A Case Report of a Novel Atypical Mycobacterial Infection: Mycobacterium Chimaera Hand Tenosynovitis.

CASE: A 76-year-old fisherman with a history of diabetes mellitus, coronary artery bypass grafting, and a previous ipsilateral elbow wound presented with a 1-year history of hand pain and swelling. Anti-inflammatories and antibiotics were administered without improvement. Magnetic resonance imaging and ultrasound demonstrated flexor tenosynovitis. Intraoperative cultures revealed Mycobacterium chimaera. The treatment course included 2 tenosynovectomies and a 1-year course of triple antimycobacterial therapy. CONCLUSION: Nontuberculous mycobacteria infections should be considered in cases of indolent tenosynovitis. M. chimaera should be considered in patients with a history of cardiopulmonary bypass given its association with cardiopulmonary heater-cooler units.

Virulence of Metarhizium brunneum (Ascomycota: Hypocreales) Strains Against Stinkbugs Euschistus heros and Dichelops furcatus (Hemiptera: Pentatomidae).

Three strains of fungi belonging to the genus Metarhizium Sorokin (ARSEF 4556, ARSEF 3297, native strain) were assayed against adults and nymphs of the Neotropical brown stinkbug Euschistus heros (F.) and the green-belly stinkbug Dichelops furcatus (F.). The most virulent strain, ARSEF 4556, caused over 90% mortality. The average survival time of the second and fifth instar nymphs and adults following immersion in 1 × 108 conidia ml-1 was 4.8, 5.7, and 5.2 d, respectively. The second instar nymphs were more susceptible than the adults. The LC50 values and median survival times for second instar and adult E. heros were 1.6 × 107 and 3.1 × 107 conidia ml-1 and 6 and 8 d, respectively. Eggs of E. heros and the closely related stinkbug, D. furcatus, were highly susceptible to ARSEF 4556 with the mean mortality of eggs immersed in 1 × 108 conidia ml-1 being 77.4% and 89.7%, respectively. The strain 3297 showed also good aptitudes for stinkbugs control with mortalities higher than 80% against nymphs and adults and eggs mortalities of 75.5% for E. heros and 79.6% for D. furcatus. This study has shown that it is possible to have a two-pronged control strategy, targeting adults and to reduce oviposition and targeting egg clusters to prevent emergence and dispersal of nymphs. Besides early instars of nymphs have been shown to be more susceptible to the fungal strains than late instars and adults.

Occurrence of human-associated Bacteroidetes genetic source tracking markers in raw and treated wastewater of municipal and domestic origin and comparison to standard and alternative indicators of faecal pollution.

This was a detailed investigation of the seasonal occurrence, dynamics, removal and resistance of human-associated genetic Bacteroidetes faecal markers (GeBaM) compared with ISO-based standard faecal indicator bacteria (SFIB), human-specific viral faecal markers and one human-associated Bacteroidetes phage in raw and treated wastewater of municipal and domestic origin. Characteristics of the selected activated sludge wastewater treatment plants (WWTPs) from Austria and Germany were studied in detail (WWTPs, n = 13, connected populations from 3 to 49000 individuals), supported by volume-proportional automated 24-h sampling and chemical water quality analysis. GeBaM were consistently detected in high concentrations in raw (median log10 8.6 marker equivalents (ME) 100 ml(-1)) and biologically treated wastewater samples (median log10 6.2-6.5 ME 100 ml(-1)), irrespective of plant size, type and time of the season (n = 53-65). GeBaM, Escherichia coli, and enterococci concentrations revealed the same range of statistical variability for raw (multiplicative standard deviations s* = 2.3-3.0) and treated wastewater (s* = 3.7-4.5), with increased variability after treatment. Clostridium perfringens spores revealed the lowest variability for raw wastewater (s* = 1.5). In raw wastewater correlations among microbiological parameters were only detectable between GeBaM, C. perfringens and JC polyomaviruses. Statistical associations amongst microbial parameters increased during wastewater treatment. Two plants with advanced treatment were also investigated, revealing a minimum log10 5.0 (10th percentile) reduction of GeBaM in the activated sludge membrane bioreactor, but no reduction of the genetic markers during UV irradiation (254 nm). This study highlights the potential of human-associated GeBaM to complement wastewater impact monitoring based on the determination of SFIB. In addition, human-specific JC polyomaviruses and adenoviruses seem to be a valuable support if highly specific markers are needed.

[Multidrug-Resistant Organisms (MDRO) in Rehabilitation Clinics in the Rhine-Main District, Germany, 2014: Risk Analysis and Hygiene Procedures]. / Multiresistente Erreger in Rehabilitationseinrichtungen im Rhein-Main-Gebiet, Deutschland, 2014: II. Ärztliche Risikoanalyse und Hygienemaßnahmen.

BACKGROUND: Many regional German MDRO-networks aim to improve the medical rehabilitation of patients with methicillin-resistant Staphylococcus aureus (MRSA) and other multidrug-resistant pathogens. In 2014, the German Commission for Hospital Hygiene and Infection Control (KRINKO) released revised recommendations for the care of patients with MRSA. In particular, for rehabilitation facilities, these recommendations stipulated a medical risk analysis to establish necessary hygiene measures, and provide specific recommendations. MATERIAL AND METHODS: Based on a large investigation carried out in 21 rehabilitation facilities covering different medical specialties, medical risk analyses according to KRINKO were performed, and the findings evaluated separately for orthopedic, cardiologic, oncologic, neurologic, or geriatric facilities, as well as for all institutions taken together. RESULTS: The overall colonization pressure, i. e. the point prevalence of MRSA and extended spectrum beta-lactamase-producing gram-negative pathogens (ESBL) among hospitalized rehabilitation patients was found to be 0.7% and 7.7%, respectively. Impairment of the intact skin (an established risk factor for persisting MRSA colonization and MRSA infection) was found in 7% of the patients, impaired mobility requiring enhanced level of care in 4.1%, and mental confusion and/or incontinence (potentially impairing the application of hygiene measures) in 11% of patients. Compared to the total study population, there was an increase in all risk factors in geriatric and neurologic rehabilitation patients: skin barrier breaches (in neurologic and in geriatric patients: 18.3 and 19.2%, respectively), impaired mobility (32.7 and 37.0%, respectively), and mental confusion/incontinence (24.5 and 28.0%, respectively). In addition, geriatric patients demonstrated an increased overall prevalence of multidrug-resistant organisms (MRSA: 9.4%; ESBL: 22.7%). DISCUSSION: Risk analysis according to KRINKO showed that in rehabilitation facilities with internal medicine or orthopedics specialties, there was a comparably lower risk for transmission, colonization, and/or infection with multidrug-resistant pathogens, as against institutions with neurologic or geriatric specialty. It appears that in the first type of rehabilitation facilities, consistently carried out basic hygiene measures are sufficient while in neurologic or geriatric rehabilitation hospitals, these measures should be supplemented with additional hygiene measures based on medical risk analysis. Furthermore, for infection control purposes in rehabilitation facilities, patient isolation will be rarely necessary or appropriate. These analyses suggest that in the future, rehabilitation programs for MRSA/ESBL-colonized patients will be more successful.

[Multidrug-Resistant Organisms (MDRO) in Rehabilitation Clinics in the Rhine-Main-District, Germany, 2014: Prevalence and Risk Factors]. / Multiresistente Erreger in Rehabilitationseinrichtungen im Rhein-Main-Gebiet, Deutschland, 2014: I. Prävalenz und Risikofaktoren.

BACKGROUND: While a limited number of studies have investigated the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in medical rehabilitation institutions, almost no data on the colonization of rehabilitation patients with multiresistant gram-negative rods is available. Here we report on a large multicenter study on the prevalence of MRSA and multiresistant pathogens in rehabilitation institutions in the Rhine-Main area in 2014. MATERIALS AND METHODS: Altogether, 21 rehabilitation hospitals participated. For all patients, age, gender, previous history of hospitalizations, surgery, previous colonization with multidrug-resistant organisms, use of a medical device, current antimicrobial therapy, and the current infection status were ascertained. On voluntary basis, nare and throat swabs were taken for analysis of MRSA and rectal swabs were tested for extended spectrum betalactamase-producing gram-negative bacteria (ESBL). RESULTS: 50% of 2 440 patients had a history of hospitalization within the previous 6 months while 39% had undergone surgery during the past 30 days. Approximately a quarter of the patients had been transferred to a rehabilitation hospital directly from an acute care hospital, had been under antimicrobial therapy with the past three months, or had travelled to a foreign country within the previous year. Risk factors such as lesions of the intact skin or presence of medical devices were rarely reported (< 5%) within the exception of patients undergoing geriatric or neurologic acute care rehabilitation. 0.7% (15/2155) of the patients were colonized with MRSA, while 7.7% (110/1434) showed a positive result for ESBL. The highest prevalence rates for multiresistant organisms were encountered among patients with neurologic rehabilitation (MRSA, 1.3%, and ESBL, 10.2%) or with geriatric rehabilitation (MRSA, 9.4%, and ESBL, 22.7%). CONCLUSION: In the rehabilitation patient population, the prevalence rates of MRSA and ESBL were found to be in the range of rates encountered in the general population (reported rates for MRSA, 0.5%, and ESBL, 6.3%). The known risk factors for MRSA such as skin lesions, medical devices and previous history for MRSA were also confirmed among this patient population. Direct transfer from an acute care hospital, antimicrobial treatment during the past 3 months, and wounds proved significant risk factors for ESBL colonization. Patients of neurologic rehabilitation and geriatric patients showed the highest rates of risk factors and the highest prevalence rates of multidrug-resistant organisms. It appears to be of importance for rehabilitation hospitals to be geared to the needs of patients with multidrug-resistant organisms, and prevent the transmission of these pathogens by appropriate hygiene measures.

Avaliação morfométrica de equinos do esquadrão de polícia montada dos municípios de lages, joinville e florianópolis-sc / Morphometric evaluation of equine from squadron of mounted police in lages, joinville and florianopolis-sc

O objetivo do presente trabalho foi avaliar as características morfométricas de equinos utilizados no patrulhamento ostensivo pertencentes aos Esquadrões de Polícia Montada localizados nos municípios de Lages, Joinville e Florianópolis - SC. Foram utilizados 101 animais (78 machos castrados, um garanhão e 22 fêmeas), com idade média de 11,9 anos e massa corpórea de 490,82±53,51kg. Foram tomadas 20 medidas lineares individuais, por meio das quais foram determinados 13 índices zootécnicos. Os dados foram avaliados segundo análise descritiva, e a comparação simples entre médias pelo teste t de Student (P<0,05). Houve diferença significativa entre machos e fêmeas com relação ao comprimento de garupa, largura da anca, perímetro da canela e IDT nos animais pertencentes ao Esquadrão de Florianópolis. Conclui-se que os equinos dos três Esquadrões avaliados são, em geral, animais baixos de frente, "longe de terra", eumétricos e longilíneos, e classificados entre animais de tração ligeira e de tração pesada.

The aim of this study was to evaluate the morphometric characteristics of horses utilized in ostensive patrolling belonging to Squadrons of Mounted Police located in the cities of Lages, Joinville and Florianópolis - SC. One hundred and one animals were used (78 geldings, a stallion and 22 females) with a mean age of 11.9 years and body mass of 490.82±53.51kg. Twenty individual linear measurements were taken, from which 13 zootechnical indexes were determined. The data was evaluated according to descriptive analysis and simple comparison between averages by Student's t test (P<0.05). There were significant differences between males and females in relation to hip length, hip width, cannon bone circumference and dactyl-thoracic index (DTI) in animals belonging to the Squadron of Florianopolis. We conclude that equines from three evaluated Squadrons are generally low front animals, "far from the ground", middleweight and large in shape, classified between light traction and heavy traction animals.

[The Humanitarian Consultation-hour in Frankfurt am Main: Utilization by Gender, Age, Country of Origin]. / Die Humanitäre Sprechstunde in Frankfurt am Main: Inanspruchnahme nach Geschlecht, Alter und Herkunftsland.

BACKGROUND: The humanitarian consultation-hour is a voluntary, anonymous offer provided by the City of Frankfurt am Main, which was established in December 2001. Here, people without health insurance or undocumented migrants can be treated for free. The aim of this analysis is to investigate the utilization of the consultation-hour by gender, age, country of origin and diagnosis since 2008. METHODS: The digital data documentation is available since 2008. Data from the years 2008-2013 were considered. The examination date, the date of birth, sex, country of origin, frequency of visits, diseases and medication amongst other data were examined. RESULTS: In the period from 2008 to 2013, 8,574 consultations were counted and 2,384 patients were treated during office hours. The amount of consultations has doubled between 2008 (n=673) and 2009 (n=1,154) and is rising steadily since then (1,911 visits in 2013). The majority of patients come from Africa. Since 2008, an increase of patients from Bulgaria and Romania has been recorded. Approximately two-thirds of the patients are female, one third male. One fifth of those seeking help are children and adolescents under 20 years and adults over 60 years. The most common age group is between 20-40 years old. The main diagnoses include diseases of the cardiovascular and vascular system and the musculoskeletal system, metabolic diseases (diabetes mellitus), digestive diseases and pregnancy/childbirth. CONCLUSION: The humanitarian consultation-hour is an important offer provided by the Public Health Department of the City of Frankfurt am Main and is used by a large number of people who are seeking help. In particular, people from South Eastern Europe are increasingly visiting the consultation-hour. Activities such as the humanitarian consultation-hour can take over subsidiary activities for a transitional period, however long-term structural solutions must be provided to ensure access to health care for this vulnerable group.

Heat waves and mortality in Frankfurt am Main, Germany, 2003-2013: what effect do heat-health action plans and the heat warning system have?

UNLABELLED: Following the heat wave of August 2003 that caused over 70,000 fatalities in Western Europe, heat-health action plans (HHAP) and heat warning systems were implemented in many European countries, including Germany. The effect of these preventive measures (informing the population as well as nursing and medical personnel) on excess mortality during heat waves in Frankfurt am Main, Germany, is studied, taking into account newly published data on a modifying effect of air pollution on heat mortality. MATERIAL AND METHOD: Mortality data comprising all deaths registered in the city of Frankfurt was obtained from the statistical state office; air temperature and air pollution data in Frankfurt Ost were obtained from the Hessian state office for environment and geology. SPSS Version 15 was used for statistical analysis (bivariate and partial correlations, nonparametric tests/Kruskal-Wallis, and Mann-Whitney test). RESULTS: Temperature data as well as air pollution and daily mortality exhibited extreme values in summer 2003 compared to the summer periods 2004-2013. Never again were such levels of temperature and air pollution reached. In 2003, excess mortality was 78%, and as high as 113% among the population aged >80 years. During the heat wave of 2010, the total excess mortality was 23% (significant) and 38% in the population aged >80 years, while during heat waves in 2006 and 2013 no significant increase in total mortality was seen (total excess mortality 12% and 4%; not significant). CONCLUSION: Lower excess mortality could be seen in Frankfurt am Main during heat waves following the implementation of HHAP and the heat warning system. This might be an effect of the measures implemented by the HHAP to reduce heat mortality. However, it cannot be ruled out that this might also be an effect of shorter heat wave periods and lower air pollution in the subsequent years. Therefore, further efforts are needed to improve the resilience of the population, especially the elderly population, to better cope with heat waves.

[Network against multidrug-resistant organisms in the Rhine-Main region, Germany. A first evaluation]. / MRE-Netz Rhein-Main - Wie bewerten die Einrichtungen die Angebote des Netzwerks? - Eine erste Zwischenevaluation.

BACKGROUND: Multidrug-resistant organisms (MDROs) are not only a problem in the hospital but also in the community setting. The MRE-Net Rhine-Main was founded in order to decrease the rate of development and spread of MDROs in the region and to counter the stigmatisation of people with MDROs. The network attempts to achieve these goals by offering telephone support, information flyers, internet services, information events and training for health-care practitioners from hospitals (HOSP), residential and nursing homes (RNH), outpatient care services (OCS), emergency services (ES), medical practices (MP) and rehabilitation centers (RC). A first interim evaluation examined the expectations each institution had associated with its participation and how well these objectives were fulfilled. Furthermore the utilisation and acceptance of the services offered by the network were investigated. METHOD: The participating institutions (n=143) received a standardised questionnaire adapted to the type of institution by mail including questions focusing on the above-mentioned issues. RESULTS: 96 questionnaires could be evaluated (response 67.1%). More than 90% of the participants expected to participate in trainings, receive improved information, to gain more confidence in handling patients and to improve hygiene measures - with great differences between HOSP, RNH and OCS. These expectations were largely satisfied. 65.5% of the institutions participated at least once in a training, particularly RNH, OCS, whereby the usefulness of the trainings was rated high by these institutions. 14.4% of the institutions had made use of the telephone service, the gain of information was rated as high by HOSP, RNH and OCS. 81% knew of and used the flyers, but almost half of the institutions did not know the homepage of the network. CONCLUSIONS: Overall the expectations of the network participants were met well to very well and the benefit derived from the trainings and the print and online media was rated as high. Therefore the network will continue and further intensify its work.

Healthcare-associated infections in long-term care facilities (HALT) in Frankfurt am Main, Germany, January to March 2011.

Healthcare-associated infections (HAIs) are a potentially serious threat to elderly people living in longterm care facilities. Therefore, the European HALT (Healthcare-associated infections in long-term care facilities) project was launched in 2008. HAIs and the use of antibiotics were studied in all 40 nursing homes (100% response) in the city of Frankfurt am Main, Germany, from January to March 2011, using the HALT protocol. Of the 3,732 residents in the homes, 4.3% (n=161) had either signs or symptoms of infections and/or were on oral antibiotics. The most common infections were urinary tract infections (n=45; 1.2%), followed by infections of the respiratory tract (n=41; 1.1%) and skin except mycosis (n=25; 0.7%). The overall prevalence of oral antibiotic use was 2.4% (n=90). The most frequently prescribed oral antibiotics were quinolones (n=31), cephalosporins (n=19), penicillins (n=11) and co-trimoxazole (n=11). The prevalence of HAIs was about the same as that in a European pilot study carried out in November 2009 (5%), but was higher than in several national surveys carried out between May and September 2010 (1.6­3.6%).

High-resolution investigations of ripple structures formed by femtosecond laser irradiation of silicon.

We report on the structural investigation of self-organized periodic microstructures (ripples) generated in Si(100) targets after multishot irradiation by approximately 100-fs to 800-nm laser pulses at intensities near the single shot ablation threshold. Inspection by surface sensitive microscopy, e.g., atomic force microscopy (AFM) or scanning electron microscopy (SEM), and conventional and high-resolution transmission electron microscopy reveal complex structural modifications upon interaction with the laser: even well outside the ablated area, the target surface exhibits fine ripple-like undulations, consisting of alternating crystalline and amorphous silicon. Inside the heavily modified area, amorphous silicon is found only in the valleys but not on the crests which, instead, consist of highly distorted crystalline phases, rich in defects.

[Oral hygiene in nursing home residents. Impact of an oral health education programme for the nursing personnel on the residents' oral health]. / Mundhygiene und Mundgesundheit bei Bewohnern von Altenpflegeheimen. Auswirkung eines Trainingsprogramms für Pflegekräfte auf die Mundgesundheit der Bewohner.

Many studies have shown urgent need in improving oral health hygiene in nursing home residents. Deficits in the knowledge of the personnel in dental and oral hygiene are often cited as one of the causes. Therefore in the spring of 2007 the nursing personnel of three nursing homes attended an oral health education programme. This programme was evaluated by examining the oral and dental health status of the residents, prior to and up to 12 months after the hygiene education. In three nursing homes in the Frankfurt am Main area, the oral health status of 113 residents was examined by a dentist with special education in geriatric dentistry, after receiving informed consent. Mean age was 80+/-9,2 years (49-97 years, 91 women, 40 men). Before, and 4, 8, and 12 months after education of the caregivers, the following data were recorded in the residents: DMF-T index (decayed, missed, filled teeth), plaque index, sulcus bleeding index (SBI), denture hygiene index (DHI), coating of the tongue. Two-thirds of the residents were dependent on caregivers' support for dental care. Initially, in two-thirds of the residents, a high plaque index (PLI>2) and denture hygiene index (DHI>4) was found, in 90% of the residents SBI was > 50%, in 74% of them the tongue was partly or totally coated. In 45% of the residents restorative treatment was required. After the education programme for the personnel, good improvement in oral health of the residents could be stated, with 43% residents exhibiting PLI>2 and 77% showing SBI > 50%. The percentage of clean and well cared for dental prostheses had increased from ca. 30% up to 70%. Within the 4 months 29 of 57 residents with recommendations for dental therapy had been seen by the dentist, 12 months after the first examination, dental therapy had to be recommended to only 19 residents. Education of the nursing staff in nursing homes is effective in improving oral health of the residents. Therefore, all residential homes will be offered regular and free education programmes in oral health for their personnel; this programme will be offered by the chamber of dentists in Hessen, Germany, and the public health services, Frankfurt/Main, Germany.

Glutamine and alanyl-glutamine dipeptide reduce mesenteric plasma extravasation, leukocyte adhesion and tumor necrosis factor-α (TNF-α) release during experimental endotoxemia.

Glutamine (GLN) appears to be an essential nutrient during organism development and critical illness. The aim of our study was to evaluate the effects of GLN and its generic preparation alanyl-glutamine-dipeptide (DIP) on the microcirculation in endotoxemia in rats and its effects on tonus or aortal rings in vitro. Male Lewis rats (n=40) were separated in 4 groups. Group 1 (CON) served as healthy control group while the other groups received an endotoxin bolus i.v. (5 mg/kg lipopolysaccharide, LPS i.v.). In group 3 (LPS+GLN) 0.75 g/kg-1 GLN i.v. before LPS challenge was administered. In group 4 (LPS+DIP) DIP containing 0.75 g/kg GLN was given. Leukocyte-endothelial interactions and mesenteric plasma extravasation were determined at 0, 1 and 2 hours during the experiment by intravital fluorescence microscopy (IVM). Cytokine release (TNF-alpha, IL-1 beta, IL-6, IL-10) was measured by ELISA. GLN treatment reduced leukocyte adherence (-49.7% vs. LPS group, p<0.05) and plasma extravasation (-12.3% vs. LPS group, p<0.05) significantly during endotoxemia compared to untreated LPS animals. In group 4 (DIP+LPS), a decrease of leukocyte adherence (-56.0%) and mesenteric plasma extravasation (-18.8% vs. LPS group, p<0.05) was also found. TNF-alpha levels were reduced in both GLN and DIP (p<0.05). In vitro experiments demonstrated that glutamine agents could attenuate the response to contracting agents in presence of the vascular endothelium, implying nitric oxide pathway. In vivo, GLN as well as DIP pre-treatment diminish the detrimental impact of endotoxemia on the mesenteric microcirculation and the TNF-alpha release, the effects whose clinical importance should be further examined.

Oogenesis in Hydra: nurse cells transfer cytoplasm directly to the growing oocyte.

Oogenesis in Hydra occurs in so-called egg patches containing several thousand germ cells. Only one oocyte is formed per egg patch; the remaining germ cells differentiate as nurse cells. Whether and how nurse cells contribute cytoplasm to the developing oocyte has been unclear. We have used tissue maceration to characterize the differentiation of oocytes and nurse cells in developing egg patches. We show that nurse cells decrease in size at the same time that developing oocytes increase dramatically in volume. Nurse cells are also tightly attached to oocytes at this stage and confocal images of egg patches stained with the fluorescent membrane dye FM 4-64 clearly show large gaps (10 microm) in the cell membranes separating nurse cells from the developing oocyte. We conclude that nurse cells directly transfer cytoplasm to the developing oocyte. Following this transfer of cytoplasm, nurse cells undergo apoptosis and are phagocytosed by the oocyte. These results demonstrate that basic mechanisms of alimentary oogenesis typical of Caenorhabditis and Drosophila are already present in the early metazoan Hydra.

Phylogenetic and physiological characterization of a "Nostocoida limicola"-like organism isolated from activated sludge.

Ten strains of "Nostocoida limicola"-like organisms were isolated from a municipal wastewater treatment plant with minor industrial effluent. The near complete 16S rDNA sequences were determined for four strains to analyze the position of the organisms within the phylogenetic tree. All four isolates showed the same 16S rRNA sequence and cluster within the green non sulfur bacteria. Hybridization with oligonucleotide probe AHW183 designed complementarily to diagnostic regions of the 16S rRNA sequences showed a positive reaction with all isolated strains. Hybridization of activated sludge samples with probe AHW183 indicates the filamentous "Nostocoida limicola"-like bacteria commonly to occur inside the sludge flocs and to hardly be detected within the flocs without a specific staining. On HA-medium all strains grow as long coiled, unbranched and unsheathed filaments which usually stain gram positive and show a variable Neisser reaction. The isolates grow well in liquid HA-medium at COD values between 1 to 4 g O2 h(-1) and a pH range from 6.0-7.8. No growth is detected in liquid R2A-medium and several synthetic mineral salts media containing various carbon and nitrogen sources.

A comparative study of root canal preparation with HERO 642 and Quantec SC rotary Ni-Ti instruments.

AIM: The purpose of this study was to compare several parameters of root canal preparation using two different rotary nickel-titanium instruments: HERO 642 (Micro-Mega, Besancon, France) and Quantec SC (Tycom, Irvine, CA, USA). METHODOLOGY: Fifty extracted mandibular molars with root canal curvatures between 20 micro and 40 micro were imbedded into a muffle system. All root canals were prepared to size 45 (Quantec SC), or 40 (HERO 642), respectively. The following parameters were evaluated: straightening of curved root canals, postoperative root canal diameter, safety issues (file fractures, perforations, apical blockages, loss of working length), cleaning ability, and working time. RESULTS: Both Ni-Ti-systems maintained curvature well; the mean degree of straightening was 2.3 degrees for Quantec SC and 1.6 degrees for HERO 642. Most procedural incidents occurred with Quantec SC instruments (five fractures, three apical blockages, eight cases of loss of working length), HERO 642 preparation resulted in three blockages and one perforation. Following preparation with HERO 642, 63% of the root canals showed a round, 24% an oval, and 17% an irregular diameter; Quantec SC preparations resulted in a round diameter in 24% of the cases, oval shape in 29%, and irregular cross-section in 47% of the cases. Mean working time was shorter for HERO 642 (52 s) than for Quantec (117 s). Cleanliness of the root canal walls was investigated under the SEM using a five-score system for debris and smear layer. For debris HERO 642 achieved better results (80% scores 1 and 2) than Quantec SC (76%). The results for smear layer were similar: cleaner root canal walls were found after preparation with HERO 642 (53% scores 1 and 2), followed by Quantec SC (41%). CONCLUSIONS: Both systems respected original root canal curvature well and showed good cleaning ability; Quantec SC showed deficiencies in terms of safety.

A 6 bp Z-DNA hairpin binds two Z alpha domains from the human RNA editing enzyme ADAR1.

The Z alpha domain of the human RNA editing enzyme double-stranded RNA deaminase I (ADAR1) binds to left-handed Z-DNA with high affinity. We found by analytical ultracentrifugation and CD spectroscopy that two Z alpha domains bind to one d(CG)3T4(CG)3 hairpin which contains a stem of six base pairs in the Z-DNA conformation. Both wild-type Z alpha and a C125S mutant show a mean dissociation constant of 30 nM as measured by surface plasmon resonance and analytical ultracentrifugation. Our data suggest that short (> or = 6 bp) segments of Z-DNA within a gene are able to recruit two ADAR1 enzymes to that particular site.

The solution structure of the Zalpha domain of the human RNA editing enzyme ADAR1 reveals a prepositioned binding surface for Z-DNA.

Double-stranded RNA deaminase I (ADAR1) contains the Z-DNA binding domain Zalpha. Here we report the solution structure of free Zalpha and map the interaction surface with Z-DNA, confirming roles previously assigned to residues by mutagenesis. Comparison with the crystal structure of the (Zalpha)(2)/Z-DNA complex shows that most Z-DNA contacting residues in free Zalpha are prepositioned to bind Z-DNA, thus minimizing the entropic cost of binding. Comparison with homologous (alpha+beta)helix-turn-helix/B-DNA complexes suggests that binding of Zalpha to B-DNA is disfavored by steric hindrance, but does not eliminate the possibility that related domains may bind to both B- and Z-DNA.

Structure-function analysis of the Z-DNA-binding domain Zalpha of dsRNA adenosine deaminase type I reveals similarity to the (alpha + beta) family of helix-turn-helix proteins.

RNA editing alters pre-mRNA through site-selective adenosine deamination, which results in codon changes that lead to the production of novel proteins. An enzyme that catalyzes this reaction, double-stranded RNA adenosine deaminase (ADAR1), contains two N-terminal Z-DNA-binding motifs, Zalpha and Zbeta, the function of which is as yet unknown. In this study, multidimensional NMR spectroscopy was used to show that the topology of Zalpha is alpha1beta1alpha2alpha3beta2beta3. Long-range NOEs indicate that beta1 and beta3 interact with each other. Site-directed mutagenesis was used to identify residues in alpha3, beta3 and the loop connecting beta2 to beta3 that affect Z-DNA binding. Also identified were 11 hydrophobic residues that are essential for protein stability. Comparison with known structures reveals some similarity between Zalpha and (alpha + beta) helix-turn-helix proteins, such as histone 5 and the family of hepatocyte nuclear factor-3 winged-helix-turn-helix transcription factors. Taken together, the structural and functional data suggest that recognition of Z-DNA by Zalpha involves residues in both the alpha3 helix and the C-terminal beta-sheet.

The Zalpha domain from human ADAR1 binds to the Z-DNA conformer of many different sequences.

Z-DNA, the left-handed conformer of DNA, is stabilized by the negative supercoiling generated during the movement of an RNA polymerase through a gene. Recently, we have shown that the editing enzyme ADAR1 (double-stranded RNA adenosine deaminase, type 1) has two Z-DNA binding motifs, Zalpha and Zbeta, the function of which is currently unknown. Here we show that a peptide containing the Zalpha motif binds with high affinity to Z-DNA as a dimer, that the binding site is no larger than 6 bp and that the Zalpha domain can flip a range of sequences, including d(TA)3, into the Z-DNAconformation. Evidence is also presented to show that Zalpha and Zbeta interact to form a functional DNA binding site. Studies with atomic force microscopy reveal that binding of Zalpha to supercoiled plasmids is associated with relaxation of the plasmid. Pronounced kinking of DNA is observed, and appears to be induced by binding of Zalpha. The results reported here support a model where the Z-DNA binding motifs target ADAR1 to regions of negative supercoiling in actively transcribing genes. In this situation, binding by Zalpha would be dependent upon the local level of negative superhelicity rather than the presence of any particular sequence.