Temporal and spatial mapping of red grouper Epinephelus morio sound production.

The goals of this project were to determine the daily, seasonal and spatial patterns of red grouper Epinephelus morio sound production on the West Florida Shelf (WFS) using passive acoustics. An 11 month time series of acoustic data from fixed recorders deployed at a known E. morio aggregation site showed that E. morio produce sounds throughout the day and during all months of the year. Increased calling (number of files containing E. morio sound) was correlated to sunrise and sunset, and peaked in late summer (July and August) and early winter (November and December). Due to the ubiquitous production of sound, large-scale spatial mapping across the WFS of E. morio sound production was feasible using recordings from shorter duration-fixed location recorders and autonomous underwater vehicles (AUVs). Epinephelus morio were primarily recorded in waters 15-93 m deep, with increased sound production detected in hard bottom areas and within the Steamboat Lumps Marine Protected Area (Steamboat Lumps). AUV tracks through Steamboat Lumps, an offshore marine reserve where E. morio hole excavations have been previously mapped, showed that hydrophone-integrated AUVs could accurately map the location of soniferous fish over spatial scales of <1 km. The results show that passive acoustics is an effective, non-invasive tool to map the distribution of this species over large spatial scales.

Evaluation of pegylated lipid nanocapsules versus complement system activation and macrophage uptake.

This work consisted in defining the in vitro behavior of pegylated lipid nanocapsules (LNC) toward the immune system. LNC were composed of an oily core surrounded by a shell of lecithin and polyethylene glycol (PEG) known to decrease the recognition of nanoparticles by the immune system. The "stealth" properties were evaluated by measuring complement activation (CH50 technique and crossed-immunoelectrophoresis (C3 cleavage)) and macrophage uptake. These experiments were performed on 20-, 50-, and 100-nm LNC before and after dialysis. A high density of PEG at the surface led to very low complement activation by LNC with a slight effect of size. This size effect, associated to a dialysis effect in macrophage uptake, was due to differences in density and flexibility of PEG chains related to LNC curvature radius. Thanks to a high density, 660-Da PEG provided LNC a steric stabilization and a protective effect versus complement protein opsonization, but this protection decreased with the increase of LNC size, especially versus macrophage uptake.

The transcriptionally active factors mediating the effect of the HTLV-I Tax transactivator on the IL-2R alpha kappa B enhancer include the product of the c-rel proto-oncogene.

The transactivator HTLV-I Tax activates the promoter of the gene coding for the interleukin 2 alpha-chain receptor (IL-2R alpha) via a kappa B site that can bind several protein species of the rel family. Tax1 strongly activates the enhancer activity of this motif, in both epithelial HeLa and lymphoid Jurkat cells. This activation was not observed in undifferentiated embryocarcinoma F9 cells. Overexpression of the p50, p65 and Rel proteins in these cells showed that significant activation of the IL-2R alpha kappa B site was observed only with Rel and Rel plus p65. Moreover, whereas both Tax and phorbol 12-myristate 13-acetate (PMA) are able to efficiently induce the binding of NF-kappa B to the IL-2R alpha kappa B site, PMA is functionally inactive. Using the DNA affinity precipitation assay, we observed that Tax1 is able to efficiently induce the binding of Rel, whereas PMA is not. This established a clear difference between both stimuli, indicating that Rel is the functionally active factor. We conclude from these results that the functional activity of members of the rel family is regulated by their interaction with DNA and that Rel can be a potent transcriptional activator on specific kappa B sites.

Epstein-Barr virus polymorphic B-cell lymphoma associated with leukemia and with congenital immunodeficiencies.

Polymorphic B-cell lymphoma seen in four patients with congenital immunodeficiencies and in two patients with leukemia receiving chemotherapy was associated with the Epstein-Barr virus (EBV). The tumors had characteristic histologic features: they were polymorphic consisting of a mixture of lymphoblasts and differentiated cells including plasma cells, and areas of hemorrhagic necrosis were prominent. The tumors were either polyclonal, monoclonal, or multiclonal. Patients with congenital immunodeficiencies who developed these tumors died despite radiotherapy, corticosteroids plus acyclovir, or a combination of intravenous (IV) immunoglobulins and alpha 2 interferon. Patients with leukemia recovered when immunosuppressive drugs were discontinued and leukemia has not recurred over a period of 2 and 4 years, respectively, in the two patients.

Evidence for functional interaction between the HIV-1 Tat transactivator and the TATA box binding protein in vivo.

Tat strongly activates transcription of the HIV-1 provirus by stimulating both initiation and elongation. This transactivator binds to the TAR RNA element, but can also associate with cellular transcription factors, interacting with upstream promoter sequences. To achieve a better understanding of the role of Tat in the assembly of the transcriptional initiation complex in the living cell, we have examined how the activity of this protein is modified when the general transcription factor involved in the first step of this process, TBP, is overexpressed. The activity of Tat, either wild-type or fused to the DNA binding domain of GAL4 (GBTat), was tested using reporter constructs containing GAL4 binding sites upstream of a minimal promoter corresponding to the HIV-1 TATA box, with or without the TAR element. We found that overexpression of TBP led to a dramatic increase in the activity of the GBTat protein. In order to activate GBTat, TBP must be able to interact with the TATA box. Analysis of several Tat mutants indicated that both the cysteine-rich and the core domains of this transactivator are necessary and sufficient to activate transcription when TBP is overexpressed. In vitro experiments showed that Tat binds specifically to TBP. There was a correlation between the ability of different Tat mutants to bind TBP and their capacity to activate transcription in vivo. With the natural HIV-1 promoter, overexpression of TBP first stimulated and then suppressed the Tat-induced activity. This inhibition was abrogated by an increase in the intracellular levels of Tat. These experimental data indicate that Tat stimulates initiation of transcription by interacting with TBP in vivo.

Characterization of beta 1- and beta 3-adrenoceptors in intact brown adipocytes of the rat.

1. The binding properties of beta 1-, beta 2- and beta 3-adrenoceptors were determined in isolated brown adipocytes of the rat rather than in membrane preparations from tissue homogenates, because typical brown adipocytes represent only about 40% of the various cells present in brown adipose tissue. Binding characteristics were assessed with the hydrophilic beta-adrenoceptor radioligand, (-)-[3H]-CGP 12177. The potent beta-antagonist, bupranolol (100 microM) was used to determine nonspecific binding. Characterization was essentially performed by saturation and competition studies. 2. The saturation curve of (-)-[3H]-CGP 12177 was clearly biphasic (Hill coefficient, nH = 0.57 +/- 0.11, P < 0.01) indicating the presence of two different beta-adrenoceptor populations of high (KD = 0.24 +/- 0.04 nM) and low (KD = 80 +/- 7 nM) affinity. The low affinity sites were more numerous (Bmax = 121,000 +/- 30,000 sites/cell) than the high affinity sites (Bmax = 12,000 +/- 1,000 sites/cell). 3. (-)-[3H]-CGP 12177 (25 nM) was displaced by adrenaline (Ad), noradrenaline (NA), isoprenaline (Iso), phenylephrine (Phe) and by the new beta 3 agonist, CL 316,243 (CL) in a biphasic pattern. The order of potency for (-)-[3H]-CGP 12177 displacement from the small population of high affinity sites (Iso >> NA > Ad >> CL >> Phe was in agreement with a beta 1/beta 2-classification. In contrast, the potencies of the same agonists for displacing the radioligand from the low affinity binding sites (CL >> Iso > NA > Ad >> Phe) revealed the presence of a distinct population of adrenoceptors obeying a beta 3-classification. 5-HT did not displace (-)-[3H]-CGP 12177 (25 nM) when used at concentrations as high as 0.1 mM.4. The beta-adrenoceptor antagonist, (-)-bupranolol, was more effective than (-)-propranolol for displacing(- )-[3H]-CGP 12177 (25 nM) from the high (Ki= 0.029 =/- 0.011 and 0.19 +/- 0.07 nM, respectively and low (Ki= 0.27 +/- 0.04 microM and 1.6 +/- 0.2 lM, respectively) affinity binding sites. The selective beta 1 antagonist CGP 20712A efficiently displaced the radioligand from a small population (Ki = 65 +/- 19 pM)of binding sites, confirming the presence of beta 1-adrenoceptors.5. To evaluate whether beta 2-adrenoceptors could be identified in the population of high affinity binding sites, displacement studies were performed at a low concentration of (- )-[3H]-CGP 12177 (4 nM) that mainly labelled beta 1/beta 2-adrenoceptors. ICI 118 551 ( a selective beta 2-antagonist) and procaterol (a selective beta 2-agonist) displaced (- )-[3H]-CGP 12177 from its binding sites with very low affinity (Ki = 0.17 +/- 0.02 micro M and Ki = 11 +/- 2 micro M respectively).6. From these observations, we conclude that: (1) two kinds of binding sites with low and high affinities for (-)-[H]-CGP 12177 can be detected in intact brown adipocytes, (2) there are 10 times more low than high affinity beta-adrenoceptors, as determined by saturation or competition curve analysis, (3) the high affinity binding sites mainly correspond to beta1-adrenoceptors, whereas the low affinity sites represent beta 3-adrenoceptors, and (4) beta 2-adrenoceptors are undetectable.7. It is suggested that the low affinity beta 3-adrenoceptors represent the physiological receptors for noradrenaline secreted from sympathetic nerve endings when the concentration of the neurohormone in the synaptic cleft is very high and/or when the high affinity beta 1-adrenoceptors are desensitized by prolonged sympathetic stimulation such as chronic cold exposure.

A two-tier polymerase chain reaction direct sequencing method for detecting and typing human papillomaviruses in pathological specimens.

An in-house polymerase chain reaction direct sequencing (PCR-DS) approach for HPV detection and typing was developed, taking advantage of two widely used pairs of human papillomavirus (HPV)-specific PCR primers, MY09/MY11 and GP5/GP6, and 33P-labeled dideoxynucleotides. In this study, 105 pathological specimens were examined: 89% were diagnosed as cervical intraepithelial neoplasia (CIN) grade I-III, 76.2% were HPV-positive by PCR-DS. The PCR using GP5/GP6 (first tier) and MY09/MY11 primers (second tier for the GP5/GP6-negative samples) detected additional 15%-25% HPV-positive samples compared with each pair used separately. Direct sequencing was then used to type the HPV. A readout of a sequence as short as 34 nucleotides within a specific region in the L1 gene is sufficient to type known or novel sequences. Because of its high sensitivity and cost-effectiveness, the two-tier PCR-DS was adopted by the authors as the current method of choice for HPV diagnosis with ultimate sequence precision.

Restoration of the velocity field of the heart from two-dimensional echocardiograms.

A method to quantify the motion of the heart from digitized sequences of two-dimensional echocardiograms (2-D) echos was recently proposed. This method computes on every point of the 2-D echoes, the 2-D apparent velocity vector (or optical flow) which characterizes its interframe motion. However, further analysis is required to determine what part of this motion is due to translation, rotation, contraction, and deformation of the myocardium. A method to locally obtain this information is presented. The proposed method assumes that the interframe velocity field U(xy), V(x,y) can be locally described by linear equations in the form U(x,y)=a+Ax+By; V(x,y)=b+Cx+Dy. The additional constraint was introduced in the computation of the local velocity field by the method of projections onto convex sets. Since this constraint is only valid locally, the myocardium must be first divided into sectors and the velocity fields computed independently for each sector.

Histochemical and morphological characteristics of the vastus lateralis muscle in patients with chronic obstructive pulmonary disease.

PURPOSE AND METHODS: In this study, we examined the fiber-type proportions, cross-sectional areas (CSA), and capillarization from needle biopsies of the vastus lateralis muscle in 20 patients with chronic obstructive pulmonary disease (COPD) (FEV1 = 37 +/- 11% predicted, peak VO2 = 13 +/- 4 mL.min-1.kg-1) and nine age-matched normal subjects (peak VO2 = 33 +/- 7 mL.min-1.kg-1). The effects of endurance training on these parameters were also evaluated in 11 of the 20 patients with COPD. RESULTS: The proportion of Type I fiber was smaller in COPD than normals (34 +/- 14% vs 58 +/- 16 in normals, P < 0.0005) with a corresponding increase in Type IIb fiber (P = 0.015). The CSA of Type I, IIa, and IIab fibers was also smaller in COPD. The capillary to fiber ratio tended to be reduced in patients, but this difference did not reach statistical significance (P = 0.15). The number of capillary contact for Type I, IIa, and IIab fibers was significantly reduced in COPD compared with normal subjects (P < 0.05). When corrected for the CSA, this parameter was similar for both groups. After training, peak VO2 increased by 11% (P < 0.05), the fiber-type proportion remained unchanged, and the CSA of Type I and IIa fibers increased by 31 and 21%, respectively (P < 0.05). Although the number of capillary contact for each fiber types increased with training, the capillary to fiber ratio and the number of capillary contact for the different fiber types relative to their CSA remain unchanged. CONCLUSIONS: We conclude that in COPD, 1) the vastus lateralis muscle is characterized by a marked decrease in Type I fiber proportion, an increase in Type IIb fiber proportion, a decrease in Type I, IIa, and IIab fiber CSA and by a relatively preserved capillarization; and 2) a 12-wk training program induces a significant increase in Type I and IIa CSA.

Rectal biopsy in type 4 glycogenosis. An ultrastructural cytochemical study.

Rectal biopsy material from a patient with type 4 glycogenosis was studied by ultrastructural cytochemical methods. The diagnosis of the disease was made on the basis of the patient's clinical history, the autopsy findings, and the histopathological features. Numerous large macrophages were observed in the rectal mucosa. They contained large vacuoles filled with filamentous material and small granules. This amylopectin was stained by the Thiery method (periodic acid-thiocarbohydrazide-silver proteinate) after 18 hours of exposure to thiocarbohydrazide; only 30 minutes was sufficient to demonstrate seemingly normal beta-glycogen particles in epithelial cells.

Efficacy of APF treatments without prior toothcleaning targeted to high-risk children.

A clinical field trial was conducted, over a 2-yr period, to evaluate the efficacy of bi-annual APF gel topical applications without previous prophylaxis in reducing dental caries among high-risk children living in non-fluoridated communities. 488 children 6 yr old, presenting at least three cavities on proximal surfaces of their primary teeth, were randomly assigned to two groups. The experimental group received bi-annual topical APF gel applications and the control group received a placebo. All treatments were given at school without any prior toothcleaning. The APF gel provided a 34.3% reduction in caries incidence (P-value = 0.03) among the children with 3-14 cavities on their primary teeth at the beginning of the study. However, the treatment did not show any efficacy in reducing caries incidence among the higher-risk children having initially more than 14 cavities. These findings suggest that the efficacy of APF gel applications without previous prophylaxis varies according to the individual risk of the subjects and that more comprehensive programs should be targeted to very high-risk children.

Learning long-term dependencies with gradient descent is difficult.

Recurrent neural networks can be used to map input sequences to output sequences, such as for recognition, production or prediction problems. However, practical difficulties have been reported in training recurrent neural networks to perform tasks in which the temporal contingencies present in the input/output sequences span long intervals. We show why gradient based learning algorithms face an increasingly difficult problem as the duration of the dependencies to be captured increases. These results expose a trade-off between efficient learning by gradient descent and latching on information for long periods. Based on an understanding of this problem, alternatives to standard gradient descent are considered.

Pulmonary lymphangiectasia revisited.

PURPOSE: Pulmonary lymphangiectasia (PL) is a rare, poorly documented disease characterized by abnormal pulmonary lymphatics. Although case reports are published, little is known about survivors past the neonatal period. METHODS: This is a retrospective review of histologically proven PL in fetuses, infants, and long term survivors since 1965. RESULTS: Eleven children (8 boys, 3 girls) and 8 aborted fetuses (7 male, 1 female) were identified. The fetuses weighed 463.4 g (177 to 681 g). Six were aborted between 19 to 24 weeks of gestation for multiple malformations or anencephaly, and 2 spontaneously aborted: one with PL only, the other with twin-twin transfusion syndrome. Clinical PL was diagnosed between 0 and 11 months of age. Six children died (2 neonatal, 4 within 10 days), 5 survived. Two deaths occurred after cardiac surgery. Among survivors, the symptomatology and frequency of admissions diminished over time. Symptoms included progressive respiratory distress, chronic cough, recurrent pneumonia, bronchial asthma, and choking. One child with bilateral chylothorax was later diagnosed with Noonan syndrome; 2 patients had minor cardiac malformations. Rapid deterioration occurred with mild respiratory infections with only supportive treatment available. Chest x-ray showed marked hyperinflation with interstitial infiltrate. CONCLUSIONS: This is the first long-term study of primary PL and will help counsel parents. Although fatal in the neonatal period, survival is possible if diagnosed past the neonatal period and improvement is expected.

A twenty-year experience with thyroid carcinoma in children.

During the past 20 years, 23 patients (7 males, 16 females) were operated on for thyroid carcinoma in our institution. The average age was 13.6 years (range, 22 months to 27 years). Our series includes papillary carcinoma in 11, follicular carcinoma in four, and medullary thyroid carcinoma in eight patients. Follow-up ranged from 8 months to 20.3 years, with an average of 7.5 years for well-differentiated carcinomas and 4.3 years for medullary thyroid carcinomas. All patients are presently alive with no evidence of progressive disease. Patients with papillary and follicular carcinomas underwent partial thyroidectomy; those with medullary carcinoma underwent total thyroidectomy. Serious complications included three permanent hypoparathyroidism and two tracheostomies, all after secondary neck explorations. The overall results observed in our series of patients seem to support the current conservative approach to well-differentiated thyroid carcinoma, reserving total thyroidectomy for medullary cancer of the thyroid. A more aggressive search for familial medullary carcinoma through use of pentagastrin stimulation leads to early detection and more effective therapy.

Management of thyroid nodules in children: a 20-year experience.

The medical records and surgical slides of 58 patients with the diagnosis of thyroid nodules (solitary nodule in 50 patients) are reviewed. The most common cause of thyroid nodules in this series is follicular adenoma (27 patients or 46%). A nuclear scan (technetium or radioactive iodine) was performed in 55 patients, of which 40 showed a cold nodule. Twelve of the 40 cold nodules were malignant (30%). However, for solitary nodules the incidence of cancer is 27%. This last figure is significantly greater than the one recently reported by Hung et al (18.5%). Available diagnostic methods are reviewed and the clinical management as derived from our experience is presented.

Caries predictors suitable for mass-screenings in children: a literature review.

This paper reviews the predictors used to identify children and adolescents at high risk of developing dental caries. They are presented with their degree of association with caries, their validity as screening tests and their methods of determination. The most promising predictors are identified and caries prediction models are also briefly reviewed. The article concludes with some comments about weaknesses encountered in the conduct of screening studies and makes some suggestions for improving the validity of the prediction models.

A multivariate model to predict caries increment in Montreal children aged 5 years.

A study was carried out in Montreal (Canada) to predict caries development over the period of one year in primary teeth of kindergarten children (mean age 5 years 8 months +/- 4 months) living in a non-fluoridated area. The 302 children were examined at school on two occasions, one year apart. At the first examination selected predictors were collected: caries experience, salivary S. mutans and lactobacilli, buffer capacity, debris index, parents' education, fluoride consumption and family structure (one or two parents). Regression analysis was performed to select the significant factors. A total of 143 children developed new caries over the study period; the mean increment for the whole group was 2.1 dmfs. Sensitivity (Sn) and specificity (Sp) were calculated for each predictor and for the final model. The best model comprised only two factors, caries experience and lactobacillus. This could identify 81.8 per cent of children who would develop new caries during the next 12 months (Sn) and 77.4 per cent of those who would not (Sp). Among the single predictors caries experience alone reached 78.3 per cent for sensitivity and 77.4 per cent for specificity. None of the other predictors, except parents' education, was very good at predicting caries increment over one year.

Factors affecting the ingestion of fluoride dentifrice by children.

Several factors affecting the amount of fluoride ingested during toothbrushing by 2- to 7-year-old children were investigated. The specific purpose of this study was to determine the contribution of age, the amount of dentifrice used, and rinsing after brushing to the variation in the ingestion of fluoride dentifrice. Four hundred and five children brushed their teeth in front of a portable sink. The tubes of dentifrice in gel (0.24% NaF) were weighed before and after use to determine the amount of toothpaste used. The fluoride content of the collected liquids was determined with a fluoride-ion-specific electrode. The amount of fluoride ingested was derived by determining the difference between the amounts used and recovered. The amount of dentifrice used, the age, and the rinsing habits, entered in a multiple regression model, explained up to 66 percent of the total variation in the amount of fluoride ingested. The amount of dentifrice used accounted by itself for 60 percent of the total variation. Therefore, these results indicate that the quantity of dentifrice used was the most important factor affecting the ingestion of fluoride through toothbrushing by young children.

Ingestion of fluoride from dentifrices by children aged 12 to 24 months.

The increase of dental fluorosis is largely imputable to the ingestion of dietary fluoride supplements and fluoride toothpastes. However, the toothbrushing habits of very young children is poorly documented. The purpose of this pilot study was to determine the toothbrushing habits of 12- to 24-month-old children and to estimate the quantity of fluoride ingested during toothbrushing. Fifty-nine parents completed a questionnaire regarding the toothcleaning habits of their children. When a dentifrice was used, a dental hygienist scheduled a meeting with the parents in order to observe and measure the amount of toothpaste used. Of the 36 parents who cleaned the teeth of their children, 69% used a toothpaste. Furthermore 20% of the children ingested more than 0.25 mg of fluoride per day by toothbrushing alone. Therefore the practice of toothbrushing and the use of fluoridated dentifrices are widespread among 12- to 24-month old children, and the amount of fluoride ingested from toothpaste could constitute a substantial proportion of the total daily intake of fluoride. Several measures are suggested to enhance the safe use of fluoride dentifrices.