A PIXE and ICP-MS analysis of metallic atmospheric contaminants in tree bark tissues, a basis for biomonitoring uses

The qualitative and quantitative metallic content of tree barks of Argania spinosa (L.) Skeels were studied. Argania spinosa is an endemic species in Morocco. This tree is adapted to semi-arid climates and exposed to specific conditions of relative humidity, temperature, wind, and particle transport. Three sites were sampled in Morocco: the large town of Rabat, the harbor of Agadir, and A?t Baha, a countryside location exposed to continuous desert wind. The methodologies included (1) in situ microanalysis with proton-induced X-ray emission (PIXE) and (2) trace element determinations by mass spectrometry with inductively coupled plasma (ICP-MS) associated with extraction procedures. Both methods allowed detection of elements coming from different bark compartments. The profile of airborne contaminants in the barks was typical of the sampling sites. The level of lead in barks sampled in Rabat reached 100 ng cm(-2), or higher, while it varied between 3 and 35 ng cm(-2) in A?t Baha. The in situ study of the microscopic structure of the bark provided the location of major and minor elements at various depths inside the bark. A differential between free deposit on the bark surface and penetrated content was found for the major and trace elements. The free deposit on the bark surface was suspected to be mostly the result of recent contamination. Part of the contaminants spread out on the surface penetrated the superficial suber. This long-term accumulation affected mostly Pb. In deeper levels, airborne elements at low concentrations and elements resulting from root uptake were concurrently present and resulted in a complex situation, as noted for zinc.     

The monitoring of hematopoietic stem cell transplant donors and recipients from endemic areas for malaria

Malaria is an unusual complication after hematopoietic stem cell transplantation in non-endemic countries. However, transplant candidates, recipients and donors living in endemic regions frequently report previous episodes of malaria. This fact could represent an important risk for immunosuppressed recipients that could develop severe malaria cases. We report a case of hematopoietic stem cell transplant (HSCT) in which the donor had a history of previous malaria, and close monitoring was performed before and after procedure by parasitological and molecular tests. The donor presented Plasmodium vivax in thick blood smears one month after transplant and was treated according to Brazilian Health Ministry guidelines. The polymerase chain reaction (PCR) was able to detect malaria infection in the donor one week earlier than thick blood film. Even without positive results, the recipient was pre-emptively treated with chloroquine in order to prevent the disease. We highlight the importance of monitoring recipients and donors in transplant procedures with the aim of reducing the risk of malaria transmission.     

Attitudes of health care workers to influenza vaccination: why are they not vaccinated?

BACKGROUND: Compliance rates with influenza vaccination among health care workers (HCW) are historically low. Although a safe and effective vaccine is available, the reasons for such poor compliance are not well understood. METHODS: After a campaign encouraging HWC to vaccinate against influenza, we conducted an epidemiologic survey to evaluate the reasons for compliance and accompanied the impact of these measures (campaign and questionnaire) during the subsequent 2 years. RESULTS: Compliance rate was 34.4%. Multivariate analysis showed that "older age" (P = .008), "believing that most departmental colleagues had been vaccinated" (P < .0001), and "having cared for patients suffering from severe influenza" (P = .031) were significantly associated with compliance with influenza vaccination. The main reason given for being vaccinated was "individual protection" and, to a lesser extent, "protection for the patient." In subsequent years, compliance rates among those participating in the survey fell to 20.2% in 2004, when the only measure taken was the questionnaire, and to 12.75% in 2005, when no educational intervention was scheduled. CONCLUSION: We conclude that a better understanding of HCW's negative attitude regarding influenza vaccination is needed as are more appealing and convincing continuous education programs, to ensure motivation for influenza vaccination over a longer period.     

A randomized single-blind trial of whole versus split-dose polyethylene glycol-electrolyte solution for colonoscopy preparation

BACKGROUND: Colonoscopy preparation regimens are often poorly tolerated because they require use of large-volume bowel preparation solution and diet restrictions for adequate cleansing. This study evaluated the efficacy and tolerability of a split-dose polyethylene glycol-electrolyte solution plus bisacodyl and a regular diet. METHODS: A total of 187 patients (104 men, 83 women; age range 18-91 years) were randomly assigned to receive either 3 L of polyethylene glycol-electrolyte solution (n = 96; Group A) with a liquid diet on the day before colonoscopy, or 2 L of polyethylene glycol-electrolyte solution, one tablet of bisacodyl, and a minimally restricted diet on the day before colonoscopy, and then 1 L of the same solution on the day of colonoscopy (n = 91; Group B). Acceptability, adverse events, and willingness to retake the preparation were assessed by questionnaire. The quality of the preparation was graded by an endoscopist, blinded to the type of preparation, by using a previously described scale (excellent to poor). RESULTS: There were 96 patients in Group A and 91 in Group B. Colon cleansing was significantly better in Group B with regard to the overall quality of the preparation (p lt; 0.05). Compliance was significantly higher in Group B as evidenced by the lower number of patients who discontinued the preparation (4 vs. 15; p = 0.02) because of side effects such as nausea or vomiting. The degree of discomfort, adverse events, and willingness to retake the preparation were not significantly different between the groups. CONCLUSIONS: Colonic preparation with split-dose polyethylene glycol-electrolyte provided better quality colon cleansing and higher compliance, with less dietary restrictions, than preparation with whole-dose polyethylene glycol-electrolyte.     

Live measles vaccine expressing the secreted form of the West Nile virus envelope glycoprotein protects against West Nile virus encephalitis

The Schwarz strain of measles virus (MV), a live attenuated RNA virus, is one of the safest and most effective human vaccines available. Immunization with MV vaccine expressing heterologous antigen is an attractive strategy to prevent emerging viral diseases. West Nile virus (WNV), which recently emerged in North America, is an important mosquito-borne flavivirus that causes numerous cases of human encephalitis, thus urging the development of a vaccine. To evaluate the efficacy of recombinant MV for the prevention of WNV encephalitis, we constructed a live attenuated Schwarz MV (MVSchw-sE(WNV)) expressing the secreted form of the envelope glycoprotein from the virulent IS-98-ST1 strain of WNV. Inoculation of MV-susceptible mice with MVSchw-sE(WNV) induced both high levels of specific anti-WNV neutralizing antibodies and protection from a lethal challenge with WNV. Passive administration with antisera to MVSchw-sE(WNV) prevented WNV encephalitis in BALB/c mice challenged with a high dose of WNV. The present study is the first to report that a recombinant live attenuated vector based on an approved and widely used MV vaccine can protect against a heterologous, medically important pathogen.     

Retrospective epidemiological study of Latin American patients with transfusional hemosiderosis: the first Latin American epidemiological study in iron overload--the RELATH study

The retrospective epidemiological study of Latin Americans with transfusional hemosiderosis is the first regional patient registry to gather data regarding the burden of transfusional hemosiderosis and patterns of care in these patients. Retrospective and cross-sectional data were collected on patients ≥2 years with selected chronic anemias and minimum 20 transfusions. In the 960 patients analyzed, sickle-cell disease (48·3%) and thalassemias (24·0%) were the most frequent underlying diagnoses. The registry enrolled 355 pediatric patients (187 with sickle-cell disease/94 with thalassemia). Serum ferritin was the most frequent method used to detect iron overload. Complications from transfusional hemosiderosis were reported in ~80% of patients; hepatic (65·3%), endocrine (27·5%), and cardiac (18·2%) being the most frequent. These data indicate that hemoglobinopathies and complications due to transfusional hemosiderosis are a significant clinical problem in the Latin American population with iron overload. Chelation therapy is used insufficiently and has a high rate of discontinuation.     

Comparison of direct immunofluorescence, conventional cell culture and polymerase chain reaction techniques for detecting respiratory syncytial virus in nasopharyngeal aspirates from infants

A total of 316 samples of nasopharyngeal aspirate from infants up to two years of age with acute respiratory-tract illnesses were processed for detection of respiratory syncytial virus (RSV) using three different techniques: viral isolation, direct immunofluorescence, and PCR. Of the samples, 36 (11.4%) were positive for RSV, considering the three techniques. PCR was the most sensitive technique, providing positive findings in 35/316 (11.1%) of the samples, followed by direct immunofluorescence (25/316, 7.9%) and viral isolation (20/315, 6.3%) (p < 0.001). A sample was positive by immunofluorescence and negative by PCR, and 11 (31.4%) were positive only by RT-PCR. We conclude that RT-PCR is more sensitive than IF and viral isolation to detect RSV in nasopharyngeal aspirate specimens in newborn and infants.     

Lack of evidence of premature atherosclerosis in untreated severe isolated growth hormone (GH) deficiency due to a GH-releasing hormone receptor mutation

BACKGROUND: GH deficiency (GHD) acquired at adult age as a result of pathological processes of the pituitary gland or the hypothalamus causes changes that are associated with worsening cardiovascular risk. They include increase in abdominal obesity, total and low- density lipoprotein cholesterol, and C-reactive protein. GHD adults also have thickening of the carotid arteries. It has been postulated that GHD is the link between hypopituitarism and the increase in cardiovascular and cerebrovascular mortality observed in hypopituitarism. However, several confounding factors exist, such as associated pituitary deficits and replacement of other hormones or surgical or radiological therapies used to treat the underlying pituitary of hypothalamic pathologies. OBJECTIVE: The aim of this study was to determine the consequences of lifetime isolated GHD (IGHD) on the metabolic and cardiovascular status of adult members of a large Brazilian cohort with severe IGHD due to a homozygous mutation in the GHRH receptor gene. DESIGN: Twenty-two GH naive adult dwarfs (10 men and 12 women; aged 44 +/- 12 yr) were compared with 22 healthy volunteers (10 men and 12 women; aged 45 +/- 12 yr) living in the same area. RESULTS: GHD subjects had increased abdominal obesity, higher total and low-density lipoprotein cholesterol, and higher C-reactive protein than controls. They did not have an increase in carotid wall thickness, and there was no evidence of premature atherosclerosis as evaluated by exercise echocardiography. CONCLUSIONS: In this homogeneous cohort residing in a rural area of Brazil, lifetime, untreated severe IGHD is not associated with evidence of premature atherosclerosis despite unfavorable cardiovascular risk profile.