Environmental and anthropic variabilities at Guanabara Bay (Brazil): A comparative perspective of metal depositions in different time scales during the last 5,500 yrs.

The determination of age-dated metal sediment accumulation rates in a representative South American bay is able to portray the dimension of human impacts during the colonial occupation and industrial periods. Many studies have assessed metal distribution and chronology at Guanabara Bay, in Brazil. However, understanding natural variabilities associated to paleoclimatic changes and comparing these natural variabilities to anthropogenic processes are not well established to date. Accurate geochronological control integrating ages determined by 210Pb and 14C chronologies through an exponential spline fit model allowed for a precise definition of changes associated to the holocene marine transgression, as well as the colonial period, leading to intense land use changes, and the industrial period. The reference values of the system were defined based on their concentrations and the accumulation rates of ecotoxicologically important metals. Al, Ba, Fe, Cd, Cu, Cr, Li, Ni, Mn, Pb, Si, Ti, V, and Zn distributions were determined in a Guanabara Bay core (BG-28) by the EPA 3051 method. Elemental distribution profile assessment allowed for the identification of variabilities associated to weathering processes, predominantly of lithogenic origin, mainly for Al, Ba, Fe, Li, Si, and V. Weathering processes occurred simultaneously to land use changes in the drainage basin since the colonial period, at 400 cal yr BP, and during the industrial period, mainly after the 1960s, denoted by Cd, Cr, Cu, Mn, Pb and Zn increases. The highest average metal enrichment values metals associated to industrial processes reached 5.95, with 119.1-fold higher accumulation rates than the background accumulation values observed between 4200 and 500 cal yr BP.

Heteronuclear molecules from matrix isolation sublimation and atomic diffusion.

We demonstrate the production of cryogenic beams of heteronuclear molecules from the matrix isolation sublimation (MISu) technique. A sapphire mirror serves as a substrate whereupon a solid Ne matrix is grown. Atoms of Li, H, Ca, and C are implanted into the matrix via subsequent laser ablation of different solid precursors such as Ca, Li, LiH, and graphite. The matrix is sublimated into vacuum generating a cryogenic beam of Ne carrying the previously isolated neutral atomic and molecular species. A compact and low energy electron source and time-of-flight mass spectrometer was designed to fit this system at low temperature. With electron ionization time-of-flight mass spectrometry, we analyze the species coming from MISu and demonstrate the formation of heteronuclear molecules in the matrix. In this first study, we produced LiCa from the sequential implantation of Li and Ca into the matrix and some clusters of CnLim after Li and C ablation. Also from ablation of a single LiH pellet, we observed clusters of LinHm. This novel technique opens up the opportunity to generate cryogenic beams of different molecules for precision physics and chemistry studies. Laser or microwave high resolution spectroscopy of a molecular beam benefits from low translational and rovibrational temperatures and forward velocities, such as the ones produced in this technique. Toward the prospect of enhancing the molecular formation, we introduce a new method to study the atomic diffusion of Li and Ca in the Ne matrix via laser spectroscopy during sublimation. We estimate a small diffusion coefficient at 7 K, but a surprisingly linear atomic dispersion during sublimation. The method is extensive to other species and matrices.

Cryogenic mount for mirror and piezoelectric actuator for an optical cavity.

We present the development of a mount that accommodates a mirror and a piezoelectric actuator with emphasis on physical needs for low temperature operation. The design uses a monolithic construction with flexure features that allow it to steadily hold the mirror and the piezoelectric actuator without glue and accommodate differential thermal contraction. The mount is small and lightweight, adding little heat capacity and inertia. It provides a pre-loading of the piezoelectric actuator as well as a good thermal connection to the mirror and a thermal short across the piezoelectric actuator. The performance of the assemblies has been tested by thermally cycling from room temperature down to 3 K more than a dozen times and over one hundred times to 77 K, without showing any derating. Such mounts are proposed for the cryogenic optical enhancement cavities of the ALPHA experiment at CERN for laser spectroscopy of antihydrogen and for hydrogen spectroscopy in our laboratory at UFRJ.

Identification of differentially expressed genes induced by hydroxyurea in reticulocytes from sickle cell anaemia patients.

1. The major effect associated with hydroxyurea (HU) treatment of sickle cell anaemia (SCA) patients is an increase in fetal haemoglobin (HbF) synthesis, which inhibits the polymerization of haemoglobin S. 2. Hydroxyurea improves clinical symptoms by reducing the frequency of pain and vaso-occlusive crises, acute chest syndrome, transfusion requirements and hospitalization. 3. The molecular mechanisms responsible for HU-mediated induction of fetal globin transcription are not completely understood. Therefore, the aim of the present study was to identify differentially expressed genes participating in these mechanisms. 4. We established two suppression subtractive hybridization (SSH) libraries from reticulocytes obtained from SCA patients either not on or on HU treatment. The gene expression of some of the genes identified was subsequently evaluated by real-time polymerase chain reaction (PCR). 5. Genes identified with altered expression included SUDS3, FZD5 and PHC3, which may be associated with the regulation of globin expression. 6. This is the first demonstration of an association between HU treatment and the expression of genes identified in erythroid cells.

Respiratory viruses in children younger than five years old with acute respiratory disease from 2001 to 2004 in Uberlândia, MG, Brazil.

The main viruses involved in acute respiratory diseases among children are: respiratory syncytial virus (RSV), influenzavirus (FLU), parainfluenzavirus (PIV), adenovirus (AdV), human rhinovirus (HRV), and the human metapneumovirus (hMPV). The purpose of the present study was to identify respiratory viruses that affected children younger than five years old in Uberlândia, Midwestern Brazil. Nasopharyngeal aspirates from 379 children attended at Hospital de Clínicas (HC/UFU), from 2001 to 2004, with acute respiratory disease, were collected and tested by immunofluorescence assay (IFA) to detect RSV, FLU A and B, PIV 1, 2, and 3 and AdV, and RT-PCR to detect HRV. RSV was detected in 26.4% (100/379) of samples, FLU A and B in 9.5% (36/379), PIV 1, 2 and 3 in 6.3% (24/379) and AdV in 3.7% (14/379). HRV were detected in 29.6% (112/379) of the negative and indeterminate samples tested by IFI. RSV, particularly among children less than six months of life, and HRV cases showed highest incidence. Negative samples by both IFA and RT-PCR might reflect the presence of other pathogens, such as hMPV, coronavirus, and bacteria. Laboratorial diagnosis constituted an essential instrument to determine the incidence of the most common viruses in respiratory infections among children in this region.

Omeprazole, clarithromycin and furazolidone for the eradication of Helicobacter pylori in patients with duodenal ulcer.

AIM: To evaluate the efficacy of omeprazole plus clarithromycin and furazolidone in Helicobacter pylori eradication and duodenal ulcer healing in Brazilian patients. METHODS: Forty H. pylori-positive patients with duodenal ulcer were randomized to receive 20 mg omeprazole o.m. or b.d. for 1 month plus 500 mg clarithromycin (b.d. ) and 200 mg furazolidone (b.d.) for 1 week. RESULTS: Three months after the end of the treatment the eradication rates were 90% by intention-to-treat analysis, and 97% by per protocol analysis. Mild side-effects were observed in 25 patients, none of whom abandoned the protocol. No difference was observed between the 20 mg and 40 mg omeprazole daily doses. Cure or significant improvement of the symptoms and of the histological alterations were observed after H. pylori eradication. CONCLUSION: Our results demonstrate that clarithromycin and furazolidone in combination with omeprazole are a good alternative for H. pylori eradication in Brazilian patients with duodenal ulcer.

The use of ethanol injection under endoscopic control to palliate dysphagia caused by esophagogastric cancer.

Nine patients with dysphagia caused by unresectable tumors of the esophagus and cardia (eight with squamous-cell carcinomas and one with adenocarcinoma) were treated with absolute (95 g/l) alcohol mixed with 0.5% methylene blue. Total volumes ranging from 16 to 41 ml were injected endoscopically during sessions separated at 5-day intervals. The results were evaluated by endoscopic and radiological follow-up, as well as clinically, according to Bown's dysphagia score. Treatment had to be stopped in one patient with a preexisting esophagobronchial fistula. In the remaining eight patients, the mean dysphagia score decreased from 3.4 before treatment to 1.2 after treatment. After treatment, all patients were able to swallow a solid or semisolid diet. Treatment was repeated when dysphagia recurred, with a mean interval of 31.5 days between treatments. No complications were encountered. In our view, the preliminary results using this simple and inexpensive technique warrant comparative trials with other methods of palliation.

Management of cysts and pseudocysts complicating chronic pancreatitis. A retrospective study of 143 patients.

One hundred and forty-three patients presenting with 170 cysts and pseudocysts complicating chronic pancreatitis were followed between 1980 and 1990. Thirteen patients were managed conservatively and pseudocysts spontaneously disappeared in 11 patients. Cysts were small (average 28 mm), often communicating with the ductal system without dilatation of the main pancreatic duct. Percutaneous puncture was performed in 47 patients with a low morbidity rate (5%) but a high rate of recurrence (57%). Thirteen of 39 patients (33%) who underwent percutaneous puncture as initial treatment did not require further therapy. Communication of pancreatic cysts with the ductal system was associated with poorer results after percutaneous puncture. Percutaneous drainage was performed in 9 patients with a low morbidity rate (12%). The mean duration of drainage was 10.4 days. Five patients were definitively cured. Seventy-eight endoscopic cystoenterostomies were performed in 71 patients. Complications occurred in 12 patients (15.3%) and one patient died (1.3%). Endoscopic cystoenterostomy was effective in 39 of 54 patients initially treated with this technique (72.2%). Sixty-three patients underwent surgical management, principally internal drainage (83%), with a morbidity rate of 13.2% and a mortality rate of 1.3%. Twenty-one of the 29 patients (72%) who underwent surgery as initial treatment did not require further therapy. Endoscopic cystoenterostomy is an efficient treatment of cysts and pseudocysts complicating CP when anatomical conditions are favorable. Percutaneous drainage also appears to be a satisfactory treatment modality. Surgery should be considered in cases of failure or technical impossibility of endoscopic or percutaneous approaches.

Treatment of granular cell tumor of the esophagus by endoscopic injection of dehydrated alcohol.

Granular cell tumor of the esophagus (GCTE) is a rare and mostly benign neoplasm. Its etiology is unknown and its histogenesis is uncertain. It is usually an incidental finding, detected during esophagogastroduodenoscopy. In symptomatic cases, or when the lesions are more than 1 cm in diameter, the treatment of choice has been local resection. Asymptomatic patients or tumors smaller than 1 cm are followed endoscopically. We describe a case of GCTE successfully treated by endoscopic injection of dehydrated ethyl alcohol. To our knowledge, it is the first time that such a tumor was treated by this accessible and low-cost technique.

[Treatment of pseudocysts in acute pancreatitis. Retrospective study of 45 patients]. / Traitement des pseudokystes de pancréatite aiguë. Etude rétrospective de 45 patients.

A total of 55 pancreatic pseudocysts in 45 patients with acute pancreatitis were managed between 1980 and 1990. Six patients were managed conservatively with resolution of pseudocysts in 5 patients. All pancreatic pseudocysts that disappeared were smaller than 35 mm. CT or ultrasound-guided aspiration were performed in 26 patients with a morbidity rate of 5%. Nine among 21 patients (42%) who were initially treated by percutaneous puncture were definitively cured: all pseudocysts were smaller than 55 mm. Nine patients were managed by long-term percutaneous drainage: 3 minor complications occurred and in 7 patients, no other treatment was necessary even for large pseudocysts. Endoscopic cystoenterostomy was performed in 12 patients. Only 15 pseudocysts (27%) bulged into the digestive wall, mainly of the stomach. Three complications (following 2 cystogastrostomies) occurred and one patient died after endoscopic cystogastrostomy. In 7 patients (58%), no other treatment was necessary even for large pancreatic pseudocysts. Surgery was required in 13 patients but only 4 patients underwent surgery as primary treatment. One major complication occurred and one patient died. Percutaneous drainage and endoscopic cystoenterostomy when technically feasible, are effective treatments of pancreatic pseudocysts complicating acute pancreatitis.