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J Perez

Publications and source records attributed to J Perez.

At least 19 recordsLinked to original sources
PubMed2006

Impulsivity and bipolar disorder.

Impulsivity is frequently associated with bipolar disorder (BD) during manic episodes, but may also be present in euthymic bipolar patients. Aggression is an impulsivity-related behavior also found during manic episodes. The objective of this review is to further clarify the relationship between impulsivity and BD. A search in Medline and Psycinfo databases, combined with a manual search of selected references, was conducted to identify available literature on BD and impulsivity-related features. Although few studies have directly measured impulsivity in BD, available findings suggest that impulsivity is not only state-related, but also a trait component of BD, which could represent a core feature of the illness. Further research exploring the neurobiology of the impulsivity/BD relationship may contribute to elucidate the pathophysiology and to improve the diagnosis and treatment of this severe illness.

Aggression↗
PubMed2006

Seroprevalence of and risk factors for HIV-1 infection among female commercial sex workers in South America.

OBJECTIVE: Assessment of HIV prevalence and associated risk behaviours among female commercial sex workers (FCSW) across major cities in South America. METHODS: Seroepidemiological, cross sectional studies of 13 600 FCSW were conducted in nine countries of South America during the years 1999-2002. Participants were recruited in brothels, massage parlours, hotels, and streets where anonymous questionnaires and blood samples were collected. HIV infection was determined by enzyme linked immunosorbent assay (ELISA) screening and western blot confirmatory tests. RESULTS: The overall HIV seroprevalence was 1.2% (range 0.0%-4.5%). The highest HIV seroprevalences were reported in Argentina (4.5%) and Paraguay (2.6%); no HIV infected FCSW were detected in Venezuela and Chile. Consistent predictors of HIV seropositivity were: (1) a previous history of sexually transmitted infections (STI, AORs = 3.8-8.3), and (2) 10 years or more in commercial sex work (AORs = 2.2-24.8). In addition, multiple (> or =3) sexual contacts (AOR = 5.0), sex with foreigners (AOR = 6.9), use of illegal drugs (AOR = 3.2), and marijuana use (AOR = 8.2) were associated with HIV seropositivity in Southern Cone countries. CONCLUSIONS: Consistently low HIV seroprevalences were detected among FCSW in South America, particularly in the Andean region. Predictors of HIV infection across the continent were STI and length of commercial sex work; however, use of illegal drugs, especially marijuana, and sexual contacts with foreigners were also found to be associated risk factors in the Southern Cone region. Interventions for the control of HIV and other STI need to be region and country specific; drug use appears to have an ever increasing role in the spread of HIV among heterosexually active populations.

Adult↗
PubMed2006

An unusual case of generalized soft-tissue mineralization in a suckling foal.

An atypical case of severe soft-tissue mineralization in a 3-week-old foal from a herd of Andalusian horses is described. The herd clinical history and the laboratory findings were compatible with a diagnosis of secondary hyperparathyroidism due to a mineral imbalance in the diet (low calcium and high phosphorus intake). Mares showed a marked increase in serum parathyroid hormone (PTH) approximately 10 times normal levels. Serum PTH was marginally elevated in foals. Clinical signs (unthriftiness, painful joints, lameness in one or more limbs, and stiff gait) were more pronounced in foals than in mares. Two foals died and necropsy of one of them revealed extensive soft-tissue mineralization of arterial walls and pulmonary parenchyma. Clinical signs in mares and foals resolved by 4 weeks after diet adjustment.

Animals↗
PubMed2005

Clinical efficacy of anti-pneumococcal vaccination in patients with COPD.

BACKGROUND: A study was undertaken to evaluate the clinical efficacy of the 23-valent pneumococcal polysaccharide vaccine (PPV) in immunocompetent patients with chronic obstructive pulmonary disease (COPD). METHODS: A randomised controlled trial was carried out in 596 patients with COPD of mean (SD) age 65.8 (9.7) years, 298 of whom received PPV. The main outcome was radiographically proven community acquired pneumonia (CAP) of pneumococcal or unknown aetiology after a mean period of 979 days (range 20-1454). RESULTS: There were 58 first episodes of CAP caused by pneumococcus or of unknown aetiology, 25 in the intervention group and 33 in the non-intervention group. Kaplan-Meier survival curves for CAP did not show significant differences between the intervention and non-intervention arms (log rank test = 1.15, p = 0.28) in the whole group of patients. The efficacy of PPV in all patients was 24% (95% CI -24 to 54; p = 0.333). In the subgroup aged <65 years the efficacy of PPV was 76% (95% CI 20 to 93; p = 0.013), while in those with severe functional obstruction (forced expiratory volume in 1 second <40%) it was 48% (95% CI -7 to 80; p = 0.076). In younger patients with severe airflow obstruction the efficacy was 91% (95% CI 35 to 99; p = 0.002). There were only five cases of non-bacteraemic pneumococcal CAP, all in the non-intervention group (log rank test = 5.03; p = 0.025). Multivariate analysis gave a hazard ratio for unknown and pneumococcal CAP in the vaccinated group, adjusted for age, of 0.20 (95% CI 0.06 to 0.68; p = 0.01). CONCLUSIONS: PPV is effective in preventing CAP in patients with COPD aged less than 65 years and in those with severe airflow obstruction. No differences were found among the other groups of patients with COPD.

Adult↗
PubMed2005

Transabdominal pre-peritoneal (TAPP) versus totally extraperitoneal (TEP) laparoscopic techniques for inguinal hernia repair: a systematic review.

BACKGROUND: The choice of approach to the laparoscopic repair of inguinal hernia is controversial. There is a scarcity of data comparing the laparoscopic transabdominal preperitoneal (TAPP) approach with the laparoscopic totally extraperitoneal (TEP) approach, and questions remain about their relative merits and risks. METHODS: Electronic databases were searched to identify reports of trials comparing laparoscopic TAPP with laparoscopic TEP. In addition, selected conference proceedings were hand-searched, websites consulted, reference lists of all included papers were scanned, and experts contacted for other potentially eligible reports. All published and unpublished randomised controlled trials and quasi-randomised controlled trials comparing laparoscopic TAPP with laparoscopic TEP for inguinal hernia repair were eligible for inclusion. Large non-randomised prospective studies were also eligible for inclusion to provide further comparative evidence of complications and serious adverse events. Two reviewers independently extracted data and assessed study quality. Statistical analyses were performed using the fixed effects model and the results expressed as relative risk (RR) for dichotomous outcomes and weighted mean difference (WMD) for continuous outcomes with 95% confidence intervals (CI). RESULTS: The search identified one RCT which reported no statistically significant difference between TAPP and TEP when considering duration of operation, haematoma, length of stay, time to return to usual activities, and recurrence. The eight non-randomised studies suggest that TAPP is associated with higher rates of port-site hernias and visceral injuries whilst there appear to be more conversions with TEP. Vascular injuries and deep/mesh infections were rare and there was no obvious difference between the groups. No studies reporting economic evidence were identified. CONCLUSIONS: There is insufficient data to allow conclusions to be drawn about the relative effectiveness of TEP compared with TAPP. Efforts should be made to start and complete adequately-powered randomised controlled trials (RCTs), which compare the different methods of laparoscopic repair.

Female↗
PubMed2005

Transabdominal pre-peritoneal (TAPP) vs totally extraperitoneal (TEP) laparoscopic techniques for inguinal hernia repair.

BACKGROUND: The choice of approach to the laparoscopic repair of inguinal hernia is controversial. There is a scarcity of data comparing the laparoscopic transabdominal preperitoneal (TAPP) approach with the laparoscopic totally extraperitoneal (TEP) approach and questions remain about their relative merits and risks. OBJECTIVES: To compare the clinical effectiveness and relative efficiency of laparoscopic TAPP and laparoscopic TEP for inguinal hernia repair. SEARCH STRATEGY: We searched Medline Extra, Embase, Biosis, Science Citation Index, Cochrane Central Register of Controlled Trials (CENTRAL), Journals@ Ovid Full Text and the electronic version of the journal, Surgical Endoscopy. Recent conference proceedings by the following organisations were hand searched: Association of Endoscopic Surgeons of Great Britain & Ireland; International Congress of the European Association for Endoscopic Surgery; Scientific Session of the Society of American Gastrointestinal & Endoscopic Surgeons (SAGES); and the Italian Society of Endoscopic Surgery. In addition, specialists involved in research on the repair of inguinal hernia were contacted to ask for information about any further completed and ongoing trials, relevant websites were searched and reference lists of the all included studies were checked for additional reports. SELECTION CRITERIA: All published and unpublished randomised controlled trials and quasi-randomised controlled trials comparing laparoscopic TAPP with laparoscopic TEP for inguinal hernia repair were eligible for inclusion. Non-randomised prospective studies were also eligible for inclusion to provide further comparative evidence of complications and adverse events. DATA COLLECTION AND ANALYSIS: Statistical analyses were performed using the fixed effects model and the results expressed as relative risk (RR) for dichotomous outcomes and weighted mean difference (WMD) for continuous outcomes with 95% confidence intervals (CI). MAIN RESULTS: The search identified one RCT which reported no statistical difference between TAPP and TEP when considering duration of operation, haematoma, length of stay, time to return to usual activity and recurrence. The eight non-randomised studies suggest that TAPP is associated with higher rates of port-site hernias and visceral injuries whilst there appear to be more conversions with TEP. Vascular injuries and deep/mesh infections were rare and there was no obvious difference between the groups. No studies reporting economic evidence were identified. Very limited data were available on learning effects but these data suggest that operators become experienced at between 30 and 100 procedures. AUTHORS' CONCLUSIONS: There is insufficient data to allow conclusions to be drawn about the relative effectiveness of TEP compared with TAPP. Efforts should be made to start and complete adequately powered RCTs, which compare the different methods of laparoscopic repair.

Hernia, Inguinal↗
PubMed2005

Laparoscopic surgery for inguinal hernia repair: systematic review of effectiveness and economic evaluation.

OBJECTIVES: To determine whether laparoscopic methods are more effective and cost-effective than open mesh methods of inguinal hernia repair, and then whether laparoscopic transabdominal preperitoneal (TAPP) repair is more effective and cost-effective than laparoscopic totally extraperitoneal (TEP). DATA SOURCES: Electronic databases. Conference proceedings. Manufacturers' submissions to the National Institute for Clinical Excellence (NICE) were reviewed. REVIEW METHODS: Selected studies were rigorously assessed. Dichotomous outcome data were combined using the relative risk method and continuous outcomes were combined using the Mantel-Haenszel weighted mean difference method. Time to return to usual activities was described using hazard ratios derived from individual patient data reanalysis. A review of economic evaluations undertaken by NICE in 2001 was updated and an economic evaluation was performed. The estimation of cost-effectiveness focused on the comparison of laparoscopic repair with open flat mesh. A Markov model incorporating the data from the systematic review was used to estimate cost-effectiveness for a time horizon up to 25 years. RESULTS: Thirty-seven randomised control trials (RCTs) and quasi-RCTs met the inclusion criteria on effectiveness. Fourteen studies were included in the review of economic evaluations. Laparoscopic repair was associated with a faster return to usual activities and less persisting pain and numbness. There also appeared to be fewer cases of wound/superficial infection and haematoma. However, operation times are longer and there appears to be a higher rate of serious complications in respect of visceral (especially bladder) injuries. Mesh infection is very uncommon with similar rates noted between the surgical approaches. There is no apparent difference in the rate of hernia recurrence. Laparoscopic repair was more costly to the health service than open repair, with an estimated extra cost from studies conducted in the UK of about 300-350 pounds per patient. The point estimates of cost provided by the economic model also suggest that the laparoscopic techniques are more costly (approximately 100-200 pounds more per patient after 5 years). From the review of economic evaluations, the estimates of incremental cost per additional day at usual activities were between 86 pounds and 130 pounds. Where productivity costs were included, they eliminated the cost differential between laparoscopic and open repair. Additional analysis incorporating new trial evidence suggested that TEP was associated with significantly more recurrences than open mesh but these data did not greatly influence cost-effectiveness. CONCLUSIONS: For the management of unilateral hernias, the base-case analysis and most of the sensitivity analysis suggest that open flat mesh is the least costly option but provides less quality adjusted life years (QALYs) than TEP or TAPP. TEP is likely to dominate TAPP (on average TEP is estimated to be less costly and more effective). It is likely that, for management of symptomatic bilateral hernias, laparoscopic repair would be more cost-effective as differences in operation time (a key cost driver) may be reduced and differences in convalescence time are more marked (hence QALYs will increase) for laparoscopic compared with open mesh repair. When possible repair of contralateral occult hernias is taken into account, TEP repair is most likely to be considered cost-effective at threshold values for the cost per additional QALY above 20,000 pounds. The increased adoption of laparoscopic techniques may allow patients to return to usual activities faster. This may, for some people, reduce any loss of income. For the NHS, increased use of laparoscopic repair would lead to an increased requirement for training and the risk of serious complications may be higher. Chronic pain should now be addressed prospectively using standard definitions and allowing assessment of the degree of pain. More evidence is required on the loss of utility caused by persisting pain and numbness, as well as serious complications resulting from minor surgery. Prospective population-based registries of new surgical procedures may be the best way to address this, as a complement to randomised trials assessing effectiveness. Further research relating to whether the balance of advantages and disadvantages changes when hernias are recurrent or bilateral is also required as current data are limited. Methodologically sound RCTs are needed to consider the relative merits and risks of TAPP and TEP. Further methodological research is required into the complexity of laparoscopic groin hernia repair and the improvement of performance that accompanies experience.

Cost-Benefit Analysis↗
PubMed2005

Grain size distribution of metals and polycyclic aromatic hydrocarbons in silt trap sediments from the combined sewer network of Paris (France).

For three years (2001 - 2003), sediment samples were extracted from about 100 silt traps (STs) spread out all over the combined sewer network of Paris. These STs, whose volume varied from 21 to 325 m3, were cleaned out as soon as their filling capacities were reached. All these sediment samples were analysed for physicochemical parameters (pH, organic matter (OM) content, grain size distribution), total hydrocarbons (THs), 16 polycyclic aromatic hydrocarbons (PAHs) selected from the priority list of the US-EPA, and heavy metals (Al, Ag, As, Cd, Cu, Cr, Sn, Fe, Mn, Hg, Ni, Pb, Zn). For each silt trap, six sediment samples were extracted before the clean out procedure: three samples were extracted from the sediment surface (5-10 cm depth) and three other samples were extracted from a deeper sediment layer (approximately at 1 m depth). The location of these sampling points allowed us to take into account the possible spatial fluctuation of pollutant loads in each ST. The first results showed that there were some important inter-site variations of pollutant contents. These variations have to be taken into account by the sewer manager for the fate of the ST sediments. Therefore, we decided to assess the grain size distribution of some pollutants. OM, heavy metals and PAHs have been investigated on the five grain size fractions (> 20 mm, 8-20 mm, 0.5-8 mm, 50-500 microm, < 50 microm) for 9 STs, which have been selected on their heavy metal content basis. This work aims at understanding the distribution of the pollutant contents and at improving the knowledge of the ST sediment pollution.

Drainage, Sanitary↗
PubMed2004

GATE: a simulation toolkit for PET and SPECT.

Monte Carlo simulation is an essential tool in emission tomography that can assist in the design of new medical imaging devices, the optimization of acquisition protocols and the development or assessment of image reconstruction algorithms and correction techniques. GATE, the Geant4 Application for Tomographic Emission, encapsulates the Geant4 libraries to achieve a modular, versatile, scripted simulation toolkit adapted to the field of nuclear medicine. In particular, GATE allows the description of time-dependent phenomena such as source or detector movement, and source decay kinetics. This feature makes it possible to simulate time curves under realistic acquisition conditions and to test dynamic reconstruction algorithms. This paper gives a detailed description of the design and development of GATE by the OpenGATE collaboration, whose continuing objective is to improve, document and validate GATE by simulating commercially available imaging systems for PET and SPECT. Large effort is also invested in the ability and the flexibility to model novel detection systems or systems still under design. A public release of GATE licensed under the GNU Lesser General Public License can be downloaded at http:/www-lphe.epfl.ch/GATE/. Two benchmarks developed for PET and SPECT to test the installation of GATE and to serve as a tutorial for the users are presented. Extensive validation of the GATE simulation platform has been started, comparing simulations and measurements on commercially available acquisition systems. References to those results are listed. The future prospects towards the gridification of GATE and its extension to other domains such as dosimetry are also discussed.

Computer Simulation↗
PubMed2004

Stress and hippocampal abnormalities in psychiatric disorders.

The hippocampus plays a main role in regulating stress response in humans, but is itself highly sensitive to neurotoxic effects of repeated stressful episodes. Hippocampal atrophy related to experimental stress has been reported in laboratory studies in animals. Several controlled brain imaging studies have also shown hippocampal abnormalities in psychiatric disorders, including posttraumatic stress disorder (PTSD), major depressive disorder (MDD), and borderline personality disorder (BPD). This paper reviews the physiological role of the hippocampus in stress circuitry and the effects of stress on cognitive functions mediated by the hippocampus. We also review brain imaging studies investigating hippocampus in PTSD, MDD, and BPD. This literature suggests that individuals with PTSD, MDD, and BPD may suffer hippocampal atrophy as a result of stressors associated with these disorders. Prospective, longitudinal studies will be needed in high-risk offspring and first-episode subjects to explore the relationship between stress and hippocampal atrophy in these neuropsychiatric illnesses.

Animals↗
PubMed2004

Documentation of subtype C HIV Type 1 strains in Argentina, Paraguay, and Uruguay.

HIV subtypes B, F, and BF recombinants have been previously reported in South America. This report describes the presence of HIV-1 subtype C infection in the countries of Argentina, Uruguay, and Paraguay dating back to at least 1999. Surveillance for uncommon non-B/non-F subtype viruses circulating in South America has been conducted in samples obtained from nine countries. Peripheral blood mononuclear cells (PBMC), dried filter paper (FP), and fresh blood (FB) samples were collected from HIV-positive patients from Ecuador, Colombia, Venezuela, Peru, Chile, Bolivia, Argentina, Uruguay, and Paraguay. From a total of 2962 HIV seropositive samples examined during a 9-year period (1995-2003), only 11 (0.4%) were found to be infected with non-B/non-F HIV variants. Eight of these 11 strains were determined to be subtype C by heteroduplex mobility assay (HMA). Five of these 8 strains were further characterized by sequencing and phylogenetic analysis of the protease (Pro) and reverse transcriptase (RT) region of the genome and two were sequenced full length. One of the strains was found to be a unique BC recombinant. The spread of a third subtype of HIV, subtype C, should raise the question of its potential future role in the HIV epidemic in this region.

Adult↗
PubMed2004

Modelling a spatially heterogeneous biofilm and the bulk fluid: selected results from benchmark problem 2 (BM2).

The numerical simulation of mass transfer and conversion in spatially heterogeneous biofilms on the meso-scale requires an accurate description of the hydrodynamics in the biofilm systems and of spatial effects. This leads to systems of three-dimensional nonlinear partial differential equations that are numerically very expensive to solve and to data requirements that are not easy to meet. In this paper several modeling approaches to reduce the physical complexity and, hence, accelerate the computation are compared. They range from a mere reduction of dimensionality by lumping the problem along a secondary flow direction to global mass balances or empirical correlations, at the core of which a one-dimensional boundary value problem must be solved. It is found that even strongly simplified models can describe the qualitative behaviour of the model with regard to variations in the geometrical and hydrodynamic model parameters quite well. In order to obtain also quantitatively reliable results the hydrodynamics must be considered in an appropriate manner.

Bacteria↗
PubMed2004

Results from the multi-species benchmark problem (BM3) using one-dimensional models.

The IWA's Biofilm Modeling Task Group created a multi-species benchmark problem in which heterotrophic bacteria, nitrifying bacteria, and inert biomass coexist in a biofilm. Members of the Task Group submitted solutions from nine different one-dimensional models. The most important distinctions among the models were (1) whether the model required a full numerical solution or was solved with a spreadsheet, and (2) the way the biomass types were distributed in the biofilm. The models that protected the slow-growing species by having them accumulate away from the outer surface always had the largest surface coverage by nitrifiers and inerts, but the heterotroph coverage declined to compensate. Coverage by heterotrophs and removal of substrate COD were most strongly affected by dilution from nitrifiers and inerts near the outer surface. Models that did not allow the nitrifiers and inerts to dilute the heterotrophs significantly in the outer layer predicted more removal of COD than did the other models. The choice of the model to use depends on the user's needs and the relative importance of including protection of slow-growing species and/or dilution of fast-growing species.

Bacteria↗
PubMed2003

Painful vascular compression syndrome of the sciatic nerve caused by gluteal varicosities.

The authors report three patients with chronic sciatic pain without focal neurologic deficit. Sitting or lying on the affected side provoked pain, and standing and walking relieved it. MRI revealed varicotic gluteal vessels compressing the sciatic nerve. Decompression of the nerve resulted in complete and permanent pain relief. Sciatic or buttock pain in patients with varicosities and pain provocation in the sitting or lying position suggests this neurovascular compression syndrome.

Aged↗
PubMed2003

GABAergic dysfunction in mood disorders.

The authors review the available literature on the preclinical and clinical studies involving GABAergic neurotransmission in mood disorders. Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter present almost exclusively in the central nervous system (CNS), distributed across almost all brain regions, and expressed in interneurons modulating local circuits. The role of GABAergic dysfunction in mood disorders was first proposed 20 years ago. Preclinical studies have suggested that GABA levels may be decreased in animal models of depression, and clinical studies reported low plasma and CSF GABA levels in mood disorder patients. Also, antidepressants, mood stabilizers, electroconvulsive therapy, and GABA agonists have been shown to reverse the depression-like behavior in animal models and to be effective in unipolar and bipolar patients by increasing brain GABAergic activity. The hypothesis of reduced GABAergic activity in mood disorders may complement the monoaminergic and serotonergic theories, proposing that the balance between multiple neurotransmitter systems may be altered in these disorders. However, low GABAergic cortical function may probably be a feature of a subset of mood disorder patients, representing a genetic susceptibility. In this paper, we discuss the status of GABAergic hypothesis of mood disorders and suggest possible directions for future preclinical and clinical research in this area.

Brain Chemistry↗
PubMed2003

Paracoccidioidomycosis and larynx carcinoma.

Report of a case of paracoccidioidomycosis associated with a carcinoma: both located in the larynx in a patient whose therapeutic response to antifungal treatment produced a recovery of physical conditions. This case shows the importance of taking into account the diagnosis of paracoccidioidomycosis in all patients with problems in the larynx, especially those who inhabit or inhabited endemic areas of Paracoccidioides brasiliensis.

Aged↗
PubMed2003

Circulating recombinant form CRF02_AG in South America.

With the objective of monitoring the distribution of HIV-1 subtypes and circulating recombinant forms (CRFs)in South America, population-based surveillance studies were performed in seven countries. Peripheral blood mononuclear cell, filter paper, fresh blood, and cocultivation samples were collected from HIV-positive patients from Colombia, Ecuador, Peru, Bolivia, Chile, Argentina, and Uruguay, during a 7-year period(1995-2001). DNA was prepared and HIV envelope subtypes were determined by heteroduplex mobility as-say and DNA sequencing from 1289 HIV-positive samples. While subtypes B and F were the most commonly observed subtypes, two CRF02_AG strains were detected, in Ecuador. This is the first report of the existence of this CRF in South America.

Adult↗