Comparison of the Carlsson-Dent and GERD-Q questionnaires for gastroesophageal reflux disease symptom detection in a general population. / Comparación de los cuestionarios Carlsson-Dent y GERD-Q para detección de síntomas de enfermedad por reflujo gastroesofágico en población general.

INTRODUCTION: Gastroesophageal reflux disease (GERD) is an extremely common pathology in the general population and one of the main reasons for consultation in gastroenterology. There are different instruments for detecting its symptoms, but few studies comparing one tool with another have been conducted in Mexico. AIMS: To compare the effectiveness of the Carlsson-Dent questionnaire (CDQ) and the GERD-Q questionnaire (GQQ) in detecting GERD symptoms in a general population. MATERIALS AND METHODS: A prospective, descriptive, cross-sectional study was conducted on 220 individuals in an open population within the time frame of May-June 2015. The subjects were evaluated through the self-assessment CDQ and GQQ. The positive scores from the CDQ (≥ 4) were compared with those of the GQQ (≥ 8), to determine which of the two instruments more easily detected patients with GERD symptoms. RESULTS: Fifty-seven percent of the patients were men and the mean patient age was 38.1 years. Fifty percent of the subjects presented with GERD symptoms with a positive score in at least one questionnaire; 45% had positive CDQ results and 23% had positive GQQ results. Fifty-seven percent of the patients with a positive CDQ score presented with overweight/obesity, as did 72% of the patients with a positive GQQ result. Finally, 20% of the individuals had positive results for reflux symptoms in both questionnaires. CONCLUSIONS: There was a prevalence of GERD symptoms in 50% of the individuals studied from a general population. The GQQ detected a greater number of GERD symptoms in patients that presented with overweight/obesity and the CDQ was considered easier for patients to understand and answer. It is striking that there was only 20% agreement between the two questionnaires, suggesting that they may be useful for identifying GERD symptoms in different populations.

Effect of Supplemental Corn Dried Distillers Grains with Solubles Fed to Beef Steers Grazing Native Rangeland during the Forage Dormant Season.

Two experiments were conducted to evaluate the effects of the level of corn dry distillers grains with solubles (CDDGS) supplementation on growing performance, blood metabolites, digestion characteristics and ruminal fermentation patterns in steers grazing dormant forage. In Exp. 1, of growth performance, 120 steers (204±5 kg initial body weight [BW]) were distributed randomly into 3 groups (each of 40 steers), which were provided with the following levels of CDDGS supplement: 0%, 0.25%, or 0.50% BW. All groups of steers were grazed for 30 days in each of 3 grazing periods (March, April, and May). Approximately 1,000 ha of the land was divided with electric fencing into 3 equally sized pastures (333 ha in size). Blood samples were collected monthly from 20 steers in each grazing group for analysis of glucose (G), urea-nitrogen (UN) and non-esterified fatty acids. Final BW, average daily gain (ADG) and supplement conversion (CDDGS-C) increased with increasing levels of CDDGS supplementation (p<0.05).The CDDGS supplementation also increased the plasma G and UN concentrations (p<0.05). In Exp. 2, of digestive metabolism, 9 ruminally cannulated steers (BW = 350±3 kg) were distributed, following a completely randomized design, into groups of three in each pasture. The ruminally cannulated steers were provided the same levels of CDDGS supplementation as in the growing performance study (0%, 0.25%, and 0.50% BW), and they grazed along with the other 40 steers throughout the grazing periods. The dry matter intake, crude protein intake, neutral detergent fiber intake (NDFI), apparent digestibility of dry matter (ADDM), crude protein (ADCP) and neutral detergent fiber (ADNDF) increased with increasing levels of CDDGS supplementation (p<0.05). The ruminal degradation rates of CP (kdCP), NDF (kdNDF) and passage rate (kp) also increased with increasing levels of CDDGS supplementation (p<0.05). Ruminal ammonia nitrogen (NH3-N) and propionate concentrations also increased with increasing levels of CDDGS supplementation (p<0.05). However, acetate concentrations decreased with increasing levels of CDDGS supplementation (p<0.05). Liquid dilution rate increased with increasing levels of CDDGS supplementation but ruminal liquid volume decreased (p<0.05). On the basis of these findings, we can conclude that CDDGS supplementation enhanced the productive performance of cattle grazing native rangeland without negatively affecting forage intake, glucose and urea-nitrogen blood concentrations, ruminal degradation and ruminal fermentation patterns.

Distribution and feeding habitat characterization of whale sharks Rhincodon typus in a protected area in the north Caribbean Sea.

The relationship between the distribution of the whale shark Rhincodon typus and hydrobiological variables in the Caribbean Sea during 2005-2009 was analysed. Monthly trips were made to the R. typus aggregation area during the months when this species is present in the region (May to September) to record sightings and hydrological data and to collect samples to determine nutrients, chlorophyll a (Chl a) and zooplankton biomass. A total of 2104 R. typus were counted and three zones of high abundance were identified: Cabo-Catoche, Contoy (both within the Whale Shark Biosphere Reserve, WSBR) and the zone knows as Afuera. The zones of greatest R. typus density within the WSBR were characterized by high Chl a concentrations (median: 1·1 mg m-3 , interpercentile range: 0·5-1·8 mg m-3 ) and high nutrient concentrations, such as ammonium (median: 2·5 µmol l-1 , interpercentile range: 0·5-6·4 µmol l-1 ), due to the influence of local upwelling. A generalized additive model (GAM) was used to explore the relationship between R. typus distribution and the environmental variables inside WSBR. Zooplankton biomass was the most influential environmental variable, supporting the close relationship between R. typus distribution and biological productivity. Copepods were the dominant zooplankton group within the WSBR. In the Afuera zone, there were large R. typus aggregations (>80 individuals) associated with zooplankton dominated by fish eggs and significantly higher mean ± s.d. biomass (3356·1 ± 1960·8 mg m-3 ) compared with that recorded inside the WSBR (103·5 ± 57·2 mg m-3 ). The differences among zones generated changes in R. typus distribution patterns and provided opportunities to develop local management strategies for this species.

Diagnostic validity of the Alzheimer's disease functional assessment and change scale in mild cognitive impairment and mild to moderate Alzheimer's disease.

BACKGROUND: The Alzheimer's Disease Functional Assessment and Change Scale (ADFACS) is a functional assessment instrument widely used in clinical research. AIMS: To test the diagnostic and concurrent validity of the Spanish version of this scale and to describe the functional deficit pattern for mild cognitive impairment (MCI) and Alzheimer's disease (AD) dementia. METHODS: The ADFACS, the Interview for Deterioration in Daily Living Activities in Dementia (IDDD), and the Mini Mental State Examination (MMSE) were administered to 146 control subjects (CS) and 165 patients (67 MCI and 98 AD). Nonparametric tests were used to compare the diagnostic groups. Cronbach's α and correlations with the MMSE and the IDDD were calculated. Sensitivity, specificity and predictive values were studied. RESULTS: The ADFACS had a high internal consistency (α = 0.95). Three cutoff points of 1, 4, and 17 were provided to separate CS and MCI patients, MCI and mild AD patients, and mild AD and moderate AD patients, respectively. The ADFACS strongly correlated with functional (IDDD, 0.927) and cognitive (MMSE, 0.747) measures. A similar pattern of dysfunction, but in different grades, was found for the MCI and AD groups. CONCLUSION: The ADFACS is a reliable, valid, and sensitive instrument to assess functional abilities; it is useful in dementia assessment for elderly populations.

A quality improvement intervention on surgical prophylaxis impact in antibiotic consumption and cost in selected surgical procedures.

BACKGROUND: Improper compliance with antibiotic prophylaxis (AP) in surgery is associated with an increased risk of surgical site infection (SSI), and impacts the efficiency of healthcare. OBJECTIVE: Evaluate the impact of an intervention in compliance with AP in selected surgical procedures and its effect on antibiotic consumption and cost. METHODS: A prospective interventional study was performed in a community hospital from January to December 2022. The baseline period was considered January-April 2022 and the intervention period May-December 2022. All patients who underwent cesarean section, appendectomies, hernia surgery, open reduction and internal fixation (ORIF), abdominoplasty, and cholecystectomy during the study period were selected. The intervention includes staff education, pharmacy interventions, monitoring the quality of prescriptions and feedback, and improved role of anesthesia staff, and department champions. RESULTS: The study involved 192 and 617 surgical procedures in the baseline and intervention periods respectively. The compliance with timing, selection, dose, and discontinuation achieved 100%, 99.2%, and 97.6% from baseline figures of 92.7%, 95.8%, and 81.3%, respectively. The antibiotic consumption was reduced by 55.1% during the intervention with a higher contribution of other antibiotics (94.1% reduction) in comparison with antibiotics as per policy (31.2% reduction). The cost was reduced by 47.2% (antibiotic as per policy 31.9%, other antibiotics 94.2%). CONCLUSION: The implemented strategy was effective in improving the quality of antibiotic prophylaxis with a significant impact in reducing antibiotic consumption and cost.

Structure and diversity of Erica ciliaris and Erica tetralix heathlands at different successional stages after cutting.

In NW Europe, it is known that cutting is a useful tool for managers with regard to decisions about the conservation and management of wet heathlands. Nevertheless it is rarely described quantitatively in the international literature. In Spain, knowledge about this is scarce or lacking. In this study, twenty communities were selected in Galicia (NW Spain) that would represent from one to four stages of vegetation development after cutting. Two 5 × 5 m plots were established for each stage to characterise the vegetation on the basis of its species composition, frequency values, vertical structure and linear cover features. The Diversity Shannon index was calculated and multivariate analyses were performed. As succession advanced, notable changes were produced in the cover of dominant species, Erica ciliaris and Ulex gallii in the first stages and Erica tetralix and Genista berberidea in mature ones. Also, the species richness decreased because of the reduced number of herbs species in the mature stages and, finally, the cover values are indicators of the degree of vegetation development, together with the other parameters of height, overlayering or diversity. Cutting is a useful tool for management of heathlands because the existence of vegetation units belonging to different succession stages increases the internal diversity of communities. On the other hand, the vertical and horizontal structure reflects the formidable resilience of the vegetation community to this practice. This study offers a global vision of the dynamics of wet heathlands after cutting, with very useful ecological information that can be used by the people responsible for their management.

[Treatment of supracondylar fractures of humerus in children with percutaneous internal fixation versus reduction without internal fixation]. / Tratamiento de las fracturas supracondíleas de húmero en niños con fijación interna percutánea versus reducción sin fijación interna.

INTRODUCTION: Supracondylar fractures of humerus are the second most frequent type of fractures in children. OBJECTIVE: To describe the results of the treatment, the patients according to age, sex, complications, and final results. MATERIAL AND METHODS: A retrospective descriptive study was conducted in patients with supracondylar fractures of humerus during the years 2018-2019. Absolute frequencies and percentages were calculated. RESULTS: Fractures were more frequent in males (69.6%) and in the age group of six to 10 years for both sexes. 60.8% of the fractures were treated with reduction plus internal fixation with Kirschner needles, in the group with internal fixation type IV predominates and in the group that does not need internal fixation predominate type I, the most frequent complication was the loss of reduction in the group that was not fixed with needles. Better results were obtained when the reduction was performed combined with internal fixation (91.2%). CONCLUSIONS: Fractures predominated in the male sex and in the age group of six to 10 years, the reduction was more frequent more internal fixation with Kirschner needles, in the group with internal fixation predominates type IV, predominated the loss of reduction in the group that was not fixed with needles. Better results were obtained when reduction was performed combined with internal fixation.

INTRODUCCIÓN: Las fracturas supracondíleas de húmero constituyen el segundo tipo de fracturas más frecuente en niños. OBJETIVO: Describir los resultados del tratamiento, los pacientes según edad, sexo, complicaciones y resultados finales. MATERIAL Y MÉTODOS: Se realizó un estudio descriptivo retrospectivo, en pacientes con fracturas supracondíleas de húmero durante los años 2018-2019. Se calcularon frecuencias absolutas y porcentajes. RESULTADOS: Las fracturas fueron más frecuentes en el sexo masculino (69.6%) y en el grupo de edad de seis a 10 años para ambos sexos. 60.8% de las fracturas se trataron con reducción más fijación interna con agujas de Kirschner, en el grupo con fijación interna predominan las tipo IV y en el grupo que no necesitó fijación interna predominó el tipo I, la complicación más frecuente fue la pérdida de la reducción en el grupo que no se fijó con agujas. Se obtuvieron mejores resultados cuando se realizó la reducción combinada con fijación interna (91.2%). CONCLUSIONES: Las fracturas predominaron en el sexo masculino y en el grupo de edad de seis a 10 años, fue más frecuente la reducción más fijación interna con agujas de Kirschner, en el grupo con fijación interna predomina las tipo IV, predominó la pérdida de la reducción en el grupo que no se fijó con agujas. Se obtuvieron mejores resultados cuando se realizó la reducción combinada con fijación interna.

Genetic variation in the CHRNA5 gene affects mRNA levels and is associated with risk for alcohol dependence.

Alcohol dependence frequently co-occurs with cigarette smoking, another common addictive behavior. Evidence from genetic studies demonstrates that alcohol dependence and smoking cluster in families and have shared genetic vulnerability. Recently a candidate gene study in nicotine dependent cases and nondependent smoking controls reported strong associations between a missense mutation (rs16969968) in exon 5 of the CHRNA5 gene and a variant in the 3'-UTR of the CHRNA3 gene and nicotine dependence. In this study we performed a comprehensive association analysis of the CHRNA5-CHRNA3-CHRNB4 gene cluster in the Collaborative Study on the Genetics of Alcoholism (COGA) families to investigate the role of genetic variants in risk for alcohol dependence. Using the family-based association test, we observed that a different group of polymorphisms, spanning CHRNA5-CHRNA3, demonstrate association with alcohol dependence defined by Diagnostic and Statistical Manual of Mental Disorders, 4th edn (DSM-IV) criteria. Using logistic regression we replicated this finding in an independent case-control series from the family study of cocaine dependence. These variants show low linkage disequilibrium with the SNPs previously reported to be associated with nicotine dependence and therefore represent an independent observation. Functional studies in human brain reveal that the variants associated with alcohol dependence are also associated with altered steady-state levels of CHRNA5 mRNA.

New insight into the environmental impact of two imidazolium ionic liquids. Effects on seed germination and soil microbial activity.

The next generation of ionic liquids must be synthetized taking into account structures that guarantee the suitable properties for a defined application as well as ecological data. Thus, searching of the right methodologies to know, quickly and efficiently, the ecological effects of these compounds is a preliminary task. The effects of two imidazolium based ionic liquids with different anions, 1-butyl-3-methylimidazolium tetrafluoroborate, [C4C1Im][BF4], and 1-propyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C3C1Im][NTf2], on seedling emergence of six tree species and on the microbial behaviour of two soils were determined in this work. Results showed that the highest doses of both ionic liquids caused the total inhibition of germination for almost all the species studied and that the seeds are more sensitive to the presence of these compounds than soil microbial activity. Nevertheless, signals of stress and death are observed from the results of heat released by microorganisms after the addition of the highest doses of both ionic liquids. The novelty of this work resides in the enlargement of knowledge of toxicity of ILs on complex organisms such as arboreal species and microbial activity of soils studied for the first time through a microcalorimetric technique.

Tratamiento de las fracturas supracondíleas de húmero en niños con fijación interna percutánea versus reducción sin fijación interna / Treatment of supracondylar fractures of humerus in children with percutaneous internal fixation versus reduction without internal fixation

Resumen: Introducción: Las fracturas supracondíleas de húmero constituyen el segundo tipo de fracturas más frecuente en niños. Objetivo: Describir los resultados del tratamiento, los pacientes según edad, sexo, complicaciones y resultados finales. Material y métodos: Se realizó un estudio descriptivo retrospectivo, en pacientes con fracturas supracondíleas de húmero durante los años 2018-2019. Se calcularon frecuencias absolutas y porcentajes. Resultados: Las fracturas fueron más frecuentes en el sexo masculino (69.6%) y en el grupo de edad de seis a 10 años para ambos sexos. 60.8% de las fracturas se trataron con reducción más fijación interna con agujas de Kirschner, en el grupo con fijación interna predominan las tipo IV y en el grupo que no necesitó fijación interna predominó el tipo I, la complicación más frecuente fue la pérdida de la reducción en el grupo que no se fijó con agujas. Se obtuvieron mejores resultados cuando se realizó la reducción combinada con fijación interna (91.2%). Conclusiones: Las fracturas predominaron en el sexo masculino y en el grupo de edad de seis a 10 años, fue más frecuente la reducción más fijación interna con agujas de Kirschner, en el grupo con fijación interna predomina las tipo IV, predominó la pérdida de la reducción en el grupo que no se fijó con agujas. Se obtuvieron mejores resultados cuando se realizó la reducción combinada con fijación interna.

Abstract: Introduction: Supracondylar fractures of humerus are the second most frequent type of fractures in children. Objective: To describe the results of the treatment, the patients according to age, sex, complications, and final results. Material and methods: A retrospective descriptive study was conducted in patients with supracondylar fractures of humerus during the years 2018-2019. Absolute frequencies and percentages were calculated. Results: Fractures were more frequent in males (69.6%) and in the age group of six to 10 years for both sexes. 60.8% of the fractures were treated with reduction plus internal fixation with Kirschner needles, in the group with internal fixation type IV predominates and in the group that does not need internal fixation predominate type I, the most frequent complication was the loss of reduction in the group that was not fixed with needles. Better results were obtained when the reduction was performed combined with internal fixation (91.2%). Conclusions: Fractures predominated in the male sex and in the age group of six to 10 years, the reduction was more frequent more internal fixation with Kirschner needles, in the group with internal fixation predominates type IV, predominated the loss of reduction in the group that was not fixed with needles. Better results were obtained when reduction was performed combined with internal fixation.

High-dose recombinant apolipoprotein A-I(milano) mobilizes tissue cholesterol and rapidly reduces plaque lipid and macrophage content in apolipoprotein e-deficient mice. Potential implications for acute plaque stabilization.

BACKGROUND: Repeated doses of recombinant apolipoprotein A-I(Milano) phospholipid complex (apoA-I(m)) reduce atherosclerosis and favorably change plaque composition in rabbits and mice. In this study, we tested whether a single high dose of recombinant apoA-I(m) could rapidly mobilize tissue cholesterol and reduce plaque lipid and macrophage content in apoE-deficient mice. METHODS AND RESULTS: High cholesterol-fed, 26-week-old apoE-deficient mice received a single intravenous injection of saline (n=16), 1080 mg/kg dipalmitoylphosphatidylcholine (DPPC; n=14), or 400 mg/kg of recombinant apoA-I(m) complexed with DPPC (1:2.7 weight ratio; n=18). Blood was sampled before and 1 and 48 hours after injection, and aortic root plaques were evaluated for lipid content and macrophage content after oil-red O and immunostaining, respectively. One hour after injection, the plasma cholesterol efflux-promoting capacity was nearly 2-fold higher in recombinant apoA-I(m)-treated mice compared with saline and DPPC-treated mice (P<0.01). Compared with baseline values, serum free cholesterol, an index of tissue cholesterol mobilization, increased 1.6-fold by 1 hour after recombinant apoA-I(m) injection, and it remained significantly elevated at 48 hours (P<0.01). Mice receiving recombinant apoA-I(m) had 40% to 50% lower lipid content (P<0.01) and 29% to 36% lower macrophage content (P<0.05) in their plaques compared with the saline- and DPPC-treated mice, respectively. CONCLUSIONS: A single high dose of recombinant apoA-I(m) rapidly mobilizes tissue cholesterol and reduces plaque lipid and macrophage content in apoE-deficient mice. These findings suggest that this strategy could rapidly change plaque composition toward a more stable phenotype.

[Impact of Lean methodology to improve care processes and levels of satisfaction in patient care in a clinical laboratory]. / Impacto de la metodología Lean en la mejora de procesos asistenciales y niveles de satisfacción en la atención de pacientes en un laboratorio clínico.

INTRODUCTION: The application of the Lean methodology in health institutions is an effective tool to improve the capacity and workflow, as well as to increase the level of satisfaction of patients and employees. OBJECTIVE: To optimise the time of outpatient care in a clinical laboratory, by implementing a methodology based on the organisation of operational procedures to improve user satisfaction and reduce the number of complaints for delays in care. MATERIAL AND METHODS: A quasi-experimental before and after study was conducted between October 2011 to September 2012. XBar and S charts were used to observe the mean service times and standard deviation. The user satisfaction was assessed using service questionnaires. RESULTS: A reduction of 17 minutes was observed in the time of patient care from arrival to leaving the laboratory, and a decrease of 60% in complaints of delay in care. Despite the high staff turnover and 38% increase in the number of patients seen, a culture of empowerment and continuous improvement was acquired, as well as greater efficiency and productivity in the care process, which was reflected by maintaining standards 12 months after implementation. CONCLUSION: Lean is a viable methodology for clinical laboratory procedures, improving their efficiency and effectiveness.

'Integron'-bearing vectors: a method suitable for stable chromosomal integration in highly restrictive corynebacteria.

A pBR322-derived plasmid (pCGL107) that carries the Corynebacterium melassecola ATCC17965 analogue of Escherichia coli gdhA gene (encoding glutamate dehydrogenase), was introduced into the related strain, Brevibacterium lactofermentum CGL2002, by electroporation and integrated into its chromosome by homologous recombination. However, pCGL107 cannot integrate into C. melassecola, since the host restriction prevents successful electroporation by E. coli-modified DNA. Nevertheless, B. lactofermentum-modified replicative plasmid DNA can be transformed by electroporation into C. melassecola; thus pCGL519-2, a shuttle plasmid that carries the C. melassecola analogue of E. coli gltA (encoding citrate synthase), was extracted from the former host and electroporated into the latter. Rare restriction sites conveniently placed in pCGL519-2 were used to recover a replicon-less cartridge called 'integron', that contains a selectable marker and gtlA within a single fragment. Integron prepared from pCGL519-2 DNA which had been extracted from C. melassecola, and thus, was capable of eluding the C. melassecola restriction barrier(s), was successfully electroporated into this host. The molecular analysis of the resulting transformants suggests that they result from the integration of a single circular integron molecule by homologous recombination between the gltA regions of the host genome and the integron. These transformants were stable for 30 generations in the absence of selection.

Human proliferative sparganosis in Venezuela: report of a case.

A case of human proliferative sparganosis, the first in the southern hemisphere, is reported. The patient had multiple nodular, papular, acne-like lesions, gynecomastia, and large subcutaneous abscesses. Laboratory findings showed that he also had severe anemia of the type associated with infection and chronic diseases, leukocytosis, eosinophilia, and severe hypoalbuminemia and hypergammaglobulinemia. His cellular and humoral immune responses were unaltered. New aspects on the functional repercussion of the parasitism of the human host by Sparganum proliferum are discussed. Treatment with mebendazole was ineffective; the patient's tolerance for the newer drug praziquantel was extremely poor.

Epidemiologic aspects of American visceral leishmaniasis in an endemic focus in Eastern Venezuela.

An endemic focus of American visceral leishmaniasis (AVL) in eastern Venezuela has been evaluated in terms of patients (n = 48), immunologic reactivity to Leishmania in household contacts (n = 187) and neighborhood controls (n = 170), detection of Leishmania (L. donovani complex) in dogs and wild animals by the polymerase chain reaction (PCR) and characteristics of the sandfly population. The male:female ratio of patients was 1.18:1; 89.6% were < or =12 years old. Serologic reactivity was significantly higher in household contacts than in controls (P = 0.0008), as was the size of leishmanin reactions in contacts < or =10 years of age (P = 0.0141). Leishmania donovani complex-specific PCRs were positive in dogs, an opossum (Didelphis marsupialis), and a black rat (Rattus rattus). Lutzomyia longipalpis and Lu. evansi, both implicated in the transmission of AVL, were identified among the 386 sand flies examined. These observations provide the bases for an active control program as well as further studies of reservoirs and vector-host relationships in this area.

Improved electro-transformation of highly DNA-restrictive corynebacteria with DNA extracted from starved Escherichia coli.

Differences of up to 33 000-fold in electro-transformability of highly DNA restrictive corynebacteria are observed in the DNA of a shuttle plasmid extracted from Escherichia coli hosts propagated in different nutritional conditions. Growth of the host in minimal medium increases plasmid transformability, whereas growth on rich media decreases it. In the E. coli DH5 alpha host, the starvation-dependent increase DNA transformability is reverted by supplementing with methionine, an obligate 5-adenosyl-methionine (SAM) precursor. This suggests that an E. coli nutritionally modulated SAM-dependent DNA-methyltransferase may be involved in this phenomenon.

Positively regulated expression of the Escherichia coli araBAD promoter in Corynebacterium glutamicum.

In Corynebacterium glutamicum the promoter of the araBAD Escherichia coli gene is positively regulated by both arabinose and the araC gene product, as it is the case in the natural host. If the L-arabinose inducer and an active araC gene are present, significant amounts of araBAD promoter expression take place in the absence of the E. coli CRP protein. These results show that the C. glutamicum RNA polymerase is activated by the E. coli positive regulator of transcription AraC.

Interspecies electro-transformation in Corynebacteria.

Plasmid DNA was efficiently electro-transformed into intact cells of nine Corynebacteria strains belonging to Brevibacterium lactofermentum, Brevibacterium flavum, Corynebacterium glutamicum and Corynebacterium melassecola. Relationships were explored between transformation efficiency and parameters such as electric field strength and pulse length, DNA concentration, physiological state and concentration of the cells. In optimal conditions, more than 10(7) transformants per microgram of DNA could be obtained. Electro-transformation with plasmid DNA isolated from different sources indicates that DNA modification may play a role in transformation efficiency.

Effect of the position of a basic amino acid on C-terminal rearrangement of protonated peptides upon collision-induced dissociation.

Internal rearrangement involving the loss of the C-terminal amino acid residue upon collision-induced dissociation (CID) or metastable decomposition was studied for protonated peptides. To investigate the structural characteristics of peptides responsible for this rearrangement, a series of synthetic peptides were prepared and subjected to B/E-linked scan or tandem mass spectrometric analyses using a four-sector instrument. The results showed that the position of a basic amino acid in the peptide sequence and its basicity have a significant influence on the rearrangement. Arginine (Arg) located at the n-1 position facilitates the rearrangement with about twice as many rearrangement ions as is observed for the other Arg-containing peptides. This can be attributed to the interaction of a positively charged guanidino group of Arg with its own carbonyl group via a salt bridge which is tightly formed in vacuo between a guanidino and carboxylate groups, the mechanism of which is analogous to that previously proposed for the formation of similar rearrangement ions observed in the spectra of metal-cationized peptides. This association would result in the facile attack of the C-terminal hydroxyl group on the penultimate carbonyl group, leading to the rearrangement. In addition, the rearrangement ion was observed both in metastable decomposition and high-energy CID spectra obtained by B/E-linked scan analyses without or with gas, respectively, but in a sequence dependent manner.