Fracturas intraarticulares de radio distal: reducción bajo fluoroscopía versus asistencia artroscópica. Revisión sistemática / Distal radius intraarticular fractures: fluoroscopy reduction versus arthroscopic assistance. Systematic review

Resumen: Introducción: Las fracturas intraarticulares de radio distal son un desafío terapéutico para el cirujano ortopedista. Hay estudios que avalan el uso de la fluoroscopía y otros promueven la artroscopia. Con este trabajo intentamos resumir la evidencia, para determinar si la asistencia artroscópica aporta beneficios adicionales para evitar incongruencias articulares en comparación con los resultados obtenidos bajo asistencia fluoroscópica. Material y métodos: Búsqueda sistemática de estudios prospectivos, retrospectivos, de cohortes, seguimiento, ensayos clínicos en PubMed, MEDLINE, Scopus, Scielo, Embase, Google Scholar y otras fuentes nacionales, incluyendo como palabras clave los términos: intraarticular distal radius fracture, wrist arthroscopy, arthroscopy, fluoroscopy. Los valores medios y desvíos estándar para cada característica, obtenidos de los trabajos seleccionados fueron analizados usando estadística descriptiva y gráficos ilustrativos. Resultados: Fueron evaluados 463 pacientes (256 mujeres y 207 hombres), con una edad promedio de 48.29 años y rango de 39 a 64 años. Los dos tratamientos (A y F) fueron homogéneos en cuanto a la edad de los pacientes que reportan (p = 0.5820) y el tiempo de seguimiento promedio (p = 0.9597). Sólo la desviación cubital y el DASH, para las cuales el grupo de artroscopía tuvo mejor desempeño, en las variables restantes las diferencias no fueron significativas. Conclusión: La evidencia disponible hasta la fecha es controvertida y no permite hacer recomendaciones a favor o en contra de estas intervenciones, encontrando otros factores que podrían influir en la toma de decisiones.

Abstract: Introduction: Intraarticular distal radius fractures are a therapeutic challenge for the orthopedist surgeon there are studies that support the use of fluoroscopy, and others promote arthroscopy, with this work we try to summarize the evidence, to determine whether arthroscopic assistance provides additional benefits to avoid joint incongruities compared to results obtained under fluoroscopic assistance. Material and methods: Systematic search for prospective, retrospective, cohort, follow-up, clinical trials on PubMed, MEDLINE, Scopus, Scielo, Embase, Google Scholar and other national sources, including as keywords the terms: «intra-articular distal radius fracture¼, «wrist arthroscopy¼, «arthroscopy¼, «fluoroscopy¼. The average values and standard offsets for each characteristic, obtained from the selected works, were analyzed using descriptive statistics and illustrative graphs. Results: 463 patients (256 women and 207 men) were evaluated, with an average age of 48.29 years and range from 39 to 64 years. The two treatments (A and F) were homogeneous in terms of the age of the patients reporting (p = 0.5820) and the average follow-up time (p = 0.9597). Only the ulnar deviation and DASH score, for which the arthroscopy group performed best, in the remaining variables the differences were not significant. Conclusion: The evidence available to date is conflicting, and does not allow recommendations to be made for or against these interventions, finding other factors that could influence decision-making.

Fish-processing effluent discharges influenced physicochemical properties and prokaryotic community structure in arid soils from Patagonia.

Along the Patagonian coast, there are processing factories of marine products in land that produce fish-processing effluents. The aim of the present study was to assess the physicochemical properties and the prokaryotic community composition of soils receiving fish-processing effluent discharges (effluent site-ES), and to compare them with those of unaltered soils (control site-CS) in the arid Patagonian steppe. We analyzed soil prokaryotic communities (using amplicon-based sequencing of 16S rRNA genes), soil physicochemical properties and fish-processing effluent characteristics. Soil moisture, electrical conductivity (EC), total and inorganic C were significantly higher in ES than in CS (p < .05). Effluent discharges induced a decrease in the total number of operational taxonomic units (OTUs) and in the Shannon diversity index (p = .0009 and .01, respectively) of soil prokaryotic community. Proteobacteria, Actinobacteria and Acidobacteria were the dominant phyla in CS, while ES soil showed a more heterogeneous composition of phyla. Linear discriminant analysis (LDA) effect size (LEfSe) analysis showed that fish-processing effluent discharges promoted an enrichment of Firmicutes and Bacteroidetes, which are active contributors to organic matter mineralization, along with a decrease of oligotrophic phyla such as Acidobacteria, Chloroflexi, Armatimonadetes and Nitrospirae, commonly found in nutrient-poor arid soils. The concentrations of inorganic C and ammonium, the EC and the soil moisture explained 73% of the total variation within the community composition. Due to its salinity and nutrients, fish-processing effluents have potential mainly for native salt-tolerant plant irrigation, however the impacts of soil prokaryotic community shifts over plant growth remain to be determined.

[Distal radius intraarticular fractures: fluoroscopy reduction versus arthroscopic assistance. Systematic review]. / Fracturas intraarticulares de radio distal: reducción bajo fluoroscopía versus asistencia artroscópica. Revisión sistemática.

INTRODUCTION: Intraarticular distal radius fractures are a therapeutic challenge for the orthopedist surgeon there are studies that support the use of fluoroscopy, and others promote arthroscopy, with this work we try to summarize the evidence, to determine whether arthroscopic assistance provides additional benefits to avoid joint incongruities compared to results obtained under fluoroscopic assistance. MATERIAL AND METHODS: Systematic search for prospective, retrospective, cohort, follow-up, clinical trials on PubMed, MEDLINE, Scopus, Scielo, Embase, Google Scholar and other national sources, including as keywords the terms: "intra-articular distal radius fracture", "wrist arthroscopy", "arthroscopy", "fluoroscopy". The average values and standard offsets for each characteristic, obtained from the selected works, were analyzed using descriptive statistics and illustrative graphs. RESULTS: 463 patients (256 women and 207 men) were evaluated, with an average age of 48.29 years and range from 39 to 64 years. The two treatments (A and F) were homogeneous in terms of the age of the patients reporting (p = 0.5820) and the average follow-up time (p = 0.9597). Only the ulnar deviation and DASH score, for which the arthroscopy group performed best, in the remaining variables the differences were not significant. CONCLUSION: The evidence available to date is conflicting, and does not allow recommendations to be made for or against these interventions, finding other factors that could influence decision-making.

INTRODUCCIÓN: Las fracturas intraarticulares de radio distal son un desafío terapéutico para el cirujano ortopedista. Hay estudios que avalan el uso de la fluoroscopía y otros promueven la artroscopia. Con este trabajo intentamos resumir la evidencia, para determinar si la asistencia artroscópica aporta beneficios adicionales para evitar incongruencias articulares en comparación con los resultados obtenidos bajo asistencia fluoroscópica. MATERIAL Y MÉTODOS: Búsqueda sistemática de estudios prospectivos, retrospectivos, de cohortes, seguimiento, ensayos clínicos en PubMed, MEDLINE, Scopus, Scielo, Embase, Google Scholar y otras fuentes nacionales, incluyendo como palabras clave los términos. RESULTADOS: intraarticular distal radius fracture, wrist arthroscopy, arthroscopy, fluoroscopy. Los valores medios y desvíos estándar para cada característica, obtenidos de los trabajos seleccionados fueron analizados usando estadística descriptiva y gráficos ilustrativos. Fueron evaluados 463 pacientes (256 mujeres y 207 hombres), con una edad promedio de 48.29 años y rango de 39 a 64 años. Los dos tratamientos (A y F) fueron homogéneos en cuanto a la edad de los pacientes que reportan (p = 0.5820) y el tiempo de seguimiento promedio (p = 0.9597). Sólo la desviación cubital y el DASH, para las cuales el grupo de artroscopía tuvo mejor desempeño, en las variables restantes las diferencias no fueron significativas. CONCLUSIÓN: La evidencia disponible hasta la fecha es controvertida y no permite hacer recomendaciones a favor o en contra de estas intervenciones, encontrando otros factores que podrían influir en la toma de decisiones.

Validación de un método para cuantificar ácido-11-nor-9-carboxi-delta 9-tetrahidrocannabinol en orina por cromatografía gaseosa-espectrometría de masas previa extracción en fase sólida / Validation of a method for quantify 11-nor-9-carboxy-delta 9-tetrahydrocannabinol in human urine using solid phase extraction and gas chromatography-mass spectrometry

El cannabis es una de las drogas ilegales más usadas a nivel mundial. Su consumo se relaciona con diferentes hechos en el ámbito forense, laboral, deportivo y clínico. Para su detección se utilizan métodos con diferentes fundamentos y alcances (inmunológicos, cromatográficos). En este trabajo se describe un método preciso, reproducible y validado, para la cuantificación del principal metabolito urinario del Δ9-tetrahidrocannabinol, el ácido-11-nor-9-carboxi- Δ 9-tetrahidrocannabinol (THC-COOH), por cromatografía gaseosa-espectrometría de masas (GC-MS). Se efectuó una extracción en fase sólida (SPE) a partir de la orina, previa hidrólisis alcalina. Se utilizó el análogo deuterado (THC-COOH D3) como estándar interno. El análisis por GC-MS se realizó en modo SIM. La curva de calibración fue lineal en el rango de trabajo (10-100 ng/ml, r > 0,999) y el límite de cuantificación fue de 10 ng/ml. La recuperación absoluta estuvo comprendida entre el 91,0 y 99,0 %. La precisión intra e inter ensayo fue de 1,06 a 1,26 y 3,59 a 9,80 %, respectivamente. El método fue aplicado a muestras reales, positivas por test inmunológico, resultando ser muy útil y fiable en el análisis de rutina de THC-COOH en orina humana con fines toxicológicos.

Cannabis is one of the most widely used illegal drug in the world. Its consumption is related to different forensic, work, sports and clinical events. In order to determinate the presence of cannabis, different methods with distinct fundamentals and scopes (immunoassay and chromatography) are applied. This report described an accurate, reproducible, and validated gas chromatography-mass spectrometry (GC-MS) method for the quantitation of 11-nor-9-carboxy- Δ9-tetrahydrocannabinol (THCCOOH), the major metabolite of Δ9-tetrahydrocannabinol in urine. A solid phase extraction (SPE), previous alkaline hydrolysis, was performed on the urine sample. Its deuterated analog (THC-COOH D3) was used as internal standard. The GC-MS analysis made by selected ion monitoring (SIM). Calibration curve was linear over the specified range (10 -100 ng/ml; r > 0.999) and limit of quantitation was 10 ng/ml. Absolute recoveries ranged from 91.0 to 99.0. Intra-assay and inter assay precision ranged from 1.06 to 1.26 and 3.59 to 9.80 %, respectively. The method has been applied to real samples, positive to immunological screening test, resulting to be very useful and reliable in routine analysis of THC-COOH in human urine for toxicological purposes.

Minimally invasive plate osteosynthesis in distal radius fractures with metaphyseal extension: A series of 13 cases.

UNLABELLED: To evaluate objective and subjective outcomes after minimally invasive volar locked plate fixation of distal radius fractures with metaphyseal extension, we retrospectively evaluated 13 patients with unstable distal radius fractures with metaphyseal extension, treated by minimally invasive volar locked plating. Patients' average age was 41 years. Two volar incisions, 2 to 3cm long, were made; indirect reduction was performed and a volar locked T-plate was placed submuscularly under fluoroscopy guidance. Twelve fractures healed after an average of 2.46 months; one patient needed revision due to a new injury. The plate had to be removed in one patient. On X-rays, radial height averaged 12.78mm, radial inclination averaged 21.34° and volar tilt averaged 8.22°. Flexion averaged 75°, extension 71.5°, pronation 82.08° and supination 83.08°. Grip strength averaged 83.75% of the contralateral wrist. The DASH score averaged 13.91 points and pain assessed on VAS averaged 0.92 points. In unstable distal radius fractures with metaphyseal extension, minimally invasive plate osteosynthesis using volar locked plates led to good reduction and stable fixation, with low pain levels, and good functional and esthetic results. Indirect reduction techniques, fluoroscopy, and restoration of radial length, rotation and alignment, are necessary to achieve these outcomes. LEVEL OF EVIDENCE: IV.

Feedlot performance and carcass traits of hairbreed ewe lambs in response to zilpaterol hydrochloride and soybean oil supplementation.

The aim of the present study was to evaluate the impact of zilpaterol hydrochloride (ZH; 0 or 10 mg/lamb daily) and soybean oil (SBO; 0 or 6%) supplementation on feedlot performance, carcass traits, and wholesale cut yield of 32 Dorper × Pelibuey ewe lambs (30.55 ± 2. 57 kg of initial BW). Lambs were blocked by BW and randomly assigned to treatments under a randomized complete block design with a 2 × 2 factorial arrangement. After a 34-d feeding period, all ewes were slaughtered. No ZH × SBO interactions were detected (P ≥ 0.11) for the variables evaluated. In the overall feeding period and first 17 d of experiment, feedlot performance was not affected (P ≥ 0.26) by ZH supplementation, but from d 18 to 34, ZH increased (P ≤ 0.03) total gain, ADG, and G:F without affecting DMI (P = 0.58). Also, ZH increased (P ≤ 0.02) HCW, cold carcass weight, dressing percentage, LM area, and leg perimeter. Lung weight as percentage of final BW decreased (P = 0.05) whereas other noncarcass components and wholesale cut yields were not affected (P ≥ 0.06) by ZH supplementation. Inclusion of SBO did not affect (P ≥ 0.08) feedlot performance or wholesale cut yields. The LM pH at 24 h postmortem as well as liver and peritoneum percentages were decreased (P ≤ 0.05) by SBO supplementation, but no other carcass characteristics or noncarcass components were affected (P ≥ 0.08) by SBO. In conclusion, feedlot performance and carcass characteristics were not altered by the interaction of ZH × SBO. However, ZH alone increased the growth of ewes during the last 17 d of the feeding period. Likewise, carcass characteristics of economic importance (i.e., HCW, dressing percentage, LM area, and leg perimeter) increased with ZH supplementation. In general, feedlot performance, carcass traits, and wholesale cut yields were not altered by including 6% of SBO in the finishing diet of ewe lambs.

Marine Lactobacillus pentosus H16 protects Artemia franciscana from Vibrio alginolyticus pathogenic effects.

Vibrio alginolyticus is an opportunistic pathogen which may affect different aquatic organisms. The aim of this study was to assess the probiotic properties and the protective mode of action of Lactobacillus pentosus H16 against V. alginolyticus 03/8525, through in vitro and in vivo studies using Artemia franciscana (hereafter Artemia). This strain showed antimicrobial activity against V. alginolyticus 03/8525 and Aeromonas salmonicida subsp. salmonicida ATCC33658 possibly related to lactobacilli organic acid production. It was able to survive at high rainbow trout bile concentrations and showed high selective adhesion to rainbow trout mucus (1.2×10(5)±8.0×10(3) cells cm(-2)). H16 outcompeted V. alginolyticus 03/8525 and A. salmonicida subsp. salmonicida ATCC33658, greatly reducing their adherence to rainbow trout mucus (64.8 and 74.1%, respectively). Moreover, H16 produced a cell-bound biosurfactant which caused an important decrease in the surface tension. H16 also protected Artemia nauplii against mortality when it was administered previous to V. alginolyticus 03/8525 inoculation. Furthermore, H16 bioencapsulated in Artemia, suggesting that it is possible to use live carriers in its administration. We conclude that the ability of L. pentosus H16 to selectively adhere to mucosal surfaces and produce cell-bound biosurfactants, displacing pathogenic strains, in addition to its antimicrobial activity, confer H16 competitive advantages against pathogens as demonstrated in in vivo challenge experiments. Thus, L. pentosus H16, a marine bacterium from the intestinal tract of hake, is an interesting probiotic for Artemia culture and also has the potential to prevent vibriosis in other aquaculture activities such as larvae culture and fish farming.

Effects of free ferulic acid on productive performance, blood metabolites, and carcass characteristics of feedlot finishing ewe lambs.

The aim of this study was to evaluate effects of free ferulic acid (FA) supplementation on productive performance, some blood metabolite concentrations, and carcass characteristics of ewe lambs finished in a feedlot. Dorper×Pelibuey ewe lambs (n=20; BW=28.5±0.5 kg; age=5 mo) were individually housed in pens and assigned under a randomized complete block design to the following dietary treatments (n=10): daily feeding without (control) or with 300 mg of FA/animal. The feedlot feeding period lasted 34 d and then all ewe lambs were slaughtered. Free FA did not affect (P≥0.16) BW gain, ADG, DMI, and G:F during the first 17 d, but BW gain (P=0.10) and ADG (P=0.10) tended to decrease for FA from d 17 to 34 and from d 1 to 34 without affecting (P≥0.16) DMI and G:F in ewe lambs. Serum concentrations of glucose, cholesterol, triglyceride, total protein, and urea were not affected (P>0.05) by FA at d 1, 17, and 34 of the feeding period. Carcass characteristics were not affected (P>0.05) by FA. Stomach percentage tended (P=0.08) to decrease and leg yields increased (P=0.02) for FA. Other noncarcass components and wholesale cut yields were not affected (P>0.10) by FA. In conclusion, FA supplementation did not improve productive performance, metabolic status, and carcass characteristics of ewe lambs receiving a feedlot finishing diet.

Effects of zilpaterol hydrochloride and soybean oil supplementation on feedlot performance and carcass characteristics of hair-breed ram lambs under heat stress conditions.

Forty Dorper × Pelibuey ram lambs initially weighing 31.7 ± 2.30 kg were stratified by BW and randomly assigned to treatments under a completely randomized design with a 2 × 2 factorial arrangement of treatments to evaluate effects of zilpaterol hydrochloride (ZH; 0 or 10 mg/lamb daily) and soybean oil (SBO; 0 or 6%) on feedlot performance, carcass characteristics, and wholesale cut yield of ram lambs under heat stress conditions. After a 34-d feeding period, all lambs were harvested. Climatic conditions were of moderate heat stress (average temperature 35.7°C) for lambs during the study. Interactions ZH × SBO were not observed (P ≥ 0.11) for any of the variables evaluated. During the first 17 d of experiment, ZH increased (P ≤ 0.05) BW, ADG, and G:F without affecting feed intake (P = 0.40), but from d 18 to 34 and the entire 34-d feeding period, feedlot performance was not affected (P = 0.18) by ZH. Also, ZH decreased KPH, dressing percent, LM area, LM pH at 24 h postmortem, and leg perimeter (P ≤ 0.04). Renal fat (P = 0.03) decreased with ZH while other noncarcass components were not affected (P ≥ 0.06) by ZH supplementation. Leg yield (P = 0.01) and plain loin (P = 0.04) decreased with ZH and yields of other wholesale cuts were not affected (P ≥ 0.10) by ZH. Feedlot performance (P ≥ 0.20) and wholesale cut yield (P ≥ 0.21) were not affected by SBO. Additionally, dressing percentage decreased (P < 0.01) with SBO while other carcass characteristics (P ≥ 0.12) were not affected by SBO. In conclusion, inclusion of both ZH and SBO in feedlot finishing diets did not improve feedlot performance, carcass characteristics, or wholesale cut yield of hair-breed ram lambs under moderate heat stress. Feedlot performance responded only to ZH and only during the first 17 d of the feeding period. In addition, some carcass characteristics of economic importance, such as dressing, LM area, and leg yield, were improved by ZH.

Response surface methodology for predicting quality characteristics of beef patties added with flaxseed and tomato paste.

Response surface methodology was used to study the effect of flaxseed flour (FS) and tomato paste (TP) addition, from 0 to 10% and 0 to 20% respectively, on beef patty quality characteristics. The assessed quality characteristics were color (L, a, and b), pH and texture profile analysis (TPA). Also, sensory analysis was performed for the assessment of color, juiciness, firmness, and general acceptance. FS addition reduced L and a values and decreased weight loss of cooked products (P<0.05). An opposite effect was observed when TP was added (P<0.05). All TPA parameters decreased when percentages of FS and TP were increased in the formulation of beef patties. Furthermore, FS and TP addition adversely affected the sensory characteristics of the cooked product (P<0.05); nevertheless, all sensory characteristics evaluated had an acceptable score (>5.6). Thus FS and TP are ingredients that can be used in beef patty preparation.

Effects of zilpaterol hydrochloride on growth performance, carcass characteristics, and wholesale cut yield of hair-breed ewe lambs consuming feedlot diets under moderate environmental conditions.

Twenty-four Dorper × Pelibuey ewe lambs initially weighing 25.1 ± 0.6 kg were used in a 34-d feeding experiment and after slaughter to evaluate the effect of zilpaterol hydrochloride (ZH) on feedlot performance, carcass characteristics, and wholesale cut yield. Ewe lambs were individually housed in pens, blocked by initial BW, and assigned randomly within BW blocks to 1 of 2 treatments: 1) control (no ZH) and 2) supplemented with ZH (10 mg/ewe lamb daily) during 32-d and a 2-d withdrawal preslaughter period. Feeding ZH increased (P < 0.01) final BW, ADG, and G:F of ewe lambs, whereas feed intake was unaffected (P = 0.80). Hot and cold carcass weights, dressing percentage, and conformation score were improved (P < 0.001) when ZH was fed. Likewise, LM area was 3.7 ± 0.41 cm(2) larger (P < 0.001) for ZH than control ewe lambs. Feeding ZH did not affect (P ≥ 0.29) cooling loss, carcass length, fat thickness, or KPH. With exception of peritoneum (P < 0.001), head (P = 0.021), and neck (P < 0.001), ZH did not increase (P ≥ 0.12) noncarcass components or wholesale cut yield percentage. A trend to increase (P = 0.060) loin percentage from HCW was observed in lambs supplemented with ZH. In conclusion, feeding ZH to Dorper × Pelibuey ewe lambs improved feedlot performance and also some carcass traits (HCW, cool carcass weight, dressing percentage, and LM area) of economic importance; however, fat deposition was not affected by ZH.

Degradation of linear alkylbenzene sulfonate by a bacterial consortium isolated from the aquatic environment of Argentina.

AIMS: To isolate and identify linear alkylbenzene sulfonate (LAS)-degrading bacteria from Río de la Plata and adjacent waters, and to assay their degradation capability as a consortium and as single organisms. METHODS AND RESULTS: A consortium consisting of four bacterial strains: Aeromonas caviae (two strains), Pseudomonas alcaliphila and Vibrio sp. was identified by 16S rRNA analysis. Isolates grown as a consortium produced higher biomass from LAS and CO(2) release (mineralization) than individual cultures, and degraded 86% of LAS (20 mg l(-1)), whereas pure strains degraded between 21% and 60%. Bacterial desulfonation from LAS was evidenced in the consortium and A. caviae strains. A complete disappearance of LAS (10 mg l(-1)) was accomplished, and LAS levels of 50 and 100 mg l(-1) led to a pronounced decrease in the biodegradation extent and inhibition of culture growth. CONCLUSIONS: A bacterial consortium capable of complete LAS degradation was isolated from the Río de la Plata and adjacent waters. This consortium was more efficient for LAS degradation than individual cultures, and was sensitive to high LAS concentrations. SIGNIFICANCE AND IMPACT OF THE STUDY: The autochthonous consortium with high effectiveness on LAS biodegradation is a useful tool for LAS depletion from these polluted ecosystems.

Biodegradation of bilge waste from Patagonia with an indigenous microbial community.

Oily residues that are generated in normal ship operation are considered hazardous wastes. A biodegradation assay with autochthonous microbiota of Bilge Waste Oily Phase (BWOP) was performed in a bioreactor under controlled conditions. Petroleum, diesel oil, and PAH degraders were isolated from bilge wastes. These bacteria belong to the genus Pseudomonas and are closely related to Pseudomonas stutzeri as shown by 16S rDNA phylogenetic analysis. The indigenous microbial community of the bilge waste was capable of biodegrading the BWOP (1% v/v) with biodegradation efficiencies of 70% for hexane extractable material (HEM), 68% for total hydrocarbons (TH) and 90% for total aromatics hydrocarbons (TA) in 14 days. Solid phase microextraction (SPME) was successfully applied to evaluate hydrocarbon evaporation in a control experiment and demonstrated a mass balance closure of 88%. The SPME and biodegradation results give useful information to improve and scale up the process for BWOP treatment.

Microbial characterization and hydrocarbon biodegradation potential of natural bilge waste microflora.

Shipping operations produce oily wastes that must be managed properly to avoid environmental pollution. The aim of this study was to characterize microorganisms occurring in ship bilge wastes placed in open lagoons and, particularly, to assess their potential to degrade polycyclic aromatic hydrocarbons (PAHs). A first-order kinetic was suitable for describing hydrocarbon biodegradation after 17 days of treatment. The calculated rate constants were 0.0668 and 0.0513 day(-1) with a corresponding half-life of 10.3 and 13.5 days for the aliphatic and aromatic hydrocarbon fractions, respectively. At day 17, PAH removal percentages were: acenaphtylene 100, fluorene 95.2, phenanthrene 93.6, anthracene 70.3, and pyrene 71.5. Methyl phenanthrene removals were lower than that of their parent compound (3-methyl phenanthrene 83.6, 2-methyl phenanthrene 80.8, 1-methyl phenanthrene 77.3, 9-methyl phenanthrene 75.1, and 2,7-dimethyl phenanthrene 76.6). Neither pure cultures nor the microbial community from these wastes showed extracellular biosurfactant production suggesting that the addition of an exogenously produced biosurfactant may be important in enhancing hydrocarbon bioavailability and biodegradation. DNA analysis of bilge waste samples revealed a ubiquitous distribution of the nahAc genotype in the dump pools. Although almost all of the isolates grew on naphthalene as sole carbon source, only some of them yielded nahAc amplification under the experimental conditions used. The variety of PAHs in bilge wastes could support bacteria with multiple degradation pathways and a diversity of catabolic genes divergent from the classical nah-like type.

Percutaneous mechanical mitral commissurotomy performed with a Cribier's metallic valvulotome. Initial results.

OBJECTIVE: To evaluate the immediate results of percutaneous mechanical mitral commissurotomy. METHODS: Thirty patients underwent percutaneous mechanical mitral commissurotomy performed with a Cribier's metallic valvulotome from 8/11/99 to 2/4/00. Mean age was 30.7 years, and 73.3% were women. With regards to functional class, 63.3% were class III, and 36.7% were class IV. The echocardiographic score had a mean value of 7.5+/- 1.8. RESULTS: The mitral valve area increased from 0.97+/-0.15cm2 to 2.16+/-0.50cm2 (p>0.0001). The mean diastolic gradient decreased from 17.9+/-5.0mmHg to 3.2+/-1.4mmHg. The mean left atrial pressure decreased from 23.6+/-5.4mmHg to 8.6+/-3.1mmHg, (p>0.0001). Systolic pressure in the pulmonary artery decreased from 52.7+/-18.3mmHg to 32.2+/-7.4mmHg. Twenty-nine cases were successful. One patient developed severe mitral regurgitation. Interatrial septal defect was observed and one patient. One patient had cardiac tamponade due to left ventricular perforation. No deaths occurred. CONCLUSION: This method has proven to be safe and efficient in the treatment of rheumatic mitral stenosis. The potential advantage is that it can be used multiple times after sterilization, which decreases procedural costs significantly.

A complex multienzyme system encoded by five polyketide synthase genes is involved in the biosynthesis of the 26-membered polyene macrolide pimaricin in Streptomyces natalensis.

BACKGROUND: Polyene macrolides are a class of large macrocyclic polyketides that interact with membrane sterols, having antibiotic activity against fungi but not bacteria. Their rings include a chromophore of 3-7 conjugated double bonds which constitute the distinct polyene structure. Pimaricin is an archetype polyene, important in the food industry as a preservative to prevent mould contamination of foods, produced by Streptomyces natalensis. We set out to clone, sequence and analyse the gene cluster responsible for the biosynthesis of this tetraene. RESULTS: A large cluster of 16 open reading frames spanning 84985 bp of the S. natalensis genome has been sequenced and found to encode 13 homologous sets of enzyme activities (modules) of a polyketide synthase (PKS) distributed within five giant multienzyme proteins (PIMS0-PIMS4). The total of 60 constituent active sites, 25 of them on a single enzyme (PIMS2), make this an exceptional multienzyme system. Eleven additional genes appear to govern modification of the polyketide-derived framework and export. Disruption of the genes encoding the PKS abolished pimaricin production. CONCLUSIONS: The overall architecture of the PKS gene cluster responsible for the biosynthesis of the 26-membered polyene macrolide pimaricin has been determined. Eleven additional tailoring genes have been cloned and analysed. The availability of the PKS cluster will facilitate the generation of designer pimaricins by combinatorial biosynthesis approaches. This work represents the extensive description of a second polyene macrolide biosynthetic gene cluster after the one for the antifungal nystatin.

Enhancement of hydrocarbon waste biodegradation by addition of a biosurfactant from Bacillus subtilis O9.

A non-sterile biosurfactant preparation (surfactin) was obtained from a 24-h culture of Bacillus subtilis O9 grown on sucrose and used to study its effect on the biodegradation of hydrocarbon wastes by an indigenous microbial community at the Erlenmeyer-flask scale. Crude biosurfactant was added to the cultures to obtain concentrations above and below the critical micelle concentration (CMC). Lower concentration affected neither biodegradation nor microbial growth. Higher concentration gave higher cell concentrations. Biodegradation of aliphatic hydrocarbons increased from 20.9 to 35.5% and in the case of aromatic hydrocarbons from nil to 41%, compared to the culture without biosurfactant. The enhancement effect of biosurfactant addition was more noticeable in the case of long chain alkanes. Pristane and phytane isoprenoids were degraded to the same extent as n-C17 and n-C18 alkanes and, consequently, no decrease in the ratios n-C17/pri and n-C18/phy was observed. Rapid production of surfactin crude preparation could make it practical for bioremediation of ship bilge wastes.