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A Morales

Publications and source records attributed to A Morales.

At least 73 records · Page 4Linked to original sources
PubMed2001

Reinventing patient-centered computing for the twenty-first century.

Despite evidence over the past decade that patients like and will use patient-centered computing systems in managing their health, patients have remained forgotten stakeholders in advances in clinical computing systems. We present a framework for patient empowerment and the technical realization of that framework in an architecture called CareLink. In an evaluation of the initial deployment of CareLink in the support of neonatal intensive care, we have demonstrated a reduction in the length of stay for very-low birthweight infants, and an improvement in family satisfaction with care delivery. With the ubiquitous adoption of the Internet into the general culture, patient-centered computing provides the opportunity to mend broken health care relationships and reconnect patients to the care delivery process. CareLink itself provides functionality to support both clinical care and research, and provides a living laboratory for the further study of patient-centered computing.

Humans↗
PubMed2000

CFTR mutations in three Latin American countries.

We analyzed 192 cystic fibrosis (CF) alleles in three Latin American countries: Mexico, Colombia, and Venezuela. Mutation screening was performed by polymerase chain reaction (PCR) and a reverse dot blot detection kit that enables determination of 16 of the most common CF mutations worldwide. Mutations were detected in 47.9% of the screened CF alleles. The most prevalent CF allele was DeltaF508 (39. 6%). The remaining 16 non-DeltaF508 detectable mutations represented 8.3% of the CF alleles. Among them, the G542X, N1303K, and 3849+10kb C>T were the most common. Although the frequency of DeltaF508 described here is lower than that reported for Caucasian populations, including in Spain, it is remarkable that mutation prevalences found in this study resemble those observed in Spain. Two of these mutations, G542X and 3849+10kb C>T, that were relevant in this analysis, have a particularly high incidence in Spanish communities. The low frequency of DeltaF508 described here may be explained by the Amerindian, Caucasian, and Black admixture that occurred in Latin America after the discovery of the New World, and also by the probable occurrence of mutations contributed by the original natives, which were undetectable in this analysis.

Colombia↗
PubMed2000

Growth efficiency in transgenic tilapia (Oreochromis sp.) carrying a single copy of an homologous cDNA growth hormone.

Growth hormone (GH) has been shown to have a profound impact on fish physiology and metabolism. However, detailed studies in transgenic fish have not been conducted. We have characterized the food conversion efficiency, protein profile, and biochemical correlates of growth rate in transgenic tilapia expressing the tilapia GH cDNA under the control of human cytomegalovirus regulatory sequences. Transgenic tilapia exhibited about 3.6-fold less food consumption than nontransgenic controls (P < 0.001). The food conversion efficiency was significantly (P < 0.05) higher (290%) in transgenic tilapia (2.3 +/- 0.4) than in the control group (0.8 +/- 0.2). Efficiency of growth, synthesis retention, anabolic stimulation, and average protein synthesis were higher in transgenic than in nontransgenic tilapia. Distinctive metabolic differences were found in transgenic juvenile tilapia. We had found differences in hepatic glucose, and in agreement with previous results we observed differences in the level of enzymatic activities in target organs. We conclude that GH-transgenic juvenile tilapia show altered physiological and metabolic conditions and are biologically more efficient.

Animals↗
PubMed2000

Increased sodium-calcium exchange current in right ventricular cell hypertrophy induced by simulated high altitude in adult rats.

Ventricular hypertrophy is associated with an increase in action potential (AP) duration which is potentially arrhythmogenic. The implication of the Na-Ca exchange current (I(Na-Ca)) in the lengthening of the AP is controversial. The role of this current in the increased duration of the low plateau of the AP in hypertrophied adult rat ventricular myocytes by simulated chronic high-altitude exposure ( approximately 4500 m) was evaluated. Electrophysiological experiments were carried out on isolated right ventricular myocytes from exposed and control rats with the perforated patch or the conventional whole-cell technique in current or in voltage clamp condition. With the two techniques, a significant increase of the low plateau duration was observed in hypertrophied myocytes as compared to controls. The low plateau in hypertrophied myocytes was depressed when Na was replaced by Li and was no longer recorded when intracellular Ca was buffered with EGTA. Inward tail currents, evoked either on repolarization to -80 mV following a depolarizing pulse to +10 mV or by interrupted AP technique, were greater in hypertrophied than in control myocytes and were abolished when Na was replaced by Li or when intracellular Ca was buffered with EGTA, indicating an increased Na-Ca exchange activity. The Li-sensitive current-voltage curves, obtained by a voltage clamp ramp protocol with an intracellular calcium buffered solution, were not significantly different in both hypertrophied and control myocytes, suggesting no modification in the density of the Na-Ca exchange protein. This was corroborated by the lack of difference in NCX1 mRNA levels between right ventricles from control and exposed rats. We conclude that increased duration of the low plateau of rat ventricular AP in altitude cardiac hypertrophy may be attributed to an increase of the inward I(Na-Ca). This augmented I(Na-Ca)may result from a modification in the intracellular Ca homeostasis.

Action Potentials↗
PubMed2000

Functional incorporation of exogenous proteins into the Xenopus oocyte membrane does not depend on intracellular calcium increase.

Fusion of membranes occurs in diverse biological events and, in most cases, Ca2+ greatly augments its rate. The aim of this work was to study the role played by Ca2+ when transplanting exogenous proteins into Xenopus oocyte membranes. Lipid vesicles carrying nicotinic acetylcholine (ACh) receptors (nAChRs) from Torpedo electroplaques were injected into oocytes. The time course of nAChR incorporation was assessed by recording ACh-evoked currents at different times from injection. An incorporation peak was found at 16 h, but responses were maintained for over 48 h. To assess the role played by Ca2+, two groups were considered: control and chelator-loaded oocytes. In the latter group, cells were incubated with 50 microM 1,2-bis (2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, tetrakis(acetoxymethyl)ester (BAPTA-AM) or loaded with ca. 5 nmol ethyleneglycol-bis (beta-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) 2 h before nAChR injection. Both groups responded to ACh, although the current amplitude was smaller in chelator-loaded than in control cells. These results indicate that the slow fusion of lipoproteosome vesicles with the oocyte plasma membrane does not depend on intracellular Ca2+ increase and therefore belongs to the type called "constitutive". This membrane fusion process is thus different from those involved in resealing of disrupted oocyte membranes or in the fusion of cortical granules with the egg membrane.

Acetylcholine↗
PubMed2000

Andropause: a misnomer for a true clinical entity.

PURPOSE: A progressive decrease in androgen production is common in males after middle age. The resulting clinical picture has been erroneously named male menopause or andropause. A more appropriate designation is androgen decline in the aging male (ADAM). The syndrome is characterized by alterations in the physical and intellectual domains that correlate with and can be corrected by manipulation of the androgen milieu. We review the epidemiological aspects of aging and endocrinological manifestations of ADAM, and provide recommendations for treatment and monitoring of these patients. MATERIALS AND METHODS: We performed MEDLINE, Pubmed, Current Contents and Pharmaceutical Abstracts searches of relevant peer reviewed publications on andropause, male climacteric, adult hypogonadism and aging. In addition, conference proceedings were researched to provide a more complete review of the literature. Information was scrutinized and collated, and contributory data were reviewed and summarized. RESULTS: ADAM is a clinical entity characterized biochemically by a decrease not only in serum androgen, but also in other hormones, such as growth hormone, melatonin and dehydroepiandrosterone. Clinical manifestations include fatigue, depression, decreased libido, erectile dysfunction, and alterations in mood and cognition. CONCLUSIONS: The onset of ADAM is unpredictable and its manifestations are subtle and variable, which has led to a paucity of interest in its diagnosis and treatment. Urological practice commonly includes a large proportion of men older than 50 years. Therefore, it is important for urologists to recognize the manifestations of and be familiar with evaluations necessary to document ADAM as well as its treatment and monitoring.

Aged↗
PubMed2000

Initial assessment of a new preparatory tool for board certification in urology.

OBJECTIVES: To establish a Canadian national examination simulating the qualifying Urology examinations of the Royal College of Physicians and Surgeons of Canada (RCPSC) and to survey candidate perceptions regarding the mock examination's utility as a preparatory tool for the RCPSC examinations and the adequacy of examination preparation provided by their residency training program. METHODS: From January 1997 to February 1999, the Queen's Urology Examination Skills Training (QUEST) program was established, consisting of a short answer question component and an objective structured clinical examination. All participants and residency program directors received detailed feedback regarding candidate performance. RESULTS: All 11 Canadian training programs were represented, for a total of 64 participants. The 56 final-year candidates participating in QUEST and the RCPSC examinations in the same calendar year represented 66% of Canadian residents attempting the RCPSC examinations during that period. QUEST participants were surveyed immediately after the RCPSC examinations (response rate 84%). Of the respondents, 96% believed that QUEST was representative of the RCPSC examinations, and 100% said they would recommend it to future residents. Most respondents (92%) believed that the QUEST program improved their performance on the RCPSC examinations. Regarding the examination preparation received, 32 (68%) of 47 believed their program provided inadequate preparation for the RCPSC examinations. CONCLUSIONS: Support is strong among Canadian urology residents for a preparatory examination such as the QUEST program. A significant majority of residents believed that they received inadequate preparation for the RCPSC examinations from their residency training program.

Canada↗
PubMed2000

Sympathetic control of glucagon receptor mRNA levels in brown adipose tissue of cold-exposed rats.

Brown adipose tissue (BAT) is implicated in both cold-induced thermogenesis and regulation of energy expenditure and is mainly controlled by sympathetic innervation. To clarify the permissive and/or complementary roles of glucagon in cold-induced BAT activation, glucagon receptor gene expression and its modulation by sympathetic activity were investigated in rats. One pad of interscapular BAT was surgically denervated while the other pad was sham operated, then rats were either cold-exposed (CE) for 1 week at 4 degrees C or kept near thermoneutrality (25 degrees C, TN). Using a semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assay, it was shown that cold exposure decreased (-44%) the relative abundance of BAT glucagon receptor mRNA, an effect which was prevented by unilateral surgical sympathectomy of BAT. The present results show a negative control by sympathetic nervous activity of glucagon receptor gene expression and/or of glucagon receptor mRNA stability in BAT of cold-exposed rats. The down-regulation of glucagon receptor expression during cold exposure does not support a major role of the peptide in the thermogenic control of BAT.

Adipose Tissue, Brown↗
PubMed2000

The prevalence and influence of significant psychiatric abnormalities in men undergoing comprehensive management of organic erectile dysfunction.

Psychiatric factors are etiologically important in a proportion of patients with erectile dysfunction. We determined the prevalence of psychopathology and the impact it has on current erectile dysfunction (ED) assessment and management. A group of 120 consecutive men with ED presenting to the Human Sexuality Clinic for the first time was prospectively investigated. All patients participated in a standardized evaluative protocol, including history, physical exam, assessment by a psychiatrist (using DSM-IV criteria), selective hormonal screen, and diagnostic intracavernosal injection. Follow-up appointments were to discuss diagnostic findings and, eventually, treatment choices. The prevalence of significant psychiatric pathology, excluding interview stress, was 33%. Only 16 of 40 cases were recognized and highlighted in the initial assessments by urological staff. There was no significant difference in the modalities of treatment choices between patients with psychiatric problems and those without. 10% of the patients had multiple organic risk factors, normal ICI, and significant psychiatric pathology. Psychopathology or emotional factors play a significant role in the etiology of ED and they are difficult to identify in a non-directed assessment. Even in the face of significant vascular risk factors, psychological abnormalities may be the primary etiology. Treating the 'phallodynamically challenged' individual without adequately addressing the possible presence of psychopathology, will account for treatment failures and have the potential for leaving untreated serious emotional problems.

Erectile Dysfunction↗
PubMed2000

Pre-penile arteries are dominant in the regulation of penile vascular resistance in the rat.

The amount of blood flow into the penis that will produce an erection is dependent on the sum of inflow resistance from the feeder arteries, arterioles and the intra-penile vasculature. In the present study, our objective was to determine quantitatively the contribution to inflow resistance of these different components of the rat penile vasculature. Using methods developed previously, we determined the resistance properties of the isolated perfused whole penis in situ, both in an intact system and after serial transactions of the vessels. These cuts eliminated progressively larger distal segments of the vascular bed. Perfusion pressures were recorded at different flow rates (0.5-3 ml/min/kg body weight) under conditions of maximal dilatation and maximal vasoconstriction induced by methoxamine (MXA, 40 microg/ml). Regardless of the level of vascular tone, the pudendal artery contributes approximately 70% of the total resistance of the penile vasculature. In contrast, the vasculature within the penis (tip, shaft, crus) contributes only about one quarter of the resistance. Penile arterial inflow resistance properties both at maximal vasodilation and maximal alpha1-adrenergic constriction are dominated by the extra-penile vasculature in the rat. The implications of these findings are that alterations in the pudendal-artery (eg vasodilation, vasoconstriction, stenosis) would have primary control of arterial inflow and suggest an important role for pharmacological agents which can promote a more generalized vasodilation (eg phosphodiesterase inhibitors) in contrast to selective corpus cavernosal agents.

Adrenergic alpha-Agonists↗
PubMed2000

Developmental status of topical therapies for erectile and ejaculatory dysfunction.

The most common of the sexual dysfunctions in men are premature ejaculation and impotence. Large strides have been made in the treatment of erectile disturbances but only limited and temporary successes have been achieved in the therapy of ejaculatory abnormalities. This manuscript examines the realm of topical therapy, its current limitations and the challenges that must be addressed if topical therapy is ever to have a niche in the urologist's treatment armamentarium. Topical agents for the treatment of premature ejaculation include anesthetics and herbal medications. The limited nature of the studies reported to date does not yet permit a reliable assessment of their efficacy. For the treatment of erectile dysfunction, some of the drugs administered by various other systemic routes appear to have some efficacy when delivered transdermally. Again, the studies and results are too limited for the urologist to develop a clear opinion about their efficacy. Further investigation of these drugs with the use of absorption enhancers is needed. International Journal of Impotence Research (2000) 12, Suppl 4, S80-S85.

Administration, Topical↗
PubMed2000

Testosterone replacement: when is there a role?

Hypogonadism is an uncommon cause of erectile dysfunction. Unfortunately, hypogonadal states in adult males are difficult to diagnose on purely clinical grounds and it is necessary to seek biochemical support. The simplest way to establish the diagnosis of hypogonadism is by determination of serum testosterone levels. Several methods exist but total testosterone determination plus assessment of sex hormone-binding globulin or bio-available testosterone appear to be the most reliable and accessible. Once a diagnostic of hypogonadism has been established in a man with erectile difficulties, a trial of androgen supplementation is warranted if no contraindications exist. Knowledgeable monitoring is essential. In the absence of an adequate response, co-morbidities should be diligently sought out. In the absence of reliable guidelines for androgen administration to patients with erectile failure, a set of recommendations are provided. International Journal of Impotence Research (2000) 12, Suppl 4, S112-S118.

Androgens↗
PubMed2000

Remission status defined by immunofixation vs. electrophoresis after autologous transplantation has a major impact on the outcome of multiple myeloma patients.

We have retrospectively analysed 344 multiple myeloma (MM) patients (202 de novo patients) treated in a non-uniform way in whom high-dose therapy and autologous stem cell transplantation (ASCT) response was simultaneously measured by both electrophoresis (EP) and immunofixation (IF). Patients in complete remission (CR) by EP were further subclassified as CR1 when IF was negative and CR2 when it remained positive. Partial responders (PR) were also subclassified as PR1 (very good PR, > 90% reduction in M-component) or PR2 (50-90% reduction). CR1 patients showed a significantly better event-free survival (EFS) [35% at 5 years, 95% confidence interval (CI) 17-53, median 46 months] and overall survival (OS) (72% at 5 years, CI 57-86, median not reached) compared with any other response group (univariate comparison P < 0.00000 to P = 0. 004). In contrast, comparison of CR2 with PR1 and with PR2 did not define different prognostic subgroups (median EFS 30, 30 and 26 months respectively, P = 0.6; median survival 56, 44 and 42 months respectively, P = 0.5). The non-responding patients had the worst outcome (5-year OS 8%, median 7 months). Multivariate analysis confirmed both the absence of differences among CR2, PR1 and PR2 and the highly discriminatory prognostic capacity of a three-category classification: (i) CR1 (ii) CR2 + PR1 + PR2, and (iii) non-response (EFS P < 0.00000; OS P < 0.00000; both Cox models P < 0.00000). In the logistic regression analysis, the factors significantly associated with failure to achieve CR1 were the use of two or more up-front chemotherapy lines, status of non-response pre-ASCT and inclusion of total body irradiation (TBI) in the preparative regimen. Tandem transplants or the use of multiple agents (busulphan and melphalan) in the preparative regimen resulted in a higher CR1 level; none of the biological factors explored influenced the possibility of achieving CR1. These results confirm that, in MM patients undergoing ASCT, achieving a negative IF identifies the patient subset with the best prognosis; accordingly, therapeutic strategies should be specifically designed to achieve negative IF.

Electrophoresis↗
PubMed2000

Human placenta sphingomyelinase, an exogenous acidic pH-optimum sphingomyelinase, induces oxidative stress, glutathione depletion, and apoptosis in rat hepatocytes.

Ceramide has been identified as a putative lipid messenger that mediates diverse cellular processes including cell death. Since glutathione (GSH) depletion is known to sensitize cells to many cytotoxic agents and as a result of the reported regulation of neutral sphyngomyelinase (NSMase) by GSH, the present study compared the role of individual SMases in the induction of oxidative stress, regulation of cellular GSH, and apoptosis of rat hepatocytes. Exposure of cultured rat hepatocytes to exogenous Bacillus cereus sphingomyelinase (bSMase), a neutral SMase, or human placenta sphingomyelinase (hSMase), an acidic SMase (ASMase), generated similar ceramide levels in a dose-dependent manner. However, whereas bSMase increased hepatocellular GSH levels, hSMase depleted GSH stores, an effect that was prevented by monensin and mannose 6-phosphate (M-6-P), suggesting that exogenous hSMase enters hepatocytes by endocytosis and is delivered to an endosomal/lysosomal acidic compartment. Interestingly, despite the differential effect of either SMases on cell GSH levels, both bSMase and hSMase increased gamma-glutamylcysteine synthetase heavy-subunit chain (gamma-GCS-HS) mRNA levels. Consistent with these findings on GSH regulation, hSMase, but not bSMase, generated reactive oxygen species (ROS), being accompanied by mitochondrial depolarization, suggesting that hSMase targeted mitochondria, leading to oxidative stress. Accordingly, hepatocytes displayed a selective sensitivity to hSMase in contrast to bSMase exposure, and depletion of GSH stores enhanced susceptibility to hSMase as a result of potentiation of ROS formation and caspase 3 activation. Thus, these findings reveal the ability of ASMase to induce oxidative stress as a result of the targeting of mitochondria, and that GSH depletion sensitizes hepatocytes to the ASMase-induced apoptosis.

Animals↗
PubMed2000

Removal of amphipathic epitopes from genetically engineered antibodies: production of modified immunoglobulins with reduced immunogenicity.

Several approaches have been developed to reduce the human immune response to nonhuman antibodies. However, chimeric antibodies and humanized antibodies often have decreased binding affinity. We described a new approach for reducing the immunogenicity of chimeric antibodies while maintaining the affinity. This approach seeks to prevent the recognition of murine immunogenic peptides from the antibody variable region by human lymphocytes. Putative immunogenic epitopes in the variable region are identified and subjected to site directed mutagenesis to make them human and/or to break the amphipathic motifs. The R3 antibody, which blocks the epidermal growth factor (EGF) receptor, was used as a model system to test this approach. Four segments containing possible amphipathic epitopes were found in the heavy variable domain using the program AMPHI. Six amino acids within two of these segments were substituted by the corresponding residues from a homologous human sequence. No mutations were made in the murine light variable domain. Experiments in monkeys suggested that the "detope" R3 antibody was less immunogenic than its chimeric analogue. A search for possible amphipathic epitopes in the Kabat database revealed the presence of conserved patterns in the different families of variable region sequences, suggesting that the proposed method may be of general applicability.

Algorithms↗