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Biomedical subjects

J Flores

Publications and source records attributed to J Flores.

At least 19 recordsLinked to original sources
PubMed2006

Wannier-stark ladders in one-dimensional elastic systems.

The optical analogues of Bloch oscillations and their associated Wannier-Stark ladders have been recently analyzed. In this Letter we propose an elastic realization of these ladders, employing for this purpose the torsional vibrations of specially designed one-dimensional elastic systems. We have measured, for the first time, the ladder wave amplitudes, which are not directly accessible either in the quantum-mechanical or optical cases. The wave amplitudes are spatially localized and coincide rather well with theoretically predicted amplitudes. The rods we analyze can be used to localize different frequencies in different parts of the elastic systems and vice versa.

Journal Article↗
PubMed2005

Captopril effect on prostaglandin E2, thromboxane B2 and proteinuria in lupus nephritis patients.

OBJECTIVE: High urinary Prostaglandin E2 (PGE2) and thromboxane B2 (TxB2) levels have been reported in lupus nephritis (LN). Captopril diminishes proteinuria and improves glomerular filtration rate (GFR), and may have effect on immune function. We evaluate captopril effect on urinary PGE2, and TxB2. METHODS: Eighteen LN patients were randomly assigned to two groups. Group 1 received only prednisone plus cyclophosphamide. Group 2 received also captopril. Serum creatinine, GFR, RPF, urinary proteins, PGE2 and TxB2, were assessed. RESULTS: There were no differences between the initial and final assessments in Group 1. Group 2 showed a significant decrement in proteinuria (p=0.003) and serum creatinine (p=0.01) at the end of the study. PGE2 decreased significantly when compared with the initial value (p=0.02). CONCLUSION: Captopril plus usual treatment, improved serum creatinine and decreased proteinuria in parallel with prostaglandin E2 reduction. This effect is not related to changes in GFR or RPF. Captopril may have an immunomodulatory effect on local inflammatory processes in lupus nephritis.

Adolescent↗
PubMed2005

Slow phase relaxation as a route to quantum computing beyond the quantum chaos border.

We reveal that phase memory can be much longer than energy relaxation in systems with exponentially large dimensions of Hilbert space; this finding is documented by 50 years of nuclear experiments, though the information is somewhat hidden. For quantum computers Hilbert spaces of dimension 2(100) or larger will be typical and therefore this effect may contribute significantly to reduce the problems of scaling of quantum computers to a useful number of qubits.

Journal Article↗
PubMed2005

Leishmaniasis as an opportunistic infection in HIV-infected patients: determinants of relapse and mortality in a collaborative study of 228 episodes in a Mediterreanean region.

The clinical presentation of visceral leishmaniasis shares similarities with other geographically specific infectious diseases associated with AIDS in terms of relapsing course and atypical presentation. However, visceral leishmaniasis has not, until now, been included in the AIDS case definition. The aim of this study was to describe the clinical features and determinants for relapse and case-fatality of visceral leishmaniasis in HIV-infected patients from a Spanish Mediterranean area. A chart review was conducted in 16 hospitals in the autonomous communities of Valencia and Murcia (Spain). From 1988 to 2001, a total of 228 episodes of visceral leishmaniasis were diagnosed in 155 HIV-infected patients by the detection of amastigotes in bone marrow aspirates or in other tissue samples. Most patients had advanced HIV disease, with a median CD4(+) lymphocyte cell count of 55 cells x 10(9) l, and 56% of them had a previous AIDS-indicator disease. The median duration of follow-up was 8.4 months. HIV-infected patients with visceral leishmaniasis presented with fever (76%), hepatomegaly (77%), splenomegaly (78%), and varying degrees of cytopenias. Leishmania was detected in atypical sites in 22 (14%) patients. A total of 37 (24%) patients had a relapse of visceral leishmaniasis. Female gender was a risk factor for relapse, whereas administration of secondary prophylaxis for visceral leishmaniasis and a completed therapy for visceral leishmaniasis were protective factors against relapse. A total of 86 (54%) patients died. Independent determinants for survival were CD4(+) lymphocyte cell count, completed therapy for leishmania, and secondary prophylaxis for visceral leishmaniasis. The findings show that, in HIV-infected patients, visceral leishmaniasis occurs in late stages of HIV disease and often has a relapsing course. Secondary prophylaxis reduces the risk of relapse. Visceral leishmaniasis in the HIV-infected population should be included in the CDC clinical category C for the definition of AIDS in the same way that other geographically specific opportunistic infections are included.

AIDS-Related Opportunistic Infections↗
PubMed2005

Importance of early repair of isolated abdominal aortic dissecting aneurysm.

BACKGROUND: Since the available information on isolated abdominal aortic dissecting aneurysm (AADA) is mainly related to case reports or reports of small groups of patients, its natural history remains undetermined and there is no agreement on its optimal management. The purpose of this study is to define the features and pattern of development of this unusual entity as well as to propose criteria for treatment based on our own experience and previously published data. PATIENTS AND METHODS: We retrospectively evaluated the history of 6 patients diagnosed with AADA. The patients were 5 males and 1 female. The mean age was 71 +/- 8 years (range: 61-80 years), and the mean aneurysm diameter was 54 +/- 14 mm (range: 35-70 mm). All of these patients were hypertensive (100%). History of cerebrovascular accident, ischemic heart disease, peripheral arterial disease, or diabetes mellitus was present in 1 patient, respectively. Two patients developed mycotic AADA. RESULTS: Emergency operations had been performed in 3 cases, and scheduled surgical reconstruction in the remaining 3 cases. Operation consisted of aneurysmectomy and graft replacement of the diseased aortic segment in all cases. One patient treated in an emergency setting died subsequently of multisystem organ failure, but the others did well. CONCLUSION: Symptomatic patients or patients at good risk should undergo surgical repair earlier than in the case of abdominal aortic aneurysm without dissection (AAA). Dissection in addition to an AAA will further increase the weakness of the aortic wall and the possibility of aortic rupture will become higher.

Aged↗
PubMed2005

Locally periodic Timoshenko rod: experiment and theory.

The flexural vibrations of a locally periodic rod, which consists of N unit cells, are discussed both from the experimental and theoretical points of view. Timoshenko's beam theory and the transfer matrix method are used to calculate the normal-mode frequencies and amplitudes. The theoretical values are then compared with the experimental ones, which are obtained using an electromagnetic acoustic transducer (EMAT). Good agreement between the numerical results and the experimental measurements is obtained. It is shown that as N grows, a band spectrum emerges.

Acoustics↗
PubMed2004

Excision and V-Y plasty reconstruction for giant condyloma acuminatum.

BACKGROUND: Condyloma acuminata is the most common anorectal lesion in patients infected with human immunodeficiency virus (HIV). Surgical treatment can be challenging in cases where the size and extension into the anal canal make individual excision impossible. These patients require large resections and reconstruction using grafts or local flaps. METHODS: Six patients were treated for giant perianal condylomas between 1999 and 2001. Four patients were HIV-positive, and were selected for surgical intervention after achieving a T4 count >350 and low viral replication. In 5 cases, the lesions were circularly resected up to the pectinate line and the defect was reconstructed using a bilateral V-Y plasty. In the remaining case, fulguration was possible on one side and a unilateral V-Y plasty was performed. RESULTS: There were no infections or healing delays in this series, and the functional and aesthetic results are satisfactory. CONCLUSION: V-Y plasties are a valid method for perianal reconstruction after resection of giant anal condyloma, with good results in selected patients with HIV infection.

Adolescent↗
PubMed2004

Taste and odor profiles (off-flavors) in the drinking waters of the Barcelona area (1996-2000).

The Aigües de Barcelona laboratory systematically monitors the organoleptic quality of the water it supplies. The water comes mainly from the Llobregat and Ter rivers, with the two sources having cleary differentiated chemical characteristics. Water is monitored by the tasting panel, which works according to FPA (Flavor Profile Analysis) principles. This paper reports the results from the period 1996-2000: characteristic organoleptic profiles, evolution of descriptors and the overall organoleptic evaluation of the water. The results show that in Llobregat water the descriptors chlorinous, medicinal, rubbery and salty are the most relevant, whereas in Ter water fresh nature/grassy and metallic are. The Aesthetic Quality Index drawn up by our laboratory confirms that Ter water has better organoleptic quality than Llobregat water. Monitoring also found that neither water lost quality significantly within the distribution network.

Cities↗
PubMed2004

Stenosis of the abdominal aorta caused by fibromuscular dysplasia.

Fibromuscular dysplasia of the aorta is an exceedingly rare disease with 26 cases reported to date in Medline. We present a case of stenosis of the infrarenal abdominal aorta in a 49-year-old woman with a history of intermittent claudication. The patient underwent aortic endarterectomy, and subsequent anatomopathologic examination of the specimen revealed fibromuscular dysplasia. The possible causes of aortic stenosis in this case, its angiographic findings, and the alternatives of treatment are discussed.

Aorta, Abdominal↗
PubMed2003

Immunogenicity of a recombinant human immunodeficiency virus (HIV)-canarypox vaccine in HIV-seronegative Ugandan volunteers: results of the HIV Network for Prevention Trials 007 Vaccine Study.

In the first preventative human immunodeficiency virus (HIV) vaccine study to be carried out in Africa, 40 HIV-seronegative Ugandan volunteers were randomly assigned to receive a canarypox vector containing HIV-1 clade B (env and gag-pro) antigens (ALVAC-HIV; n = 20), control vector containing the rabies virus glycoprotein G gene (n = 10), or saline placebo (n = 10). Cytotoxic T lymphocyte activity against target cells expressing clade A, B, and D antigens was assessed using standard chromium-release and confirmatory interferon-gamma enzyme-linked immunospot (ELISPOT) assays. Neutralizing antibody responses to cell line-adapted strains and primary isolates in all 3 clades were also tested. Twenty percent of vaccine recipients generated detectable cytolytic responses to either Gag or Env, and 45% had vaccine-induced HIV-specific CD8(+) T cell responses, as measured by the ELISPOT assay. In contrast, only 5% of the control group had vaccine-specific responses. Neutralizing antibodies against primary and laboratory-adapted HIV-1 clade B strains were seen in 10% and 15% of vaccine recipients, respectively, but responses against clades A and D were not detected. Although the immunogenicity of this clade B-based vaccine was low, ALVAC-HIV elicited CD8(+) T cell responses with detectable cross-activity against clade A and D antigens in a significant proportion of vaccine recipients.

AIDS Vaccines↗
PubMed2003

Spinal cord compression due to tumoral idiopatic calcinosis.

STUDY DESIGN: A case of thoracic spinal cord compression due to tumoral calcinosis (TC) is reported. SETTING: Galiza, Spain. CASE REPORT: A 59-year-old man was admitted to our hospital with a 2-month history of gradual leg weakness and sensory deficit. The neurological examination revealed paraparesis with T12 sensory level. Magnetic resonance imaging (MRI) showed an extradural right posterolateral mass at T11-T12 level, resulting in a marked spinal cord compression. He underwent T11-T12 laminectomy and mass excision. Histological examination finally led to the diagnosis of TC. CONCLUSION: TC is an uncommon cause of mass lesions of the spine. Since there is no typical spine TC MRI appearance, the final diagnosis is done by histological studies. TC should be considered in differential diagnosis of spinal cord compression and constitutes a treatable cause of paraparesis.

Calcinosis↗
PubMed2002

Compressional and torsional wave amplitudes in rods with periodic structures.

To measure and detect elastic waves in metallic rods a low-frequency electromagnetic-acoustic transducer has been developed. Frequencies range from a few hertz up to hundreds of kilohertz. With appropriate configuration of the transducer, compressional or torsional waves can be selectively excited or detected. Although the transducer can be used in many different situations, it has been tested and applied to a locally periodic rod, which consists of a finite number of unit cells. The measured wave amplitudes are compared with theoretical ones, obtained with the one-dimensional transfer matrix method, and excellent agreement is obtained.

Journal Article↗
PubMed2002

Metastatic lymphangiosarcoma in a horse.

A lymphangiosarcoma with metastases was found in a horse that presented with respiratory distress and edema in the ventral thorax and abdomen. The necropsy revealed diffuse edema in the subcutaneous connective tissue. Mediastinal, mesenteric, iliac, and renal lymph nodes were enlarged and white with soft, yellowish necrotic areas. Histologic examination revealed numerous channels and disorganized vessels lined by large polyhedral, polymorphic cells. Tumor metastases were observed in the spleen, lungs, and kidneys. Immunohistochemical evaluation of the tumor cells demonstrated positive staining for factor VIII, vimentin, and keratin. Laminin was scarce, and collagen IV staining was negative, consistent with a discontinuous or absent basement membrane.

Animals↗
PubMed2002

Prosthetic grafts for above-knee femoropopliteal bypass. A multicenter retrospective study of 564 grafts.

BACKGROUND: Many prosthetic grafts including expanded polytetrafluoroethylene (ePTFE) and polyethylene terephthalate (Dacron) have recently been used for above-knee femoropopliteal bypass. The purpose of this study was to identify the factors affecting patency performance and patient survival. METHODS: A multicenter retrospective analysis of 496 patients who received 564 grafts between 1990 and 1999 (325 ePTFE and 239 Dacron). Follow-up extended to 114.5 months, with a mean of 30.8 months (+/-25.9 months). RESULTS: The overall primary patency rate for all grafts was 71.4% at 5 years, 73.7% for ePTFE, and 68.9% for Dacron grafts. The secondary patency rates at 5 years were 84.1% for ePTFE, and 83.8% for Dacron. No significant differences were found. The logistic regression analysis revealed that younger age at operation and smoking history were correlated with decreased primary patency rate. The patency rates were unaffected by postoperative administration of oral anticoagulants or antiplatelet agents, although pharmacotherapy contributed to the improvement of survival rates. Renal failure, cerebral infarction and Dacron decreased survival rate. CONCLUSIONS: We conclude that the patency performances of prosthetic grafts are satisfying. However, the choice of prosthetic grafts for younger patients or patients with a smoking history need to be carefully considered. Cerebral infarction, chronic renal failure and Dacron grafts may decrease the survival rate. The operative indications should be determined carefully in these cases. The administration of beraprost sodium is recommended for postoperative pharmacotherapy.

Aged↗
PubMed2002

A rare case of atherosclerotic popliteal artery aneurysm in a young adult.

Popliteal artery aneurysms are not so clinically frequent but are the most common peripheral aneurysms. They usually affect older men aged over 60 and are caused by atherosclerosis. Whenever they occur in younger men, other more unusual etiologies such as trauma, infection, inflammatory arteritis or popliteal entrapment are responsible. In this paper we present the case of a young male with an atherosclerotic popliteal artery aneurysm without a history of penetrating trauma or other possible etiologies.

Adult↗
PubMed2002

Albumin-coated knitted Dacron aortic prosthses. Study of postoperative inflammatory reactions.

BACKGROUND: The purpose of this study was to investigate the postoperative inflammatory reactions to albumin-coated Dacron grafts (ACGs), which are used in the repair of abdominal aortic aneurysm (AAA). METHODS EXPERIMENTAL DESIGN: a retrospective study with a follow-up period of 14 days. SETTING: University hospital. PATIENTS: 50 patients admitted for elective AAA repair from January 1997 to January 2000. INTERVENTIONS: each patient underwent AAA repair with an ACG (Bard, albumin-coated Dacron graft). MEASURES: the white blood cell (WBC) count, plasma C-reactive protein (CRP) concentration, and body temperature (BT) were determined. The preoperative data, the highest values of the postoperative data, and the values 2 weeks postsurgery were analyzed. RESULTS: The BT, CRP, and WBC increased and peaked at the 1st week postsurgery and then decreased gradually. The BT and WBC levels returned to normal within 2 weeks. The CRP level continued to show slightly elevated values in the 2nd week, but it was not significantly different compared to the preoperative data. CONCLUSIONS: The use of an albumin-impregnated prosthesis for the reconstruction of AAA is biocompatible, since no significant increases in inflammatory reactions are observed in the 2nd week postsurgery.

Aged↗