Degradation of 2,4,6-trichlorophenol via chlorohydroxyquinol in Ralstonia eutropha JMP134 and JMP222

The aim of this work was to study the catabolic pathway of the pollutant 2,4,6-trichlorophenol in Ralstonia eutropha JMP134. 2,6-dichlorohydroquinone was detected as transient intermediate. Enzymatic transformations of 6-chlorohydroxyquinol to 2-chloromaleylacetate, and of this compound to maleylacetate were detected in crude extracts. Therefore, the degradation of 2,4,6-trichlorophenol proceeded through an hydroxyquinol pathway, different from the other chloroaromatic pathways reported in this strain. The same results were observed in two other 2,4,6-trichlorophenol degrading strains: R. eutropha JMP222, a derivative of strain JMP134 lacking the chlorocatechol catabolism-encoding pJP4 plasmid, and a river isolate, Ralstonia sp. PZK.     

Endoscopic ultrasound-guided biliary drainage-current status and future perspectives

Endoscopic retrograde cholangiopancreatography (ERCP) with stenting is the treatment modality of choice for patients with benign and malignant bile duct obstruction. ERCP could fail in cases of duodenal obstruction, duodenal diverticulum, ampullary neoplastic infiltration or surgically altered anatomy. In these cases percutaneous biliary drainage (PTBD) is traditionally used as a rescue procedure but is related to high morbidity and mortality and lower quality of life. Endoscopic ultrasound-guided biliary drainage (EUS-BD) is a relatively new interventional procedure that arose due to the development of curvilinear echoendoscope and the various endoscopic devices. A large amount of data is already collected that proves its efficacy, safety and ability to replace PTBD in cases of ERCP failure. It is also possible that EUS-BD could be chosen as a first-line treatment option in some clinical scenarios in the near future. Several EUS-BD techniques are developed EUS-guided transmural stenting, antegrade stenting and rendezvous technique and can be personalized depending on the individual anatomy. EUS-BD is normally performed in the same session from the same endoscopist in case of ERCP failure. The lack of training, absence of enough dedicated devices and lack of standardization still makes EUS-BD a difficult and not very popular procedure, which is related to life-threatening adverse events. Developing training models, dedicated devices and guidelines hopefully will make EUS-BD easier, safer and well accepted in the future. This paper focuses on the technical aspects of the different EUS-BD procedures, available literature data, advantages, negative aspects and the future perspectives of these modalities.     

Selective association of N-methyl aspartate and quisqualate types of L-glutamate receptor with brain postsynaptic densities.

Recognition sites for the excitatory neurotransmitter, L-glutamate, were studied in synaptic plasma membranes and postsynaptic densities (PSDs) isolated from rat brains. The results demonstrate (i) that L-glutamate binding sites may be resolved into three distinct subtypes (categories A1, A2, and A4), each corresponding to an electrophysiologically identified receptor class, and (ii) that the N-methyl aspartate (A1) and quisqualate (A2) receptor types are selectively associated with PSDs. L-[3H]Glutamate bound to an apparently homogeneous population of sites in PSDs with a Kd of 3.39 X 10(-7) M and a Bmax (maximum number of binding sites) of 6.1 pmol/mg of protein. Inhibition studies demonstrated that these sites could be resolved into two distinct subtypes. N-Methyl aspartate maximally inhibited 58% of PSD-located L-glutamate binding sites with a Ki of 7.2 X 10(-6) M (the A1 site), and quisqualate inhibited 42% with a Ki of 1.1 X 10(-6) M (the A2 site); the effects of both substances were additive. Experiments with a range of acidic amino acid analogues indicated that the ligand selectivities of these two binding sites conformed to those of the N-methyl D-aspartate and quisqualate receptor classes defined electrophysiologically. The Cl--dependent population of L-glutamate binding sites (the A4 site), which predominates in synaptic membranes, was absent from isolated PSDs.     

Compensation of slice profile mismatch in combined spin‐ and gradient‐echo echo‐planar imaging pulse sequences

Combined acquisition of gradient‐echo and spin‐echo signals in MRI time series reveals additional information for perfusion‐weighted imaging and functional MRI because of differences in the sensitivity of gradient‐echo and spin‐echo measurements to the properties of the underlying vascular architecture. The acquisition of multiple echo trains within one time frame facilitates the simultaneous estimation of the transversal relaxation parameters R₂ and R. However, the simultaneous estimation of these parameters tends to be incorrect in the presence of slice profile mismatches between signal excitation and subsequent refocusing pulses. It is shown here that improvements in pulse design reduced R₂ and R estimation errors. Further improvements were achieved by augmented parameter estimation through the introduction of an additional parameter δ to correct for discordances in slice profiles to facilitate more quantitative measurements. Moreover, the analysis of time‐resolved acquisitions revealed that the temporal stability of R₂ estimates could be increased with improved pulse design, counteracting low contrast‐to‐noise ratios in spin‐echo‐based perfusion and functional MRI. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.     

Estimate of the cost/benefit ratio of measles vaccination

Among primary health care programs, one of those that has the highest benefit/cost ratio is measles immunization. An estimate of cases, complicated cases and deaths that could have occurred if such immunization program would not have been run, and costs of medical care (hospitalization, physician's visits, medical treatment and rehabilitation), were calculated. Since population at risk has a steady-state given by those who enter -births- and releave it -when they are 15 years old-, if the program did not exist more than 2 million cases and at least 60,000 deaths from measles would have occurred annually. This hypothetical situation is compared with the actual situation of measles in Mexico during the 80's; 1) no more than 100,000 cases could have been estimated to occur in the very extreme case of notifying only one out of 10 cases. 2) The proportions of vaccinated and immune children under five reach 70 percent; this situation has produced 3) a fade out of epidemicity and has increased the critical size of community population for epidemics and doubled the interepidemic interval with the corollary of 4) increasing the average age of infection. The average cost of vaccinating a child was estimated near 1.25 dollars (US). Estimated costs of disease are related to individual losses. Taking into account these factors, benefit/cost ratio of measles immunization in Mexico is, at least, 100:1. Measles transmission patterns in Mexico are discussed since they lead to increase the benefit/cost ratio as compared to countries where the age of infection was put up before the immunization era. To expand investments on measles immunization is recommended.     

Adjuvant chemotherapy for Dukes B2 and C colon cancer combining 5-fluorouracil and folinic acid with or without carboplatin. Feasibility and comparison between standard and chronomodulated deliveries

Thirty-seven patients operated from a Dukes B2-C colon cancer were randomised to receive as adjuvant infusional chemotherapy, nine 5 FU and folinic acid courses with or without carboplatin, as standard (de Gramont; 2 days every 2 weeks) or chronomodulated administration (4 days every 2 weeks). The overall tolerance was judged excellent with less than 7% courses with dose-adaptations. The two carboplatin arms presented an enhanced haematological toxicity, while some more cutaneous toxicity was observed in the chronomodulated arm with the three drugs.     

A growth perspective on the care of chronically Ill hospitalized children

Caring for hospitalized chronically ill children highlights aspects of child care work not generally emphasized. The work of child care is directed in response to ambivalences acquired toward psychological growth. The child care worker can strengthen impulses to grow psychologically by responding sensitively to the manifestations of growth conflict.