New Radiation Dosimetry Estimates for [18F]FLT based on Voxelized Phantoms.

3'-Deoxy-3-[18F]fluorothymidine, or [18F]FLT, is a positron emission tomography (PET) tracer used in clinical studies for noninvasive assessment of proliferation activity in several types of cancer. Although the use of this PET tracer is expanding, to date, few studies concerning its dosimetry have been published. In this work, new [18F]FLT dosimetry estimates are determined for human and mice using Monte Carlo simulations. Modern voxelized male and female phantoms and [18F]FLT biokinetic data, both published by the ICRP, were used for simulations of human cases. For most human organs/tissues the absorbed doses were higher than those reported in ICRP Publication 128. An effective dose of 1.70E-02 mSv/MBq to the whole body was determined, which is 13.5% higher than the ICRP reference value. These new human dosimetry estimates obtained using more realistic human phantoms represent an advance in the knowledge of [18F]FLT dosimetry. In addition, mice biokinetic data were obtained experimentally. These data and a previously developed voxelized mouse phantom were used for simulations of animal cases. Concerning animal dosimetry, absorbed doses for organs/tissues ranged from 4.47 ± 0.75 to 155.74 ± 59.36 mGy/MBq. The obtained set of organ/tissue radiation doses for healthy Swiss mice is a useful tool for application in animal experiment design.

Using the mini-VIDAS(®) Easy Salmonella protocol to assess contamination in transitional and coastal waters.

Classical methodologies for Salmonella detection may be too long in time to assure public safety. Presently, one of the fastest assays for Salmonella detection using the mini-VIDAS(®) system is the Easy Salmonella protocol. This assay, developed for food matrixes analysis, was here assessed for the applicability on the detection of these bacteria in transitional and saltwaters. The presence of Salmonella was detected in 4.2 % of the samples studied. In these transitional waters, the proposed protocol presented an efficiency of 79.1 %, due to a high false positive rate (20.8 %), and a false negative rate of 0 %-implying reducing analysis time, the use of enrichment broths, and making it more cost effective. Despite the multitude of samples nature, the method here described revealed to be an efficient and promising tool for transitional waters analysis.

The comparative biomechanics of the reinforced interdental crossover and the Stout loop composite splints for mandibular fracture repair in dogs.

OBJECTIVES: To describe a new technique, the reinforced interdental crossover composite splint (RIC), for transverse mandibular fracture repair in dogs. This technique was compared biomechanically with the established reinforced interdental Stout loop composite splint (RIS) technique. METHODS: Six pairs of mandibles from young adult small breed dogs were used for the study. Osteotomies were created in a standardized fashion and fixed with either RIC or RIS. All composite splint constructs were tested biomechanically with a cantilever bending force, using a single column testing machine at a rate of 2 mm/min. The time of application, amount of composite used, ultimate force, stiffness, total displacement, and total energy absorbed during displacement of the rostral mandibular segment were calculated and compared between the two groups. RESULTS: No significant difference was found when comparing the time of application of the RIC and the RIS techniques. All implants failed by either composite resin fracture over the region of the osteotomy or by fracture between the first and second molar followed by detachment of the resin from the lingual enamel surface of the first molar. Differences between the RIC and RIS in force (80.5 N ± 40.3 and 51.8 N ± 27.4. respectively) and stiffness (16.2 N/mm ± 4.4 and 10.1 N/mm ± 4.1 respectively) were significant (p = 0.03). However differences between the two techniques in displacement and total energy absorbed were not significant. CLINICAL SIGNIFICANCE: In experimentally fractured mandibles of young adult dogs there is evidence that RIC is biomechanically similar to RIS.

Cafeteria diet inhibits insulin clearance by reduced insulin-degrading enzyme expression and mRNA splicing.

Insulin clearance plays a major role in glucose homeostasis and insulin sensitivity in physiological and/or pathological conditions, such as obesity-induced type 2 diabetes as well as diet-induced obesity. The aim of the present work was to evaluate cafeteria diet-induced obesity-induced changes in insulin clearance and to explain the mechanisms underlying these possible changes. Female Swiss mice were fed either a standard chow diet (CTL) or a cafeteria diet (CAF) for 8 weeks, after which we performed glucose tolerance tests, insulin tolerance tests, insulin dynamics, and insulin clearance tests. We then isolated pancreatic islets for ex vivo glucose-stimulated insulin secretion as well as liver, gastrocnemius, visceral adipose tissue, and hypothalamus for subsequent protein analysis by western blot and determination of mRNA levels by real-time RT-PCR. The cafeteria diet induced insulin resistance, glucose intolerance, and increased insulin secretion and total insulin content. More importantly, mice that were fed a cafeteria diet demonstrated reduced insulin clearance and decay rate as well as reduced insulin-degrading enzyme (IDE) protein and mRNA levels in liver and skeletal muscle compared with the control animals. Furthermore, the cafeteria diet reduced IDE expression and alternative splicing in the liver and skeletal muscle of mice. In conclusion, a cafeteria diet impairs glucose homeostasis by reducing insulin sensitivity, but it also reduces insulin clearance by reducing IDE expression and alternative splicing in mouse liver; however, whether this mechanism contributes to the glucose intolerance or helps to ameliorate it remains unclear.

A retrospective study of 109 dogs with mandibular fractures.

OBJECTIVE: To determine patient factors and fracture morphology of dogs presented with mandibular fractures to a small animal referral centre in South Africa. METHODS: Patient data on age, sex, breed and aetiology of dogs with mandibular fractures were recorded. The fractures were classified according to the anatomical location, displacement, fracture type, fracture line direction, periodontal pathology, and whether there were teeth in the fracture line or not by evaluation of preoperative radiographs. Clinical observations indicated whether these fractures were open or closed. RESULTS: In total, 109 dogs with 135 mandibular fractures were included in the study. Small breed dogs and dogs less than eight months of age predominated (102/109). Dog fights were the most common aetiology in this study (68/109). The molar region was the most commonly affected region (56/135). Evaluation of the radiographs revealed that transverse (73/135), relatively unstable (116/135), and displaced (112/135) fractures were the most common. The majority of fractures involved teeth in the fracture line (100/135), with the first molar frequently involved (54/135). The majority of fractures were open (104/135). CLINICAL SIGNIFICANCE: The results obtained from this study may be used to guide patient and fracture morphology selection in biomechanical studies of mandibular fracture repair techniques. Screening of this patient population may inspire the search for new treatment options for mandibular fracture repair in South Africa.

Recovery of renal function in heart transplantation patients after conversion from a calcineurin inhibitor-based therapy to sirolimus.

BACKGROUND: Renal failure is the most important comorbidity in patients with heart transplantation, it is associated with increased mortality. The major cause of renal dysfunction is the toxic effects of calcineurin inhibitors (CNI). Sirolimus, a proliferation signal inhibitor, is an imunossupressant recently introduced in cardiac transplantation. Its nonnephrotoxic properties make it an attractive immunosuppressive agent for patients with renal dysfunction. In this study, we evaluated the improvement in renal function after switching the CNI to sirolimus among patients with new-onset kidney dysfunction after heart transplantation. METHODS: The study included orthotopic cardiac transplant (OHT) patients who required discontinuation of CNI due to worsening renal function (creatinine clearance < 50 mL/min). We excluded subjects who had another indication for initiation of sirolimus, that is, rejection, malignancy, or allograft vasculopathy. The patients were followed for 6 months. The creatinine clearance (CrCl) was estimated according to the Cockcroft-Gault equation using the baseline weight and the serum creatinine at the time of introduction of sirolimus and 6 months there after. Nine patients were included, 7 (78%) were males and the overall mean age was 60.1 +/- 12.3 years and time since transplantation 8.7 +/- 6.1 years. The allograft was beyond 1 year in all patients. There was a significant improvement in the serum creatinine (2.98 +/- 0.9 to 1.69 +/- 0.5 mg/dL, P = .01) and CrCl (24.9 +/- 6.5 to 45.7 +/- 17.2 mL/min, P = .005) at 6 months follow-up. CONCLUSION: The replacement of CNI by sirolimus for imunosuppressive therapy for patients with renal failure after OHT was associated with a significant improvement in renal function after 6 months.

Antioxidant status in the aqueous humour of patients with glaucoma associated with exfoliation syndrome.

PURPOSE: To establish the antioxidant status of the aqueous humour in glaucoma associated with exfoliation syndrome (XFG) and to compare it to primary open-angle glaucoma (POAG) and cataract patients. METHODS: Patients were diagnosed with POAG, XFG, or cataract (n=25 for each group). Total reactive antioxidant potential (TRAP) was measured by chemiluminescence. Ascorbic acid levels and the activities of catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD) were measured spectrophotometrically.ResultsTRAP value was lower in XFG (28+/-2 microM Trolox) than in POAG (55+/-8 microM Trolox; P<0.001). TRAP values in both glaucomas were lower than the cataract value (124+/-5 microM Trolox; P<0.001). A decrease in ascorbic acid was measured in XFG (230+/-20 microM) compared with POAG (415+/-17 microM; P<0.001). Ascorbic acid in both glaucomas was lower than in cataract (720+/-30 microM; P<0.001). A significant increase in GPx was found in XFG (30+/-2 U/ml) compared with POAG (16+/-3 U/ml). GPx activity in both glaucomas was increased when compared with cataracts (6+/-2 U/ml; P<0.001). A significant increase of 67% in SOD activity was observed in the glaucoma group vscataract group (27+/-3 U/ml; P<0.001), but no changes were found between both glaucomas. CONCLUSIONS: The antioxidant status of the aqueous humour may play a role in the pathophysiology of both glaucomas.

Estimating exposed pulp lengths of tusks in the African elephant (Loxodonta africana africana).

Captive and wild African elephants frequently suffer tusk fractures. Several institutions shorten the tusks of captive elephants to reduce fractures and injury as a result of behaviour within enclosures. Fracturing or coronal amputations that expose pulp lead to pain for the elephant. Estimating coronal pulp lengths may thus help to minimise the risk of pulp exposure during amputations. We aimed to determine the length of the pulp beyond the lip margin from an external tusk characteristic. Tusks collected from elephants in Namibia and the Kruger National Park had similar morphological relationships. This statistical property allowed us to correct for missing data in our data sets. Pulp volume and pulp length correlated with tusk circumference at the lip. Even so, the circumference at the lip could not predict the length of the pulp in the crown external to the lip. Our findings suggest that tusks, irrespective of sex or age, amputated further than 300 mm from the lip should not expose pulp.

Inferences on the number and frequency of S-pollen gene (SFB) specificities in the polyploid Prunus spinosa.

In flowering plants, self-incompatibility is a genetic mechanism that prevents self-fertilization. In gametophytic self-incompatibility (GSI), pollen specificity is encoded by the haploid genotype of the pollen tube. In GSI, specificities are maintained by frequency-dependent selection, and for diploid species, at equilibrium, equal specificity frequencies (isoplethy) are expected. This prediction has been tested in diploid, but never in polyploid self-incompatible species. For the latter, there is no theoretical expectation regarding isoplethy. Here, we report the first empirical study on specificity frequencies in a natural population of a polyploid self-incompatible species, Prunus spinosa. A total of 32 SFB (the pollen S gene) putative specificities are observed in a large sample from a natural population. Although P. spinosa is polyploid, the number of specificities found is similar to that reported for other diploid Rosaceae species. Unequal specificity frequencies are observed.

Tusklessness and tusk fractures in free-ranging African savanna elephants (Loxodonta africana).

The incidence of tusklessness varies between free-ranging African elephant populations. Sex-linked genetic drift predicts 2 outcomes--the condition becomes fixed and sex-specific incidences diverge when populations are small and/or heavily poached. By contrast, for large and intact populations, tusklessness diminishes and there is no variation between sexes. We tested these predictions by comparing sex-specific incidences between 15 populations: a small one with a skewed founder effect towards tusklessness; 5 that had experienced intense levels of poaching; 2 that had been subjected to non-selective culling and 7 that are relatively pristine. Patterns of rainfall were studied of tusk fractures amongst these populations to correct for any effect that acquired tusklessness may have on our predictions. The incidence of tusk fractures was related to annual rainfall, but the mechanism that leads to an increase of the condition in drier areas was not clear Incidences of tusk fractures in free-ranging populations implied that the frequency of acquired bilateral tusklessness is low and should not affect our results. All males had tusks. Tusklessness in females was high in the small skewed founder population and some of those where there was a history of poaching. The incidence is expected to decline if the residual population is large.

Anthropogenic and natural disturbance effects on a macrobenthic estuarine community over a 10-year period.

For some decades, the Mondego estuary has been under severe ecological stress, mainly caused by eutrophication. The most visible effect was the occurrence of macroalgal blooms and the concomitant decrease of the area occupied by Zostera noltii beds. Since the end of 1998, mitigation measures were implemented in the estuary to promote the recovery of the seagrass beds and the entire surrounding environment. The present study offers a unique opportunity to evaluate the impact of disturbance and the success of the initial recovery process (before and after implementation of the management measures), over a 10-year period, having secondary production as the descriptor. Before the implementation of the mitigation measures, in parallel with the decrease of the Z. noltii beds, species richness, mean biomass and production also decreased, lowering the carrying capacity of the whole Mondego's south arm. Yet, after the introduction of management measures, the seagrass bed seemed to recover. Consequently, the biomass and production also increased substantially, for the whole intertidal area. Nevertheless, even after the mitigation measures implementation, natural-induced stressors, such as strong flood events induced a drastic reduction of annual production, not seen before the implementation of those measures. This shows that the resilience of the populations may have been lowered by a prior disturbance history (eutrophication) and consequent interactions of multiple stressors.

Recovery of Candida dubliniensis and other yeasts from human immunodeficiency virus-associated periodontal lesions.

Oral and subgingival samples from periodontal lesions were collected from 54 human immunodeficiency virus (HIV)-positive and 20 HIV-negative patients and cultured for yeast species. Of the 54 samples cultured from HIV-positive patients, 44 (82%) were positive for yeast species, of which 29 (66%) were subgingival. A total of 19 (48%) patients were positive for Candida dubliniensis, of which 15 (79%) were colonized in subgingival sites. Seven isolates of Candida glabrata, two isolates of Candida parapsilosis, and one isolate of Saccharomyces cerevisiae were recovered. This study reports for the first time the recovery of C. dubliniensis from subgingival intraoral sites and confirms the presence of Candida species in sites of periodontal disease associated with HIV.

Constrictive chronic pericarditis in children.

Constrictive pericarditis is a uncommom disease in children. We have now encountered pericardial thickening as the cause of severe constrictive physiology in two patients, one also having haemodynamic features of restrictive cardiomyopathy. Both patients, who had refractory ascites and evidence of increased systemic venous pressure, underwent Doppler echocardiography, cardiac catheterisation, and magnetic resonance imaging. Resonance imaging failed to show any thickning of the pericardium, but cardiac catheterisation revealed diastolic equalisation of pressures in all four chambers, with only mild elevation of pulmonary pressure in the first patient, but nearly equalisation of diastolic pressure, and a very high pulmonary arterial pressure with a difference of 7 mm Hg between the end diastolic pressures in the two ventricles in the second patient. Doppler revealed a restrictive pattern of mitral inflow, with high E and small A velocities and a short deceleration time. The clinical background did not suggest pericardial disease in either of the patients. We conclude that a careful search is needed to uncover constrictive pericarditis when there is no previous disease which may suggest late pericardial constriction. The haemodynamic features of restrictive cardiomyopathy can co-exist with pericardial restriction, and differentiation between the two entities is critical in view of the diverse management and prognosis of the two conditions.

Oral hairy leukoplakia. Histopathologic and cytopathologic features of a subclinical phase.

Accurate diagnosis of oral hairy leukoplakia (OHL) is important because it may be an early indicator of undiagnosed HIV infection; moreover, it may be a prognostic indicator. Our purpose was to investigate the histopathologic features of subclinical OHL and to evaluate and support the rationale of detecting subclinical OHL with cytopathology. The Epstein-Barr virus (EBV) was detected by immunohistochemistry and in situ hybridization in 4 cases of macroscopically normal lateral borders of tongue mucosa from 8 AIDS necropsies and in none of 8 controls. The histopathologic features were specific when based on nuclear changes: Cowdry type A inclusion, ground glass, and nuclear beading. Smears were obtained from 50 patients with AIDS, without OHL, from the scraping of lateral borders of the tongue. Numerous clusters of the cells were associated with Candida organisms (30% of cases). Nuclear changes were observed in 12 patients (24%) on both sides of the tongue. We describe the histopathologic features of subclinical OHL, and our observations suggest that cytopathology can detect OHL in the subclinical phase.

Left ventricular pseudoaneurysm complicating infective pericarditis.

Cross sectional echocardiography demonstrated a pseudoaneurysm of the left ventricular posterolateral wall close to the atrioventricular junction in a 4 year old girl with infective pericarditis complicating lobar pneumonia. Colour flow Doppler demonstrated bidirectional flow across the communication hole. Surgical resection was successful.

Detection of cardiovascular abnormalities in the nursery of a general hospital in the Amazon region: correlation with potential risk factors.

Congenital heart diseases have been studied much more extensively in children than in neonates. In this study, we report on the findings from 57 neonates seen from June of 1995 through June 1996 in the nursery of a large public hospital in Belém, Pará, Brazil. All were routinely examined by a paediatrician just after birth, and, when indicated, these babies were referred to the cardiology unit of our Hospital for assessment by a paediatric cardiologist. Most of the diagnoses were made by means of Doppler and cross-sectional echocardiography with color flow mapping. Several abnormalities of the cardiovascular system were diagnosed. The most frequent was patency of the arterial duct. But, since many ducts closed spontaneously, ventricular septal defect was the most frequent lesion seen even in the nursery. Four defects (patent arterial duct, ventricular septal defect, atrial septal defect and pulmonary stenosis) together accounted for two thirds of all cardiac abnormalities. Associated non-cardiac anomalies were more frequent in those with simple lesions within the heart. All the babies with complex heart disease, and the majority of those designated as having significant lesions, died before they could be discharged. Several risk factors were investigated. Among maternal drugs, misoprostol emerged as having a possible teratogenic effect.

Detection of enteroviral sequence in endomyocardial tissues from patients with cardiac diseases in northern Brazil.

In the present report we describe the results from a pilot study aimed at detecting enterovirus sequence in cardiac tissues, obtained through endomyocardial biopsies, from patients suffering from cardiac diseases in the Amazon region. Six samples that were collected from three patients were analysed by RT-PCR showing 3 positive and 3 negative results. These preliminary findings suggest the participation of enteroviruses in the etiology of cardiac diseases, mainly myocarditis, and warrant further and broader local studies on this subject.

Detection of enteroviral sequence in endomyocardial tissues from patients with cardiac diseases in northern Brazil

No presente trabalho, são mostrados resultados de um estudo piloto direcionado à detecção de seqüências de enterovirus em tecido cardíaco obtido a partir de biópsias endomiocárdicas de pacientes com doenças cardíacas na região Amazônica. Seis amostras coletadas de três pacientes foram analisadas por RT-PCR obtendo-se três espécimes positivos e três negativos. Esses achados preliminares sugerem a participação dos enterovirus na etiologia de doenças cardíacas, principalmente miocardites, e justificam estudos mais amplos nesse assunto.

In the present report we describe the results from a pilot study aimed at detecting enterovirus sequence in cardiac tissues, obtained through endomyocardial biopsies, from patients suffering from cardiac diseases in the Amazon region. Six samples that were collected from three patients were analysed by RT-PCR showing 3 positive and 3 negative results. These preliminary findings suggest the participation of enteroviruses in the etiology of cardiac diseases, mainly myocarditis, and warrant further and broader local studies on this subject.

[High risk percutaneous transluminal coronary angioplasty after mechanical recanalization of the unprotected left main stem coronary artery and during myocardial infarction]. / Angioplastica coronariana transluminal percutânea de alto risco após recanalização mecânica do tronco de artéria coronária esquerda não protegido e infarto agudo do miocárdio.

A 70 years-old man, with acute myocardial infarction, was submitted to successfull percutaneous transluminal coronary angioplasty of the left main stem coronary artery, following recanalization of that artery.