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Biomedical subjects

R Martinez

Publications and source records attributed to R Martinez.

At least 55 records · Page 3Linked to original sources
PubMed2000

Singing "the baby blues": a content analysis of popular press articles about postpartum affective disturbances.

A content analysis was conducted to evaluate the description of postpartum mood disturbances in magazine articles that appeared during the years 1980-1998. Nineteen articles about postpartum depression and eight articles about "the baby blues" were identified and analyzed for their discussion of etiologies, symptoms, treatments, resources, and demographic assumptions about their readers. The results indicate a strong bias in favor of the medical model of postpartum affective disorders. The articles contained contradictory information about the definition, prevalence, onset, duration, symptoms, and treatment of postpartum disorders, and the authors generally assumed that their readers were heterosexual, married, and middle class. Although the purpose of the articles was to educate readers about an important topic in women's health, they failed to provide accurate information, and thus are not a sufficient resource for new mothers who are seeking to learn about psychosocial aspects of the postpartum period.

Bibliometrics↗
PubMed2000

Semiclosed endarterectomy for long superficial femoral artery atherosclerotic occlusive disease. One-year angiographic results.

BACKGROUND: The anatomic results of endarterectomy of long occlusive lesions in the superficial femoral artery (SFA) are required for reconsidering this procedure and comparing the results with those of newly developed endovascular techniques. We designed a prospective study to determine the arteriographic findings one year after a successful semiclosed endarterectomy of long occlusive lesions in the SFA. METHODS: From January 1995 until July 1996, an endarterectomy in the SFA was attempted in 12 successive patients and was successfully performed in 10 patients (6 men and 4 women), with an average age of 73 years (range 66 to 90 years). Indications for successfully performed procedures were claudication in 6, non healing ulcer in 2, local gangrene in 2 patients. The mean length of the occlusion was 17 cm (12-33). Six patients had poor run-off with 0 to 1 patent tibial artery. The mean length of the endarterectomised segment was 31 cm (27-39). An angioscopy and an angiography were performed in all procedures. There were no postoperative complications. All patients had an angiography at 12 months or before because of ipsilateral disease. Primary angiographic patency was defined as patency of the treated artery with stenosis of less than 30%. A short stenosis was defined as <5 cm. These lesions were an indication of percutaneous balloon angioplasty (PTA) and the final results were listed as secondary patency. RESULTS: Angiography revealed 3 patent arteries, 5 short stenosis, 2 long stenosis and no occlusions. The primary patency rate was 30% at 12 months. The secondary patency was 80% with a mean follow-up of 19 months (ranging from 13 to 25 months). The mortality and amputation rate at 12 months was nil. CONCLUSIONS: Despite a modern intraoperative control, there was a high incidence of restenosis after semiclosed endarterectomy performed for long occlusive lesions of the SFA. As a result of a close surveillance and PTA, the secondary patency at one year was good. Before a widespread use of newly developed endovascular techniques, comparative patency studies with the mere endarterectomy should be performed. Endarterectomy followed by a PTA in cases of restenosis, is an alternative to bypass when the vein is not available.

Aged↗
PubMed2000

[Intravascular ultrasound: limitation and prospects].

The aims of intravascular ultrasound (IVUS) are visualization of the arterial wall, characterization of the arterial plaque, measurement of vessel diameter and endoluminal procedure assessment. The main sources of errors are: limitation of resolution, distortion of images due to non uniform angular velocity of mechanical type transducers, overestimation or underestimation of cross sectional area secondary to eccentric position or non coaxial orientation of the catheter. Awareness of these problems may prevent misinterpretations. Combined balloon imaging catheters, forward-looking sector scanners and ultrasound imaging guide wires may be achieve by miniaturization of transducers. Three dimensional imaging, blood flow quantification, local elasticity of tissues may be achieve by new softwares.

Arteries↗
PubMed2000

Landing periodicity of Aedes aegypti with implications for dengue transmission in Trinidad, West Indies.

The diel landing/biting periodicity of the Trinidad strain of Aedes aegypti (L.) was monitored using human-bait during January-August 1999. Hourly light intensities were measured both indoors and outdoors at both urban and rural sites. The periodicity of females was diurnal and nocturnal, with 90% arriving during daylight and twilight and 10% during the night. The pattern of landing was trimodal, with consistent peaks at 0700 h, 1100 h and 1700 h. The diel periodicities at indoor and outdoor urban sites were virtually identical. In contrast, the periodicities in rural areas differed, with no nocturnal activities being recorded at indoor and outdoor sites. At both urban and rural sites, larger numbers of adults were collected outside than inside houses. A significant correlation between light intensities and mosquito landing patterns was observed. The implications of the changing landing patterns of Ae. aegypti within urban areas are discussed in light of the epidemiology and control of dengue fever in Trinidad.

Aedes↗
PubMed2000

A model for boundary dilemmas: ethical decision-making in the patient-professional relationship.

The current "slippery slope" concept in boundary dilemmas is linked to a rule-based approach to ethical decision making. The author reviews the current "slippery slope" concept and professional ethics pertinent to boundary dilemmas. A graded-risk model for boundary dilemmas is introduced to offer a "process" approach to ethical decision making in boundary dilemmas. This model divides boundary crossings into four categories. Each category considers six variables: (a) the potential harm to the patient, (b) the potential benefit to the patient, (c) the presence or absence of coercive and exploitative elements in the boundary crossing, (d) the professional's motives and intentions, (e) the professional's aspiration to professional ideals, and (f) the context of the boundary crossing. This model of boundary crossings introduces complexity and specificity necessary for clinical decisions, teaching, retrospective judgements, and research in boundary dilemmas.

Coercion↗
PubMed1999

Accumulation of mercury in neurosecretory neurons of mice after long-term exposure to oral mercuric chloride.

Inorganic mercury (HgCl2) was administered to adult mice in drinking water (20 mg/l). Animals were sacrificed after one or two years and fixed by whole-body perfusion. Sections of the hypothalamus and neurohypophysis were subjected to silver acetate autometallography for visualization of mercury at light and electron microscopy levels. Mercury deposits, which can be seen by light microscopy as black granules, were found to accumulate within neuronal perykaria of the supraoptic and paraventricular nuclei. Electron microscopy demonstrated that mercury deposits in neurosecretory neurons were detected exclusively within lysosomes. Mercury was also present in small vesicles, 40-70 nm in diameter, and in endocytic vacuoles within the axon terminals of the neurohypophysis. No mercury could be seen in sections obtained from control animals that had been drinking uncontaminated water. Mechanisms involved in uptake and transport of mercury to neuronal bodies are discussed.

Administration, Oral↗
PubMed1999

Identification and medical importance of coagulase-negative staphylococci species.

A total of 126 coagulase-negative staphylococci strains (CNS) were isolated from blood samples and from the intravenous catheters and cerebrospinal fluid of 103 patients admitted to the University Hospital of Ribeirão Preto. Staphylococcus epidermidis (68.2%), S. haemolyticus (11.1%) and S. hominis (3.2%) were the most frequent species. The last two CNS showed greater resistance to antimicrobial agents than S. epidermidis. CNS were the agents of infection in 10. 7% of the patients and the agents of intravenous catheter colonization in 18.4% of the cases.

Bacteremia↗
PubMed1999

Mass spectral fragmentation patterns of new 5-acetyl-4-aryl-6-methyl-2(1H)pyridones

The electron impact mass spectra of new 5-acetyl-4-aryl-6-methyl-2(1H)pyridones have been studied. A dominant peak in all the spectra is due to cleavage of the CO-NH bond of the amido group with charge retention on the carbonyl group. This fragmentation is followed by a hydrogen rearrangement to the nitrogen atom forming ketene intermediates; this pathway leads to a highly stabilized ion which constitutes the base peak in the spectra in most of the compounds studied. Copyright 1999 John Wiley & Sons, Ltd.

Journal Article↗
PubMed1999

Resistance to bacillus thuringiensis Cry1Ac toxin in three strains of heliothis virescens: proteolytic and SEM study of the larval midgut

In a previous study, we demonstrated that resistance to Bacillus thuringiensis toxins in Heliothis virescens might be related to differences in the composition of the proteolytic extracts from insect midgut. There, we found specific proteolytic bands present in the gut extracts of the resistant strain and absent from the susceptible one. Here we report related facts using a new resistant strain (KCB) and a cross between the two strains used in our previous study. As would be expected, no quantitative differences in total proteolytic activity were found between the strains, although qualitative differences related to the presence or absence of specific proteolytic activity bands using SDS-PAGE could be responsible for the observed resistance phenomenon. Moreover, an SEM study made at different time intervals after intoxication shows that in the initial hours following intoxication, both the susceptible and the resistant strains show significant damage to the midgut epithelium. In the interval between 3 and 48 h, however, the resistant strain recovered such that by 48 h it had fully recovered whereas the susceptible strain did not. Arch. Copyright 1999 Wiley-Liss, Inc.

Journal Article↗
PubMed1999

Posterior sagittal anorectoplasty in adults: secondary repair for persistent incontinence in patients with anorectal malformations.

PURPOSE: Posterior sagittal anorectoplasty, regarded as a standard surgical primary repair for anorectal malformations in infancy, was evaluated for effectiveness when performed as a secondary operation for establishing continence in the adult. The purpose of this review was to evaluate our results of performing posterior sagittal anorectoplasty in adult patients and to emphasize the extensive evaluation required to perform proper patient selection. METHOD: From January 1, 1992, to December 31, 1996, eight patients with Grade 3 incontinence underwent posterior sagittal anorectoplasty. The ages ranged from 13 to 40 (mean, 26) years. RESULTS: All patients had diverting stomas at the time of repair and all but one had restoration of intestinal continuity. Of eight patients who underwent posterior sagittal anorectoplasty, one failed secondary to rectal ischemia and retained a diverting stoma. Six patients had restoration of continuity. Five patients were continent and one had incontinence only to gas. DISCUSSION: We have established that posterior sagittal anorectoplasty can effectively be used to establish continence as a secondary procedure for a select group of adult patients.

Adolescent↗
PubMed1999

Virtual management of radiology examinations in the virtual radiology environment using common object request broker architecture services.

In the Department of Defense (DoD), US Army Medical Command is now embarking on an extremely exciting new project--creating a virtual radiology environment (VRE) for the management of radiology examinations. The business of radiology in the military is therefore being reengineered on several fronts by the VRE Project. In the VRE Project, a set of intelligent agent algorithms determine where examinations are to routed for reading bases on a knowledge base of the entire VRE. The set of algorithms, called the Meta-Manager, is hierarchical and uses object-based communications between medical treatment facilities (MTFs) and medical centers that have digital imaging network picture archiving and communications systems (DIN-PACS) networks. The communications is based on use of common object request broker architecture (CORBA) objects and services to send patient demographics and examination images from DIN-PACS networks in the MTFs to the DIN-PACS networks at the medical centers for diagnosis. The Meta-Manager is also responsible for updating the diagnosis at the originating MTF. CORBA services are used to perform secure message communications between DIN-PACS nodes in the VRE network. The Meta-Manager has a fail-safe architecture that allows the master Meta-Manager function to float to regional Meta-Manager sites in case of server failure. A prototype of the CORBA-based Meta-Manager is being developed by the University of Arizona's Computer Engineering Research Laboratory using the unified modeling language (UML) as a design tool. The prototype will implement the main functions described in the Meta-Manager design specification. The results of this project are expected to reengineer the process of radiology in the military and have extensions to commercial radiology environments.

Algorithms↗
PubMed1999

Meta-manager: a requirements analysis.

The digital imaging network-picture-archiving and communications system (DIN-PACS) will be implemented in ten sites within the Great Plains Regional Medical Command (GPRMC). This network of PACS and teleradiology technology over a shared T1 network has opened the door for round the clock radiology coverage of all sites. However, the concept of a virtual radiology environment poses new issues for military medicine. A new workflow management system must be developed. This workflow management system will allow us to efficiently resolve these issues including quality of care, availability, severe capitation, and quality of the workforce. The design process of this management system must employ existing technology, operate over various telecommunication networks and protocols, be independent of platform operating systems, be flexible and scaleable, and involve the end user at the outset in the design process for which it is developed. Using the unified modeling language (UML), the specifications for this new business management system were created in concert between the University of Arizona and the GPRMC. These specifications detail a management system operating through a common object request brokered architecture (CORBA) environment. In this presentation, we characterize the Meta-Manager management system including aspects of intelligence, interfacility routing, fail-safe operations, and expected improvements in patient care and efficiency.

Arizona↗
PubMed1999

Gamma Knife radiosurgery of the glomus jugulare tumour - early multicentre experience.

Leksell Gamma Knife was used to treat 66 patients with glomus jugulare tumour at 6 European sites between 1992-1998. The age of the patients ranged between 18-80 years (median 54 years). Gamma Knife radiosurgery was a primary treatment in 30 patients (45. 5%). Open surgery preceded radiosurgery in 24 patients (36.4%), embolisation in 14 patients (21.2%) and fractionated radiotherapy in 5 patients (7.6%). The volume of the tumour ranged 0.5-27 cm(3) (median 5,7 cm(3)). The minimal dose to the tumour margin ranged between 10-30 Gy (median 16.5 Gy). After radiosurgery 52 patients were followed, the follow up period was 3-70 months (median 24 months). Neurological deficit improved in 15 patients (29%) and deteriorated in 3 patients (5,8%), one transient and two persistant. Neuroradiological follow up using MRI or CT was performed in 47 patients 4-70 months (median 24 months) after radiosurgery. Tumour size decreased in 19 patients (40%) while in the remaining 28 patients (60%) no change in the tumour volume was observed. None of the tumours increased in volume during the observation period. Control angiography was performed in 6 patients. Pathological vascularisation completely disappeared in one patient, reduced in two and there was no change in the remaining three. Radiosurgery proves to be a safe treatment for glomus jugulare tumour with no mortality and no acute morbidity. Because of its naturally slow growth rate, up to 10 years of follow up will be necessary to establish a cure rate after radiosurgery for these lesions.

Adolescent↗
PubMed1999

Stenting for atherosclerotic occlusive disease of the subclavian artery.

The purpose of this study was to evaluate the results of stenting subclavian artery pathologic lesions. Between July 1991 and December 1995, 69 patients (36 males: mean age 67 years, range 34-87 years) underwent intraluminal balloon dilatations followed by stent implantations in 70 subclavian arteries to treat primary atherosclerotic stenoses > 70%. Twenty-three patients (34%) were treated for vertebrobasilar insufficiency (VBI), 25 patients (36%) were treated for upper limb ischemia (ULI), and 10 patients (15%) were treated for both VBI and ULI. Other indications included symptomatic subclavian steal phenomenon (SSS), protection of dialysis arteriovenous fistula, coronary steal syndrome, protection of axilloaxillary bypass, distal embolization, and protection of left internal mammary artery (LIMA)-coronary bypass. Fifty-three cases (78%) were treated for stenosis and 17 cases (22%) for total occlusion of the origin of the subclavian artery. The results of this series indicate that stenting of subclavian artery stenosis appears safe and feasible with good short and mid-term patency, improving at those intervals the initial disappointing reports of balloon angioplasty alone. However, its long-term durability is at present unknown.

Aged↗
PubMed1999

Caspr2, a new member of the neurexin superfamily, is localized at the juxtaparanodes of myelinated axons and associates with K+ channels.

Rapid conduction in myelinated axons depends on the generation of specialized subcellular domains to which different sets of ion channels are localized. Here, we describe the identification of Caspr2, a mammalian homolog of Drosophila Neurexin IV (Nrx-IV), and show that this neurexin-like protein and the closely related molecule Caspr/Paranodin demarcate distinct subdomains in myelinated axons. While contactin-associated protein (Caspr) is present at the paranodal junctions, Caspr2 is precisely colocalized with Shaker-like K+ channels in the juxtaparanodal region. We further show that Caspr2 specifically associates with Kv1.1, Kv1.2, and their Kvbeta2 subunit. This association involves the C-terminal sequence of Caspr2, which contains a putative PDZ binding site. These results suggest a role for Caspr family members in the local differentiation of the axon into distinct functional subdomains.

Amino Acid Sequence↗
PubMed1999

Comparative efficacy of fluconazole and amphotericin B in the parenteral treatment of experimental paracoccidioidomycosis in the rat.

Patients with severe and complicated paracoccidioidomycosis are treated with amphotericin B by the intravenous route. Fluconazole is active in vitro against Paracoccidioides brasiliensis and can also be administered intravenously, but few clinical or experimental data are available about its action against the infection caused by this fungus. In the present study, the efficacy of fluconazole and amphotericin B was assessed comparatively in rats inoculated parenterally with P. brasiliensis. The treatment was performed 3 times a week for 4 weeks starting one week after infection. Fluconazole administered intraperitoneally (14 mg/kg body weight/dose) was more effective (P < 0.001) than amphotericin B (2 mg/kg body weight/dose) in reducing the number of colony forming units in the lungs and spleen. When administered intravenously at the dose of 3 mg/kg body weight, fluconazole was as effective as amphotericin B (0.8 mg/kg body weight) in reducing the pulmonary fungal burden. Under these conditions, the rats treated with fluconazole had a smaller number of colony forming units than untreated animals (P < 0.001), but amphotericin B was more effective than fluconazole in reducing spleen infection (P < 0.005). Except for this result obtained with a low dose, fluconazole showed an antifungal action equal to or higher than that of amphotericin B. The activity of fluconazole at doses equivalent to those used for human treatment suggests that this antifungal agent may be an alternative to amphotericin B for the early intravenous treatment of patients with paracoccidioidomycosis.

Amphotericin B↗
PubMed1999

Dietary chromic oxide does not affect the utilization of organic compounds but can alter the utilization of mineral salts in gilthead sea bream Sparus aurata.

This study was conducted to determine whether the level of chromic oxide supplemented to diets containing gelatinized starch as the carbohydrate source affects digestibility, body composition, growth performances, and liver enzyme activities in gilthead sea bream, Sparus aurata. Gilthead sea bream fingerlings were fed diets containing gelatinized corn starch as the carbohydrate source and several levels of chromic oxide (0, 5, 10 and 20 g/kg) for 6 wk. No effect of dietary chromium level was detected on carbon, nitrogen, or dry matter digestibility. Calcium and phosphorus digestibility were higher in fish fed the diet supplemented with 5 g/kg chromic oxide than in fish fed the other supplemented diets. Dietary chromium did not affect dry matter, carbon, nitrogen, protein, or lipid concentrations in fish. However, fish fed 5 g/kg chromic oxide generally had higher levels of calcium, phosphorus, and ash than fish fed the other Cr-containing diets. Chromium concentration was significantly higher in fish fed the diets with 0.5 and 1% chromic oxide than in fish fed the control diet. Chromium supplementation of the diets did not affect the specific growth rate, the food efficiency ratio, the protein efficiency ratio, or, protein or nitrogen retention of the fish. Blood glucose and the activity of several liver enzymes involved in carbohydrate metabolism were unaffected by dietary chromic oxide. Alanine aminotransferase was lower in the fish fed the diet with 10 g/kg of chromic oxide than in unsupplemented controls. Our results indicate that chromic oxide can be used as a neutral marker in fish nutrition studies involving organic compounds, but not mineral salts.

Animals↗