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Biomedical subjects

M Perez

Publications and source records attributed to M Perez.

At least 19 recordsLinked to original sources
PubMed2006

Performance of anaerobic thermophilic fluidized bed in the treatment of cutting-oil wastewater.

This paper examines the effect of organic loading rate on the removal efficiency of COD and TOC anaerobic thermophilic fluidized bed reactor (AFBR) in the treatment of cutting-oil wastewater at different hydraulic retention time (HRT) conditions. The essays are development at laboratory scale using a porous support medium. The AFBR reactor was subjected to a programme of steady-state operation over a range of hydraulic retention times, HRTs, in the range 12-2h and organic loading rates, OLRs, between 11.9 and 51.3kgCOD/m(3)d. The highest efficiency was 95.9% for an OLR of 13kgCOD/m(3)d and HRT of 11h. Over an operating period of 92 days, an OLR of 51.3kgCOD/m(3)d was achieved with 67.1% COD removal efficiency (71.3% TOC) in the experimental AFBR reactor. Although the level of biogas generation was not high, the anaerobic fluidized bed technology provided significant advantages over the conventional physico-chemical treatment applied in the factory. The effluent had a better quality (lower organic loading) and it was possible to reuse it in different applications in the factory (e.g., irrigation of gardens). The biological treatment did not lead to the generation of oily sludge, which is considered as hazardous waste by legislation. Furthermore, a continuous stream is produced and this reduced the impact of large flows discharged 4-5 times per week to the urban collector and MWWTP (municipal wastewater treatment plant).

Anaerobiosis↗
PubMed2006

Expression of TCL1 and CD27 in primary cutaneous B-cell lymphomas.

AIMS: To investigate by immunohistochemical analysis the expression of the TCL1 oncogene product and of CD27 in 25 cases of primary cutaneous B-cell lymphomas (PCBCL) classified according to the World Health Organization-European Organization for Research and Treatment of Cancer classification of cutaneous lymphomas. In B-cell ontogenesis TCL1 is mainly expressed by 'naive' B lymphocytes and by a subset of germinal centre B cells, whereas CD27 is expressed by a subset of germinal centre B cells, 'memory' B lymphocytes and plasma cells, suggesting that their expression in physiological conditions is mutually exclusive. METHODS AND RESULTS: Overall, TCL1 was expressed in 5/25 cases (20%) and CD27 in 15/25 cases (60%). Furthermore, 7/25 cases (28%) were TCL1- and CD27- and 2/25 cases (8%) were TCL1+ and CD27+. In particular, primary cutaneous follicle-centre lymphomas (10 cases) showed a variable expression of both TCL1 and CD27, whereas primary cutaneous marginal-zone B-cell lymphomas (eight cases) showed, with the exception of a single case, a definite CD27+/TCL1- profile. CONCLUSIONS: These findings indicate: (i) the TCL1 oncogene product is uncommonly expressed in PCBCL (20% of cases, mainly of the follicle-centre subtype); (ii) in contrast, CD27 is often expressed in PCBCL (60% of cases), mainly of the marginal-zone subtype; (iii) the coexpression of TCL1 and CD27 may be seldom observed in PCBCL (8% of cases); (iv) PCBCL does not seem to show, in terms of either TCL1 or CD27 expression, significant differences compared with its systemic counterparts.

Biomarkers, Tumor↗
PubMed2006

Exercise capacity in a 78 year old patient with McArdle's disease: it is never too late to start exercising.

The case is reported of a 78 year old man with McArdle's disease and a history of treated coronary heart disease. Despite the pre-exercise administration of sucrose allowing the patient to exercise with normal physiological responses, and without typical McArdle's symptoms or biochemical evidence of muscle damage, his exercise capacity was very low (V(O2)peak = 10.7 ml/min/kg), probably attributable to his lifetime of sedentary living. The data suggest that, with pre-exercise sucrose administration, such patients may be candidates for systematic reconditioning, which may improve functional capacity and quality of life.

Aged↗
PubMed2006

Evaluating the strengths and weaknesses of tuberculosis educational activities for prisoners in Honduras.

SETTING: Prisons throughout Honduras. OBJECTIVE: To assess the strengths, weaknesses, and opportunities to improve non-standardized tuberculosis (TB) educational campaign materials utilized in prisons. DESIGN: A qualitative assessment was conducted. Prison staff completed a survey describing development and implementation of educational activities at each prison (n=25). Completed surveys with photographs or copies of educational materials were collected and cataloged. The content, literacy demand, illustrations, learning stimulation, and cultural appropriateness of cataloged items were assessed using an adapted version of the Suitability Assessment of Materials Instrument. Results from this assessment were examined in conjunction with information collected through focus groups conducted with prisoners and interviews with prison staff. RESULTS: Campaign strengths included the development and dissemination of print materials appropriate for individuals with low literacy levels. By actively engaging prisoners in the campaigns, materials often incorporated the language, values, and experiences encountered within prison culture. Content of print materials and presentations focused on correcting misperceptions and facilitating acceptance of TB control activities. Campaign weaknesses included the creation of illustrations that could perpetuate the stigma associated with TB and use of some materials in which the purpose was not apparent. CONCLUSIONS: The campaigns were generally suitable, and the evaluation allowed for their improvement.

Adult↗
PubMed2005

The role of mesopores in intracrystalline transport in USY zeolite: PFG NMR diffusion study on various length scales.

PFG NMR has been applied to study intracrystalline diffusion in USY zeolite as well as in the parent ammonium-ion exchanged zeolite Y used to produce the USY by zeolite steaming. The diffusion studies have been performed for a broad range of molecular displacements and with two different types of probe molecules (n-octane and 1,3,5-triisopropylbenzene) having critical molecular diameters smaller and larger than the openings of the zeolite micropores. Our experimental data unambiguously show that, in contrast to what is usually assumed in the literature, the intracrystalline mesopores do not significantly affect intracrystalline diffusion in USY. This result indicates that the intracrystalline mesopores of USY zeolite do not form a connected network, which would allow diffusion through crystals only via mesopores.

Adsorption↗
PubMed2005

Comparison of the benefits and complications between laparoscopic and open Roux-en-Y gastric bypass surgeries.

BACKGROUND: In recent years, there has been an increase in numbers of individuals seeking laparoscopic surgical procedures for obesity. The current study compared the benefits and risks between laparoscopic and open Roux-en-Y gastric bypass (RYGBP) performed at the same center for more than 2,000 patients. METHODS: The study population consisted of 1,077 laparoscopic and 1,198 open RYGBP procedures performed between the years 1999 and 2002. Measurements included population characteristics, anthropometries, complications, and hospital stay. RESULTS: The laparoscopic RYGBP has both advantages and disadvantages. The disadvantages include a longer operative time and a higher incidence of fistulas, internal hernias, and small bowel obstruction. The advantages of the laparoscopic procedure are shorter hospital stay, lower incidence of wound infection, and fewer incisional hernias. Both procedures cause similar changes in body weight, but laparoscopic RYGBP is associated with less lean tissue loss during the early postoperative period. CONCLUSION: Both laparoscopic and open RYGBP are effective in inducing massive weight loss. There are, however, differences in the benefits and risks between the two procedures.

Adult↗
PubMed2005

Pulsed-field gradient nuclear magnetic resonance study of transport properties of fluid catalytic cracking catalysts.

Pulsed-field gradient nuclear magnetic resonance (PFG NMR) has been applied to study molecular diffusion in industrial fluid catalytic cracking (FCC) catalysts and in USY zeolite for a broad range of molecular displacements and temperatures. The results of this study have been used to elucidate the relevance of molecular transport on various displacements for the rate of molecular exchange between catalyst particles and their surroundings. It turned out that this rate, which may determine the overall rate and selectivity of FCC process, is primarily related to the diffusion mode associated with displacements larger than the size of zeolite crystals located in the particles but smaller than the size of the particles. This conclusion has been confirmed by comparative studies of the catalytic performance of different FCC catalysts.

Catalysis↗
PubMed2005

Risk factors for disease progression in patients with lower urinary tract symptoms/benign prostatic hyperplasia (LUTS/BPH): a systematic analysis of expert opinion.

Disease progression has become an important issue for the management of lower urinary tract symptoms/benign prostatic hyperplasia (LUTS/BPH). Although several risk factors have been identified, no specific patient risk profiles have been established that can be useful in the day-to-day management of LUTS/BPH. In this study, an international panel of urologists developed a risk classification based on the attribution of a risk score to 243 unique patient profiles. From the perspective of clinical decision making, it was concluded that postvoid residual, symptom severity and maximum flow rate are the most relevant determinants of the risk of disease progression.

Disease Progression↗
PubMed2005

Integrating risk profiles for disease progression in the treatment choice for patients with lower urinary tract symptoms/benign prostatic hyperplasia: a combined analysis of external evidence and clinical expertise.

The RAND appropriateness method was used to explore the relevance of risk factors for disease progression in the treatment choice for patients with lower urinary tract symptoms/benign prostatic hyperplasia (LUTS/BPH). A total of, 12 international experts assessed the appropriateness of various treatments for 243 risk profiles. Highest appropriateness rates were found for alpha1-adrenoceptor antagonists (68% of profiles) and combination therapy (46%). A large prostate volume was the dominant argument in favour of 5alpha-reductase inhibitors and combination therapy, but was irrelevant for the choice of surgery. Considerable postvoid residual, severe symptoms and poor maximum flow rate were the most important factors in favour of surgery.

Disease Progression↗
PubMed2005

Unintentional injury depictions in popular children's television programs.

OBJECTIVES: The frequency and magnitude of depictions of risky events and unintentional injuries in top ranked children's animated and live action television programs was assessed. METHODS: Qualitative and quantitative media content analysis were used. Scenes from television episodes were examined for the depiction of risky events and unintentional injuries. RESULTS: A total of 201 actual and potential injury related events were tabulated in 99 episodes aired in 2003 and 2004. Only 26% of the risky events depicted led to an injury or physical consequence. More than 80% of the events involved behavioral or environmental risk factors. Safety factors were not present in over 90% of risky events depicted. The general tone and context of events was humor or indifference rather than concern or action, with little or no relevance to the plot. CONCLUSION: Unintentional injuries are the leading cause of death and disability for children, yet animated and live action television programs marketed to children continue to portray injury risk inaccurately. Working with the children's television production industry to improve injury depiction is a much needed advocacy activity.

Child↗
PubMed2004

Serum activity/concentration profiles of a sustained-released formulation of sulphathiazole-trimethoprim (2.5:1) in calves.

Thirty-six two-week-old healthy Holstein-Friesian calves weighing between 52 and 58 kg were divided at random into three groups of 12; group A calves were given a single oral bolus containing 2.5 g sulphathiazole and 1 g trimethoprim in a sustained-release formulation; group B received the same doses of the drugs but the trimethoprim was not in a sustained-release formulation; group C received a bolus containing 2.5 g sulphathiazole and 0.5 g conventional trimethoprim. Blood samples were collected at intervals for two days, the serum was separated and the composite antibacterial activity profiles of the mixture were analysed by an agar-diffusion microbiological method. The mean maximum activities in the serum of the three groups were 23.4 microg/ml in group A, 9.25 microg/ml in group B and 8.01 microg/ml in group C. The mean areas under the curves of the serum activity time curves were 838 microg/ml/hour in group A, 216 microg/ml/hour in group B and 182 microg/ml/hour in group C.

Animals↗
PubMed2004

Normal skin of HIV-infected individuals contains increased numbers of dermal CD8 T cells and normal numbers of Langerhans cells.

Dysregulation of the skin immune system (SIS) could explain the high prevalence of skin disorders in HIV+ individuals. The present study was carried out to determine whether alterations in the cell population of SIS and epidermal immunoactivation occur in the normal skin of HIV+ individuals. Forty-five biopsies were taken from the normal upper arm skin of 45 HIV+ patients and of 15 healthy controls. HIV+ individuals were divided into three categories according to their CD4 cell blood count (<200, 200-499 and > or = 500/microl). Hematoxylin-eosin was used to stain tissue sections for morphological analysis and immunohistochemistry was used for the evaluation of the frequency of macrophages, Langerhans cells, and CD lymphocyte subsets. In addition, semiquantitative analysis of LFA-1, ICAM-1 and HLA-DR was determined in epidermal cells. Macrophages, Langerhans cells, and CD lymphocyte subsets did not differ significantly between any of the patient categories and the control group. When all HIV+ individuals were compared as a group to the control group, a significant increase in dermal CD8+ T lymphocytes (P < 0.01) and lower CD4-CD8 ratios (P < 0.01) were observed in the HIV+ individuals. Epidermal ICAM-1 and HLA-DR expression was negative in both HIV+ and normal skin biopsies. No evidence of a depletion of the SIS population or of epidermal immunoactivation in normal skin from HIV+ individuals was demonstrable, suggesting that alterations in the central immune system are not necessarily reflected in the SIS of HIV-infected patients.

Adult↗
PubMed2004

Estradiol inhibits GSK3 and regulates interaction of estrogen receptors, GSK3, and beta-catenin in the hippocampus.

Estrogens regulate a wide set of neuronal functions such as gene expression, survival and differentiation in a manner not very different from that exerted by neurotrophins or by growth factors. The best-studied hormonal action is the transcriptional activation mediated by estrogen receptors. However, the direct effects of estrogen on growth factor signaling have not been well clarified. The present data show that estradiol, in vivo, induces a transient activation of GSK3 in the adult female rat hippocampus, followed by a more sustained inhibition, as inferred from phosphorylation levels of Tau. Similar data was obtained from cultured hippocampal neurons when treated with the hormone. The transient activation was confirmed by direct measure of GSK3 kinase activity. In addition, our results show a novel complex of estrogen receptor alpha, GSK3, and beta-catenin. The presence of the hormone removes beta-catenin from this complex. There is a second complex, also affected by estradiol, in which Tau is associated with GSK3, beta-catenin, and elements of the PI3 kinase complex. Considering the role of GSK3 in neurodegeneration, our data suggest that part of the neuroprotective effects of estrogen may be due to the control of GSK3.

Animals↗
PubMed2003

[NADIS 2000, development of an electronic medical record for patients infected by HIV, HBV and HCV].

OBJECTIVE: to develop an electronic medical record for patients living with HIV, HBV or HCV in order to improve their management, facilitate communication between all the caregivers, and to create a useful medical database for research and assessments. This project (NADIS 2000) involved 6 centres of Infectious Diseases in France in partnership with Fédialis Médica (subsidiary of the GSK group in France). METHODS: A specifications sheets was drawn-up by a piloting Committee regrouping the various correspondents in each centre and a computer expert representing Fédialis Médica. A Scientific and Development committee regrouped the heads of departments of each centre and the representatives from Fédialis Médica and GSK and was charged with defining the general concept of the project and guaranteeing the scientific and clinical aspects. RESULTS: NADIS 2000 version 1.0 was activated in the departments of infectious diseases in Nice and Toulouse in November 2000 and in others Units at the end of 2001. NADIS 2000 permitted real-time use by the physicians in the Outpatients and Day-care Units and was easily handled by all the practitioners. Its use was eased by the principles clearly defined before its application (department project, progressive but exhaustive use), an intuitive interface simulating a consultation, and functions proposing direct benefits for the physicians (graphical visualization of the biological variables, printing of prescriptions and letters). CONCLUSION: The activation and input methods of NADIS 2000 are user friendly and the physicians find it rapidly easy to use. New functional aspects are being developed as well as its use in other hospital departments.

Computer Communication Networks↗
PubMed2003

A pilot study to evaluate the safety and feasibility of the administration of AZT/3TC fixed dose combination to HIV infected pregnant women and their infants in Rio de Janeiro, Brazil.

OBJECTIVES: To evaluate the safety and feasibility of zidovudine and lamivudine (AZT/3TC) given to HIV infected pregnant women and their infants in Rio de Janeiro, Brazil. METHODS: This open label phase II study enrolled 40 HIV infected antiretroviral naive women >or=20 weeks gestation, CD4 <500 cells x10(6)/l, from two public hospitals. TREATMENT: fixed dose AZT 300 mg/3TC 150 mg by mouth every 12 hours until labour; AZT 300 mg by mouth every 3 hours until delivery; infants: AZT 4 mg/kg every 12 hours plus 3TC 2 mg/kg every 12 hours for 6 weeks. Blood haematology and chemistry were monitored; adherence evaluated by pills count; efficacy measured by changes in lymphocyte (CD4) and viral load, and by HIV RNA-PCR tests performed at birth, 6 and 12 weeks, to diagnose infant infection. No women breast fed. RESULTS PATIENT CHARACTERISTICS: mean age 24.48 (SD 3.5) years; gestational age 24.5 (4.5) weeks; AZT/3TC duration 14.4 (4.4) weeks; vaginal delivery: 11/39; caesarean section: 28/39. Entry and pre-labour CD4: 310/486 cells x10(6)/l (p<0.001); entry and pre-labour viral load: 53 818/2616 copies/ml (p<0.001). Thirty nine women tolerated treatment with >80% adherence; one was lost to follow up. Five newborns were excluded from 3TC receipt. All 39 babies were uninfected. Haematological toxicity in newborns was common: anaemia in 27; neutropenia in five (two severe); platelets counts <100000 in two. All values recovered on study completion. CONCLUSIONS: Fixed dose AZT/3TC is well accepted, gives improvements in CD4 and viral load; no infants were HIV infected. Haematological toxicity in infants needs careful monitoring.

Administration, Oral↗
PubMed2001

An Epstein-Barr virus deletion mutant associated with fatal lymphoproliferative disease unresponsive to therapy with virus-specific CTLs.

There is a growing interest in using antigen-specific T cells for the treatment of human malignancy. For example, adoptive transfer of Epstein-Barr virus (EBV)-specific cytotoxic T lymphocytes (CTLs) has been effective prophylaxis and treatment of EBV-associated lymphoproliferative disease in immunocompromised patients. For all immunotherapies, however, there has been a hypothetical concern that mutations in tumor-specific antigens may lead to tumor escape. We now demonstrate that such events may indeed occur, with lethal outcome. A patient who developed lymphoma after marrow transplantation received donor-derived, EBV-specific CTLs but died with progressive disease. The tumor cells proved substantially less sensitive to cytolysis than the EBV-transformed B-cell line used for CTL generation. The major cytolytic activity of the donor CTL was directed against 2 HLA-A11-restricted epitopes in the viral EBNA-3B antigen. Sequence analysis of this gene in the tumor virus revealed a 245-base pair deletion, which removed these 2 CTL epitopes. Hence, the viral antigen in the tumor had mutated in a way that allowed escape from CTLs. Analysis of EBV polymorphisms demonstrated that before CTL infusion, more than one virus was present, including a virus with wild-type EBNA-3B. After CTL infusion, only the virus with the EBNA-3B deletion could be detected, suggesting that the infused CTLs had selected a resistant strain in vivo. Such an occurrence, even when polyclonal CTL lines are used against genetically stable virus antigens, suggests that escape mutants may be a serious problem when CTL therapy is directed against more unstable tumor cell-derived targets.

Adolescent↗