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Background: Astrocytomas are the most common form of primary intracranial tumor; however, survival of patients with high-grade tumors has not changed much compared with that reported in the early 1970s. OBJECTIVE. Our objective was to assess the efficacy, security, and survival rate of postoperative chemotherapy with ifosfamide, carboplatin, and etoposide (ICE) in pediatric patients with anaplastic astrocytomas (AA) and glioblastoma multiforme (GM)., Methods: In a phase II study, we evaluated 25 children with AA or GM. The proposed treatment was four courses of chemotherapy with ICE followed by hyperfractionated radiotherapy, and then four more courses of ICE. Patients were evaluated using MRI after surgery, after the second course of chemotherapy, and again after the last. Toxicity was determined before each course., Results: The overall and disease-free survival at 60 months was 67% and 56% respectively. For supratentorial localization it was 92% at 60 months and 20% at 18 months for brain stem tumors. Fourteen patients had a complete response and 9 died as a result of tumor progression., Conclusions: Postoperative chemotherapy with ICE reduces the tumor size and increases the survival rate of pediatric patients with malignant astrocytomas with minimal toxicity.

Magnetic Resonance Imaging opens an alternative way to analyze wood structures using a non-destructive technology. It provides high resolution, compound-based contrast manipulation and increased data acquisition flexibility. The technique is particularly useful for tree logs, since they present several characteristics that can be used to reduce the long scan time. This study proposes a method that takes advantage of the log cylindrical symmetry, acquiring transverse 1-D projections with a helical and undersampled pattern. Linear interpolation is used to estimate the skipped data and slice images are reconstructed by filtered backprojection. The sequence is improved using selective multi-pass scanning, without major variations of the scan time. Computer simulations and experimental results show that the proposed technique can increase the scan speed by a factor of 6, while maintaining the ability to identify typical tree log characteristics.

The authors previously reported increased expression of the Salmonella enterica serovar Typhi (S. typhi) rfaH gene when the bacterial cells reach stationary phase. In this study, using a lacZ fusion to the rfaH promoter region, they demonstrate that growth-dependent regulation of rfaH expression occurs at the level of transcription initiation. It was also observed that production of the lipopolysaccharide (LPS) O-antigen by S. typhi Ty2 correlated with the differential expression of rfaH during bacterial growth. This was probably due to the increased cellular levels of RfaH, since expression of the distal gene in the O-antigen gene cluster of S. typhi Ty2, wbaP, was also increased during stationary growth, as demonstrated by RT-PCR analysis. Examination of the sequences upstream of the rfaH coding region revealed homologies to potential binding sites for the RcsB/RcsA dimer of the RcsC/YopJ/RcsB phosphorelay regulatory system and for the RpoN alternative sigma factor. The expression of the rfaH gene in rpoN and rcsB mutants of S. typhi Ty2 was measured. The results indicate that inactivation of rpoN, but not of rcsB, suppresses the growth-phase-dependent induction of rfaH expression. Furthermore, production of beta-galactosidase mediated by the rfaH-lacZ fusion increased approximately fourfold when bacteria were grown in a nitrogen-limited medium. Nitrogen limitation was also shown to increase the expression of the O-antigen by the wild-type S. typhi Ty2, as demonstrated by a similar electrophoretic profile to that observed during the stationary phase of growth in rich media. It is therefore concluded that the relationship between LPS production and nitrogen limitation parallels the pattern of rfaH regulation under the control of RpoN and is consistent with the idea that RpoN modulates LPS formation via its effect on rfaH gene expression during bacterial growth.

The invasion of Pseudomonas aeruginosa and Salmonella enterica serovar Typhi into epithelial cells depends on the cystic fibrosis transmembrane conductance regulator (CFTR) protein as an epithelial receptor. In the case of P. aeruginosa, the bacterial ligand for CFTR is the outer core oligosaccharide portion of the lipopolysaccharide (LPS). To determine whether serovar Typhi LPS is also a bacterial ligand mediating internalization, we used both P. aeruginosa and serovar Typhi LPS as a competitive inhibitor of serovar Typhi invasion into the epithelial cell line T84. P. aeruginosa LPS containing a complete core efficiently inhibited serovar Typhi invasion. However, neither killed wild-type Typhi cells nor purified LPS were effective inhibitors. LPS from mutant Typhi strains defective in O side-chain synthesis, but with an apparently normal core, was capable of inhibiting invasion, but LPS obtained from a deeper rough mutant strain with alterations in fast-migrating core oligosaccharide failed to inhibit invasion. Lastly, exposure of wild-type serovar Typhi to T84 cultures before heat killing resulted in a structural alteration in its LPS that allowed the heat-killed cells to inhibit invasion of wild-type serovar Typhi. These data indicate that the serovar Typhi LPS core, like the P. aeruginosa LPS core, is a ligand mediating internalization of bacteria by epithelial cells, and that exposure of this ligand on wild-type Typhi is induced by the bacteria's interaction with host cells.

We have cloned and sequenced the rfaH gene from Salmonella enterica serovar Typhi strain Ty2. The gene showed a high degree of similarity to the rfaH genes from Escherichia coli K-12 and S. enterica serovar Typhimurium. A rfaH mutant was constructed by site-directed mutagenesis. This mutant produced a rough lipopolysaccharide (LPS), with an incomplete core region. The defect in LPS expression that results from the rfaH mutation was corrected by a plasmid carrying the intact gene. The plasmid-borne rfaH gene also restored normal LPS synthesis in a rfaH mutant of E. coli. Reverse transcription-polymerase chain reaction analyses were performed to determine the effects of various environmental conditions on the expression of rfaH. The transcription of rfaH showed a growth-phase-dependent regulation, with maximal expression at the late exponential phase. Other environmental conditions, such as temperature or medium osmolarity, did not affect transcription of rfaH.

Endocytosis is now considered a basic cellular process common to plant cells. Although both non-specific and receptor-mediated endocytosis appear to take place in plant cells, the physiological role of the latter remains unclear. We have investigated the endocytic process in rice cell suspensions using two biotinylated proteins, peroxidase and bovine serum albumin (bHRP and bBSA), as markers. First, we show that markers are internalized by rice cells and appear in intracellular membranes. The uptake of the two markers is temperature dependent, saturable with time and markers dose and it is competed by free biotin. Thus, it shows the properties of a receptor-mediated process. We also show that uptake of markers is strongly influenced by growth phase as optimal uptake occurs during the lag phase, but the initiation of the exponential growth phase decreases uptake drastically. Arrest of the cell cycle by starvation of either a nutrient (phosphate) or a growth regulator (2,4-dichlorophenoxyacetic acid), both components of the culture medium, does not modify the rate of bBSA uptake. Subsequent readdition of these components results in growth recovery and a dramatic decrease in bBSA uptake. On the other hand, nocodazole treatment, a method to arrest the cell cycle by microtubule depolymerization, inhibited bBSA uptake. The possible causes for this arrest of endocytosis are discussed.

Membrane traffic in eukaryotic cells is mediated by COP (coat protein)-coated vesicles. Their existence in plant cells has not yet been unequivocally demonstrated, although coated vesicles (probably with a COP coat) can be seen by electron microscopy. At the gene level, plant cells seem to contain all the components necessary to form COP-coated vesicles. In this paper, we have used antibodies raised against mammalian COPI coat proteins to detect putative homologues in rice (Oryza sativa) cells. Using these antibodies, we have found that rice cells contain alpha-, beta-, beta'-, and gamma-COP, as well as ADP-ribosylation factor (ARF) 1 protein. In addition, we show that antibodies against mammalian beta'-COP can immunoprecipitate not only beta'-COP but also alpha-, beta-, and gamma-COP, suggesting that COPI components in rice cells exist as a complex (or coatomer) in the cytosol, as in mammalian cells. Finally, we show that COP binding to membranes is GTP-dependent, and that ARF1 also binds to membranes in a GTP-dependent manner., (Copyright 2000 Academic Press.)

We investigated the effect of glutaraldehyde-fixed Salmonella typhi Ty2 (Vi(-)) wild-type (World Health Organization's vaccine strain) and mutant strains MEI028 (rough, O-antigen(-)) and MEI012 [smooth (O-antigen(+)95%), immunomagnetically isolated NK cell preparations. Incubation of PBMC with each and every one of the S. typhi strains studied consistently and significantly, increased this cellular immune function, as well as the supernatant level of the various cytokines tested e.g. IFN-gamma, TNF-alpha, IL-10 and IL-12 (ELISA). In similar experiments, a significant increase in the cytolytic activity of HPNK cells was elicited by S. typhi Ty2 but not by mutant strain MEI028; neither of the cytokines assayed (IFN-gamma and TNF-alpha) was detected in the supernatant. Our results suggest that S. typhi O-antigen plays an essential role in a mechanism resulting in the direct activation of NK cell activity in HPNK cell preparations. However, the relative quantitative significance of this antigen in the direct stimulation of NK cell cytotoxicity expression in PBMC samples is less clear, as it appears that in this case bacterial-induced monocyte-released cytokines plays a most important role. Incubation with S. typhi Ty2 or MEI028 elicited significant expression of CD69, an early marker of NK cell activation, in PBMC but not in HPNK cell samples (flow cytometry); in similar experiments, the expression of CD16/56 and activation marker CD25 remained essentially unchanged.

Background: Central nervous system (CNS) tumors are the second most common pediatric tumors. Astrocytomas represent 35% of all CNS tumors in children. Traditional treatment of anaplastic astrocytoma (AA) and glioblastoma multiforme (GM) consisting of surgery-radiotherapy-chemotherapy with nitrosoureas has resulted in a survival rate of 26% at 1 year. Neoadjuvant chemotherapy has proven good results in the treatment of other solid tumors. Chemotherapy with ifosfamide, carboplatin, and etoposide (ICE) permits synergism among the different drugs and sensitizes the tumor to radiotherapy. Our objective was to evaluate the efficacy, security, and survival rate of postoperative chemotherapy with ICE in pediatric patients with AA or GM., Methods: Phase II study. We evaluated 11 children with AA or GM who had received no prior treatment. A magnetic resonance image (MRI) study of the tumor was made after surgery to evaluate residual tumor and routine laboratory analysis. Chemotherapy with carboplatin, ifosfamide and etoposide was given every 3 weeks for four courses. MRI studies were repeated after the second and last courses and laboratory analyses were carried out before each course to evaluate toxicity. Each patient then received hyperfractionated radiotherapy and a final MRI was done at the end of the treatment., Results: Sixty percent of the patients had partial response, 30% complete response after two courses, and 60% of CR after four courses. Supratentorial and infratentorial tumors had a good response to chemotherapy. Brainstem tumors had an initial response after two courses and then increased in size. AA was the tumor with the greatest reduction of residual tumor after treatment. Overall and free survival at 53 months was 70%. To date, three patients have died secondary to tumoral progression. There have been no relapses in the seven patients with a CR., Conclusions: Postoperative chemotherapy with ICE reduces the tumor size and increases the survival rate of pediatric patients with malignant astrocytomas with minimal toxicity. Brainstem responded poorly to treatment.

Background: Oil-aspiration pneumonia is still a health problem in countries where infants are forced to receive vegetable or animal oil due to traditional habits. The aim of this paper is to present clinical and imagenological characteristics of lipoid pneumonia (LP) in children and a review of the literature. Distinguishing features of and differences between other series are presented., Methods: Series of cases. We retrospectively analyzed all records of children with lipoid pneumonia between 1991 and 1996., Results: We found 16 patients aged 1-19 months old with positive oil ingestion in 75% and history of recurrent or persistent pneumonia in 81.2%. In almost 70% of patients, there were underlying conditions known as risk factors of aspiration. Plain films and computed tomography (CT) showed that the right lung was always involved. Fat density was found in only two cases. Bronchoscopy with bronchial lavage was performed in 15 patients, with lipophages positive in each patient., Conclusions: Lipoid pneumonia must be ruled out in the differential diagnosis in infants with persistent or recurrent pneumonia with or without fever, especially in patients with aspiration risk factors. Bronchoscopy with bronchial lavage and positive lipid-laden alveolar macrophages proved a useful method for diagnosis of this condition. More studies are needed to ascertain the clinical and imagenological evolution of this condition.

By using MudJ (Kan, lac)-directed operon fusion technology, mutants of Salmonella typhi whose gene expression is induced under anaerobic growth conditions were isolated. Characterization of their phenotypes and regulatory properties revealed that two of the mutants were unable to use nitrate as a terminal electron acceptor in the absence of oxygen, suggesting that they were defective in nitrate reductase activity. Anaerobic induction of these fusions did not further increase in response to nitrate. Strains carrying an additional mutation in oxrA were constructed. They showed a lower level of beta-galactosidase expression both aerobically and anaerobically; however, the ratios of anaerobic induction remained unaltered. These MudJ insertions mapped to the 17-19 min region of the chromosome. Based upon their phenotypes and mapping, one of the mutants probably possessed a modC (chlD)::MudJ insertion and the other a moaA (chlA)::MudJ insertion. A third mutant was unable to use either nitrate or fumarate as a terminal electron acceptor. All three mutants showed a reduced ability to enter into and proliferate within HEp-2 epithelial cells. The oxrA mutation enhanced entry and proliferation of both the wild-type cells and the three mutants. Taken together, these results suggest that anaerobic respiration plays a role in S. typhi invasiveness.

The paper deals with 2 malignant fibrohistiocytoma cases sitting on the larynx, one of them associated with a laryngeal cancer "in situ". These are uncommon growths particularly in this location, of difficult anatomopathologic diagnosis. Placing of these exceptional tumors were the epiglotis and piriform sinus. The treatment of choice is a large resection alone or followed with radiotherapy, at least that is the opinion shared by several authors.

Albicans ID (bioMérieux, Marcy l'Etoile, France) is a ready-to-use medium that contains a chromogenic substrate that allows rapid detection and specific identification of Candida albicans. We have evaluated its clinical performance by culturing 846 clinical specimens from pregnant women and neonates. A 99.2% sensitivity and a 100% specificity were observed in the identification of C. albicans isolates from primary culture.

Electrophoretic analysis of outer membrane proteins showed that Salmonella typhi OmpC expression is not reciprocally regulated relative to OmpF as described for Escherichia coli and S. typhimurium. When bacteria were grown in minimal media, both OmpC and OmpF were repressed as the osmolarity increased. However, in Luria broth, expression of OmpC was slightly induced by osmolarity up to 0.3 osmM. Plasmids bearing E. coli ompC-lacZ or ompF-lacZ gene fusions were studied for their expression in S. typhi and E. coli. Under anaerobic growth conditions, expression of ompC-lacZ in S. typhi was maximal at 0.16 osmM, while in E. coli expression was maximal at 0.7 osmM. ompF-lacZ expression was similarly repressed by medium osmolarity and anaerobiosis in both species. In contrast, a drastic difference in the regulation of OmpF by temperature was observed; at 37 degrees C ompF-lacZ expression was repressed in E. coli, while in S. typhi it was induced.

This paper describes a method to achieve stable MudJ insertions in the Salmonella typhi Ty2 chromosome. The method is a modification of the genetic complementation system described previously for Salmonella typhimurium, which consists in placing the defective transposon (MudJ) near the transposase genes of a helper Mu phage on a single DNA fragment. This fragment is then introduced into a new bacterial host by means of P22 transduction. We constructed a S. typhi strain which carries MudJ and the Mu helper phage in the chromosome. This strain was induced to lytic growth and the lysate was used to infect S. typhi Ty2. The frequency of mutation was 2.0 x 10(-6) mutants per recipient bacterium. Superinfection with the Mu helper phage was about 1%. To determine the number of MudJ insertions, several mutants were subjected to Southern blot analysis. From a total of 25 mutants analyzed, only 4 contained more than one insertion. Our procedure compares well with the method described previously for the S. typhimurium-P22 system and can be applied to other Mu sensitive bacteria.

Objectives: 1. To describe the frequency in which the thorax radiography is requested in a third-level pediatric hospital, 2. To identify the frequency of detected abnormalities in such a study by the radiology service, 3. To describe the frequency and the characteristics form the information considered as useful in a clinical way, not only in the radiography application but in the radiologic report and the clinical file as well, 4. To identify the frequency in which the thorax radiography result is associated with diagnosis changes and/or therapeutic ones. DESIGN OF THE INVESTIGATION: Descriptive survey., Study Units: 371 thorax X-rays completed during December 1990 and January 1991., Primary Results: The thorax radiographies were 32% of the entire radiological study during the survey; 335 of the latter ones (90%) were requested for inpatients. The hospital services which had the highest request for such a study were the Intensive Care Unit (n = 149, 40%) and Medical Pediatrics (n = 116, 31%). The most frequent diagnosis leading to the application was pneumonia (n = 55, 15%) and solid neoplasia (n = 51, 14%). Three-hundred forty eight of the applications had diagnostic impression given by the physician in charge(94%); whereas only 127 (34%) mentioned clinical data. The radiology report was attached to the file in 162 (44%) of the cases. It was found that form the patients who had a radiology report and the thorax radiography as an initial study (n = 95), 48 (50%) suffered from abnormalities. The results of the study were transcribed in the file in 58 cases (16%); the physician's interpretation was written down in 229 cases (62%) and in 84 studies (23%) there was no reference to the results of the study (P < 0.0001). Changes in the therapeutic plan of 93 cases (50%) were identified from the studies with official report by the radiologist, other radiology studies were requested in 65 of the patients (35%), after the interpretation of such study., Conclusions: Abnormalities in 50% were identified from the total thorax radiographies requested as the patient entered. The study application mentioned as a whole (94%) the diagnostic impression which led to the application, but only in 127 cases (34%) were supporting clinical data written down. The radiology report was attached to the file in less than half the cases (44%). In 63% of the cases the supporting reason of the study was written down whereas in 23% there was no reference to the result at all.

We studied in vivo biochemical effects of insulin in the skeletal muscle of chronically uremic and control rats. The rate of disappearance of blood glucose (determined with a short intravenous test) was reduced by 38% in uremia (p less than 0.05). Intraperitoneal treatment with insulin plus glucose for 30 min caused a 3-fold increase in the activity of insulin receptor tyrosine kinase in the skeletal muscle of both rat groups. Conversely, pyruvate dehydrogenase activity increased by 115% in controls but only by 26% in uremics (p less than 0.01). Exercise (swimming for 30 min) increased muscle pyruvate dehydrogenase activity approximately 2-fold in both groups of animals. These experiments show that in uremic rats, insulin binds normally to its muscle receptors and adequately activates receptor tyrosine kinase but fails to activate an otherwise responsive pyruvate dehydrogenase.

The authors present a case of pubic pain due to detachment of the ischial tuberosity, the diagnosis of which was made with CT scan. The treatment was conservative.

The present study describes the production of cellulases by a native strain of Trichoderma pseudokoningii in the presence and absence of a catabolic repressor. We report a plate assay for selecting fungal mutants capable of synthesizing the cellulase enzymes under conditions of catabolite repression. This method was used for the selection of catabolite repression-resistant mutants. One mutant, B-1, secreted 3.3 times the extracellular protein and 3 times the endoglucanase and filter paper activity in submerged cultures when compared with the wild type strain. The cellobiase activity remained at similar levels in both strains. Although this mutant was isolated as i cellulase producer in the presence of 500 mM glycerol on agar plates, in liquid medium containing the repressor B-1 it exhibits only partial derepression of the cellulase complex.

The small amount of vitamin A in the diet of people living in some regions of Chile can be increased by adding this vitamin to sugar. In order to evaluate the effectiveness of a sugar fortification program, vitamin A fortified sugar was distributed to four indian villages in the mountainous region of Africa, whose inhabitants showed a severe vitamin A deficiency. The results of this study demonstrate that sugar fortification program is able to correct vitamin A deficiency by elevating the vitamin intake and consequently improve the circulating retinol, without substantially increasing the cost or modigying the organoleptic characteristics of sugar.

The authors briefly review the literature on total surface replacement of the hip, in particular, the indications, complications and results so far obtained. Their personal experience began five years ago with Wagner's prosthesis, and they report 20 cases operated on and followed up for 3-5 years. The results were favourable. In their view, this prosthesis is indicated in selected cases, especially in subjects aged less than 50 years, as an alternative to arthrodesis, cervico-epiphyseal resection, or total joint replacement, provided that the anatomical condition of the femoral head is satisfactory.

The chemical composition, nutritive value and potential use of the morro fruit (Crescentia alata) has received little attention. The purpose of the present study was: a) to determine appropriate conditions for processing and conservation of the morro fruit without hulls, since a significant part of the production is lost due to inadequate storage conditions, and b) to evaluate, by means of chemical analysis, the whole fruit and its products. For the preparation of dehydrated meals, the content of the fruit was subjected to sun drying and tray drying dehydration with two air temperatures, 60 degrees and 90 degrees C. The method used for the storage of the whole fruit was anaerobic fermentation achieved by ensilaging the fruit in small concrete experimental silos for 90, 145 and 180 days. At the end of each period, the silos were opened. The ensilaged material was of very good appearance and apparently free from unfavorable contaminations; it was dehydrated in tray dryers at an air temperature of 60 degrees C. Independent of processing, the chemical analysis showed the meals to contain on the average 17% crude fat, 11% crude fiber and 18% crude protein. From the amino acid content and using the 1973 FAO/WHO scoring pattern it was found that such flours were limiting in their sulfur amino acid, lysine and threonine content in the order.