Vancomycin-resistant Enterococcus.
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Anti-Bacterial Agents↗
Biomedical subjects
K Weiss
Publications and source records attributed to K Weiss.
Trends in antibiotic resistance of staphylococci over an eight-year period: differences in the emergence of resistance between coagulase positive and coagulase-negative staphylococci.
The antimicrobial susceptibilities of 1058 Staphylococcus aureus and 2,163 coagulase-negative staphylococci (CNS) isolates obtained from clinical specimen between 1988 and 1995, were determined against 13 anti-staphylococcal antibiotics. During the study period the resistance of Staphylococcus aureus to ciprofloxacin, ceftazidime, and norfloxacin increased significantly by 7%, 4%, and 6%, respectively (p < or = 0.001). By comparison, the antibiotic resistance of CNS to ceftazidime, oxacillin, norfloxacin, ciprofloxacin, fusidic acid, and cefoxitin increased by 20%, 17%, 15%, 14%, 12% and 10%, respectively (p < or = 0.001). Invasive and noninvasive S. aureus had similar antibiotic resistance, whereas CNS invasive isolates were more resistant than noninvasive isolates to every antibiotics, except vancomycin and fusidic acid. These differences were significant (p < 0.001) for oxacillin, cefoxitin, and clindamycin. Our observations confirm that staphylococci and particularly CNS isolates show an important rate of increased resistance to the standard antimicrobials used for therapy, and that the rate of emergence of resistance differ considerably between coagulase-positive and coagulase-negative staphylococci.
Anti-Bacterial Agents↗
Comparative activity of trovafloxacin and Bay 12-8039 against 452 clinical isolates of Streptococcus pneumoniae.
The principal aim of this study was to evaluate the in-vitro activity of new quinolones against clinical strains of Streptococcus pneumoniae. Four hundred and fifty-two single clinical isolates (of which 362 were susceptible to penicillin, 54 intermediate and 36 highly resistant) were tested against penicillin, cefuroxime, ciprofloxacin, levofloxacin, trovafloxacin and Bay 12-8039. Of the tested S. pneumoniae strains, 97.1 % had MICs of trovafloxacin of < or = 0.25 mg/L, and 96.7% had MICs of Bay 12-8039 of < or = 0.25 mg/L (difference not statistically significant); 81.9% of strains had MICs of cefuroxime of < or = 0.25 mg/L (P < or = 0.001 against both quinolones). Only 4% and 0.7% of the strains had MICs of levofloxacin and ciprofloxacin respectively of < or = 0.25 mg/L. Compared with older quinolones, trovafloxacin and Bay 12-8039 have good in-vitro activity against S. pneumoniae.
Anti-Infective Agents↗
Diagnostic validity of pulmonary artery catheterization for residents at an intensive care unit.
OBJECTIVE: To assess the amount of additional information provided by measurements derived from pulmonary artery catheter (PAC) use beyond that derived from clinical evaluation by intensive care residents. METHODS: One hundred forty-nine consecutive patients undergoing right-heart catheterization were prospectively included in the study. Before inserting a PAC, physicians had to predict pulmonary arterial pressure (PAP), pulmonary capillary wedge pressure (PCWP), systemic vascular resistance index (SVRI), cardiac index (CI), mixed venous oxygen saturation (SvO2), oxygen delivery (DO2), oxygen consumption (VO2), and pulmonary shunt fraction (Qs/Qt) by selecting a given option on a questionnaire. Ranges of options were chosen to create clear clinical differences among them. RESULTS: The correct value was predicted in a median of 50% of cases (range, 45-63%). PAP was predicted correctly in 55%, PCWP in 46%, SVRI in 63%, CI in 62%, SvO2 in 45%, DO2 in 45%, VO2 in 51%, and Qs/Qt in 51%. A significant difference was found between estimated and measured values for all parameters (p < 0.01). No significant differences were detected between more and less experienced physicians. There was no significant difference between estimated and measured values with respect to the different courses of intensive care unit admissions or the different indications for PAC insertion. CONCLUSION: In a selected group of critically ill patients, the PAC adds valuable and clinically relevant information to clinical assessment in about 50% of cases. Its use should not be withheld in patients with unclear hemodynamic and metabolic profiles.
Catheterization, Swan-Ganz↗
Patient-provider communication during the emergency department care of children with asthma. The National Cooperative Inner-City Asthma Study, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD.
OBJECTIVES: Poor children's reliance on emergency facilities is one factor implicated in the rise of morbidity attributed to asthma. Although studies have examined doctor-patient communication during routine pediatric visits, little data are available about communication during emergency care. This study sought to describe communication during emergency treatment of childhood asthma to learn if a "patient-centered" provider style was associated with increased parent satisfaction and increased parent and child participation. METHODS: This cross-sectional, observational study examined 104 children aged 4 to 9 years and their guardian(s) attending emergency departments in seven cities. Quantitative analysis of provider-family dialogue was performed. Questionnaires measured satisfaction with care, provider informativeness, and partnership. RESULTS: Providers' talk to children was largely supportive and directive; parents received most counseling and information. Children spoke little to providers (mean: 20 statements per visit versus 156 by parents). Providers made few statements about psychosocial aspects of asthma care (mean: three per visit). Providers' patient-centered style with parents was associated with more talk from parents and higher ratings for informativeness and partnership. Patient-centered style with children was associated with five times the amount of talk from children and with higher parent ratings for "good care," but not for informativeness or partnership. CONCLUSIONS: Communication during emergency asthma care was overwhelmingly biomedical. Children took little part in discussions. A patient-centered style correlated with increased parent and child participation, but required directing conversation toward both parents and children.
Asthma↗
Perspectives on genetic aspects of dental patterning.
Nearly a century of speculation and experimentation has gone into trying to understand the mechanisms that establish the pattern of the differentiated heterodont dentition. Regionally differing qualitative (combinatorial) expression of regulatory genes appears to be involved in this process. Work by our laboratory and others shows that the six members of the mammalian Dlx family of homeobox genes are expressed (a) at multiple times during dental development, (b) differently at different stages, (c) in a way that is related to their genomic organization as gene-pairs linked to three of the four Hox clusters of positional patterning genes. The expression appears to be involved in jaw regionalization, tooth initiation, and tooth development. However, this expression correlates with no single aspect of dental patterning or tooth development, involves redundant and complementary function, and developmental differences between the maxillary and mandibular dentition suggest that other elements remain to be identified. For example, the possibility that quantitative aspects of gene expression specify developmental fields in the dentition has not yet been investigated. Although the maxilla and mandible develop differently, indirect evidence suggests that, especially in the future midline (incisor) regions, both jaws may be patterned by a consistent process that occurs before neural crest migration takes place, and we hypothesize that signaling factors like Sonic hedgehog and Pax transcription factors may be involved.
Animals↗
High-resolution structural analysis of chromatin at specific loci: Saccharomyces cerevisiae silent mating type locus HMLalpha.
Genetic studies have suggested that chromatin structure is involved in repression of the silent mating type loci in Saccharomyces cerevisiae. Chromatin mapping at nucleotide resolution of the transcriptionally silent HMLalpha and the active MATalpha shows that unique organized chromatin structure characterizes the silent state of HMLalpha. Precisely positioned nucleosomes abutting the silencers extend over the alpha1 and alpha2 coding regions. The HO endonuclease recognition site, nuclease hypersensitive at MATalpha, is protected at HMLalpha. Although two precisely positioned nucleosomes incorporate transcription start sites at HMLalpha, the promoter region of the alpha1 and alpha2 genes is nucleosome free and more nuclease sensitive in the repressed than in the transcribed locus. Mutations in genes essential for HML silencing disrupt the nucleosome array near HML-I but not in the vicinity of HML-E, which is closer to the telomere of chromosome III. At the promoter and the HO site, the structure of HMLalpha in Sir protein and histone H4 N-terminal deletion mutants is identical to that of the transcriptionally active MATalpha. The discontinuous chromatin structure of HMLalpha contrasts with the continuous array of nucleosomes found at repressed a-cell-specific genes and the recombination enhancer. Punctuation at HMLalpha may be necessary for higher-order structure or karyoskeleton interactions. The unique chromatin architecture of HMLalpha may relate to the combined requirements of transcriptional repression and recombinational competence.
Base Sequence↗
Comparison of activity of 10 antibiotics against clinical strains of Helicobacter pylori by three different techniques.
The authors determined the susceptibility of 55 single clinical strains of Helicobacter pylori isolated in the Montreal area to 10 antibiotics by three different methods--an agar dilution technique considered to be the gold standard, a disk diffusion method and the E-test. Testing was performed on Mueller-Hinton agar supplemented with 10% sheep blood; plates were incubated at 37 degrees C for 72 h in a microaerophilic atmosphere. The metronidazole resistance rate is about 11% in the Montreal area. Macrolides are very active against H pylori isolates, with few variations in activity between older and newer molecules. Correlation among different methods was not as good as reported in the literature for metronidazole.
Anti-Bacterial Agents↗
Safety profile of interferon-alpha therapy.
Two forms of recombinant interferon-alpha (IFN-alpha2a and IFN-alpha2b) have been approved by the Food and Drug Administration for a variety of clinical indications, including hairy cell leukemia, hepatitis, acquired immunodeficiency syndrome-related Kaposi's sarcoma, chronic myelogenous leukemia (IFN-alpha2a only), and adjuvant therapy for melanoma (IFN-alpha2b only), based on their proven clinical efficacy and acceptable safety profiles. The continued postmarketing monitoring of adverse reactions associated with IFN-alpha therapy has revealed some new toxicities. The most common adverse events associated with IFN-alpha therapy are flu-like symptoms, fatigue, anorexia, and central nervous system and psychiatric reactions. In particular, the incidence of depression has only recently been fully appreciated. Some of these side effects, particularly chronic fatigue, anorexia, and neuropsychiatric reactions, may become dose limiting. New approaches to minimize and manage the side effects of IFN-alpha therapy are needed.
Adverse Drug Reaction Reporting Systems↗
Cell type-specific chromatin organization of the region that governs directionality of yeast mating type switching.
Switching of mating type in Saccharomyces cerevisiae is directional; MAT alpha cells recombine to transfer information from HMRa while MATa cells switch using the silent cassette at HML alpha. Genetic analysis recently has defined a 700 bp recombination enhancer approximately 29 kb from the left end of chromosome III that is necessary for directionality. The chromatin structure of this region differs strikingly in a- and alpha-cells. Mat alpha2p organizes a 3.7 kb chromatin domain that opposes interaction of trans-acting proteins with the enhancer. In a-cells lacking the alpha2 repressor, two footprinted regions flank an approximately 100 bp section having a unique DNA structure. This structural signature probably reflects interactions of proteins that result in directional mating type switching.
Base Sequence↗
Design and methods of the National Cooperative Inner-City Asthma Study.
The National Cooperative Inner-City Asthma Study (NCICAS) was established to identify and then intervene on those factors which are related to asthma morbidity among children in the inner-city. This paper describes the design and methods of the broad-based initial Phase I epidemiologic investigation. Eight research centers enrolled 1,528 children, 4 to 9 years of age, from English- or Spanish-speaking families, all of whom resided in major metropolitan inner-city areas. The protocol included an eligibility assessment and an extensive baseline visit, during which symptom data, such as wheezing, lost sleep, changes in activities of daily living, inpatient admissions, and emergency department and clinic visits were collected. A comprehensive medical history for each child was taken and adherence to the medical regimen was assessed. Access, as well as barriers, to the medical system were addressed by a series of questions including the location, availability, and consistency of treatment for asthma attacks, follow-up care, and primary care. The psychological health of the caretaker and of the child was also measured. Asthma knowledge of the child and caretaker was determined. Sensitization to allergens was assessed by skin-prick allergen testing and exposure to cigarette smoke and the home environment were assessed by questionnaire. For more than a third of the families, in-home visits were conducted with dust sample allergen collection and documentation of the home environment, such as the presence of pets and evidence of smoking, mildew, and roaches. Urine specimens were collected to measure passive smoke exposure by cotinine assays, blood samples were drawn for banking, and children age 6 to 9 years were given spirometric lung function assessment. At 3, 6 and 9 months following the baseline assessment, telephone interviews were conducted to ask about the child's symptoms, unscheduled emergency department or clinic visits, and hospitalizations. At this time, peak flow measurements with 2-week diary symptom records were collected.
Allergens↗
Characteristics of inner-city children with asthma: the National Cooperative Inner-City Asthma Study.
Asthma morbidity has increased dramatically in the past decade, especially among poor and minority children in the inner cities. The National Cooperative Inner-City Asthma Study (NCICAS) is a multicenter study designed to determine factors that contribute to asthma morbidity in children in the inner cities. A total of 1,528 children with asthma, ages 4 to 9 years old, were enrolled in a broad-based epidemiologic investigation of factors which were thought to be related to asthma morbidity. Baseline assessment included morbidity, allergy evaluation, adherence and access to care, home visits, and pulmonary function. Interval assessments were conducted at 3, 6, and 9 months after the baseline evaluations. Over the one-year period, 83% of the children had no hospitalizations and 3.6% had two or more. The children averaged 3 to 3.5 days of wheeze for each of the four two-week recall periods. The pattern of skin test sensitivity differed from other populations in that positive reactions to cockroach were higher (35%) and positive reactions to house dust mite were lower (31%). Caretakers reported smoking in 39% of households of children with asthma, and cotinine/creatinine ratios exceeded 30 ng/mg in 48% of the sample. High exposure (> 40 ppb) to nitrogen dioxide was found in 24% of homes. Although the majority of children had insurance coverage, 53% of study participants found it difficult to get follow-up asthma care. The data demonstrate that symptoms are frequent but do not result in hospitalization in the majority of children. These data indicate a number of areas which are potential contributors to the asthma morbidity in this population, such as environmental factors, lack of access to care, and adherence to treatment. Interventions to reduce asthma morbidity are more likely to be successful if they address the many different asthma risks found in the inner cities.
Allergens↗
Exogenous surfactant therapy in a patient with adult respiratory distress syndrome after near drowning.
A 24-year-old woman developed adult respiratory distress syndrome (ARDS) after near-drowning due to attempted suicide. Conventional mechanical ventilation together with prone positioning and inhaled nitric oxide could not provide sufficient oxygenation. Surface tension data (gamma min = 27 dyn/cm, stability index = 0.341) from a lavage sample supported the hypothesis that the surfactant function of this patient was drastically reduced due to a washout effect by aspiration of fresh water. Porcine surfactant (Curosurf, 50 mg/kg for each lung) was instilled via fibreoptic bronchoscope. The partial arterial carbon dioxide pressure (paCO2) and fraction of inspired oxygen (FiO2) ratio as well as shunt fraction (Qs/Qt) improved impressively. When respiratory situation deteriorated again, surfactant application was repeated. Altogether, six bolus instillations of surfactant (total dose 300 mg/kg = 18,000 mg) were administered until the respiratory situation had stabilized and oxygenation could be maintained by conventional mechanical ventilation. The radiological findings did not show substantial amelioration. The patient developed septic shock and died 12 days after admission. Surfactant application apparently led to a significant improvement of the respiratory function. However, the outcome could not be influenced positively. The high cost of surfactant therapy prevents the more widespread early administration in patients at risk.
Adult↗
[Fermentation process during the ensiling of green forage low in nitrate. 1. Fermentation process in untreated green forage].
The fermentation process of ensiling green forage, low in nitrate, was proved in 8 experiments with ryegrass, ochardgrass and grass-legumes mixture. It was demonstrated that also in easily fermentable green forage the absence of nitrate promote the occurrence of butyric acid simultaneously with the lactic acid fermentation even at an early stage of fermentation. It is supposed that the lack of nitrate as a natural inhibitor of clostridia leads to early formation of butyric acid. The evolution of clostridia in the beginning of the fermentation process was more rapid than expected. It seems that easily soluble carbohydrates are the substrates of butyric acid formation. That is why in green forage, low on nitrate, clostridia act as food competitors for lactic acid bacteria. Amino acids were not degraded in the early stage of fermentation. In spite of the high content of butyric acid the amount of ammonia was low. Apart from n-butyric acid volatile fatty acids > or = C4 did not occur. The lactic acid formation reached only a restricted extent, also in green forage with a high content of sucrose. It was assumed that there are differences in ensilability of carbohydrate fractions between forage plants.
Ammonia↗
[Fermentation process during the ensiling of green forage low in nitrate. 2. Fermentation process after supplementation of nitrate, nitrite, lactic acid bacteria and formic acid].
The effect of adding nitrate and nitrite (0.05% and 0.01% N in DM) of two inoculants or formic acid on the ensiling of orchardgrass and a grass-legumes-mixture, both low in nitrate, was proved in two experiments during ensiling starting in an early stage of fermentation silages without additives contained butyric acid, with increasing amounts up to 180 day of storage period. Silages with added nitrate or nitrite (0.1% N in DM) contained no butyric acid despite of a delay in the formation of lactic acid Nitrite was more effective as nitrate (both 0.05% N in DM) to suppress butyric acid fermentation. However, both additives, nitrite and nitrate, increased the lactic acid fermentation. Interpreting this facts it was hypothesized that the clostridia was inhibited by nitrate and nitrite. Addition of inoculants improved the formation of lactic acid, and decreased pH-value in comparison to control silages. The formation of butyric acid was limited, but not suppressed. The effect of inoculants differed in the intensity of fermentation and the formation of by-products of lactic acid fermentation. The effect of formic acid was not sure.
Animal Nutritional Physiological Phenomena↗
Poor immediate tolerability of amphotericin B lipid emulsion in patients with haematological malignancies. Haematology-Microbiology Group.
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Amphotericin B↗
Asystole during dipyridamole infusion in patients without coronary artery disease or beta-blocker therapy.
The authors report two patients without coronary artery disease who experienced asystole during the IV infusion of dipyridamole on routine TI-201 myocardial perfusion imaging and review the literature for possible explanations of this rare side effect. Until now, this side effect was only reported in patients with coronary artery disease or beta-blocker therapy. Yet, the cases lacked both concomitant factors and autonomic dysregulation is suggested as a cause for asystole.
Adrenergic beta-Antagonists↗