Sustainable trehalose lipid production by Rhodotorula sp.: a promising bio-based alternative

Global environmental concerns drive research toward the development of new eco-friendly compounds to replace pollutant chemicals. This study focuses on optimizing the production of trehalose lipids (TLs), which are glycolipid biosurfactants (BS) with various applications like antimicrobial or surface tension reduction. New microorganism sources, growth conditions, medium composition, purification conditions, and physicochemical properties of TLs are studied. Addressing a microscale approach, TLs production was successfully achieved using Rhodotorula sp. and Rhodococcus erythropolis to compare, with different media compositions including glucose-based and salt media supplemented with glycerol, glucose, n-hexadecane, n-dodecane. Liquid-liquid extraction using ethyl acetate and methanol was employed for compound extraction, followed by characterization using analytical methods such as Thin layer chromatography (TLC), High performance liquid chromatography (HPLC), and UHPLC. The produced TLs exhibited a minimum surface tension of 47 mN/m and a critical micellar concentration of 4.4 mg/mL. This study also identified Rhodotorula sp. as a new sustainable producer of TLs with improved productivity.

Structural Optimization of Antimycobacterial Azaaurones Towards Improved Solubility and Metabolic Stability

While N-acetyl azaaurones have already been disclosed for their potential against tuberculosis (TB), their low metabolic stability remains an unaddressed liability. We now report a study designed to improve the metabolic stability and solubility of the azaaurone scaffold and to identify the structural requirements for antimycobacterial activity. Replacing the N-acetyl moiety for a N-carbamoyl group led to analogues with sub- and nanomolar potencies against M. tuberculosis H37Rv, as well as equipotent against drug-susceptible and drug-resistant M. tuberculosis isolates. The new N-carbamoyl azaaurones exhibited improved microsomal stability, compared to their N-acetylated counterparts, with several compounds displaying moderate to high kinetic solubility. The frequency of spontaneous resistance to azaaurones was observed to be in the range of 10-8 , a value that is comparable to current TB drugs in the market. Overall, these results reveal that azaaurones are amenable to structural modifications to improve metabolic and solubility liabilities, and highlight their potential as antimycobacterial agents.

Impact of Drying Processes on the Nutritional Composition, Volatile Profile, Phytochemical Content and Bioactivity of Salicornia ramosissima J. Woods

Salicornia ramosissima J. Woods is a halophyte plant recognized as a promising natural ingredient and will eventually be recognized a salt substitute (NaCl). However, its shelf-life and applicability in several food matrices requires the use of drying processes, which may have an impact on its nutritional and functional value. The objective of this study was to evaluate the effect of oven and freeze-drying processes on the nutritional composition, volatile profile, phytochemical content, and bioactivity of S. ramosissima using several analytical tools (LC-DAD-ESI-MS/MS and SPME-GC-MS) and bioactivity assays (ORAC, HOSC, and ACE inhibition and antiproliferative effect on HT29 cells). Overall, results show that the drying process changes the chemical composition of the plant. When compared to freeze-drying, the oven-drying process had a lower impact on the nutritional composition but the phytochemical content and antioxidant capacity were significantly reduced. Despite this, oven-dried and freeze-dried samples demonstrated similar antiproliferative (17.56 mg/mL and 17.24 mg/mL, respectively) and antihypertensive (24.56 mg/mL and 18.96 mg/mL, respectively) activities. The volatile composition was also affected when comparing fresh and dried plants and between both drying processes: while for the freeze-dried sample, terpenes corresponded to 57% of the total peak area, a decrease to 17% was observed for the oven-dried sample. The oven-dried S. ramosissima was selected to formulate a ketchup and the product formulated with 2.2% (w/w) of the oven-dried plant showed a good consumer acceptance score. These findings support the use of dried S. ramosissima as a promising functional ingredient that can eventually replace the use of salt.

Identification of functional compounds in baru (Dipteryx alata Vog.) nuts: Nutritional value, volatile and phenolic composition, antioxidant activity and antiproliferative effect

This work aimed to contribute to the nutritional and functional characterization of roasted baru nuts, a seed widely consumed and produced in Brazil. Baru nut was characterized in terms of its nutritional value and volatile composition (SPME-GC-MS analysis). The ultrasound assisted extraction was used to extract free and bound phenolic compounds that were identified by LC-DAD-ESI-MS/MS method. Bioactivity assays were carried out to evaluate the antioxidant activity (ORAC and HOSC assay) and anticancer effect (inhibition of HT29 cell growth and targeting of cancer stemness) of baru nut extracts and phenolic compounds. Results showed that baru is a good source of protein and monounsaturated fatty acids, specifically oleic acid (47.20 g/100 g). The predominant volatile compounds are hexanal (71.18%) and 2,5-dimethyl-pyrazine (9.43%). The main phenolic compounds identified were gallic acid and its derivatives, such as gallic acid esters and gallotannins. Among all, gallic acid and methyl gallate seemed to be the main compounds responsible for the high antioxidant activity. The antiproliferative effect evaluated of baru extracts in HT29 cell line showed ability to impair cell growth in both monolayer and spheroid cultures and to reduce ALDH+ population. These results supply new information about the functional compounds presents in baru nut, which are important sources of natural antioxidants and antiproliferative compounds.

Study on the association of UGT1A9 gene c.98T>C polymorphism and mycophenolic acid plasma levels in renal transplant patients

Mycophenolate mofetil (MMF) is a prodrug active only after its hydrolysis to mycophenolic acid (MPA). The UGT1A9 enzyme is of special interest since it is the main enzyme involved in the glucuronidation of MPA. Single nucleotide polymorphisms (SNPs) in the UGT1A9 gene may be responsible for individual differences in the pharmacokinetics of MMF. Expression levels and the activity of UGT1A9 may depend on the presence of some SNPs located in the gene promoter region (-2152C>T and -275T>A), as well as changes in the coding region (c.98T>C). The objective of this study was to evaluate the effect of allelic variants of the UGT1A9 c.98T>C polymorphism (rs72551330; g. 87289T>C) on MMF metabolism in renal transplant patients. MPA and MPA 7-O glucuronide (MPAG) levels were determined on plasma samples of kidney transplant patients (N = 39) by high-performance liquid chromatography using ultraviolet detection. DNA was isolated from leukocytes and stored at -20°C. The presence of SNPs was investigated using polymerase chain reaction, followed by amplicon sequencing. The analysis of the UGT1A9 c.98T>C polymorphism revealed that all study patients presented the TT genotype. Diverse MPA and MPAG plasma concentrations were detected, including therapeutic, subtherapeutic, and toxic levels. A standardized molecular method permitted identification of UGT1A9 c.98T>C polymorphism genotypes in the examined renal transplant patients. All individuals of the study group presented the same genotype (c.98TT) for that polymorphism. Thereby, no association between the c.98T>C polymorphism and MPA and MPAG plasma levels could be evaluated, despite different levels of these compounds being observed.

Plant lectins ConBr and CFL modulate expression toll-like receptors, pro-inflammatory cytokines and reduce the bacterial burden in macrophages infected with Salmonella enterica serovar Typhimurium

BACKGROUND

Plant lectins have long been used in biomedical research as immunomodulators against tumor cells and microbial infections.

PURPOSE

To test the ability of plant lectins ConBr (Canavalia brasiliensis) and CFL (Cratylia argentea) to activate antimicrobial and immunomodulatory activities of murine peritoneal macrophages (pMØ) infected with a virulent strain of Salmonella enterica serovar Typhimurium (STm).

METHODS

We incubated pMØ with non-toxic amounts of ConBr and CFL either before (preventive schedule) or after (curative schedule) exposure to STm.

RESULTS

In uninfected pMØ, ConBr and CFL greatly increased levels of mRNA transcripts for IL-1β, TNF-α and IL-6 and the inducible nitric oxide synthase (iNOs), but not IL-10 and IL-12. Exposure to naïve splenocytes of culture supernatants of pMØ previously stimulated with CFL resulted in expression of IL-12 and IFN-γ. Both preventive and curative treatment schedules significantly reduced the intracellular load of Salmonella. Experiments in infected macrophages exposed to lectins in the preventive schedule showed that mRNA transcripts for IL-6 and TNF-α were increased by CFL, whereas ConBr enhanced IL-12 (subunit p40). In the curative schedule, CFL induced significant expression of IL-12 (p40) whereas ConBr enhanced expression IL-1β and TNF-α genes. The lectin treatments did not influence on iNOs expression in pMØ infected with STm C5 regardless of the treatment schedule. Curative treatments with CFL increased approximately 130-fold expression of TLR-4 whist expression of TLR-9 was increased by treatments with ConBr.

CONCLUSION

We conclude that lectins ConBr and CFL have immunomodulatory properties that are beneficial on control of cells infected by Salmonella.

Leaf malate and succinate accumulation are out of phase throughout the development of the CAM plant Ananas comosus

In plants with Crassulacean Acid Metabolism (CAM), organic acids, mainly malate are crucial intermediates for carbon fixation. In this research we studied the circadian oscillations of three organic anions (malate, citrate, and succinate) in Ananas comosus, assessing the effect of season and plant development stage. Seasonal and plant development dependencies were observed. The circadian oscillations of malate and citrate were typical of CAM pathways reported in the literature. Citrate content was quite stable (25-30 μmol g(-1) FW) along the day, with a seasonal effect. Succinate was shown to have both diurnal and seasonal oscillations and also a correlation with malate, since it accumulated during the afternoon when malate content was normally at a minimum, suggesting a possible mechanistic effect between both anions in CAM and/or respiratory metabolisms.

Mesembrinellinae (Diptera: Calliphoridae) to edge effects in the Tinguá Biological Reserve, Rio de Janeiro, Brazil

In this study we describe the diversity of Mesembrinelinae in a biological reserve in the city of Nova Iguaçu, State of Rio de Janeiro. Traps containing sardines were distributed seasonally, at four sites: Site A (22° 58.788' S, 43° 43.459' W), in a forest edge, and sites B (22° 58.523' S, 43° 44.540' W), C (22° 58.350' S, 43° 44.678' W), and D (22° 34.865' S, 43° 27.063' W), located 1,000 m, 500 m, and 2,000 m respectively, inwards from the edge. A total of 2,150 individuals of Mesembrinellinae were collected, representing ten species. Laneela nigripes Guimarães, 1977 was the most abundant species, followed by Mesembrinella bellardiana Aldrich, 1922, Eumesembrinella cyaneicincta (Surcouf, 1919) and Mesembrinella semihyalina Mello, 1967. These species were common and constant during the study period. Mesembrinella batesi Aldrich, 1922, Eumesembrinella quadrilineata (Fabricius, 1805) and Huascaromusca aeneiventris (Wiedmann, 1830) were the less abundant flies, being considered rare and accidental. Eumesembrinella besnoiti (Seguy, 1925) was rare and accessory. Eumesembrinella cyaneicincta, M. bellardiana, M. semihyalina and M. bicolor were mostly collected in site B, while L. nigripes was mostly collected in site C. The edge effect was not evident since the four sites showed similar populations. Site B showed a strong positive relationship between abundance and richness, in site C the correlation was positive and weak, and there was no correlation in A and D. The highest abundance of specimens was recorded during autumn and winter. These flies occurred from the edge up to 2,000 m inside the forest.

Antibacterial activity, chemical composition, and cytotoxicity of leaf's essential oil from brazilian pepper tree (schinus terebinthifolius, raddi)

The antibacterial potential of leaf’s essential oil (EO) from Brazilian pepper tree (Schinus terebinthifolius Raddi) against staphylococcal isolates from dogs with otitis externa was evaluated. The minimum inhibitory concentration of EO ranged from 78.1 to 1,250 μg/mL. The oil was analyzed by GC and GC/MS and cytotoxicity tests were carried out with laboratory animals.

Hydrogen peroxide induces a specific DNA base change profile in the presence of the iron chelator 2,2' dipyridyl in Escherichia coli

Pretreatment of Escherichia coli cultures with the iron chelator 2,2'-dipyridyl (1 mM) protects against the lethal effects of low concentrations of hydrogen peroxide (<15 mM). However, at H(2)O(2) concentrations equal to or greater than 15 mM, dipyridyl pretreatment increases lethality and mutagenesis, which is attributed to the formation of different types of DNA lesions. We show here that pretreatment with dipyridyl (1 mM) prior to challenge with high H(2)O(2) concentrations (>or=15 mM) induced mainly G:C-->A:T transitions (more than 100X with 15 mM and more than 250X with 20 mM over the spontaneous mutagenesis rate) in E. coli. In contrast, high H(2)O(2) concentrations in the absence of dipyridyl preferentially induced A:T-->T:A transversions (more than 1800X and more than 300X over spontaneous mutagenesis for 15 and 20 mM, respectively). We also show that in the fpg nth double mutant, the rpoB gene mutation (RifS-RifR) induced by 20 mM H(2)O(2) alone (20X higher) was increased in 20 mM H(2)O(2) and dipyridyl-treated cultures (110X higher), suggesting additional and/or different lesions in cells treated with H(2)O(2) under iron deprivation. It is suggested that, upon iron deprivation, cytosine may be the main damaged base and the origin of the pre-mutagenic lesions induced by H(2)O(2).

Inflammation-dependent expression of SPARC during development of chronic pancreatitis in WBN/Kob rats and a microarray gene expression analysis

The pathophysiology of human chronic pancreatitis is not well understood and difficult to follow on a molecular basis. Therefore, we used a rat model [Wistar-Bonn/Kobori (WBN/Kob)] that exhibits spontaneous chronic inflammation and fibrosis in the pancreas. Using microarrays we compared gene expression patterns in the pancreas during development of inflammation and fibrosis of WBN/Kob rats with age-matched healthy Wistar rats. The extracellular matrix protein SPARC (secreted protein, acidic, and rich in cysteines) and other transcripts of inflammatory genes were quantified by real-time PCR, and some were localized by immunohistochemistry. When pancreatic inflammation becomes obvious at the age of 16 wk, several hundred genes are increased between 3- and 50-fold in WBN/Kob rats compared with healthy Wistar rats. Proteins produced by acinar cells and characteristic for inflammation, e.g., pancreatitis-associated protein, are highly upregulated. Other proteins, derived from infiltrating inflammatory cells and from activated stellate cells (fibrosis) such as collagens and fibronectins are also significantly upregulated. SPARC was localized to acinar cells where it increased in the vicinity of inflammatory foci. However, acinar expression of SPARC was lost during destruction of acinar cells. In human pancreatic specimens with chronic pancreatitis, SPARC exhibited a similar expression profile. During chronic inflammation and fibrosis in the WBN/Kob rat, inflammatory genes, growth factors, and structural genes exhibit a high increase of expression. A temporal profile including pre- and postinflammatory phases indicates a concurrent activation of inflammatory and fibrotic changes. Inflammation dependent expression of SPARC appears to be lost during acinar-to-duct metaplasia both in rat and human pancreas.

Occlusal splints for treating sleep bruxism (tooth grinding)

BACKGROUND

Sleep bruxism is an oral activity characterised by teeth grinding or clenching during sleep. Several treatments for sleep bruxism have been proposed such as pharmacological, psychological, and dental.

OBJECTIVES

To evaluate the effectiveness of occlusal splints for the treatment of sleep bruxism with alternative interventions, placebo or no treatment.

SEARCH STRATEGY

We searched the Cochrane Oral Health Group's Trials Register (to May 2007); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 1); MEDLINE (1966 to May 2007); EMBASE (1980 to May 2007); LILACS (1982 to May 2007); Biblioteca Brasileira de Odontologia (1982 to May 2007); Dissertation, Theses and Abstracts (1981 to May 2007); and handsearched abstracts of particular importance to this review. Additional reports were identified from the reference lists of retrieved reports and from article reviews about treating sleep bruxism. There were no language restrictions.

SELECTION CRITERIA

We selected randomised or quasi-randomised controlled trials (RCTs), in which splint therapy was compared concurrently to no treatment, other occlusal appliances, or any other intervention in participants with sleep bruxism.

DATA COLLECTION AND ANALYSIS

Data extraction was carried out independently and in duplicate. Validity assessment of the included trials was carried out at the same time as data extraction. Discrepancies were discussed and a third review author consulted. The author of the primary study was contacted when necessary.

MAIN RESULTS

Thirty-two potentially relevant RCTs were identified. Twenty-four trials were excluded. Five RCTs were included. Occlusal splint was compared to: palatal splint, mandibular advancement device, transcutaneous electric nerve stimulation, and no treatment. There was just one common outcome (arousal index) which was combined in a meta-analysis. No statistically significant differences between the occlusal splint and control groups were found in the meta-analyses.

AUTHORS' CONCLUSIONS

There is not sufficient evidence to state that the occlusal splint is effective for treating sleep bruxism. Indication of its use is questionable with regard to sleep outcomes, but it may be that there is some benefit with regard to tooth wear. This systematic review suggests the need for further investigation in more controlled RCTs that pay attention to method of allocation, outcome assessment, large sample size, and sufficient duration of follow up. The study design must be parallel, in order to eliminate the bias provided by studies of cross-over type. A standardisation of the outcomes of the treatment of sleep bruxism should be established in the RCTs.

[Clinical and videofluoroscopic evaluation of swallowing in patients with spastic tetraparetic cerebral palsy and athetosic cerebral palsy]

AIM

To evaluate and to compare the findings of oral and pharyngeal phases of swallowing in children with both spastic tetraparetic cerebral palsy (STCP) and with athetosic cerebral palsy (ACP).

PATIENTS AND METHODS

11 children were evaluated, with their ages ranging from 10 months to 8 years old, through both clinical assessment and videofluoroscopic evaluation.

RESULTS

The children with STCP were more involved at the neurologic, clinical and speech-language and hearing aspects. At the oral phases all the children had presented some involvement. At the pharyngeal phases the clinical signs of aspiration were identified in 10 children. It was observed aspirations in 80% of children with STCP and in 67% with ACP. The changes on swallowing were similar in both cerebral palsy groups, but the performance of the children with STCP was inferior.

CONCLUSION

The videofluoroscopy was an important method which makes possible the verification of aspirations, helping the professionals at the therapeutical program for these children.

Does UVB radiation induce SoxS gene expression in Escherichia coli cells?

The SoxRS regulon is induced when bacterial cells are exposed to redox-cycling agents such as menadione or paraquat. In this paper it is shown that a physical agent, such as ultraviolet radiation with a wavelength of 312 nm (UVB) can induce soxS gene expression. The results indicate that this induction involves the RpoS protein. Moreover, an unexpected increase of soxS gene expression independent of a functional soxR gene in UVB-irradiated cells has been verified. This increase could be explained by transcription of soxS gene in a rpoS-dependent pathway.

Use of artificial neural networks to estimate production variables of broilers breeders in the production phase

1. Although the poultry industry uses state-of-the-art equipment and up-to-date services, in Brazil it generally makes decisions involving all its production variables based on purely subjective criteria. This paper reports the use of artificial neural networks to estimate performance in production birds belonging to a South Brazilian poultry farm. 2. Recorded data from 22 broiler production breeder flocks were obtained, from April, 1998 to December, 1999, which corresponded to 689 data lines of weekly recordings. 3. These data were processed by artificial neural networks using the software NeuroShell 2 version 4.0 (Ward Systems Group). The artificial neural network models generated were compared and selected based on their largest determination coefficient (R2), lowest Mean Squared Error (MSE), as well as on a uniform scatter in the residual plots. The authors conclude that it is possible to explain the performance variables of production birds, with the use of artificial neural networks. 4. The method allows the decisions made by the technical staff to be based on objective, scientific criteria, allows simulations of the consequences related to these decisions, and reports the contribution of each variable to the variables under study.

Detection and identification of salmonellas from poultry-related samples by PCR

A polymerase chain reaction (PCR) assay was developed for the generic detection of Salmonella sp. and the identification of S. Enteritidis (SE), S. Gallinarum (SG), S. Pullorum (SP) and S. Typhimurium (ST) in material collected in the field from poultry. The specificity and sensitivity of the assay combined with Rappaport-Vassiliadis selective enrichment broth (PCR-RV) were determined, and field samples were analyzed to verify the validity of the method application. Specificity of the assay was tested using 29 SE, 11 SG, 10 ST and 10 SP strains, along with 75 strains of 28 other Salmonella serovars and 21 strains of other bacterial genera. The assay was 100% specific for Salmonella detection and ST identification. The primer pair for SE, SG and SP also detected S. Berta. PCR detection limits for Salmonella at the genus level were 2 ST, 8 SE, 1.1x10(3) SG and 1.8x10(5) SP cells. At the serovar level, detection limits were 7 ST, 1.2x10(3) SE, 4.4x10(7) SG and 1.8x10(6) SP cells. At the genus level, PCR-RV detected approximately 128% more positive field samples than the standard microbiological techniques and results were ready in 48h instead of 7 days. PCR-RV method is diagnostic of Salmonella at the genus level and ST at the serovar level, although other tests are needed to identify SE, SG and SP to serovar level.

The use of ultrasound for cleaning the surface of stainless steel and nickel-titanium endodontic instruments

AIM

The aim of this study was to evaluate the efficacy of ultrasound in cleaning the surface of stainless steel and Ni-Ti endodontic instruments.

METHODOLOGY

Twenty nickel-titanium instruments (10 Quantec files and 10 Nitiflex) and 20 stainless steel K-files (10 Maillefer-Dentsply and 10 Moyco Union Broach) were removed from their original packages and evaluated using a scanning electron microscope. Scores were given for the presence of residues on the surface of the instruments. The instruments were then cleaned in an ultrasonic bath containing only distilled water or detergent solution for 15 min, and re-evaluated, using scanning electron microscopy.

RESULTS

Before cleaning, a greater amount of metallic debris was observed on the nickel-titanium Quantec instruments (P < 0.05), when compared to those made of stainless steel. Statistical analysis showed that the use of ultrasound was effective for cleaning the instruments, regardless of the irrigating solution or the instruments type (P < 0.05).

CONCLUSIONS

The use of ultrasound proved to be an efficient method for the removal of metallic particles from the surface of stainless steel and Ni-Ti endodontic instruments.

Uso de Redes Neurais Artificiais para Estimar Parâmetros de Produção de Galinhas Reprodutoras Pesadas em Recria

Uma atividade com a magnitude da avicultura, que usa equipamentos de última geração e serviços atualizados, é levada, na maioria dos casos, a tomar decisões que envolvem todos aspectos de produção, apoiada em critérios subjetivos. O presente trabalho objetiva estudar a utilização das redes neurais artificiais para serem usadas na predição dos parâmetros de desempenho das aves em recria, pertencentes a uma integração avícola sul-brasileira. Foram utilizados os registros de 11 lotes de reprodutoras pesadas para a análise por redes neurais artificiais, no período compreendido entre 09/11/97 a 10/01/99. Os dados utilizados corresponderam a 273 linhas de registros semanais. Os modelos de redes neurais artificiais foram comparados e selecionados como melhores, baseados no coeficiente de determinação múltipla (R²), Quadrado Médio do Erro (QME), bem como pela análise de gráficos, plotando a predição da rede versus a predição menos o real. Os autores concluem que é possível explicar os parâmetros de desempenho das aves em recria, através da utilização de redes neurais artificiais. A técnica permite a tomada de decisões por parte do corpo técnico, baseadas em critérios objetivos obtidos cientificamente. Além disso, esse método permite simulações das conseqüências de tais decisões e fornece a percentagem de contribuição de cada variável no fenômeno em estudo.

Effects of functional septoplasty on the facial growth of ferrets

OBJECTIVE

To determine the effects of functional septoplasty on the facial growth of ferrets.

DESIGN

Pilot study.

SETTING

Medical center.

MATERIALS

Nine 4-week-old female ferrets.

INTERVENTIONS

The ferrets were divided into 3 groups of 3. The first group served as the control group and only had bilateral mucoperichondrial flaps raised. The second group had a 5 x 3-mm piece of septal cartilage removed with preservation of the dorsal and caudal septal struts. The third group had a 4-mm piece of vomer (bone) excised with preservation of all septal cartilage. All groups had the mucoperichondrium preserved. The ferrets grew until 14 weeks of age (well beyond their growth spurt) and were then killed. Lateral cephalograms were then performed and facial analysis conducted to discern any changes in facial growth.

MAIN OUTCOME MEASURES

Facial growth based on cephalometric analysis.

RESULTS

Analysis of variance testing showed no statistically significant differences in facial growth either within or between the 3 groups.

CONCLUSION

Functional septoplasty has no effect on the facial growth of ferrets.

Rapid eye movements during paradoxical sleep in patients with cerebrovascular disease

Rapid eye movements that occur during paradoxical sleep are generated from the brainstem and are modulated by cerebral hemispheres. In an attempt to establish the participation of cerebral hemispheres on rapid eye movements, we carried out a quantitative study of eye movements density in patients bearing hemispheres vascular lesions. The polysomnographic recordings of 24 patients were compared to those of 24 healthy volunteers. Density of rapid eye movements was defined as the percentage of eye movements during the respective time of paradoxical sleep. Based on the present results, we concluded that: stroke patients with hemispheric lesions displayed increased density of rapid eye movements; there was no difference on the density of rapid eye movements according to the hemispheric lesion; higher density of rapid eye movements was observed in patients with anterior hemispheric lesion.

Update on the use of auricular cartilage in laryngotracheal reconstruction

The pediatric otolaryngologist is often called upon to aid in the diagnosis and management of subglottic stenosis. This report contains an update of our experience using auricular cartilage in laryngotracheal reconstruction. A retrospective review of the medical records at St Louis Children's Hospital identified 43 children with subglottic stenosis. Thirty-one children were treated by use of auricular cartilage with a success rate of 84%, and an overall 94% success rate after revision surgery. Eight children in whom an anterior cricoid split initially failed were secondarily treated with auricular cartilage with a success rate of 75%. Two children initially treated with costochondral cartilage underwent multiple reconstructive procedures with either auricular cartilage or costochondral cartilage with an overall success rate of 50%. The remaining 2 children had long-segment tracheal stenosis and underwent repair with auricular cartilage with a 50% success rate. We find that auricular cartilage grafts are highly effective when used in a primary single-stage procedure in children with grade I or II stenosis. We have had limited success with auricular cartilage in patients with grade III stenosis and are reluctant to use it in grade IV stenosis, long-segment tracheal stenosis, staged reconstruction, or revision of an auricular or costal cartilage graft laryngotracheal reconstruction.

Hydrogen peroxide effects in Escherichia coli cells

We analyzed DNA lesions produced by H2O2 under low iron conditions, the cross adaptive response and the synergistic lethal effect produced by iron chelator-o-phenanthroline, using different Escherichia coli mutants deficient in DNA repair mechanisms. At normal iron levels the lesions produced by H2O2 are repaired mainly by the exonuclease III protein. Under low iron conditions we observed that the Fpg and UvrA proteins as well as SOS and OxyR systems participate in the repair of these lesions. The lethal effect of H2O2 is strengthened by o-phenanthroline if both compounds are added simultaneously to the culture medium. This phenomenon was observed in the wild type cells and in the xthA mutant (hypersensitive to H2O2). E. coli cells treated with low concentrations of H2O2 (micromolar) acquire resistance to different DNA damaging agents. Our results indicate also that pretreatment with high (millimolar) H2O2 concentrations protects cells against killing, by UV and this phenomenon is independent of the SOS system, but dependent on RecA and UvrA proteins. H2O2 induces protection against lethal and mutagenic effects of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). H2O2 also protects the cells against killing by cumene hydroperoxide, possibly with the participation of Ahp protein.

Utility of conventional radiography in the diagnosis and management of pediatric airway foreign bodies

Pediatric airway foreign bodies are potentially life-threatening situations. The otolaryngologist is often consulted to aid in the diagnosis and management of these difficult cases. Although radiographic studies are often obtained, the decision for surgical intervention is usually based on a suspicious history and physical examination. Our hypothesis is that radiographic imaging should not alter the decision for surgical intervention. We retrospectively reviewed the cases of pediatric airway foreign bodies managed by the otolaryngology department at St Louis Children's Hospital between December 1990 and June 1996 with both radiographic imaging and operative intervention. Ninety-three cases of potential aspiration were identified, with a median patient age of 20 months. The most common presenting signs and symptoms were aspiration event (n = 82), wheezing (n = 76), decreased breath sounds (n = 47), cough (n = 39), respiratory distress (n = 17), fever (n = 16), pneumonia (n = 14), and stridor (n = 7). At the time of endoscopy, 73 patients were found to have an airway foreign body. The sensitivity and specificity of the imaging studies in identifying the presence of an airway foreign body in the 93 patients were 73% and 45%, respectively. Our decision for operative intervention was based on the history and physical examination, and was not changed in the presence of a negative radiographic study. The routine use of radiography should not alter the management of airway foreign bodies, providing that there is a well-equipped endoscopic team familiar with airway foreign bodies.

Hydrogen peroxide effects in Escherichia coli cells

We analyzed DNA lesions produced by H2O2 under low iron conditions, the cross adaptive response and the synergistic lethal effect produced by iron chelator-o-phenanthroline, using different Escherichia coli mutants deficient in DNA repair mechanisms. At normal iron levels the lesions produced by H2O2 are repaired mainly by the exonuclease III protein. Under low iron conditions we observed that the Fpg and UvrA proteins as well as SOS and OxyR systems participate in the repair of these lesions. The lethal effect of H2O2 is strengthened by o-phenanthroline if both compounds are added simultaneously to the culture medium. This phenomenon was observed in the wild type cells and in the xthA mutant (hypersensitive to H2O2). E. coli cells treated with low concentrations of H2O2 (micromolar) acquire resistance to different DNA damaging agents. Our results indicate also that pretreatment with high (millimolar) H2O2 concentrations protects cells against killing, by UV and this phenomenon is independent of the SOS system, but dependent on RecA and UvrA proteins. H2O2 induces protection against lethal and mutagenic effects of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). H2O2 also protects the cells against killing by cumene hydroperoxide, possibly with the participation of Ahp protein.

Background and paroxystic activities on AIDS patients' EEG. Relation with urea and creatinine seric concentration

The HIV is responsible for important metabolic and structural alterations of the brain. This affected brain must react to continuous systemic metabolic fluctuations. We search for possibly resulting cerebral electric disturbance that could be found by EEG exploration. Sixty-three AIDS patients ranked as CDC group IV had their EEG background rhythm measured, and were appointed to mutually exclusiding groups delimited by medians' values of urea (24 mg/dl) and creatinine (0.9 mg/dl) seric concentrations. These groups were independently formed for each of the parameters utilized, and each data pair generated therefrom were compared between themselves to verify whether there were differences in background rhythm and the occurrence of paroxysmal activity. Background rhythm and paroxysmal activities have not statistically differed between the group whose creatinine values were lower than 0.9 mg/dl and the group whose creatinine values were equal or higher than 0.9 mg/dl. Background rhythm has not statistically differed between the group whose urea values were < 24 mg/dl and the group whose urea values were = 24 mg/dl; contrariwise, the occurrence of paroxysmal activities in these groups has significatively differed, being higher in the patient group whose otherwise normal urea values exceeded 24 mg/dl (p = 0.02).

Jactatio capitis nocturna with persistence in adulthood. Case report

Rhythmic movement disorder, also known as jactatio capitis nocturna, is an infancy and childhood sleep-related disorder characterized by repetitive movements occurring immediately prior to sleep onset and sustained into light sleep. We report a 19-year-old man with a history of headbanging and repetitive bodyrocking since infancy, occurring on a daily basis at sleep onset. He was born a premature baby but psychomotor milestones were unremarkable. Physical and neurological diagnostic workups were unremarkable. A hospital-based sleep study showed: total sleep time: 178 min; sleep efficiency index 35.8; sleep latency 65 min; REM latency 189 min. There were no respiratory events and head movements occurred at 4/min during wakefulness, stages 1 and 2 NREM sleep. No tonic or phasic electromyographic abnormalities were recorded during REM sleep. A clinical diagnosis of rhythmic movement disorder was performed on the basis of the clinical and sleep studies data. Clonazepam (0.5 mg/day) and midazolam (15 mg/day) yielded no clinical improvement. Imipramine (10 mg/day) produced good clinical outcome. In summary, we report a RMD case with atypical clinical and therapeutical features.

Hydrogen peroxide induces protection against lethal effects of cumene hydroperoxide in Escherichia coli cells: an Ahp dependent and OxyR independent system?

Pretreatment with 2.5 mM H2O2 protects bacterial cells against cumene hydroperoxide killing. This response is independent of the OxyR system, but possibly involves the participation of Ahp protein, since ahp mutants are not protected. Treatment of bacterial cells with high H2O2 concentrations caused an alteration on the electrophoretic profile of the smaller subunit (22-kDa) of Ahp. This alteration does not require novel gene products and is not dependent on the OxyR protein. In this way, we propose that the modification of the 22-kDa subunit of Ahp by high H2O2 concentration may be responsible for the protection against the lethal effects of cumene hydroperoxide.

A protocol for otolaryngology-head and neck resident training in pneumatic otoscopy

Otitis media with effusion (OME) is one of the most frequent pediatric diagnoses and is also one of the most common indications for medical or surgical intervention in this age group. Pneumatic otoscopy is the standard for physical diagnosis of a middle ear effusion. We report on our experience with a validation program for otolaryngology-head and neck surgery residents in the use of pneumatic otoscopy to diagnose OME. Four PGY 2 residents sequentially completed a 4 month clinical and didactic training program in pneumatic otoscopy. The trainee sequentially performs pneumatic otoscopy, otomicroscopy, and myringotomy on each patient scheduled for a myringotomy and tube placement the morning of surgery. After each task the trainee is required to state if an effusion is present or not, and the accuracy of the diagnosis is immediately reinforced at the time of myringotomy. The trainee's sensitivity and specificity in diagnosing OME is then calculated for the first and second half of the study period. The trainee is validated in pneumatic otoscopy if the sensitivity is > 80% and > 70% respectively, and the trainee is validated in otomicroscopy if the sensitivity and specificity is > 90% and > 80% respectively. Four residents completed the protocol, and a total of 275 ears were examined. Four residents were validated in pneumatic otoscopy, and three residents were validated in otomicroscopy. We conclude that this protocol allows for accurate documentation of the resident's skill progression and enhances resident education.

Role of SOS and OxyR systems in the repair of Escherichia coli submitted to hydrogen peroxide under low iron conditions

There are at least two mechanisms by which H2O2 induces DNA lesions in Escherichia coli: one in the presence of physiological iron levels and the other in low iron conditions. The survival as well as the induction of SOS response in different DNA repair mutant strains of E coli was evaluated after H2O2 treatment under low iron conditions (pretreatment with an iron chelator). Our results indicate that, in normal iron conditions RecA protein has a relevant role in recombination repair events, while in low iron conditions RecA protein is important as a positive regulator of the SOS response. On the other hand, the oxy delta R mutant is sensitive to the lethal effects of H2O2 only in low iron conditions and this sensitivity cannot be correlated with DNA strand breaks.

Hydrogen peroxide induces protection against N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) effects in Escherichia coli

Cross-adaptive response is defined as the capacity of cells to become resistant to a lethal agent when pretreated with a different lethal substance. In the present paper, the cross-adaptive response between hydrogen peroxide and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was studied in Escherichia coli repair mutants. Our results suggest that high doses of H2O2 induces protection against the lethal effects of MNNG in wild-type strain, ada, ogt, ada-ogt, aidB and alkA mutants. On the other hand, the MNNG induced mutagenesis is reduced by H2O2 pretreatment in wild-type and ogt mutant strains, but not in ada mutant. Furthermore, the protecting effect induced by H2O2 is time dependent: it decreases 15 min after the pretreatment and, after 30 min, is almost abolished. This reduction in the protecting effect is followed by an augmentation in the mutation frequency when MNNG is added 30 min after H2O2 pretreatment. This cross-adaptive response may be due to a modification of the MNNG alkylation pattern in the oxidized DNA.

Alternating periodic lateralized epileptiform discharges (cerebral bigeminy)

Periodic lateralized epileptiform discharges (PLEDs) are seen, as a rule, following acute brain damage. We presented a 54-year-old diabetic male with ischemic coronary disease. Following cardiopulmonary arrest, the patient had a particular EEG pattern of PLEDs, characterized by two recurrent discharges. To our knowledge, this is the fourth published case of such EEG alteration. All of the cases were related to anoxic events.

Polysomnography in idiopathic muscle pain syndrome (fibrositis)

Muscle pain occurs in various neuromuscular disorders with characteristic physiological or biochemical abnormalities. There is, however, a group of patients in whom there is no clear physiological or structural basis for their pains. This syndrome has been called fibrositis or fibromyalgia. Sleep abnormalities have been reported in some of these patients, but have not been confirmed by others. We studied 8 patients with this disorder and found sleep abnormalities that were characterized by nocturnal myoclonus, alpha-delta sleep, and abnormalities compatible with depression. Polysomnography was, therefore, instrumental in helping direct the treatment of these patients. Therapeutic approaches aimed to correct the specific disorders were effective in improving the pain symptoms.

NCPAP for the treatment of obstructive sleep apnea

Nasal continuous positive airway pressure (NCPAP) represents a real advance in the management of obstructive sleep apnea (OSA). Our data show that except for awakenings, all sleep and respiratory parameters were significantly improved (p less than 0.05) in favor of the group treated with NCPAP. A main problem with NCPAP is the acceptance by the patient; it also may disturb the sleep, at least, on short term basis and, in a small number of patients, it does not correct the apneas. In our patients series, males responded better to NCPAP than females.

Cardiovascular and respiratory effects induced by a purified scorpion toxin (tityustoxin) in unanesthetized rats

Intravenous injection of a purified scorpion toxin (tityustoxin) into unanesthetized rats induced acute pulmonary edema, which was directly related to the dose and the time of intoxication. To study the cardiovascular and respiratory effects evoked by an edematogenic dose of the toxin (1 mg/kg), the following parameters were recorded in unanesthetized rats: systolic, diastolic and mean arterial pressure; central venous pressure; electrocardiogram; respiratory movements. The toxin induced acute systolic and diastolic hypertension, bradycardia and bradypnea. During a 1 hr period, the systolic, diastolic and mean arterial pressure fell progressively to control values, whereas the central venous pressure did not change significantly. The cardiac and respiratory rates remained lower than the control values during a 1 hr period. Several changes in the respiratory pattern were recorded, such as gasping, prolonged and labored expiration, ataxic rhythm and noisy inspiration with the mouth open. These respiratory changes were explained, in part, by the presence of edema in the lungs and froth in the trachea. From a group of 24 rats, 6 died 18-30 min after tityustoxin injection. The cause of death was apnea. The female rats were more susceptible to pulmonary edema and death than the male rats.