Four kinds of neutral and alkaline protease genes from Aspergillus oryzae and Bacillus subtilis were isolated and shuffled. The shuffled genes were selected, inserted into pGAPZαA plasmid and transformed into Escherichia coli. The gene which could express high-activity protease was selected by screening the sizes of transparent zones around the colonies on casein plates. After an ideal protease gene was selected, it was sequenced and then transformed into Pichia pastoris X33. The result showed that the base in 1022th position of shuffled protease gene was changed from thymine to cytosine, inferring that cysteine was changed to arginine in the mutant protease. After 48 h incubation for the transformed P. pastoris with the mutant or native protease genes, the mutant protease activity was 36.4% higher than the native protease (P<0.05). The optimal pH and temperature of the mutant protease were 6.5-8.0 and 30-70°C, respectively, which indicated better stability than the native protease (P<0.05).

The endophytic strain Zong1 isolated from root nodules of the legume Sophora alopecuroides was characterized by conducting physiological and biochemical tests employing gfp-marking, observing their plant growth promoting characteristics (PGPC) and detecting plant growth parameters of inoculation assays under greenhouse conditions. Results showed that strain Zong1 had an effective growth at 28 ºC after placed at 4-60 ºC for 15 min, had a wide range pH tolerance of 6.0-11.0 and salt tolerance up to 5% of NaCl. Zong1 was resistant to the following antibiotics (µg/mL): Phosphonomycin (100), Penicillin (100) and Ampicillin (100). It could grow in the medium supplemented with 1.2 mmol/L Cu, 0.1% (w/v) methylene blue and 0.1-0.2% (w/v) methyl red, respectively. Zong1 is closely related to Pseudomonas chlororaphis based on analysis the sequence of 16S rRNA gene. Its expression of the gfp gene indicated that strain Zong1 may colonize in root or root nodules and verified by microscopic observation. Furthermore, co-inoculation with Zong1 and SQ1 (Mesorhizobium sp.) showed significant effects compared to single inoculation for the following PGPC parameters: siderophore production, phosphate solubilization, organic acid production, IAA production and antifungal activity in vitro. These results suggest strains P. chlororaphi Zong1 and Mesorhizobium sp. SQ1 have better synergistic or addictive effect. It was noteworthy that each growth index of co-inoculated Zong1+SQ1 in growth assays under greenhouse conditions is higher than those of single inoculation, and showed a significant difference (p < 0.05) when compared to a negative control. Therefore, as an endophyte P. chlororaphis Zong1 may play important roles as a potential plantgrowth promoting agent.

A descriptive and cross-sectional study was conducted in 24 pairs of twins diagnosed with schizophrenia, irrespective of their zygosity, in Santiago de Cuba municipality from February to April, 2007, selected by means of a simple random sampling to characterize them. It was mainly observed that the average age of symptom onset was lower in monozygotic twins and prenatal history increased the risk of disease. The presence of family history was verified, with a predominance of first-degree relatives. There was a higher frequency of concordance between monozygotic twins, as well as a high percentage of heritability.

Se realizó un estudio descriptivo y transversal de 24 pares de gemelos con diagnóstico de esquizofrenia, independientemente de su cigosidad, del municipio de Santiago de Cuba durante el período febrero-abril de 2007, seleccionados mediante un muestreo aleatorio simple, a fin de caracterizarles. Entre las principales observaciones se tuvo en cuenta que la edad promedio de inicio de los síntomas fue más baja en los monocigóticos y los antecedentes prenatales aumentaron el riesgo de la enfermedad. Se constató la existencia de precedentes familiares, con superioridad de los parientes de primer grado. Hubo una mayor frecuencia de concordancia entre gemelos monocigóticos, así como un alto porcentaje en la heredabilidad.