Effect of consecutive rare codons on the recombinant production of human proteins in Escherichia coli.

In Escherichia coli, the expression of heterologous genes for the production of recombinant proteins can be challenging due to the codon bias of different organisms. The rare codons AGG and AGA are among the rarest in E. coli. In this work, by using the human gene RioK2 as case study, we found that the presence of consecutive AGG-AGA led to a premature stop, which may be caused by an event of -1 frameshift. We found that translational problems caused by consecutive AGG-AGA are sequence dependent, in particular, in sequences that contain multiple rare AGG or AGA codons elsewhere. Translational problems can be alleviated by different strategies, including codon harmonization, codon optimization, or by substituting the consecutive AGG-AGA codons by more frequent arginine codons. Overall, our results furthered our understanding about the relationship between consecutive rare codons and translational problems. Such information will aid the design of DNA sequence for the production of recombinant proteins.

An improved method for the heterologous production of soluble human ribosomal proteins in Escherichia coli.

Human ribosomal proteins play important structural and functional roles in the ribosome and in protein synthesis. An efficient method to recombinantly produce and purify these proteins would enable their full characterisation. However, the production of human ribosomal proteins can be challenging. The only published method about the recombinant production of human ribosomal proteins involved the recovery of proteins from inclusion bodies, a process that is tedious and may lead to significant loss of yield. Herein, we explored the use of different Escherichia coli competent cells and fusion protein tags for the recombinant production of human ribosomal proteins. We found that, by using thioredoxin as a fusion protein, soluble ribosomal protein could be obtained directly from cell lysates, thus leading to an improved method to recombinantly produce these proteins.

[Clinical evolution and cardiovascular complications in children with Kawasaki disease]. / Enfermedad de Kawasaki: evolución y complicaciones cardiovasculares en niños.

OBJECTIVE: to describe the type of presentation, the clinical manifestations, the response to treatment and the coronary artery abnormalities in eleven cases of children with Kawasaki disease. METHODS: Eleven patients who fulfill diagnostic criteria for Kawasaki disease were studied in a six years period. RESULTS: the mean age was 26 months, 80 % of patients were less than 5 years old, the male-female ratio was 1:1.2; no differences between typic and atypic presentation were found. The most frequent clinical manifestation (80 %) was non-exudative conjunctive injection, followed by polymorphic exanthema and mucosal involvement in the mouth. Nine of 11 patients (82 %) received treatment with intravenous immunoglobulin during the first 10 days of fever; seven of these patients showed coronary artery ectasia; they showed in the echocardiogram a complete resolution in the first year of follow-up. Two patients (18 %) without intravenous immunoglobulin developed coronary aneurysms. CONCLUSIONS: the Kawasaki disease is the main cause of acquired cardiopathy in the pediatric age in our hospital, an early diagnosis and treatment within 10 days of the beginning of the fever allowed a reduction of coronary artery alterations in these patients.

[Oral autopsy in dead women from breast cancer]. / Autopsia verbal de mujeres fallecidas por cáncer de mama en Baja California.

OBJECTIVE: To discover, through the use of verbal autopsies, the primary characteristics of patients who have died of breast cancer (BCa). METHODS: We reviewed 105 death certificates where BCa was registered as the cause of death in a one-year period. A verbal autopsies instrument was designed for BCa, it was validated through expert consultation. A test-retest and Spearman coefficient were applied. The instrument explored sociodemographic, biological, life-style and health services variables. Data was obtained from patients' relatives. Any patient whose family could not be located or declined to participate was excluded from the study. RESULTS: Eighty-one verbal autopsies were applied (77%). The mean age at the time of death was 53 +/- 15. There was a direct family history of BCa in 25%; and in 31 % there was overweight or obesity. Only 17% of the tumors were discovered by health care workers, and the mean survival after diagnosis was 2.3 +/- 2 years. CONCLUSION: The verbal autopsy for BCa is a useful tool. It showed that 83 % of the deceased women identified the tumor by themselves. The health services must reinforce programs for BCa early detection.

Utilización de plantilla antiequino en pacientes manejados co fijadores externos en tibia / The use of anti-equinus splint in patients who are under treatment with external fixators of the tibia

En un periodo de seis meses se captaron 18 pacientes; 11 femeninos y 7 masculinos, siendo el miembro afetado más frecuente el izquierdo (11-7), cinco con lesiones congénitas y 13 de origen adquirido, destacando el origen traumático (61.5 por ciento), infeccioso (30.9 por ciento), y un paciente con deformidad de Blount (7.6 por ciento). Se elongaron 10 miembros con un promedio de 5.8 cm, 12 requirieron de aparato modelo Ilizaro y seis fijadores modelo AO. Se mantuvieron con los fijadores y la plantilla antiequino un promedio de 4.7 meses y ningún paciente presentó complicaciones por la utilización de la plantilla antiequino ni dolor de tobillo pasterior al tratamiento. Presentaron una recuperación de los arcos de movilidad del tobillo una mínima de 80.35 por ciento y una máxima de 96.5 por ciento, mostrándose todos los pacientes satisfechos con los logros obtenidos. Ningún paciente presentó complicaciones o alteraciones en los arcos de movilidad del tobillo. La plantilla ayundó a prevenir la deformidad residual en quino en pacientes manejados con fijadores externos en tibia disminuyendo el número de reintervenciones y reingresos hospitalarios ofreciendo un método sencillo, para manejo domiciliario, proporcionando una medida económica que no interfirió con el funcionamiento de los fijadores ayudando a solucionar el problema de equino residual