42 levels in PS1-FAD patients and strongly suggest that mutant PS1 proteins alter the proteolytic processing of the beta-amyloid precursor protein at the C-terminus of A beta to favor deposition of A beta 42.
Age of Onset↗
Cryostorage of human embryos: time to decide.
Explore the source record for details and available documents.
Cryopreservation↗